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Summary Background With the experience-based hypothesis of low donor site morbidity (DSM) for free flaps from the distal femur, this cohort study aimed to evaluate the DSM according to objective and reproducible criteria. Methods One hundred and fifty-six patients who had a flap harvest from either the medial or lateral femoral condyle region between 2005 and 2017 were included. A retrospective chart review was performed for all patients. In total, 97 patients were available for a follow-up examination. Outcomes were assessed according to objective (Knee Society Score; Larson Knee Score; OAK Score; 0–100 points), patient-reported (IKDC Score; KOOS Score; 0–100 points), and radiologic criteria (Kellgren and Lawrence Score; MRI Osteoarthritis Knee Score). Results The median follow-up time was 1,529 days (range: 248–4,810). The mean Knee Society Score (94.8 ± 10.1), Larson Knee Score (94.5 ± 10.1), and OAK Score (95.5 ± 6.6) showed nearly unimpaired knee function. The overall patient-reported DSM was low (IKDC Score: 86.7 ± 17.4; KOOS Score: 89.3 ± 17.1). Osteochondral (OC) flaps had a significantly higher DSM, regardless of the donor site. Bone flaps did not show any relevant radiologic morbidity in the Kellgren and Lawrence Score. Besides the procedure-associated cartilage lesions at the OC donor sites, MRI Osteoarthritis Knee Score did not show any significant presence of further knee pathologies in the bilateral MRI Scans. The obvious cartilage lesions did not have a relevant impact on the knee function of most patients. Conclusion The DSM for bone and soft-tissue flaps from the femoral condyle region is negligible. OC flaps are associated with a significantly higher DSM, although a clinically relevant impact on knee function was not evident in the majority of patients.

Introduction The aim of this study was to assess the significance of volume computed tomography perfusion imaging of metastasizing renal cell carcinoma (mRCC) in the early period after the initiation of targeted therapy. Methods Blood flow (BF), blood volume, and clearance (CL) were calculated in 10 patients with histologically verified mRCC before and 1 month after initiation of targeted therapy using compartmental analysis algorithms. In addition, the longest diameter of tumor was measured for both time points and compared. Correlation test was performed between perfusion parameters and size changes with time to progression (TTP). Results Blood flow and CL were significantly lower after therapy initiation, whereas blood volume and the long diameter remained unchanged. Median values before and after 4 weeks of therapy were 144.2 versus 99.4 mL/min/100 mL for BF (P = 0.009) and 115.5 versus 46.8 mL/min/100 mL for CL (P = 0.007). Changes in BF and CL showed very strong negative correlation with TTP (r = -0.838, P = 0.009 and r = -0.826, P = 0.011, respectively). Conclusions Our preliminary study results indicate that volume computed tomography perfusion may assess targeted therapy response of mRCC earlier than the currently used Response Evaluation Criteria in Solid Tumors. In addition, changes in BF and CL may be a promising parameter for prediction of TTP.

We addressed a significant unknown feature of circulating tumor DNA (ctDNA), i.e., how ctDNA levels change during chemotherapy, by serially monitoring ctDNA in patients with colorectal cancer during the 48-h application of FOLFOX. Surprisingly, we did not observe a spike in ctDNA as a sign of a responsive tumor, but instead ctDNA levels initially decreased and remained low in patients with stable disease or partial response. Our observations reveal further insights into cell destruction during chemotherapy with important implications for the management of patients.

Response evaluation of cancer therapeutics relies on the assessment of the change in tumor burden, which is performed in accordance with defined criteria every 8-12 weeks. However, predictive factors for response are not available for the majority of patients with advanced stage colorectal cancer. Here we show that measurement of circulating tumor DNA (ctDNA) levels during one of the most commonly administered drug regimens, i.e. FOLFOX, allows an early, real-time assessment of treatment response. During the 48-hour FOLFOX application, we serially assessed plasma DNA and observed that ctDNA levels initially decreased during the first 23 hours. In patients with stable disease or partial response, ctDNA levels remained low, whereas in patients with progressive disease, ctDNA levels increased at the end of the treatment cycle, predicting clinical and radiologic response correctly. Hence, ctDNA monitoring during treatment may contribute to an early outcome prediction with significant implications for the management of patients.

The aim of this study was to assess the feasibility of computed tomography (CT) perfusion in early follow-up after transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC). Fifteen patients with a total of 16 HCC who were referred to our institution for TACE were included in the study. Computed tomography perfusion was performed within 1 to 3 days before and 4 to 7 days after TACE. Multiphase contrast-enhanced CT was performed 35 (SD, 20) days after TACE. Hepatic arterial blood flow and portal venous blood flow, as well as the perfusion index (PI), were calculated for each HCC using the dual input maximum slope method. Visual grading of the PI and visual grading of the amount of deposition of embolic material within the HCC were performed using a 6-step scale. Differences in perfusion before and after TACE and correlation of perfusion before TACE with the amount of embolization material depositions 1 week and 1 month after TACE were tested. No statistically significant correlation was found between pre-TACE perfusion parameters and the amount of embolization material deposition in the post-TACE studies. There was no statistically significant difference between pre- and post-TACE arterial blood flow and portal venous blood flow, whereas PI was significantly lower after TACE. Congruently, visual grading of PI was statistically significantly lower after TACE. There was no statistically significant difference in quantitative pre-TACE and post-TACE PI between tumors, which showed hypervascularization in the multiphase follow-up CT and tumors that did not show hypervascularization. However, tumors that showed hypervascularization in the multiphase follow-up CT had significantly higher visual grading of PI after TACE than tumors that did not show hypervascularization. Our findings indicate that visual interpretation of the PI of HCC derived from dual-input maximum slope CT perfusion may be an early predictor of response to TACE.

To assess the influence of the lower threshold for segmentation of the volume of interest on the perfusion values in first-pass dual input volume CT-perfusion of lung lesions.Dual input maximum slope volume CT-perfusion was performed in 48 patients (mean age±standard deviation [SD], 68±10years; range, 46-87 years) who underwent subsequent CT-guided biopsy to evaluate a lung lesion. Using commercial perfusion software, a lower and upper threshold was set for determination of the CT-value range, which again determined the volume of interest for perfusion calculation. The pulmonary arterial flow (PAF), bronchial arterial flow (BAF), and perfusion index (PI; PAF/(PAF+BAF)) were calculated at following pre contrast CT value range settings: -80 to 150HU (setting 1), -200 to 150HU (setting 2), -300 to 150HU (setting 3), and -500 to 150HU (setting 4). Perfusion parameters were compared between benign (n, 15) and malignant (n, 33) lesions for each setting. Intraobserver- and interobserver reliability were calculated for setting 4.Median PAF was significantly higher in malignant lesions than in benign lesions for all settings (53-96 versus 29-62mL/min/100mL, P0.05). There was no significant difference in BAF between malignant and benign lesions. Median PAF of all lesions was significantly influenced by the CT value range setting (P0.05), whereas the values increased from setting 1 to 4. Intraobserver analysis as well as interobserver analysis of PAF at setting 4 showed excellent reliability (Cronbach's alpha 0.98 and 0.95, respectively, P0.01).PAF derived from first-pass dual-input maximum slope volume CT perfusion is statistically significantly higher in malignant than in benign lesion, whereas the measurements are influenced by the lower threshold of the CT value range setting. This has to be considered when using cutoff values provided in the literature for differentiation between benign and malignant lung lesions.

Background: In recent years, various efforts have been made to identify biomarkers in metastatic colorectal cancer patients (mCRC), all with the goal of improving patients' outcomes, including maximizing therapeutic response and minimizing exposure to ineffective treatments. Nevertheless, there is still no valid biomarker for the early assessment of therapeutic efficacy in the patient management strategy. To address this issue, we aimed to describe the predictive value of circulating tumor DNA (ctDNA) on the efficacy of FOLFOX treatment in mCRC patients. Patients and methods: A total of 11 patients with mCRC receiving FOLFOX therapy were included in this study. During the 48-hour FOLFOX cycle, we performed serial liquid biopsy-based ctDNA analysis before treatment start (T1) and at eight further time points (T2-T9). Among the 11 patients tested, all patients had detectable variants identified by either tumor tissue genotyping or baseline sample ctDNA sequencing for longitudinal analysis. We assessed genome-wide somatic copy number alterations (SCNAs) and highly sensitive sequencing approaches were utilized to monitor changes in the ctDNA mutant allele frequencies (mAFs) between baseline and on-treatment samples. Results: We were able to clearly assess different mAF patterns across patients with either stable disease, partial response or progressive disease. However, we invariably observed an early and deep ctDNA mAF decrease in all patients, as comparing the baseline (T1) mAF levels with the mAFs at all time points revealed that the most significant ctDNA drop was 23 hours after treatment start, i.e. at time point T5 (p Conclusion: Our observations clearly demonstrated for the first time that ctDNA dynamics allow real-time, individualized evaluation of treatment response using two early time points, i.e. at T5 and T9. Therefore, our data suggest that sequential ctDNA analysis can contribute to an improved patient treatment strategy. Nevertheless, further studies are clearly required to validate this promising early on-treatment indicator of therapeutic efficacy for CRC patients. Citation Format: Tina Moser, Julie Waldispuehl-Geigl, Jelena Belic, Samantha Perakis, Sabrina Weber, Qing Zhou, Heinz Sill, Sigurd Lax, Karl Kashofer, Gerald Hoefler, Helmut Schoellnast, Thomas Bauernhofer, Ellen Heitzer, Jochen B. Geigl, Michael R. Speicher. Early circulating tumor DNA dynamics as a real-time predictor of FOLFOX efficacy in advanced colorectal cancer patients [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4295.

The purpose of this study was to assess the relationship between size and the continuity of energy application in interstitial laser-induced thermotherapy. Percutaneous computed tomography-guided laser ablation (30 W, 600 nm diode) of the lung was performed in 7 Yorkshire pigs; a total of 42 ablation zones were created. Twenty ablations were performed using a continuous cycle of 2 min (protocol A) and 22 ablations were performed using 4 intermittent cycles with a duration of 1 min for each cycle interrupted by a 10-s stop between the cycles (protocol B). The lung was harvested immediately after euthanasia for gross pathology and histopathologic evaluation. Statistical analysis was performed using the Student t test and the Spearman correlation coefficient. Laser ablation resulted in complete necrosis of variable size of lung. The mean ablation zone dimensions (±SD) were 1.9 (±0.4) cm × 1.4 (±0.3) cm for protocol A and 2.2 (±0.5) cm × 1.4 (±0.4) cm for protocol B. The size of the necrosis is not significantly different when comparing a continuous 2-min ablation to a 4-cycle intermittent ablation for 1 min each cycle interrupted by a 10-s stop between the cycles (P = 0.98 and 0.53, respectively).

Whole-body imaging modalities such as [18F]fluorodeoxyglucose (FDG)—positron emission tomography (PET)/CT or whole-body MRI (WB-MRI) appear as new promising tools to detect tumor recurrence or distant metastases. Both techniques expect to have some impact on patient management. In order to detect bone metastases, [18F]fluoride-PET/CT and SPECT/CT are further new imaging tools. This review article provides an overview over the accuracy of these imaging techniques in staging of breast cancer.

PURPOSE: To evaluate whether irreversible electroporation (IRE) has the potential to damage nerves in a porcine model and to compare histopathologic findings after IRE with histopathologic findings after radiofrequency ablation (RFA). MATERIALS AND METHODS: This study was approved by the institutional animal care and use committee. Computed tomography (CT)-guided IRE of 11 porcine sciatic nerves was performed in nine pigs, and histopathologic analysis was performed on the day of ablation or 3, 6, or 14 days after ablation. In addition, acute RFA of six porcine sciatic nerves was performed in six pigs that were harvested on the day of ablation. All nerves and associated muscles and tissues were assessed for histopathologic findings consistent with athermal or thermal injury, respectively, such as axonal swelling, axonal fragmentation and loss, Wallerian degeneration, inflammatory infiltrates, Schwann cell proliferation, and coagulative necrosis. The percentage of fascicles affected was recorded. RESULTS: All nerves had an axonal injury. The percentage of affected nerve fascicles after IRE was 50%–100%. Axonal swelling and perineural inflammatory infiltrates were detectable at every time point after ablation. Axonal fragmentation and loss, macrophage infiltration, and Schwann cell proliferation were found 6 and 14 days after ablation. Distal Wallerian axonal degeneration was observed 14 days after ablation. The endoneurium and perineurium architecture remained intact in all cases. RFA specimens at the day of ablation revealed acute coagulative necrosis associated with intense basophilic staining of extracellular matrix, including collagen of the perineurium and epineurium consistent with thermal injury. CONCLUSION: IRE has the potential to damage nerves and may result in axonal swelling, fragmentation, and distal Wallerian degeneration. However, preservation of endoneurium architecture and proliferation of Schwann cells may suggest the potential for axonal regeneration. In contrast, RFA leads to thermal nerve damage, causing protein denaturation, and suggests a much lower potential for regeneration. © RSNA, 2011

The purpose of this study was to evaluate whether hepatic periportal tracking (PPT) in patients with acute pyelonephritis correlates with the severity of pyelonephritis.A database search was conducted of patients with clinically suspected acute pyelonephritis who underwent abdominal computed tomography (CT) between January 2004 and June 2009 for disease evaluation. The final study group consisted of 274 patients (221 women, 53 men) with a mean age of 43 ± 20 years. The abdominal CT studies were retrospectively reviewed by two radiologists by consensus to assess PPT, renal wedge-shaped hypoperfusion areas, and renal abscesses. The laboratory reports obtained on the day of the CT examinations were reviewed for C-reactive protein (CRP), white blood cell count (WBCC), and leukocytes in urine. Presence of PPT was correlated with the presence of renal abscess, extension of renal hypoperfusion areas as well with levels of CRP, leukocytosis, and urine leukocytes using the Fisher's exact Test and the Wilcoxon Test.All patients showed renal hypoperfusion areas consistent with the clinical diagnosis of acute pyelonephritis. Twenty-nine patients (11%) showed PPT which was significantly associated with the extension of the wedge-shaped renal hypoperfusion areas (P0.001), the presence of a renal abscess (P0.01), as well as the level of CRP (P0.001) and urine leukocytes (P0.01). A renal abscess was observed in 36% of patients with PPT compared with 14% of patients without PPT.The PPT should be kept in mind as an extrarenal finding in acute pyelonephritis and may indicate a more serious clinical course of the disease.

Rationale and Objectives To assess the value of additional fine needle aspiration (FNA) to core needle biopsy (CNB) in computed tomography–guided biopsy of lesions of the lung, liver, pancreas, or of enlarged lymph nodes in an offsite cytopathologist setting. Materials and Methods This retrospective Health Insurance Portability and Accountability Act–compliant study was approved by the Institutional Review Board (IRB); informed consent (IC) was waived. Data of 377 patients who underwent computed tomography–guided FNA and CNB of lesions of the lung, liver, pancreas, or enlarged lymph nodes were enrolled. An onsite cytopathologist was not available. Sensitivity and specificity were calculated for FNA, CNB, and combined FNA/CNB. For the purpose of our study, positive diagnoses from CNB specimens or subsequent biopsy or surgical resection specimens or clinical follow-up data were considered as the standard of reference. Results CNB yielded a significantly higher sensitivity than FNA in all sites, except the pancreas, where the difference did not reach statistical significance. Additional FNA to CNB did not significantly increase the sensitivity. Specificity did not significantly differ between FNA, CNB, and combined FNA/CNB in all sites. Malignancies of 1.7% were detected only with FNA, without evidence of malignancy in CNB; for the remaining malignancies, CNB was positive or indeterminate. Conclusion Additional FNA to CNB without an onsite cytopathologist does not yield higher sensitivity or specificity compared to CNB alone.

Radiofrequency ablation (RFA) is a well-established method in treatment of patients with lung carcinomas who are not candidates for surgical resection. Usually computed tomographic (CT) guidance is used for the procedure, thus enabling needle placement and permitting evaluation of complications such as pneumothorax and bleeding. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is generally used for tumor activity assessment and is therefore useful in follow-up after tumor treatment. A method that provides real-time image-based monitoring of RFA to ensure complete tumor ablation would be a valuable tool. In this report, we describe the behavior of preinjected FDG during PET CT-guided RFA of a non-small-cell lung carcinoma and discuss the value of FDG as a tool to provide intraprocedure monitor ablation. The size and the form of the activity changed during ablation. Ablation led to increase of the size and blurring and irregularity of the contour compared to pretreatment imaging. The maximal standardized uptake value decreased only slightly during the procedure. Therefore, before RFA, FDG PET can guide initial needle placement, but it does not serve as a monitoring tool to evaluate residual viable tissue during the procedure.

The purpose of this report is to introduce a technique of direct lymphangiography to enable chylothorax treatment. Using a hybrid computed tomography (CT) and fluoroscopy imaging system, a 21-gauge needle was placed under CT guidance into the cisterna chyli to allow contrast lymphangiography and CT lymphangiography in two patients with presumed postoperative chylothorax. Water-soluble contrast media injection demonstrated the thoracic duct anatomy in both patients. Further successful needle disruption of the cisterna chyli was performed in one patient to interrupt lymph flow and stop the chylous leak, with subsequent resolution of the chylothorax.

Purpose The purpose of this study was to evaluate the ability of rotated paddlewheel reformations for the detection of central and peripheral pulmonary embolism (PE) compared to standard axial multi detector CT (MDCT) images. Material and methods CT scans of 35 patients with PE were reviewed by three independent readers for the detection of pulmonary emboli using standard axial CT scans and reformatted paddlewheel technique. All images were evaluated in random order. MDCT examinations were performed with a collimation of 1.25 mm, a pitch of six and a reconstruction interval of 0.8 mm. For each patient MIP were reformatted by using a paddlewheel arrangement with 5 mm slab thickness and 5° rotation. Standard of reference for PE was a consensus reading of the axial images by all three readers. Results The overall sensitivity for the axial images for the three readers ranged between 91% and 96%; for paddlewheel reformations from 78% to 83%; the specificity for both methods was 98–99%. Inter- and intraobserver agreement was also higher for axial images than for paddlewheel reformations. Conclusion Comparing standard axial MDCT scans and reformatted paddlewheel images no significant difference for the detection of central PE was found, whereas for the detection of peripheral emboli standard axial images showed a significant higher percentage of detecting PE than paddlewheel reformations.

The purpose of this study was to assess whether body weight, body mass index, and scan length influence arterial enhancement during CT angiography (CTA) of the pulmonary arteries at different iodine flow rates.CTA examinations of the pulmonary arteries performed for routine clinical care of 120 patients between March and December 2003 were retrospectively evaluated. Patients had received either 120 mL of contrast medium with an iodine concentration of 300 mg I/mL (group A) or 90 mL of contrast medium with an iodine concentration of 400 mg I/mL (group B). The iodine dose was 36 g, and the injection rate was 4 mL/s in all examinations. The iodine flow rate was 1.2 g I/s in group A and 1.6 g I/s in group B. Arterial attenuation along the z-axis was measured per patient, and the influence of body weight, body mass index, and scan length on enhancement of the pulmonary arteries in the two groups was assessed.In group A and in group B, body weight and body mass index correlated significantly with mean enhancement along the z-axis (r = -0.35 and -0.26 for group A and -0.48 and -0.40 for group B). Scan length showed no correlation with pulmonary attenuation. Mean pulmonary artery enhancement was significantly higher in group B with a difference of 51 H compared with group A.Pulmonary artery attenuation in CTA of the pulmonary arteries shows a small but significant correlation with body weight and body mass index independently of the iodine flow rate used. A higher iodine flow rate improves pulmonary artery enhancement.

To compare the diagnostic accuracy of contrast-enhanced (CE) three-dimensional (3D) moving-table magnetic resonance (MR) angiography with that of selective digital subtraction angiography (DSA) for routine clinical investigation in patients with peripheral arterial occlusive disease.Thirty-eight patients underwent CE 3D moving-table MR angiography of the pelvic and peripheral arteries. A commercially available large-field-of-view adapter and a dedicated peripheral vascular phased-array coil were used. MR angiograms were evaluated for grade of arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of selective DSA.Two hundred and twenty-six arterial segments in 38 patients were evaluated by both selective DSA and MR angiography. No complications related to MR angiography were observed. There was agreement in stenosis classification in 204 (90.3%) segments; MR angiography overgraded 16 (7%) segments and undergraded 6 (2.7%) segments. Compared with selective DSA, MR angiography provided high sensitivity and specificity and excellent interobserver agreement for detection of severe stenosis (97% and 95%, kappa = 0.9 +/- 0.03) and moderate stenosis (96.5% and 94.3%, kappa = 0.9 +/- 0.03).Compared with selective DSA, moving-table MR angiography proved to be an accurate, noninvasive method for evaluation of peripheral arterial occlusive disease and may thus serve as an alternative to DSA in clinical routine.

Our objective was to define typical MRI findings of the wrist and the hand in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA).Eighteen PsA and 21 RA patients with arthralgia of the wrist or hand joints underwent gadolinium-enhanced MRI of the wrist and hand. Two experienced radiologists interpreted abnormalities in consensus with respect to periarticular soft-tissue swelling, synovitis with or without effusion, periostitis, bone edema, bone erosions, bone cysts, and tenosynovitis. The distribution of the abnormalities also was evaluated.Erosions were statistically more frequent in patients with RA (p0.05). Periostitis was statistically seen more frequently in patients with PsA (p0.05). No statistically significant difference was found in the frequency of synovitis, bone marrow edema, bone cysts, and tenosynovitis between the two groups (p0.05). The radiocarpal joint, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints were significantly affected more frequently in patients with RA than in patients with PsA (p0.05), whereas the proximal interphalangeal joints were significantly more frequently affected in patients with PsA (p0.05).Periostitis and synovitis of the proximal interphalangeal joints are typical MRI findings in patients with PsA, whereas synovitis with erosions of the wrist, the midcarpal joints, the carpometacarpal joints, and the metacarpophalangeal joints are typical findings in patients with RA.

To retrospectively measure the adrenal gland attenuation and the percentage loss of adrenal gland enhancement at delayed contrast medium-enhanced computed tomography (CT) in patients with adrenocortical carcinomas and pheochromocytomas and to compare these data with those in patients with adenomas and metastases.The study protocol was approved by the ethics committee, which waived informed consent. Eleven patients with proved adrenocortical carcinoma, 17 with proved pheochromocytoma, 23 with adrenal adenoma, and 16 with metastasis to the adrenal gland underwent helical CT. Nonenhanced CT was followed by contrast-enhanced CT 1 minute and 10 minutes later. Attenuation and enhancement loss values were calculated.The mean attenuation of adenomas (8 HU +/- 18 [standard deviation]) was significantly lower than those of adrenocortical carcinomas (39 HU +/- 14), pheochromocytomas (44 HU +/- 11), and metastases (34 HU +/- 11) on nonenhanced CT scans (P.001). Although the mean attenuation values for nonadenomas (ie, adrenocortical carcinomas, pheochromocytomas, and metastases) were significantly higher than the value for adenomas on the 1-minute contrast-enhanced CT scans (P.001), there was more overlap in attenuation between adenomas and nonadenomas on contrast-enhanced scans than on nonenhanced scans. On the 10-minute delayed contrast-enhanced scans, the mean attenuation of adenomas (32 HU +/- 17) was significantly lower than the mean attenuations of carcinomas (72 HU +/- 15), pheochromocytomas (83 HU +/- 14), and metastases (66 HU +/- 13) (P.001). At optimal threshold values of 50% for absolute percentage of enhancement loss and 40% for relative percentage of enhancement loss at 10 minutes, both the sensitivity and the specificity for the diagnosis of adenoma were 100% when adenomas were compared with carcinomas, pheochromocytomas, and metastases.The enhancement loss in adrenocortical carcinomas and pheochromocytomas is similar to that in adrenal metastases but significantly less than that in adrenal adenomas. The percentage change in contrast material washout is a useful adjunct to absolute CT attenuation values in differentiating adrenal adenomas from adrenocortical carcinomas and pheochromocytomas.

PURPOSE To evaluate the frequency and influence of perfused side branches (lumbar arteries [LA] and inferior mesenteric artery trunks) on development of type II endoleaks (EL-II) and on volume changes of abdominal aortic aneurysms (AAA) after endovascular repair. METHODS Of 114 patients undergoing EVR of AAA, 89 patients (83 men; mean age 72+/-7.5 years, range 51-88) with >6 months' follow-up and no type I endoleaks were retrospectively analyzed to determine any relationships between retrograde perfusion, endoleaks, and sac volume. Data were derived from computed tomographic angiographic (CTA) scans taken before and after intervention, at discharge, and at 1, 3, 6, and semi-annually thereafter in follow-up. Two groups were identified and compared based on their status at 6 months post EVR: without perfused side branches (group 1) and with perfused collaterals (group 2); group 2 was further divided according to the absence (2a) or presence (2b) of endoleak. RESULTS Median follow-up was 24 months (range 6-36). Based on a total of 582 CTAs analyzed, 17 (19%) patients developed type II endoleaks (EL-II) during follow-up. There was a significant difference in the number of perfused LAs prior to EVR between groups 1 (n=44) and the 45 patients with postprocedural patent collateral arteries in group 2 (p

To assess the value of urethral sonography including a perineal approach in evaluating urethral anomalies in infants.A radiology database review identified 88 patients (mean age +/- SD, 64 +/- 84 days) who underwent voiding cystourethrography (VCUG) and urethral sonography as part of extended sonography of the urinary tract. Sonographic and VCUG images and reports were reviewed to assess agreement between both modalities for detection of urethral anomalies.Sonography facilitated the correct diagnosis of all 3 posterior urethral valves. The only urethral diverticulum, the only ectopic ureteric insertion into the urethra, the only urogenital sinus, and the only urethrovaginal fistula were also shown on sonography. In 73 (94%) of 78 cases, sonography correctly showed the absence of anomalies. In 5 infants, sonography could not reliably assess the urethra and showed indirect signs of urethral anomalies; however, these patients had normal urethras on VCUG.Our data show that sonography of the urethra is a valuable tool for diagnosis of urethral anomalies. Especially, negative findings on sonography are highly suggestive of the absence of urethral anomalies. Positive or equivocal sonographic findings should indicate VCUG.

To evaluate the accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in differentiation of pleural malignancy and cancer-unrelated pleural disease in patients with non-small cell lung cancer (NSCLC) and pleural abnormalities at computed tomography (CT).In 92 patients, pleural abnormalities were detected at contrast material-enhanced thoracic CT, which was performed for newly diagnosed NSCLC (n = 41) or restaging (n = 51). CT findings were negative for pleural malignancy when pleural effusion with attenuation of 10 HU or less and/or rib fractures with no evidence of pathologic fracture were present; findings were indeterminate when pleural effusion with attenuation greater than 10 HU and/or solid pleural abnormalities without osseous destruction of the chest wall were present; and findings were positive if any osseous destruction of the chest wall adjacent to a pleural mass was present. All patients underwent FDG PET. Findings were negative for pleural malignancy if pleural activity was absent, equal to, or less than mediastinal background activity; findings were positive if pleural activity was higher than mediastinal background activity. Reading of CT and FDG PET scans was first performed separately and then was combined. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPP), and accuracy were calculated for CT and FDG PET separately and for CT and FDG PET combined, with cytologic and/or histologic analysis as standard of reference.In detection of pleural malignancies, CT findings were indeterminate in 65 (71%) patients and true-negative in 27 (29%). Respective sensitivity, specificity, PPV, NPV, and accuracy of FDG PET in detection of pleural malignancies were 100%, 71%, 63%, 100%, and 80%; and those of CT and FDG PET combined, 100%, 76%, 67%, 100%, and 84%.Findings suggest that a negative FDG PET scan for indeterminate pleural abnormalities at CT indicates a benign character, while positive findings on an FDG PET scan are sensitive for malignancy.

The aim of this study was to determine if a saline solution flush following low dose contrast material bolus improves parenchymal and vascular enhancement during abdominal multiple detector-row computed tomography (MDCT). Forty-one patients (24 men and 17 women; mean age 49 years, age range 27-86 years) underwent abdominal MDCT (collimation 4x5 mm, 15-mm table increment, reconstruction interval 5 mm, gantry rotation period 0.8 s) with a single- as well as with a double syringe power injector. Indication for examination were benign and malignant tumors and inflammatory diseases. Patients received 100 ml nonionic contrast material (300 mgI/ml) alone or pushed with 20 ml saline solution. Mean enhancement values for both protocols were measured in the liver, the spleen, the pancreas, the renal cortex, the portal vein, the inferior vena cava and the abdominal aorta. Double syringe power-injector protocol led to significantly higher parenchymal and vascular enhancement than single syringe power-injector protocol (p0.05). The improvement in mean enhancement of the liver was 9 +/- 9 HU, of the spleen 8 +/- 10 HU, of the pancreas 7 +/- 9 HU, and of the renal cortex 8 +/- 20 HU. The improvement in mean enhancement of the portal vein was 10 +/- 17 HU of the inferior vena cava 8 +/- 13 HU and of the abdominal aorta 10 +/- 17 HU. The use of a double syringe power injector with saline flush following contrast material bolus significantly improves parenchymal and vascular enhancement during contrast-enhanced abdominal MDCT with low iodine doses.

The value of CT angiography and three-dimensional (3D) reconstructions was investigated in the postoperative care after surgical repair of aortic coarctation and compared with conventional angiography.Twenty-five patients referred because of suspicion of stenosis in the area of former coarctation were prospectively studied with CT angiography and catheter angiography. We determined the morphometric and morphologic findings such as aortic diameter, stenosis, aneurysm, intimal flaps, circumscribed pouch, or arteriosclerotic plaques with 3D reconstructions, using maximum-intensity-projection (MIP) technique and catheter angiography. The results of both techniques were compared. The ratio of the narrowest diameters of the former coarctation and the descending aorta was correlated with the systolic pullback blood pressure gradient in all patients.The former coarctation was normal in 11 patients, (44%), group A; narrowed in 12 children (48%), group B; and dilated in two children (8%), group C. An intimal flap and a circumscribed pouch were delineated in four subjects. MIP reconstructions and catheter angiography revealed identical results regarding the classification into groups A, B, C; intimal flaps; and circumscribed pouches. Statistical analysis revealed good correlation between the narrowest aortic diameters measured on MIP reconstructions and catheter angiography, whereas no correlation between the systolic pullback blood pressure gradient and the diameter ratio of the former coarctation and the descending aorta was found.CT angiography and 3D reconstructions using MIP represent a reliable noninvasive technique to replace diagnostic catheter angiography in the postoperative care of patients with coarctation and provide the clinician with valuable information concerning further invasive procedures.

Background Radiofrequency ablation (RFA) is a potential application as a salvage tool after failure of surgery, chemotherapy, or radiotherapy of non-small cell lung cancer (NSCLC). Although several studies have evaluated the use of RFA in primary NSCLC, there is little literature on its potential application as a salvage tool. Purpose To evaluate CT-guided RFA employed as a salvage therapy for pulmonary recurrences of NSCLC after prior treatment with chemotherapy, radiation therapy, and/or surgery. Material and Methods A retrospective computer database search yielded 33 patients with biopsy proven primary NSCLC who underwent CT-guided RFA of 39 recurrent tumors following surgery, chemotherapy, and/or radiotherapy. Follow-up imaging was performed with CT and PET-CT. The endpoints of interest were progression-free survival (PFS) and time to local progression (TTLP). PFS and TTLP were compared by lesion size (Results The median PFS was 8 months. For patients with a tumor size Conclusion RFA of recurrent NSCLC may be a valuable salvage tool to achieve local tumor control, especially in tumors measuring

To evaluate the effects of irreversible electroporation (IRE) on the rectum wall after IRE applied adjacent to the rectum.CT-guided IRE adjacent to the rectum wall was performed in 11 pigs; a total of 44 lesions were created. In five pigs, ablations were performed without a water-filled endorectal coil (group A); in six pigs, ablation was performed with the coil to avoid displacement of the rectum wall (group B). The pigs were killed after 7-15 days and the rectums were harvested for pathological evaluation.There was no evidence of perforation on gross postmortem examination. Perirectal muscle lesions were observed in 18 of 20 ablations in group A and in 21 of 24 ablations in group B. Inflammation and fibrosis of the muscularis propria was observed in ten of 18 lesions in group A and in ten of 21 lesions in group B. In group A, findings were limited to the external layer of the muscularis propria except for one lesion; in group B, findings were transmural in all cases. Transmural necrosis with marked suppurative mucosal inflammation was observed in seven of 21 lesions in group B and in no lesion in group A.IRE-ablation adjacent to the rectum may be uneventful if the rectum wall is mobile and able to contract. IRE-ablation of the rectum may be harmful if the rectum wall is fixed adjacent to the IRE-probe.

Pulmonary embolism (PE) is a common disease with considerable mortality. There are no specific signs or symptoms of PE; the diagnosis relies on imaging tests. The development of multi-detector computed tomography has led to an improvement in the diagnosis of PE due to faster scanning and improved spatial resolution along the longitudinal axis of the patient. Apart from fast scanning and thin collimation, optimal arterial attenuation remains one of the most crucial determinants of sufficient depiction of the pulmonary arteries. Arterial attenuation over time is generally determined by iodine flow concentration, which may be increased either by raising the contrast medium flow rate, and/or by using a high iodine concentration contrast medium. The scan duration necessary for imaging the whole thorax ranges from about 20 s with a four-detector row scanner to about 5 s with a 64-detector row detector scanner. The collimation ranges from 0.5 mm to 1 mm depending on the scanner used. This enables the most detailed display of the pulmonary arteries. Bolus triggering devices are a valuable tool for accurate timing of scanning. The administration of the contrast material bolus is performed using a power injector at a flow rate of about 4 mL/s. A saline flush immediately after contrast material administration avoids pooling of the contrast material in the arm veins and in the injection system and reduces perivenous artifacts in the superior vena cava. The use of a high concentration contrast material significantly improves attenuation of the pulmonary arteries leading to better visualisation of sub-segmental and lower order pulmonary arteries in multi-row-detector-CTA. In addition, the higher attenuation may improve the conspicuity of emboli within the pulmonary arteries.

The objective of our study was to assess the impact of endoluminal treatment on health-related quality of life in patients with peripheral arterial disease.Changes in quality of life were prospectively evaluated in 190 patients before and 1, 3, 6, and 12 months after treatment. Physical, emotional, and general health components were determined using the short-form (36 items) health survey (SF-36). Claudicant patients were compared with patients who had critical limb ischemia. The influence of the lesion location (iliac, femoropopliteal, or crural) restenosis, and additional interventions on quality of life were evaluated.Six- and 12-month follow-up data were available for 136 and 103 patients, respectively. Significant improvements in quality of life were observed in most of the patients after the intervention. Many of the SF-36 scores decreased from the 6- to the 12-month follow-up but remained significantly higher than the score before the intervention. Reduction of bodily pain was the most evident effect of treatment. Claudicant patients seemed to benefit more from treatment than patients with critical limb ischemia. In terms of SF-36 scores, percutaneous transluminal angioplasty of the crural arteries was equally as effective as endoluminal revascularization of the iliac and femoropopliteal arteries and multilevel interventions were as effective as single-level interventions. The occurrence of a restenosis was significantly related to lower SF-36 scores, and restenosis not followed by a second intervention was associated with lower SF-36 scores.Although there were several differences between the groups, significant improvements in quality of life up to 12 months after endoluminal therapy were observed in most patients.

Objective: The aim of the study was to assess the potential of density histogram analysis of unenhanced hepatic computed tomography (CT) in the diagnosis and differentiation of diffuse liver diseases. Methods: Twenty-six patients with normal liver parenchyma, 35 patients with diffuse steatosis, 14 patients with acute steatohepatitis, 15 patients with active alcoholic cirrhosis, 23 patients with inactive alcoholic cirrhosis, 15 patients with virus-induced cirrhosis, and 8 patients with hemochromatosis underwent unenhanced hepatic CT. All diffuse liver diseases and the absence of diffuse liver disease were histologically proven. Quantitative analysis of unenhanced liver parenchyma was performed in each patient. Results: The hepatic density histogram showed no significant differences in kurtosis and skewness between the groups (P > 0.05). Except for steatosis, active alcoholic cirrhosis, and hemochromatosis, diffuse liver diseases led to similar densities of liver parenchyma in unenhanced hepatic CT. Conclusion: A reliable diagnosis and differentiation of diffuse liver diseases on the basis of density histogram analysis is not possible.

Objective: The purpose of this study was to assess the influence of the iodine flow rate on parenchymal and vascular enhancement during multiphasic abdominal multidetector-row computed tomography (MDCT). Methods: Fifteen patients underwent MDCT at an iodine flow rate of 1.2 g/s as well as 1.6 g/s (group A, protocols I and 2), and 90 patients underwent MDCT at an iodine flow rate of 1.2 g/s (group B) or 1.6 g/s (group C). Measurements were performed for all groups in the liver, spleen, panereas, portal vein, inferior vena cava, and abdominal aorta. Results: Aortal and pancreatic enhancement during the arterial phase was significantly higher with the higher iodine now rate. The mean difference in aortal enhancement was 60 Hounsfield units (HU) between protocols 1 and 2 of group A, and the mean difference was 70 HU between groups B and C. The mean difference in pancreatic enhancement was 10 HU between protocols I and 2 of group A and 17 HU between groups B and C. During the portal and hepatic venous phases, no significant difference in enhancement was observed. Conclusion: A high iodine flow rate in multiphasic abdominal MDCT improves enhancement of the aorta and the pancreas during the arterial phase but does not influence later phases.

The aim of this study was to evaluate the potential of multiphasic multidetector-row CT (MDCT) in the detection and staging of transitional cell carcinomas (TCC) of the upper urinary tract. We performed a retrospective chart review of 39 consecutive patients with 41 histologically verified TCC of the renal pelvis and/or the ureter. The urinary tract was examined using MDCT performing unenhanced and contrast-enhanced scans during the corticomedullary (CMP), nephrographic (NP) and pyelographic phase (PP). Tumors were staged according to the TNM classification. MDCT and histopathological findings were correlated. The attenuation of the lesions was documented in Hounsfield units (HU). In MDCT, all 41 TCC--including two multicentric TCC--were detected. TCC confined to the organ (stage 0a-II) was correctly staged in 28/29 tumors (96.6%). Stage III-IV tumors were correctly staged in 8/12 patients (66.6%). Overall, MDCT was accurate in predicting pathologic TNM stage in 36/41 upper urinary tract TCC (87.8%). There was no significant difference of mean attenuation of TCC between CMP, NP and PP (P0.05). MDCT with its high spatial and temporal resolution is an accurate tool for detection TCC of the upper urinary tract, with 87.8% accuracy in predicting its stage.

OBJECTIVE To evaluate the potential of a saline solution flush after the contrast material bolus in abdominal multidetector row CT (MDCT) in contrast material dose and cost reduction. METHODS Abdominal MDCT was performed in 78 patients who were assigned randomly to 2 groups receiving 120 mL nonionic contrast material (300 mgI/mL) alone or 100 mL of the same contrast material pushed with 40 mL of saline solution. Mean attenuation values for both groups were measured in the liver, the spleen, the pancreas, the portal vein, the inferior vena cava, and the abdominal aorta. Cost analyses were performed for both groups. RESULTS There was no significant difference in parenchymal and vascular enhancement between both groups. The difference of the enhancement was 2 HU for the liver (P = 0.11), 2 HU for the spleen (P = 0.44), 3 HU for the pancreas (P = 0.38), 9 HU for the portal vein (P = 0.11), 3 HU for the inferior vena cava (P = 0.55), and 10 HU for the aorta (P = 0.06). Taking the costs of contrast material, saline solution, and disposal material into account, 7.30 dollars was saved by the patient using a saline solution flush. CONCLUSIONS Using a saline flush after the contrast material bolus in abdominal MDCT allows an iodine dose reduction of approximately 6 g, or 17%, without impairing mean parenchymal and vascular enhancement and a cost reduction of 7.30 dollars per patient.

The potential of semitransparent volume-rendering (STVR) computed tomographic (CT) angiography was evaluated for the assessment of hemodynamically significant stenoses in aortoiliac arteriosclerotic disease.In a prospective study, 76 patients (57 men, 19 women; mean age, 70 years) underwent single-detector (n = 26) or multidetector (n = 50) CT angiography of the aortoiliac region. Intraarterial digital subtraction angiography (DSA) was performed in each patient. STVR images with semitransparent display of arterial lumen (opacity, 50%) and vascular calcifications (opacity, 20%), as well as maximum-intensity projection (MIP), frontal/sagittal curved planar reformation (CPR), and MIP/axial studies were independently reviewed for hemodynamically significant lesions (or =70% cross-sectional area reduction). DSA combined with invasive pressure measurement was used as the standard of reference. Vessel wall calcifications were classified according to a four-point scale (0, not calcified; 1, mildly calcified; 2, moderately calcified; 3, severely calcified).Of the 380 reviewed vessel sections, 28 represented 70%-99% stenoses and 14 represented occlusions. For detecting/==" BORDER="0"70% lesions, STVR as well as CPR and MIP/axial studies revealed significantly higher specificity (91%-94%), positive predictive value (PPV; 0.62-0.72), and accuracy (90%-94%) than MIP (specificity, 59%; PPV, 0.27; accuracy, 64%; P.001) in moderately or severely calcified vessel sections. In noncalcified or mildly calcified sections, the specificity of MIP was comparable with the other rendering techniques (96%-98%; P values ranging from.34 to.77). No significant sensitivity differences were noticed among the CT angiography modalities: STVR, 79%; MIP, 88%; CPR, 83%; and MIP/axial, 93% (P values ranging from.12 to.78). Negative predictive values ranged from 0.97 to 0.99 (P values ranging from.14 to 1). Median calcification scores in sections with overestimated lumen narrowings were significantly higher (3, severely calcified) than in sections with correctly graded lumen width (1, mildly calcified) with all CT angiography modalities (P.05).With use of STVR, visualization of vascular lumen can be improved by rendering highly transparent mural calcifications. Hence, for three-dimensional presentation of aortoiliac arteriosclerotic disease, STVR studies should be preferred to MIPs as supplements to review of axial-source images.

Purpose: We investigated the clinical relevance of digital image fusion of CT and 2-[ 18 F]fluoro-2-deoxy-D-glucose ([ 18 F]FDG) positron emission tomography (PET) studies in patients with suspected abdominal and/or pelvic metastasis. Method: Nineteen patients with suspected residual/recurrent malignancies underwent CT and [ 18 F]FDG PET studies of the abdomen and/or pelvis. The data sets of both modalities were fused on a digital workstation by automatic adaptation of the pixel size and the slice thickness. Different body positions were corrected by semiautomatic adaptation of the body axes. The fused images were reconstructed in sagittal, coronal, and axial planes. Results: Good spatial correlation between both modalities was achieved in all patients. Image fusion improved the spatial allocation of pathologically increased [ 18 F]FDG uptake in 7 of 35 lesions (20%). Conclusion: This work suggests that digital image fusion of CT and [ 18 F]FDG PET data sets improves the anatomical localization of foci with increased [ 18 F]FDG enhancement of the retroperitoneum and the abdominal/pelvic wall, respectively.

Objectifs To evaluate frequency and influence of perfused lumbar arteries (pLA) and inferior mesenteric arteries (pIMA) on develop-ment and incidence of type-2 endoleaks (EL-II) and volume changes of AAA after EVR. Materiels et methodes 114 patients underwent transfemoral insertion of endoluminal stent-grafts for treatment of AAA. Pre- and post-operative CT scans before discharge, at 1, 3, 6 months and biannually thereafter were performed ; pLA and pIMA were evaluated in each follow-up scan. Volumes of the aneurysmal sacs were measured. Resultats Median follow-up was 24 months. Six months after stent-graft implantation pIMA and/or at least 2 pLA were seen in 45 patients (50,5%) ; 11 patients (12,4% of the study cohort) had an EL-II. A tendency to minor mean volume loss in patients with pLA/ ptIMA and significant trend to volume increase in patients with EL-II in later follow-ups was seen. Conclusion We found a high incidence of pLA/ptIMA in patients after EVR. Persistent lumbar and inferior mesenteric artery perfusion is associated with significantly higher EL-II rates after EVR of AAA. Significant differences in volume changes in later follow-ups were seen between patients with or without EL-II.