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Objective The accurate clinical diagnosis of cervical lymph node metastasis plays an important role in the treatment of differentiated thyroid cancer (DTC). This study aimed to explore and summarize a more objective approach to detect cervical malignant lymph node metastasis of DTC via radiomics models. Methods PubMed, Web of Science, MEDLINE, EMBASE, and Cochrane databases were searched for all eligible studies. Articles using radiomics models based on ultrasound, computed tomography, or magnetic resonance imaging to assess cervical lymph node metastasis preoperatively were included. Characteristics and diagnostic accuracy measures were extracted. Bias and applicability judgments were evaluated by the revised QUADAS-2 tool. The estimates were pooled using a random-effects model. Additionally, the leave-one-out method was conducted to assess the heterogeneity. Results Twenty-nine radiomics studies with 6160 validation set patients were included in the qualitative analysis, and 11 studies with 3863 validation set patients were included in the meta-analysis. Four of them had an external independent validation set. The studies were heterogeneous, and a significant risk of bias was found in 29 studies. Meta-analysis showed that the pooled sensitivity and specificity for preoperative prediction of lymph node metastasis via US-based radiomics were 0.81 (95% CI, 0.73-0.86) and 0.87 (95% CI, 0.83-0.91), respectively. Conclusions Although radiomics-based models for cervical lymphatic metastasis in DTC have been demonstrated to have moderate diagnostic capabilities, broader data, standardized radiomics features, robust feature selection, and model exploitation are still needed in the future. Advances in knowledge The radiomics models showed great potential in detecting malignant lymph nodes in thyroid cancer. [ABSTRACT FROM AUTHOR]

Lymphedema has traditionally been underappreciated by the healthcare community. Understanding of the underlying pathophysiology and treatments beyond compression have been limited until recently. Increased investigation has demonstrated the key role of inflammation and resultant fibrosis and adipose deposition leading to the clinical sequelae and associated reduction in quality of life with lymphedema. New imaging techniques including magnetic resonance imaging (MRI), indocyanine green lymphography, and high-frequency ultrasound offer improved resolution and understanding of lymphatic anatomy and flow. Nonsurgical therapy with compression, exercise, and weight loss remains the mainstay of therapy, but growing surgical options show promise. Physiologic procedures (lymphovenous anastomosis and vascularized lymph node transfers) improve lymphatic flow in the diseased limb and may reduce edema and the burden of compression. Debulking, primarily with liposuction to remove the adipose deposition that has accumulated, results in a dramatic decrease in limb girth in appropriately selected patients. Though early, there are also exciting developments of potential therapeutic targets tackling the underlying drivers of the disease. Multidisciplinary teams have developed to offer the full breadth of evaluation and current management, but the development of a greater understanding and availability of therapies is needed to ensure patients with lymphedema have greater opportunity for optimal care. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to establish a nomogram based on preoperative magnetic resonance imaging (MRI) features to predict the very early recurrence (VER, less than 6 months) of intrahepatic mass-forming cholangiocarcinoma (IMCC) after R0 resection. Methods: This study enrolled a group of 193 IMCC patients from our institution between March 2010 and January 2022. Patients were allocated into the development cohort (n = 137) and the validation cohort (n = 56), randomly, and the preoperative clinical and MRI features were collected. Univariate and multivariate stepwise logistic regression assessments were adopted to assess predictors of VER. Nomogram was constructed and certificated in the validation cohort. The performance of the prediction nomogram was evaluated by its discrimination, calibration, and clinical utility. The performance of the nomogram was compared with the T stage of the American Joint Committee on Cancer (AJCC) 8th edition staging system. Results: Fifty-three patients (27.5%) experienced VER of the tumor and 140 patients (72.5%) with non-VER, during the follow-up period. After multivariate stepwise logistic regression, number of lesions, diffuse hypoenhancement on arterial phase, necorsis and suspicious lymph nodes were independently associated with VER. The nomogram demonstrated significantly higher area under the curve (AUC) of 0.813 than T stage (AUC = 0.666, P = 0.006) in the development cohort, whereas in the validation cohort, the nomogram showed better discrimination performance, with an AUC of 0.808 than T stage (0.705) with no significantly difference (P = 0.230). Decision curve analysis reflected the clinical net benefit of the nomogram. Conclusion: The nomogram based on preoperative MRI features is a reliable tool to predict VER for patients with IMCC after R0 resection. This nomogram will be helpful to improve survival prediction and individualized treatment. [ABSTRACT FROM AUTHOR]

This report demonstrates the feasibility and safety of using contrast-enhanced ultrasound (CEUS) to confirm intranodal needle position in children requiring dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL). A total of 7 patients were evaluated using CEUS after nodal puncture on a detachable magenetic resonance table, with 2 nodes cannulated in each patient, resulting in a combined evaluation of 14 nodes. The nodal cannulation success rate using CEUS was 85.7% (12/14 nodes). DCMRL was performed successfully in all patients with good contrast opacification of the central conducting lymphatics. Out of the 14 nodes, 2 nodes in the same patient demonstrated persistent extravasation on CEUS despite needle readjustment, requiring conversion to fluoroscopic lymphangiography. No adverse event related to the injection technique or CEUS was reported. [ABSTRACT FROM AUTHOR]

Background and purpose: The discovery of glymphatic function in the human brain has generated interest in waste clearance mechanisms in neurological disorders such as multiple sclerosis (MS). However, noninvasive in vivo functional assessment is currently lacking. This work studies the feasibility of a novel intravenous dynamic contrast MRI method to assess the dural lymphatics, a purported pathway contributing to glymphatic clearance. Methods: This prospective study included 20 patients with MS (17 women; age = 46.4 [27, 65] years; disease duration = 13.6 [2.1, 38.0] years, expanded disability status score (EDSS) = 2.0 [0, 6.5]). Patients were scanned on a 3.0T MRI system using intravenous contrast‐enhanced fluid‐attenuated inversion recovery MRI. Signal in the dural lymphatic vessel along the superior sagittal sinus was measured to calculate peak enhancement, time to maximum enhancement, wash‐in and washout slopes, and the area under the time‐intensity curve (AUC). Correlation analysis was performed to examine the relationship between the lymphatic dynamic parameters and the demographic and clinical characteristics, including the lesion load and the brain parenchymal fraction (BPF). Results: Contrast enhancement was detected in the dural lymphatics in most patients 2–3 min after contrast administration. BPF had a significant correlation with AUC (p <.03), peak enhancement (p <.01), and wash‐in slope (p =.01). Lymphatic dynamic parameters did not correlate with age, BMI, disease duration, EDSS, or lesion load. Moderate trends were observed for correlation between patient age and AUC (p =.062), BMI and peak enhancement (p =.059), and BMI and AUC (p =.093). Conclusion: Intravenous dynamic contrast MRI of the dural lymphatics is feasible and may be useful in characterizing its hydrodynamics in neurological diseases. [ABSTRACT FROM AUTHOR]

Background: Lymphatic complications are common in patients with Fontan circulation. Three-dimensional balanced steady-state free precession (3D bSSFP) angiography by cardiovascular magnetic resonance (CMR) is widely used for cardiovascular anatomical assessment. We sought to determine the frequency of thoracic duct (TD) visualization using 3D bSSFP images and assess whether TD characteristics are associated with clinical outcomes. Methods: This was a retrospective, single-center study of patients with Fontan circulation who underwent CMR. Frequency matching of age at CMR was used to construct a comparison group of patients with repaired tetralogy of Fallot (rTOF). TD characteristics included maximum diameter and a qualitative assessment of tortuosity. Clinical outcomes included protein-losing enteropathy (PLE), plastic bronchitis, listing for heart transplantation, and death. A composite outcome was defined as presence of any of these events. Results: The study included 189 Fontan patients (median age 16.1 years, IQR 11.0–23.2 years) and 36 rTOF patients (median age 15.7 years, IQR 11.1–23.7 years). The TD diameter was larger (median 2.50 vs. 1.95 mm, p = 0.002) and more often well visualized (65% vs. 22%, p < 0.001) in Fontan patients vs. rTOF patients. TD dimension increased mildly with age in Fontan patients, R = 0.19, p = 0.01. In Fontan patients, the TD diameter was larger in those with PLE vs. without PLE (age-adjusted mean 4.11 vs. 2.72, p = 0.005), and was more tortuous in those with NYHA class ≥ II vs. class I (moderate or greater tortuosity 75% vs. 28.5%, p = 0.02). Larger TD diameter was associated with a lower ventricular ejection fraction that was independent of age (partial correlation = − 0.22, p = 0.02). More tortuous TDs had a higher end-systolic volume (mean 70.0 mL/m2 vs. 57.3 mL/m2, p = 0.03), lower creatinine (mean 0.61 mg/dL vs. 0.70 mg/dL, p = 0.04), and a higher absolute lymphocyte count (mean 1.80 K cells/µL vs. 0.76 K cells/µL, p = 0.003). The composite outcome was present in 6% of Fontan patients and was not associated with TD diameter (p = 0.50) or tortuosity (p = 0.09). Conclusions: The TD is well visualized in two-thirds of patients with Fontan circulation on 3D-bSSFP images. Larger TD diameter is associated with PLE and increased TD tortuosity is associated with an NYHA class ≥ II. [ABSTRACT FROM AUTHOR]

The lymphatic system has been poorly understood and its importance neglected for decades. Growing understanding of lymphatic flow pathophysiology through peripheral and central lymphatic flow imaging has improved diagnosis and treatment options in children with lymphatic diseases. Flow dynamics can now be visualized by different means including dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL), the current standard technique to depict central lymphatics. Novel imaging modalities including intranodal, intrahepatic and intramesenteric DCMRL are quickly evolving and have shown important advances in the understanding and guidance of interventional procedures in children with intestinal lymphatic leaks. Lymphatic imaging is gaining importance in the radiologic and clinical fields and new techniques are emerging to overcome its limitations. [ABSTRACT FROM AUTHOR]

Purpose: Resection of the tumor-draining lymph -node (TDLN) represents a standard method to identify metastasis for several malignancies. Interestingly, recent preclinical studies indicate that TDLN resection diminishes the efficacy of immune checkpoint inhibitor-based cancer immunotherapies. Thus, accurate preclinical identification of TDLNs is pivotal to uncovering the underlying immunological mechanisms. Therefore, we validated preclinically, and clinically available non-invasive in vivo imaging approaches for precise TDLN identification. Procedures: For visualization of the lymphatic drainage into the TDLNs by non-invasive in vivo optical imaging, we injected the optical imaging contrast agents Patent Blue V (582.7 g mol−1) and IRDye® 800CW polyethylene glycol (PEG; 25,000–60,000 g mol−1), subcutaneously (s.c.) in close proximity to MC38 adenocarcinomas at the right flank of experimental mice. For determination of the lymphatic drainage and the glucose metabolism in TDLNs by non-invasive in vivo PET/magnetic resonance imaging (PET/MRI), we injected the positron emission tomography (PET) tracer (2-deoxy-2[18F]fluoro-D-glucose (18F-FDG) [181.1 g mol−1]) in a similar manner. For ex vivo cross-correlation, we isolated TDLNs and contralateral nontumor-draining lymph nodes (NTDLNs) and performed optical imaging, biodistribution, and autoradiography analysis. Results: The clinically well-established Patent Blue V was superior for intraoperative macroscopic identification of the TDLNs compared with IRDye® 800CW PEG but was not sensitive enough for non-invasive in vivo detection by optical imaging. Ex vivo Patent Blue V biodistribution analysis clearly identified the right accessory axillary and the proper axillary lymph node (LN) as TDLNs, whereas ex vivo IRDye® 800CW PEG completely failed. In contrast, functional non-invasive in vivo18F-FDG PET/MRI identified a significantly elevated uptake exclusively within the ipsilateral accessory axillary TDLN of experimental mice and was able to differentiate between the accessory axillary and the proper LN. Ex vivo biodistribution and autoradiography confirmed our in vivo18F-FDG PET/MRI results. Conclusions: When taken together, our results demonstrate the feasibility of 18F-FDG-PET/MRI as a valid method for non-invasive in vivo, intraoperative, and ex vivo identification of the lymphatic drainage and glucose metabolism within the TDLNs. In addition, using Patent Blue V provides additive value for the macroscopic localization of the lymphatic drainage both visually and by ex vivo optical imaging analysis. Thus, both methods are valuable, easy to implement, and cost-effective for preclinical identification of the TDLN. [ABSTRACT FROM AUTHOR]

The article focuses on a case of a six and half month-old infant with Noonan syndrome and central conducting lymphatic anomaly. Topics include the infant experienced respiratory distress after cardiac surgery and developed chylothorax; the father also showed signs of Noonan syndrome; and the potential benefits of trametinib treatment are discussed.

Background: To describe the radiological features of Gorham–Stout disease (GSD) as evaluated using plain radiography and dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) imaging techniques. Methods: Clinical and conventional imaging data were retrospectively reviewed for 15 patients with GSD between January 2001 and December 2020. After December 2018, DCMRL examinations were performed for lymphatic vessel evaluation in patients with GSD and reviewed in four patients. Results: The median age at diagnosis was 9 years (range: 2 months–53 years). The clinical manifestations were dyspnea in seven patients (46.7%), sepsis in 12 (80.0%), orthopedic problems in seven (46.7%), and bloody chylothorax in seven (46.7%). The common sites of osseous involvement were the spine (73.3%) and pelvic bone (60.0%). Among the non-osseous involvements, peri-osseous infiltrative soft-tissue abnormalities adjacent to the area of bone involvement were the most common (86.7%), followed by splenic cysts (26.7%) and interstitial thickening (26.7%). DCMRL demonstrated weak central conducting lymphatic flow in two patients with abnormal giant tortuous thoracic ducts and no flow in one patient. All patients who underwent DCMRL in this study presented with altered anatomical lymphatics and functional flow with collateralization. Conclusion: DCMRL imaging and plain radiography are very useful for determining the extent of GSD. DCMRL is a novel imaging tool for the visualization of abnormal lymphatics in patients with GSD, which helps in further treatment. Therefore, in patients with GSD, it might be necessary to obtain not only plain radiographs but also MR and DCMRL images. [ABSTRACT FROM AUTHOR]

Lymphatic congestion is known to play an important role in the development of late Fontan complications. This study aimed to (1) develop a gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) contrast three-dimensional heavily T2-weighed MR technique that can detect abnormal lymphatic pathway in the abdomen while simultaneously evaluating hepatocellular carcinoma (HCC) and to (2) propose a new classification of abnormal abdominal lymphatic pathway using a non-invasive method in adults with Fontan circulation. Twenty-seven adults with Fontan circulation who underwent Gd-EOB-DTPA abdominal MR imaging were prospectively enrolled in this study. We proposed MR lymphangiography that suppresses the vascular signal on heavily T2-weighted imaging after EOB contrast. The patients were classified as follows: grade 1 with almost no lymphatic pathway, grade 2 with a lymphatic pathway mainly around the bile duct and liver surface, and grade 3 with a lymphatic pathway mainly around the vertebral body and inferior vena cava. The grade 3 group showed the lowest oxygen saturation level, highest central venous pressure, highest incidence of massive ascites, HCC, and focal nodular hyperplasia. This group also tended to have patients with the oldest age and highest cardiac index; however, the difference was not statistically significant. As for the blood test, the grade 3 group showed the lowest platelet count and serum albumin level and the highest fibrosis-4 index. A novel technique, Gd-EOB-DTPA MR lymphangiography, can detect abnormal abdominal lymphatic pathways in Fontan circulation, which can reflect the severity of failing Fontan. [ABSTRACT FROM AUTHOR]

Objectives: To contribute to a more in-depth assessment of shape, volume, and asymmetry of the lower extremities in patients with lipedema or lymphedema utilizing volume information from MR imaging. Methods: A deep learning (DL) pipeline was developed including (i) localization of anatomical landmarks (femoral heads, symphysis, knees, ankles) and (ii) quality-assured tissue segmentation to enable standardized quantification of subcutaneous (SCT) and subfascial tissue (SFT) volumes. The retrospectively derived dataset for method development consisted of 45 patients (42 female, 44.2 ± 14.8 years) who underwent clinical 3D DIXON MR-lymphangiography examinations of the lower extremities. Five-fold cross-validated training was performed on 16,573 axial slices from 40 patients and testing on 2187 axial slices from 5 patients. For landmark detection, two EfficientNet-B1 convolutional neural networks (CNNs) were applied in an ensemble. One determines the relative foot-head position of each axial slice with respect to the landmarks by regression, the other identifies all landmarks in coronal reconstructed slices using keypoint detection. After landmark detection, segmentation of SCT and SFT was performed on axial slices employing a U-Net architecture with EfficientNet-B1 as encoder. Finally, the determined landmarks were used for standardized analysis and visualization of tissue volume, distribution, and symmetry, independent of leg length, slice thickness, and patient position. Results: Excellent test results were observed for landmark detection (z-deviation = 4.5 ± 3.1 mm) and segmentation (Dice score: SCT = 0.989 ± 0.004, SFT = 0.994 ± 0.002). Conclusions: The proposed DL pipeline allows for standardized analysis of tissue volume and distribution and may assist in diagnosis of lipedema and lymphedema or monitoring of conservative and surgical treatments. Key Points: • Efficient use of volume information that MRI inherently provides can be extracted automatically by deep learning and enables in-depth assessment of tissue volumes in lipedema and lymphedema. • The deep learning pipeline consisting of body part regression, keypoint detection, and quality-assured tissue segmentation provides detailed information about the volume, distribution, and asymmetry of lower extremity tissues, independent of leg length, slice thickness, and patient position. [ABSTRACT FROM AUTHOR]

This brief report demonstrates the diagnostic utility of cone-beam CT lymphangiography (CBCTL) with intranodal injection of water-soluble iodinated contrast agent for assessing lymphatic disorders in two infants who were contraindicated for MRI and oil-based contrast agent. Both infants had dextro-transposition of the great arteries (d-TGA) and presented with high-output chylothoraces that were recalcitrant to conservative medical therapy. Both infants were diagnosed with central lymphatic flow disorder based on the CBCTL findings. [ABSTRACT FROM AUTHOR]

Background: Idiopathic recurrent cervical swelling may be caused by lymphatic abnormalities. Methods: Ten patients (9 females, mean age 51.2 ± 7) with idiopathic recurrent cervical swelling underwent MR‐lymphangiography (MRL). MR‐lymphangiograms were evaluated regarding lymphatic anatomy and flow. Individualized treatment was recommended according to MRL‐findings. Results: 8/10 patients presented with left‐sided, 2/10 with right‐sided swelling. Pathological lymph‐flow was identified in all cases: thoracic duct dilatation in patients with left‐sided and right lymphatic duct dilatation in right‐sided swelling, accessory thoracic lymphatics in 7/10 and reflux in 8/10 cases. In two cases, a lymphatic thrombus was identified. After treatment, symptoms resolved completely in 6/10 cases and partially in 1/10 cases. The remaining three patients have intermittent swellings but have no treatment wish. Conclusion: Idiopathic recurrent cervical swelling can be caused by lymphatic anomalies. MRL displays impaired lymphatic drainage, lymphatic vessel dilatation, and chylolymphatic reflux as hallmarks of this condition and may aid in targeted treatment planning. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide OBJECTIVES Complications after Fontan surgery have been associated with arise and classification of abnormal thoracic lymphatic perfusion pattern. This study compiles abnormal abdominal lymphatic perfusion patterns and investigates their impact on serum protein readings. METHODS We performed a retrospective analysis of patients who underwent magnetic resonance imaging with T2-weighted lymphatic imaging and serum protein measurements 6 months after having Fontan surgery. The abdominal lymphatic images were classified according to the anatomical lymphatic drainage patterns into 2 categories: (1) para-aortic (types 1–4); (2) portal-venous (types 1–3). Thoracic lymphatic images were classified (types 1–4) as described earlier. RESULTS A total of 71 patients were included in the study. Para-aortic lymphatic perfusion patterns were classified as type 1 in 4, type 2 in 13, type 3 in 37 and type 4 in16 out of 71 patients. Portal-venous lymphatic perfusion patterns were classified as type 1 in 20, type 2 in 10 and type 3 in 41 patients. Thoracic lymphatic perfusion patterns were classified as type 1 in 8, type 2 in 11, type 3 in 39 and type 4 in 13 patients. The serum protein level was 66 (interquartile range: 7.5) g/l (< standard value in 37%). Higher-grade para-aortic (p = 0.0062), portal-venous (p = 0.022) and thoracic (p = 0.011) lymphatic abnormalities were correlated with lower total serum protein levels. Higher ratings of para-aortic lymphatic abnormalities were significantly associated with higher ratings of portal-venous abnormalities (p < 0.0001). Ratings of para-aortic and portal-venous classifications were correlated with the thoracic classification (p < 0.001). CONCLUSIONS Abnormal abdominal lymphatic perfusion patterns can be classified according to anatomical structures with increasing severity. Higher grade abdominal and thoracic lymphatic perfusion patterns are associated with lower serum protein values. [ABSTRACT FROM AUTHOR]

Congenital heart disease can lead to various lymphatic complications including traumatic leaks, lymphatic overproduction, conduction abnormalities or lymphedema. Advancements in the imaging of central lymphatics and guided interventions have improved outcomes in these children. Dynamic contrast-enhanced magnetic resonance (MR) lymphangiography allows for the assessment of abnormal lymphatic drainage. This technique is preferred for evaluating lymphatic conditions such as plastic bronchitis, chylothorax, chyloptysis, chylopericardium, protein-losing enteropathy and chylous ascites, among other lymphatic disorders. In this review, we discuss lymphatic abnormalities encountered on MRI in children with congenital heart disease. We also briefly review treatment options. [ABSTRACT FROM AUTHOR]

Reliable localization of lymph nodes (LNs) in multi-parametric MRI (mpMRI) studies plays a major role in the assessment of lymphadenopathy and staging of metastatic disease. Radiologists routinely measure the nodal size in order to distinguish benign from malignant nodes, which require subsequent cancer staging. However, identification of lymph nodes is a cumbersome task due to their myriad appearances in mpMRI studies. Multiple sequences are acquired in mpMRI studies, including T2 fat suppressed (T2FS) and diffusion weighted imaging (DWI) sequences among others; consequently, the sizing of LNs is rendered challenging due to the variety of signal intensities in these sequences. Furthermore, radiologists can miss potentially metastatic LNs during a busy clinical day. To lighten these imaging and workflow challenges, we propose a computer-aided detection (CAD) pipeline to detect both benign and malignant LNs in the body for their subsequent measurement. We employed the recently proposed Dynamic Head (DyHead) neural network to detect LNs in mpMRI studies that were acquired using a variety of scanners and exam protocols. The T2FS and DWI series were co-registered, and a selective augmentation technique called Intra-Label LISA (ILL) was used to blend the two volumes with the interpolation factor drawn from a Beta distribution. In this way, ILL diversified the samples that the model encountered during the training phase, while the requirement for both sequences to be present at test time was nullified. Our results showed a mean average precision (mAP) of 53.5% and a sensitivity of ∼ 78% with ILL at 4 FP/vol. This corresponded to an improvement of ≥ 10% in mAP and ≥ 12% in sensitivity at 4FP (p ¡ 0.05) respectively over current LN detection approaches evaluated on the same dataset. We also established the out-of-distribution robustness of the DyHead model by training it on data acquired by a Siemens Aera scanner and testing it on data from the Siemens Verio, Siemens Biograph mMR, and Philips Achieva scanners. Our pilot work represents an important first step towards automated detection, segmentation, and classification of lymph nodes in mpMRI. • We propose a pipeline for lymph node detection in multi-parametric MRI studies. • T2 fat suppressed (T2FS) and DWI series were linearly interpolated to preserve their traits during training. • We used a Dynamic Head (DyHead) neural network integrated with the complete IoU loss. • At test time, either T2FS can be used alone or blended with any available DWI series (after co-registration). • A 53.5% precision and ∼ 78% sensitivity at 4 FP/vol was seen with ≥ 10% improvement (p < 0.05) over prior works. [ABSTRACT FROM AUTHOR]

Magnetic resonance imaging (MRI) is a routinely used imaging modality for the diagnosis and treatment planning of many health conditions in children and adults. Yet, its use has been limited in many institutions for patients with cardiac implantable electronic devices (CIEDs) due to safety concerns. Current evidence relates primarily to devices with transvenous leads. However, patients with complex cardiac anatomy and palliative surgery procedures often require epicardial pacemakers. To date, very few studies have addressed MRI safety considerations with non-conditional CIEDs or abandoned epicardial leads in infants, and to our knowledge, this is the first report that shows Fontan palliation patients who underwent Dynamic Contrast enhanced MR Lymphangiography (DCMRL) with these types of devices. We present our institutional experience with five cases where a DCMRL was safely performed in three children and two adults with Fontan palliation to evaluate their lymphatic anatomy and guide interventional procedures. Regarding our brief experience, we concluded that DCMRL may be considered in post-Fontan patients with non-conditional CIEDs, including epicardial leads, seeking the best diagnostic and treatment options available. Institutional protocols must be revised in advance to perform this technique in a controlled setting. • Patients with MR non-conditional cardiac implantable electronic devices (CIEDs) are still restricted from the use of MRI due to safety concerns. • Fontan patients have a complex anatomy that usually comes with abnormal lymphatic drainage. • The recent utilization of Dynamic Contrast enhanced MR Lymphangiography (DCMRL) in Fontan patients has improved their prognosis by allowing the visualization and treatment of their lymphatic leakages. • DCMRL may be considered in post-Fontan patients with non-conditional CIEDs, including epicardial leads, seeking the best diagnostic and treatment options available. [ABSTRACT FROM AUTHOR]

Purpose: To assess the feasibility of direct intra-lymphatic administration of diluted ferumoxytol as a T1-positive contrast agent for dynamic contrast-enhanced MR lymphangiography (DCMRL) imaging of the central lymphatics in children with renal disease.Methods: In vitro scan of dilute ferumoxytol was initially performed using time-resolved and high-resolution 3D gradient echo (GRE) sequences with short TE values (1 to 1.5 ms). A ferumoxytol concentration of 0.25 to 0.40 mg/mL was found to retain high signal in the T1-weighted sequences. DCMRL was then performed in 4 children with renal disease with the same 3D GRE sequences administrating diluted ferumoxytol via intra-mesenteric (IM), intra-hepatic (IH), and intra-nodal (IN) routes (6 to 9 mL to each site; average total dose of 0.75 mg/kg) by slow hand injection (0.5 to 1.0 mL/min). The signal-to-noise ratio (SNR) of the lymphatics was measured for quantitative evaluation.Results: Ferumoxytol-enhanced DCMRL was technically successful in all patients. Contrast conspicuity within the lymphatics was sufficient without subtraction. The mean SNR was significantly higher than the muscle (50.1 ± 12.2 vs 13.2 ± 2.8; t = 15.9; p < .001). There were no short-term complications attributed to the administration of ferumoxytol in any of the four patients.Conclusion: Magnetic resonance lymphangiography using ferumoxytol via IN, IH, and IM access is a new method to directly visualize the central lymphatic system and can be applied safely in patients with renal failure based on our preliminary report of four cases. Ferumoxytol-enhanced DCMRL shows diagnostic image quality by using 3D GRE sequences with short TE values and appropriate dilution of ferumoxytol.Key Points: • MR lymphangiography using ferumoxytol via intra-nodal, intra-hepatic, and intra-mesenteric access is a new method to directly visualize the central lymphatic system from the groin to the venous angle. • FDCMRL can be applied safely in patients with renal failure based on our preliminary report of four cases. • FDCMRL shows diagnostic image quality by using 3D GRE sequences with short TE values and appropriate dilution of the ferumoxytol. [ABSTRACT FROM AUTHOR]

Lymphatic flow disorders include a broad spectrum of abnormalities that can originate in the lymphatic or the venous system. The development of these disorders is multifactorial and is most commonly associated with congenital heart diseases and palliative surgeries that these patients undergo. Central lymphatic disorders might be secondary to traumatic leaks, lymphatic overproduction, conduction abnormalities or lymphedema, and they can progress to perfusion anomalies. Several imaging modalities have been used to visualize the lymphatic system. However, the imaging of central lymphatic flow has always been challenging. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) allows for visualization of central lymphatic flow disorders and has been recently applied for the assessment of plastic bronchitis, protein-losing enteropathy, chylothorax and chylopericardium, among other lymphatic disorders. The hepatic and mesenteric accesses are innovative and promising techniques for better identification and understanding of these abnormalities. The main objectives of this review are to discuss the physiology and anatomy of the lymphatic system and review the current uses of DCMRL in the diagnosis and management of lymphatic flow disorders. [ABSTRACT FROM AUTHOR]

Sentinel lymph node biopsy (SLNB) has efficiently replaced axillary lymph node dissection (ALND) in axillary staging in node-negative breast cancer patients. Dual sentinel lymph node (SLN) localization using radioisotopes and blue dye is the standard technique for SLN mapping. Yet, nuclear medicine facilities are not widely available worldwide. In Japan, Computed tomography lymphography (CTLG) is presented as an SLN mapping technique which was first suggested in 2003 by Suga et al. Multiple subsequent studies confirmed the efficacy of CTLG in SLN mapping in breast cancer. Further applications of the technique followed; such as prediction of SLN metastasis using CTLG, the use of CTLG guided SLN biopsy after neoadjuvant therapy, video-assisted CTLG guided SLN biopsy, the use of real-time virtual sonography with 3-D CTLG, and preoperative localization of the CTLG mapped SLN using either real-time virtual sonography (RVS) guided Indocyanine green (ICG) injection or its marking using liquid charcoal and silver wire and the use of SPIO enhanced magnetic resonance imaging (MRI) for prediction of metastasis in SLNs detected by CTLG. This efficacy and variable applications open the door for conducting wide-scale randomized controlled trials to suggest using CTLG as an efficient alternative for the use of radioisotopes in SLN mapping in breast cancer patients, especially in low and middle-income countries. [ABSTRACT FROM AUTHOR]

Chyluria is characterized by chyle in the urinary tract and often presents as milky-white urine. We present a case of chyluria from a lymphatic malformation in a 13-year-old boy diagnosed using dynamic intranodal contrast-enhanced magnetic resonance (MR) lymphangiography. This report demonstrates the utility of intranodal lymphangiography and interstitial lymphatic embolization to treat a pediatric patient presenting with persistent chyluria. Glue migration into the urinary collecting system is a potential complication of this procedure that can be mitigated by adjusting the n-butyl cyanoacrylate dilution with Lipiodol. [ABSTRACT FROM AUTHOR]

Background: Due to passive blood flow in palliated single ventricle, central venous pressure increases chronically, ultimately impeding lymphatic drainage. Early visualization and treatment of these malformations is essential to reduce morbidity and mortality. Cardiovascular magnetic resonance (CMR) T2-weighted lymphangiography (T2w) is used for lymphatic assessment, but its low signal-to-noise ratio may result in incomplete visualization of thoracic duct pathway. 3D-balanced steady state free precession (3D-bSSFP) is commonly used to assess congenital cardiac disease anatomy. Here, we aimed to improve diagnostic imaging of thoracic duct pathway using 3D-bSSFP. Methods: Patients underwent CMR during single ventricle or central lymphatic system assessment using T2w and 3D-bSSFP. T2w parameters included 3D-turbo spin echo (TSE), TE/TR = 600/2500 ms, resolution = 1 × 1 × 1.8 mm, respiratory triggering with bellows. 3D-bSSFP parameters included electrocardiogram triggering and diaphragm navigator, 1.6 mm isotropic resolution, TE/TR = 1.8/3.6 ms. Thoracic duct was identified independently in T2w and 3D-bSSFP images, tracked completely from cisterna chyli to its drainage site, and classified based on severity of lymphatic abnormalities. Results: Forty-eight patients underwent CMR, 46 of whom were included in the study. Forty-five had congenital heart disease with single ventricle physiology. Median age at CMR was 4.3 year (range 0.9–35.1 year, IQR 2.4 year), and median weight was 14.4 kg (range, 7.9–112.9 kg, IQR 5.2 kg). Single ventricle with right dominant ventricle was noted in 31 patients. Thirty-eight patients (84%) were status post bidirectional Glenn and 7 (16%) were status post Fontan anastomosis. Thoracic duct visualization was achieved in 45 patients by T2w and 3D-bSSFP. Complete tracking to drainage site was attained in 11 patients (24%) by T2w vs 25 (54%) by 3D-bSSFP and in 28 (61%) by both. Classification of lymphatics was performed in 31 patients. Conclusion: Thoracic duct pathway can be visualized by 3D-bSSFP combined with T2w lymphangiography. Cardiac triggering and respiratory navigation likely help retain lymphatic signal in the retrocardiac area by 3D-bSSFP. Visualizing lymphatic system leaks is challenging on 3D-bSSFP images alone, but 3D-bSSFP offers good visualization of duct anatomy and landmark structures to help plan interventions. Together, these sequences can define abnormal lymphatic pathway following single ventricle palliative surgery, thus guiding lymphatic interventional procedures. [ABSTRACT FROM AUTHOR]

Cerebral lipiodol embolisation is a rare but serious complication of lymphangiography. A man in his seventies had undergone lymphangiography for a refractory chyle leak following oesophagectomy. The day after lymphangiography, his conscious level dropped with bilaterally miotic pupils, increased muscle tone and double incontinence. CT scan of the head showed patchy high density throughout basal ganglia, cortex and cerebellum but no infarct, in keeping with lipiodol embolisation. He was managed initially in intensive care and subsequently underwent thoracoscopy with clipping and suturing of the left thoracic duct, and later a talc pleurodesis. At 3 months, he had some cognitive limitations and was walking with a stick. [ABSTRACT FROM AUTHOR]

Lymphangiectasias are lymphatic malformations characterized by the abnormal dilation and morphology of the lymphatic channels. The classification and treatment of these disorders can be challenging given the limited amount of literature available in children. Various imaging modalities are used to confirm suspected diagnosis, plan the most appropriate treatment, and estimate a prognosis. Prenatal evaluation is performed using both prenatal US imaging and fetal MRI. These modalities are paramount for appropriate parental counseling and planning of perinatal care. During the neonatal period, chest US imaging is a useful modality to evaluate pulmonary lymphangiectasia because other modalities such as conventional radiography and CT display nonspecific findings. Finally, the recent breakthroughs in lymphatic imaging with MRI have allowed us to better classify lymphatic disorders. Dynamic contrast-enhanced lymphangiography, conventional lymphangiography and percutaneous lymphatic procedures offer static and dynamic evaluation of the central conducting lymphatics in children, with excellent spatial resolution and the possibility to provide treatment. The purpose of this review is to discuss the normal and abnormal development of the fetal lymphatic system and how to best depict it by imaging during the prenatal and postnatal life. [ABSTRACT FROM AUTHOR]

Percutaneous thoracic duct embolization (TDE) is an accepted treatment for leaks of the central lymphatic ducts. In this study, we correlate the imaging findings on pre-procedural MRI lymphangiography with findings on conventional lymphangiography, and with operator ability to perform a technically successful TDE. The aim was to examine whether MRI is a good screening mechanism to support an invasive procedure in strong candidates, and avert one in poor candidates. MRI and conventional lymphangiograms of 96 patients (62 male and 34 female; mean age 63 ± 11 years, range 29–92 years) were retrospectively reviewed. The diameter and level of the best target for access were assessed for each study. Technical success rates were evaluated with respect to presence of a cisterna chyli, target duct size, and target level concordance. Presence of a cisterna chyli on MRI significantly increased the likelihood of a successful TDE (68% vs. 42%, p = 0.03). Presence of a duct 4 mm or larger, by either modality, significantly improved the chance of successful TDE (for MRI, 65% vs. 41%, p = 0.04; for lymphangiography, 70% vs. 44%, p = 0.03). MRI was not helpful for localizing a lymphatic target, as less than half were seen within one and one-half vertebrae of the predicted level. There was a weak correlation (Pearson coefficient = +0.30) between duct size as measured on the two modalities. 95% of those without an identifiable target on MRI had a viable target on lymphangiography, and successful TDE was performed in 47% of those patients. Identification of a cisterna chyli and/or 4 mm or greater target on pre-procedural MRI indicated higher likelihood of technically successful TDE. MRI did not help predict unsuccessful TDE procedures. Better target level concordance was not associated with improved technical outcomes. • An identified cisterna chyli or a duct measuring at least 4 mm increases technically successful thoracic duct embolization. • Nearly all patients without an MRI target had one on lymphangiogram and successful embolization was performed in about half. • MRI did not predict the location of a lymphatic target and better target level concordance did not improve technical success. [ABSTRACT FROM AUTHOR]

Background: Pulmonary involvement in lymphatic anomalies (LA) is associated with significant morbidity and mortality. Dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) is capable of imaging the lymphatic system in a variety of pulmonary lymphatic disorders.Research Question: The objective of this study is to describe the central lymphatic anatomy in patients with LA and pulmonary involvement on DCMRL.Study Design and Methods: This prospective observational study enrolled 16 patients with LA (mean age, 17 years; range, 6-63 years; ratio of female to male patients, 9:7) with pulmonary involvement. All patients underwent DCMRL. The lymphatic system was assessed for the presence of mediastinal masses, interstitial lung disease, size and tortuosity of the thoracic duct (TD), and presence of abnormal pulmonary lymphatic flow.Results: T2-weighted imaging showed the following: mediastinal soft tissue masses in 10 patients, diffuse pulmonary interstitial thickening in 13 patients, and bone involvement in 15 patients. DCMRL revealed abnormal pulmonary lymphatic flow in 14 of 16 patients. Abnormal pulmonary lymphatic flow originated from the TD in three of 14 patients, the retroperitoneum in six of 14 patients, and both the TD and retroperitoneum in four of 14 patients. In nine of 16 patients, the TD was dilated and tortuous. In two patients the TD was not identified, and in five patients it was normal.Interpretation: Abnormal pulmonary lymphatic flow/perfusion from the TD or retroperitoneum into the lung parenchyma occurred in the majority of patients in this study. These findings can explain the interstitial lung disease and chylothorax resulting in deterioration of respiratory function in these patients. Future studies will determine whether mechanical cessation of this abnormal flow can improve pulmonary function and prolong survival in patients with LA.Clinical Trial Registration: Clinicaltrials.gov; No.: NCT02744027; URL: www.clinicaltrials.gov. [ABSTRACT FROM AUTHOR]

Chylothorax is a rare condition characterized by lymph accumulation in the pleural space. When it occurs independent of trauma, it is even more rare and difficult to treat as identification of lymphatic leak is unpredictable. In addition, treatment of this condition with conventional lymphangiography and thoracic duct embolization may not result in positive outcomes. As such, the role of contrast-enhanced dynamic magnetic resonance lymphangiography to guide treatment is key to maximizing success with the advantage of localizing the site of lymphatic leak. Herein, we summarize etiologies of nontraumatic chylothorax, offer an updated treatment algorithm to stratify affected patients and determine appropriate treatment options, and review procedural techniques critical to efficient and effective treatment. [ABSTRACT FROM AUTHOR]

Objectives: To describe the technique and report on our initial experience with the use of intrahepatic dynamic contrast magnetic resonance lymphangiography (IH-DCMRL) for evaluation of the lymphatics in patients with hepatic lymphatic flow disorders.Methods: This is a retrospective review of the imaging and clinical findings in six consecutive patients undergoing IH-DCMRL. The technique involves injection of a gadolinium contrast agent into the intrahepatic lymphatic ducts followed by imaging of the abdomen and chest with both heavily T2-weighted imaging and dynamic time-resolved imaging.Results: In six consecutive patients, IH-DCMRL was technically successful. There were four patients with protein-losing enteropathy (PLE) and two with ascites in this study. In the four patients with PLE, IH-DCMRL demonstrated hepatoduodenal connections with leak of contrast into the duodenal lumen not seen by conventional lymphangiography. In one patient with ascites, IH-DCMRL demonstrated lymphatic leakage into the peritoneal cavity not seen by intranodal lymphangiography. In the second patient with ascites, retrograde lymphatic perfusion of mesenteric lymphatic networks and nodes was seen. Venous contamination was seen in two patients. No biliary contamination was identified. There were no short-term complications.Conclusions: IH-DCMRL is a cross-sectional technique which successfully evaluated hepatic lymphatic flow disorders and warrants further investigation.Key Points: • Intrahepatic dynamic contrast magnetic resonance lymphangiography (IH-DCMRL) is a new imaging technique to evaluate hepatic lymphatic flow disorders such as protein-losing enteropathy. • In comparison to conventional liver lymphangiography, IH-DCMRL offers a 3D imaging technique and better distal lymphatic contrast distribution and does not use ionizing radiation. [ABSTRACT FROM AUTHOR]

Background: Children with Noonan syndrome are known to have increased risk for lymphatic disorders, the extent and nature of which are poorly understood.Objective: Our objective was to describe the imaging findings of the central lymphatic abnormalities in children with Noonan syndrome who underwent central lymphatic imaging.Materials and Methods: We conducted a single-center retrospective review of all children with a confirmed history of Noonan syndrome who presented for lymphatic imaging over a 5-year period. Imaging evaluation was performed on unenhanced T2-weighted (T2-W) imaging, dynamic-contrast MR lymphangiography or conventional lymphangiography. Two readers evaluated the imaging in consensus for the distribution of fluid on T2-W imaging and for lymphatic flow of intranodal contrast agent and thoracic duct abnormalities on dynamic-contrast MR lymphangiography and conventional lymphangiography. We performed a chart review for clinical history and outcomes.Results: We identified a total of 10 children, all but one of whom had congenital heart disease. Presenting symptoms included chylothorax (n=9) and ascites (n=1). Nine had T2-W imaging, seven had dynamic-contrast MR lymphangiography, and seven had conventional lymphangiography. All with T2-W imaging had pleural effusions. On both dynamic-contrast MR lymphangiography and conventional lymphangiography, perfusion to the lung was seen (n=6), with intercostal flow also seen on dynamic-contrast MR lymphangiography (n=6). The thoracic duct was not present in three children and the central thoracic duct was not present in three. A double thoracic duct was seen in two children.Conclusion: Children with Noonan syndrome and clinical evidence of lymphatic dysfunction have central lymphatic abnormalities characterized by retrograde intercostal flow, pulmonary lymphatic perfusion, and thoracic duct abnormalities. [ABSTRACT FROM AUTHOR]

Background: We aimed to assess the feasibility of a novel hybrid endoscopic/laparoscopic non-exposed, full-thickness, single-wall gastric resection technique guided by a fluorescence lymphangiography to identify the lymphatic pathway and the sentinel node basin.Methods: Eight large white pigs (4 acute and 4 survival models) were included. Indocyanine green was injected submucosally around a pseudo-tumor at four points (1 ml, 0.1 mg/ml). The lymphatic spreading pathway was identified by the means of near-infrared (NIR) laparoscopic camera, and the resection line was planned outside of the fluorescent signals, to include all the potential lymphatic channels. Lymph node (LN) dissection was performed at greater curvature side and the infrapyloric area preserving the infragastric artery for all pigs. At the lesser curvature, 3-4 branches of the gastric artery were preserved in all acute and in two survival (group A), while in the remaining animals, 1-2 branches were preserved (group B). Perfusion of the remaining stomach was examined by NIR angiography. The gastric motility and function were evaluated by the means of a dynamic MRI immediately after the procedure and repeated after 1 week in surviving animals.Results: The hybrid full-thickness resection with bilateral sentinel LN basin dissection were successfully performed with no intra-operative or post-operative complications. The removed specimen was including all the area with florescent signal. The remaining stomach demonstrated a good perfusion at the NIR angiography. The dynamic MRI revealed a preserved emptying function in the acute animals and in the group A, and a loss of function in the group B.Conclusions: Fluorescence-lymphangiography guided hybrid resection was feasible to remove a relatively large part of the stomach including the lymphatic spreading pathway and sentinel basin. The extent of dissection in the lesser curvature side can affect the post-operative function and further researches are warranted to optimize the concept. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the capability of indirect computed tomography and magnetic resonance lymphography (CT/MR-LG) with gadolinium-loaded, polyethylenimine-entrapped gold nanoprobes (Gd-Au PENPs) for assessing lingual sentinel lymph node (SLN) metastasis in a tongue VX2 carcinoma model. Materials and methods: Seventeen rabbits were used to establish a metastatic cervical lymph node model by implanting VX2 carcinoma suspension into the ventral tongue muscle. CT and MR images were acquired one hour after Gd-Au PENPs injection into the tongue submucosa bilaterally, on 1w (n = 4), 2w (n = 6) and 3w (n = 7) tumour-bearing rabbits after carcinoma transplantation. Then, the filling defects and enhancement features of the lingual SLN on indirect CT/MR-LG were assessed. Results: The enhanced lingual SLNs were observed bilaterally in all rabbits using indirect CT/MR-LG. In total, 15 enhanced SLNs displayed oval or round shape with uniform density and no filling defects or only local small filling defects, and all nodes were metastasis-negative, while 19 enhanced SLNs demonstrated irregular morphologies with filling defects, non-uniform densities and unclear borders, of which 14 nodes were metastatic. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value when using SLN enhancement with irregular morphology, filling defects, non-uniform density and unclear border as diagnostic criteria for metastasis were 100%, 75.0%, 85.3%, 73.7% and 100%, respectively. Conclusions: Indirect CT/MR-LG with Gd-Au PENPs can be used for the metastatic diagnosis of lingual SLN in tongue cancer. [ABSTRACT FROM AUTHOR]

The article presents case study of a male neonate with a birth weight of 854 g, born by cesarean section after 25 weeks of pregnancy, was admitted immediately after birth to the neonatal intensive care unit. Genetic test of Tuberous sclerosis complex (TSC) was not performed, and other complications of TSC for example renal angiomyolipomas, lymphangiomyomatosis, hydrocele were not detected.

Purpose To validate usefulness of magnetic resonance (MR) lymphangiography for evaluation of peripheral lymphedema in upper extremities by comparison with lymphoscintigraphy. Materials and methods This prospective study had institutional review board approval and written informed consent was obtained from all patients. Initially, protocol of MR lymphangiography for upper extremity was established in seven healthy volunteers with 3.0T fat-saturated three-dimensional gradient-echo MR after gadobutrol injection. Then six patients with unilateral lymphedema of the upper extremities were examined with MR lymphangiography and lymphoscintigraphy, and the results were correlated with each other. Four categories were defined to scale the quality of drainage. Results of both techniques were separately evaluated by two radiologists and a nuclear physician. We evaluated sensitivity, specificity and correlation of both techniques. Results MR lymphangiography showed sensitivities of 100% for all four categories, while lymphoscintigraphy yielded a sensitivity of 83.3% for delineation of lymph vessels and 100% for the other three categories. Specificity of MR lymphangiography was 85.7% for delay of drainage and 100% for other three categories, while lymphoscintigraphy showed specificity of 66.7% for pattern of lymphatic drainage and 100% for other three categories. Delay and pattern of drainage was same in 83.3% and non-visualization of axillary LNs was indistinguishably noted in all patients on both techniques. Anatomic level of enhanced lymph vessel was identical in 66.7% of the patients. Conclusion MR lymphangiography showed better performance for depiction of lymph vessels. MR lymphangiography and lymphoscintigraphy yielded same results in all or most patients for evaluation of axillary lymph nodes enhancement and lymphatic drainage in upper extremity. [ABSTRACT FROM AUTHOR]

Objective: To review the technical aspects and categorize the imaging findings of dynamic contrast enhanced magnetic resonance lymphangiography (DCMRL) and correlate the findings with patient management options.Materials and Methods: A retrospective review of patients who underwent DCMRL between June 2012 and August 2017 at a tertiary care paediatric hospital was performed. Twenty-five DCMRL studies were performed in 23 patients (9 males, 13 females, 1 ambiguous gender) with a median age of 4 years (range: 1 month-29 years). DCMRL imaging findings were reviewed, categorized and the impact on patient management was studied.Results: DCMRL was technically successful in 23/25 (92%) studies. DCMRL findings were categorized based on the status of central conducting lymphatics (CCL) and alternate lymphatic pathways as follows: Type 1 - normal CCL with no alternate lymphatic pathways, Type 2 - partial (2a) or complete (2b) non-visualization of CCL with reflux of contrast into alternate pathways and Type 3 - normal CCL with additional filling of alternate pathways. Type 1 DCMRL patients (n = 5) were reassured and conservative management was continued, Type 2 patients (n = 10) had evidence of CCL obstruction hence thoracic duct ligation or embolization was avoided and other options such as lymphatic fluid diversion using Denver® shunt or lympho-venous anastomosis were used, and Type 3 patients (n = 8) were evaluated for elevated central venous pressure as a cause of lymphatic backflow in addition to Denver® shunt, lympho-venous anastomosis, thoracic duct ligation or embolization.Conclusion: DCMRL is an evolving imaging technique for understanding abnormalities of the central conducting lymphatics. Categorization of imaging findings may be helpful in guiding selection of management options. [ABSTRACT FROM AUTHOR]

Chylothorax is a rare cause of pleural effusion in children, and it is usually difficult to identify the location of chyle leakage due to the small size of the thoracic duct in children. Herein we report an infant case with chylothorax whose leakage of the thoracic duct was successfully located by magnetic resonance lymphangiography (MRL) using pre-contrast MR cholangiopancreatography (MRCP) and gadodiamide-enhanced spectral presaturation inversion recovery (SPIR) T 1 -weighted imaging, which demonstrate the imaging method is easy and effective for detecting the focal disruption of the thoracic duct in children with chylothorax and younger than 8 months old. [ABSTRACT FROM AUTHOR]

Objective: The popularity of contemporary microsurgical techniques in treatment of lower-limb lymphedema calls for better visualization of the lymphatic system, both preoperatively and intra-operatively. The aim of this prospective study was to investigate the feasibility of a novel combination of Ga-NEB positron emission tomography (PET) with magnetic resonance lymphography (MRL) in evaluating lymphedema and guiding surgical intervention. Methods: A total of 11 patients (F 9, M 2, age range 29-69 y) with lower-limb lymphedema classified into stage I to III were recruited. PET acquisition was performed at 30, 60 and 90 min after subcutaneous injection of the albumin-binding radiotracer Ga-NEB into the bilateral first web spaces of the feet. All the patients were also subjected to Tc-sulfur colloid (SC) lymphoscintigraphy for comparison. Gd-DTPA-enhanced magnetic resonance imaging (MRI) was performed using sequences specialized for lymphatic vessel scans. All the patients underwent surgical interventions within a week. The surgical approach includes the use of a linear marker for edema localization and indocyanine green (ICG) lymphography with a near-infrared surgical navigation system intra-operatively. Results: Lymph transport in lymphatic channels was clearly observed by visualization of Ga-NEB activity in the lymphatic vessels and within lymph nodes for all 11 patients as well as the visualization of the edema section plane with dermal backflow (DB), abnormally increased and disconnected uptake along the lymphatic channels. Preoperative Ga-NEB PET combined with MRL provides advantageous three-dimensional images, higher temporal resolution, significantly shorter time lapse before image acquisition after tracer injection and more accurate pathological lymphatic vessel distribution than Tc-SC lymphoscintigraphy combined with MRI. Conclusion: This study documented an effective imaging pattern to combine Ga-NEB PET and MRL in patients with lower-limb lymphedema. This strategy demonstrated significant advantage over Tc-SC lymphoscintigraphy/MRL in the evaluation of lymphedema severity, staging and pathological location of lymph vessels to make an individualized treatment plan. Dual Ga-NEB PET/MRL is thus recommended before the operation for staging and therapy planning. [ABSTRACT FROM AUTHOR]

Lymphatic malformations (LMs; especially those involving the central conducting lymphatic channels) are characterized by dysplastic and incompetent lymphatic channels in multiple tissues and organs. The major cause of mortality and morbidity in patients with thoracic LM is deterioration of pulmonary function due to chronic chylous effusions and progressive interstitial lung disease. The etiology of these pulmonary processes is unknown, although lymphatic involvement is certain. Understanding of the changes in the lymphatic anatomy in patients with LM has been hindered by difficulty of imaging of the lymphatic system. Recently developed dynamic contrast-enhanced magnetic resonance lymphangiography (DCMRL) allows dynamic MR imaging of the lymphatic system by injecting gadolinium contrast agent in the groin lymph nodes. Using this technique, pathological lymphatic flow from the central lymphatic system and/or retroperitoneal and mediastinal masses into lung parenchyma ("pulmonary lymphatic perfusion syndrome") has been demonstrated in patients with LM. This abnormal lymphatic perfusion overflows pulmonary parenchyma and results in deterioration of pulmonary function due to interstitial process and/or compression effect of chylous effusions. Percutaneous thoracic duct embolization or lymphatic interstitial embolization of the lymphatic masses results in cessation of the pulmonary lymphatic overflow and significant improvement in pulmonary symptoms in these patients. [ABSTRACT FROM AUTHOR]

Unlabelled: The thoracic duct is the body's largest lymphatic conduit, draining upwards of 75 % of lymphatic fluid and extending from the cisterna chyli to the left jugulovenous angle. While a typical course has been described, it is estimated that it is present in only 40-60% of patients, often complicating already challenging interventional procedures. The lengthy course predisposes the thoracic duct to injury from a variety of iatrogenic disruptions, as well as spontaneous benign and malignant lymphatic obstructions and idiopathic causes. Disruption of the thoracic duct frequently results in chylothoraces, which subsequently cause an immunocompromised state, contribute to nutritional depletion, and impair respiratory function. Although conservative dietary treatments exist, the majority of thoracic duct disruptions require embolization in the interventional suite. This article provides a comprehensive review of the clinical importance of the thoracic duct, relevant anatomic variants, imaging, and embolization techniques for both diagnostic and interventional radiologists as well as for the general medical practitioner.Key Points: • Describe clinical importance, embryologic origin, and typical course of the thoracic duct. • Depict common/lesser-known thoracic duct anatomic variants and discuss their clinical significance. • Outline the common causes of thoracic duct injury and indications for embolization. • Review the thoracic duct embolization procedure including both pedal and intranodal approaches. • Present and illustrate the success rates and complications associated with the procedure. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether atlas-based anatomical information can improve a fully automated lymph node detection system for pelvic MR lymphography (MRL) images of patients with prostate cancer. Methods: Their data set contained MRL images of 240 prostate cancer patients who had an MRL as part of their clinical work-up between January 2008 and April 2010, with ferumoxtran-10 as contrast agent. Each MRL consisted of at least a 3D T1-weighted sequence, a 3D T2*-weighted sequence, and a FLASH-3D sequence. The reference standard was created by two expert readers, reading in consensus, who annotated and interactively segmented the lymph nodes in all MRL studies. A total of 5089 lymph nodes were annotated. A fully automated computer-aided detection (CAD) system was developed to find lymph nodes in the MRL studies. The system incorporates voxel features based on image intensities, the Hessian matrix, and spatial position. After feature calculation, a GentleBoost-classifier in combination with local maxima detection was used to identify lymph node candidates. Multiatlas based anatomical information was added to the CAD system to assess whether this could improve performance. Using histogram analysis and free-receiver operating characteristic analysis, this was compared to a strategy where relative position features were used to encode anatomical information. Results: Adding atlas-based anatomical information to the CAD system reduced false positive detections both visually and quantitatively. Median likelihood values of false positives decreased significantly in all annotated anatomical structures. The sensitivity increased from 53% to 70% at 10 false positives per lymph node. Conclusions: Adding anatomical information through atlas registration significantly improves an automated lymph node detection system for MRL images. [ABSTRACT FROM AUTHOR]

Aims: To dynamically observe the color change and enhancement effect of gadolinium-loaded polyethylenimine-entrapped gold nanoparticles (Gd-Au PENPs) as a dual-mode CT/MRI contrast agent for sentinel lymph node (SLN) identification.Methods: In 6 rabbits, Gd-Au PENPs were injected into the right side tongue submucosa, after which the color change of cervical draining lymph nodes was observed. Then the draining lymph nodes were examined by CT/MRI scan. Another 6 rabbits were randomly divided into a CT lymphography (CT-LG) and a MRI lymphography (MRI-LG) group and examined by CT/MRI scan 1 and 30 min after injection. Then SLNs were identified under the guidance of CT/MRI-LG.Results: The ipsilateral afferent lymphatic vessels, cervical draining lymph nodes and efferent lymphatic vessels were stained black orderly and constantly after Gd-Au PENPs injection. Thirty minutes after injection, all cervical lymph nodes were excised to be examined by CT/MRI scan, and only the black-stained draining lymph nodes were enhanced. The 6 rabbits with CT/MRI-LG showed clear enhancement of SLNs. With indirect lymphography, the black-stained SLNs were easily visualized at autopsy. In all rabbits, the identification rate of lingual SLNs was 100%.Conclusions: Rabbit lingual SLNs could be identified with indirect lymphography using Gd-Au PENPs as a dual-mode contrast agent. [ABSTRACT FROM AUTHOR]

Background: Plastic bronchitis is a potentially fatal disorder occurring in children with single-ventricle physiology, and other diseases, as well, such as asthma. In this study, we report findings of abnormal pulmonary lymphatic flow, demonstrated by MRI lymphatic imaging, in patients with plastic bronchitis and percutaneous lymphatic intervention as a treatment for these patients.Methods and Results: This is a retrospective case series of 18 patients with surgically corrected congenital heart disease and plastic bronchitis who presented for lymphatic imaging and intervention. Lymphatic imaging included heavy T2-weighted MRI and dynamic contrast-enhanced magnetic resonance lymphangiogram. All patients underwent bilateral intranodal lymphangiogram, and most patients underwent percutaneous lymphatic intervention. In 16 of 18 patients, MRI or lymphangiogram or both demonstrated retrograde lymphatic flow from the thoracic duct toward lung parenchyma. Intranodal lymphangiogram and thoracic duct catheterization was successful in all patients. Seventeen of 18 patients underwent either lymphatic embolization procedures or thoracic duct stenting with covered stents to exclude retrograde flow into the lungs. One of the 2 patients who did not have retrograde lymphatic flow did not undergo a lymphatic interventional procedure. A total of 15 of 17(88%) patients who underwent an intervention had significant symptomatic improvement at a median follow-up of 315 days (range, 45-770 days). The most common complication observed was nonspecific transient abdominal pain and transient hypotension.Conclusions: In this study, we demonstrated abnormal pulmonary lymphatic perfusion in most patients with plastic bronchitis. Interruption of the lymphatic flow resulted in significant improvement of symptoms in these patients and, in some cases, at least temporary resolution of cast formation. [ABSTRACT FROM AUTHOR]

Background Different imaging techniques have been used for the investigation of the lymphatic channels and lymph glands. Noncontrastmagnetic resonance (MR) lymphography has significant advantages in comparison with other imaging modalities. Methods Noncontrast MR lymphography uses very heavily T2-weighted fast spin echo sequences which obtain a nearly complete signal loss in tissue background and specific display of lymphatic vessels with a long T2 relaxation time. The raw data can be processed with different algorithms such as maximum intensity projection algorithm to obtain an anatomic representation Results Standard T2-weightedMR images easily demonstrate the location of edema. It appears as subcutaneous infiltration of soft tissue with a classical honeycomb pattern. True collection around the muscular area may be demonstrated in case of severe lymphedema. Lymph nodes may be normal in size, number, and signal intensity; in other cases, lymph nodesmay be smaller in size or number of lymph nodes may be restricted. MR lymphography allows a classification of lymphedema in aplasia (no collecting vessels demonstrated); hypoplasia (a small number of lymphatic vessels), and numerical hyperplasia or hyperplasia (with an increased number of lymphatic vessels of greater and abnormal diameter). Conclusion Noncontrast MR lymphography is a unique noninvasive imaging modality for the diagnosis of lymphedema. It can be used for positive diagnosis, differential diagnosis, and specific evaluation of lymphedema severity. It may also be used for follow-up evaluation after treatment. [ABSTRACT FROM AUTHOR]

Background: USPIO is a contrast agent for MRI that can generate T2W images with low signal intensities. After subcutaneous or intravenous injection of USPIO, normal lymph node tissues uptake these nano-particles, but tumor cells do not. Thus, tumor metastasis can be detected using this contrast agent. Objective: The aim of this study was to access the feasibility of USPIO enhanced MRI for the detection of cervical lymph node metastasis in a pyriform sinus carcinoma animal model and to investigate the ability of USPIO to enhance images of cervical lymph node metastases. Methods and Findings: Twenty New Zealand rabbits were randomly divided into tumor and inflammatory groups, and each group contained 10 rabbits. In the inflammatory group, a 0.5 ml egg yolk emulsion was injected into the sub-mandibular muscle of the rabbits to induce an inflammatory reaction in their cervical lymph nodes. In the tumor group, a VX2 tumor tissue suspension was transplanted into the pyriform sinus sub-mucosa of the rabbits using direct laryngoscope. Four weeks after the tumor or egg yolk injection, MRIs were performed before and after USPIO injection to observe the imaging enhancement features of USPIO. After that, a histo-pathological analysis was performed for all rabbits. We found the metastatic lymph nodes had no signal reduced intensity or irregular signal reduced intensity on T2-weighted image by using USPIO enhancement. In the tumor group,the sensitivity and specificity of plain MRI were 57.6% and 60.7%. The corresponding values of USPIO-enhanced MRl were 96.1% and 85.7%. (P<0.05) Conclusion: The features and the extent of the lymph node metastases corresponded to those observed on USPIO-enhanced MR images. USPIO-enhanced MRI is useful for the detection and estimation of lymph node metastasis in this cervical carcinoma animal model. [ABSTRACT FROM AUTHOR]

Aim: To investigate the feasibility of evaluating tumour lymphangiogenesis using magnetic resonance imaging (MRI) in vivo. Materials and methods: Water-soluble polyethylene glycol (PEG)-GoldMag nanoparticles were obtained by combining GoldMag with PEG. The PEG-GoldMag nanoparticles were bound to anti-podoplanin antibody (PodAb) to construct PEG-GoldMag-pod molecular probes targeting lymphatic endothelial cells (LECs). The characteristics of the PEG-GoldMag-pod nanoparticles were tested. Using these nanoparticles, tumour lymphangiogenesis was evaluated using MRI in vitro and in vivo. Results: The average size of PEG-GoldMag nanoparticles was about 66.8 nm, and the nanoparticles were stably dispersed in the liquid phase for at least 15 days. After incubation for 24 h at different iron concentrations ranging from 5–45 μg/ml, the LECs were labelled with PEG-GoldMag-pod nanoparticles, in particular the breast cancer LECs. Dose-dependence was observed in the labelling efficiencies and MRI images of the labelled cells. In vitro, the labelling efficiencies and MRI images showed that the nanoparticles could detect podoplanin expression in LECs. In induced rat models of breast cancer, PEG-GoldMag-pod nanoparticles combined with lymphatic vessels were significantly detectable at MRI 60 min after nanoparticle administration, the signal intensity was negatively correlated with the lymphatic vessel density of breast cancer (r = −0.864, P = 0.000). Conclusions: The present study proves the feasibility of evaluating tumour lymphangiogenesis with MRI in vivo. [Copyright &y& Elsevier]

Background: The prognosis of prostate cancer patients with lymph node metastases so small they can only be visualized by new imaging techniques as MR lymphography (MRL) is unknown. The purpose of this study was to investigate the prognosis of prostate cancer patients with non-enlarged metastatic lymph nodes on MRL and to identify a subgroup of MRL-positive patients who might be candidates for curative treatment. Methods: The charts of 138 prostate cancer patients without enlarged lymph nodes on CT, in whom a pre-treatment MRL was performed were reviewed. Endpoints were distant metastases-free survival and overall survival. Relation between the following factors and outcome were investigated: T-stage, PSA value at diagnosis, Gleason score, diameter (short axis and long axis) of the largest MRL-positive lymph node, number of MRL-positive lymph nodes, the presence of extra-pelvic nodal disease, and the extent of resection of the positive lymph nodes. Kaplan-Meier analysis was performed to estimate the survival functions. Results: Of the 138 patients, 24 (17%) had a positive MRL. Patients with a short axis of the largest positive lymph node of ⩽8 mm had a significantly better 5-year distant metastases-free (79% vs 16%) and overall survival (81% vs 36%) than patients with larger positive lymph nodes. This also accounted for patients with a largest long axis of ⩽10 mm (71% vs 20% and 73% vs 40%, respectively). Outcome was also better in patients in whom all positive lymph nodes had been resected. Conclusion: A selection of MRL-positive patients with a good prognosis could be identified, consisting of patients with small positive lymph nodes. In these patients, cure might be pursued. [ABSTRACT FROM AUTHOR]

Background Lymphangioma circumscriptum ( LC) is a rare, superficial, cutaneous lymphatic malformation. Management is difficult because of high recurrence rates, regardless of the treatment modality chosen. The carbon dioxide ( CO2) laser may offer a less-invasive option than surgery that provides satisfactory functional and cosmetic results. Objectives To systematically review the efficacy and safety of the CO2 laser for the treatment of LC. Methods The terms 'lymphangioma circumscriptum' and 'microcystic lymphatic malformation' were combined with 'treatment,' 'laser,' and 'carbon dioxide' during separate searches in the PubMed database. The articles retrieved were then evaluated based on set criteria. Results We identified 16 studies (11 case reports, 5 case series) with a total of 28 separate patients who had been treated for LC using a CO2 laser. Eight patients remained disease free from 4 months to 3 years, 10 experienced partial recurrence, and two experienced complete recurrence. Various laser parameters were reported, and adverse effects were generally minor and infrequent, such as dyspigmentation and mild scarring. Conclusions Available evidence indicates that the CO2 laser is a safe and efficacious option for the treatment of LC, particularly in large lesions that may not be amenable to surgical intervention. [ABSTRACT FROM AUTHOR]

Conclusion: This is the first report on human sentinel node (SN) detection by interstitial magnetic resonance (MR) lymphography with superparamagnetic iron oxide (SPIO) in tongue cancer patients who also underwent lymphoscintigraphy. Our results indicate that further studies are warranted, as this novel method may replace current scintigraphic techniques. Objectives: To examine the feasibility of interstitial MR lymphography using SPIO for SN detection in the head and neck region. Methods: MR images were acquired sequentially at 10 min, 30 rain, and 24 h after submucosally injecting 0.1 ml SPIO (ferucarbotran) around the tumor in three patients with tongue cancer without cervical lymph node metastasis (clinical T2NOM0). Results: The SNs were clearly visualized in the 10 min interstitial MR lymphography images and were complete concordant with those visualized by 99mTc-radiocolloid lymphoscintigraphy and a gamma probe in all cases. Iron incorporation into the SNs was confirmed by pathological examination. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To investigate the pattern of lymph node spread on magnetic resonance lymphography (MRL) in prostate cancer patients and compare this pattern to the clinical target volume for elective pelvis irradiation as defined by the radiation therapy oncology group (RTOG-CTV). Methods and materials: The charts of 60 intermediate and high risk prostate cancer patients with non-enlarged positive lymph nodes on MRL were reviewed. Positive lymph nodes were assigned to a lymph node region according to the guidelines for delineation of the RTOG-CTV. Five lymph node regions outside this RTOG-CTV were defined: the para-aortal, proximal common iliac, pararectal, paravesical and inguinal region. Results: Fifty-three percent of the patients had an MRL-positive lymph node in a lymph node region outside the RTOG-CTV. The most frequently involved aberrant sites were the proximal common iliac, the pararectal and para-aortal region, which were affected in 30%, 25% and 18% respectively. Conclusion: More than half of the patients had an MRL-positive lymph node outside the RTOG-CTV. To reduce geographical miss while minimizing the toxicity of radiotherapy, image based definition of an individual target volume seems to be necessary. [Copyright &y& Elsevier]