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Introduction: In developing Computer-Aided Diagnosis (CAD), a Convolutional Neural Network (CNN) has been commonly used as a Deep Learning (DL) model. Although it is still early, DL has excellent potential in implementing computers in medical diagnosis., Methods: This study reviews the use of DL for Anterior Cruciate Ligament (ACL) tear diagnosis. A comprehensive search was performed in PubMed, Embase, and Web of Science databases from 2018 to 2024. The included study criteria used MRI images to evaluate ACL tears, and the diagnosis of ACL tears was performed using the DL model. We summarized the paper by reporting their model accuracy, model comparison with arthroscopy, and explainable., Results: AI implementation in tabular format; we conclude that many medical professionals believe that arthroscopic diagnosis is the most reliable method for diagnosing ACL tears. However, due to its intrusive treatment, CAD is projected to be able to produce similar outcomes from MRI scan results. To gain the trust of physicians and meet the demand for reliable knee injury detection systems, an algorithm for CAD should also meet several criteria, such as being transparent, interpretable, explainable, and easy to use. Therefore, future works should consider creating an Explainable DL model for ACL tear diagnosis. It is also essential to evaluate the performance of this Explainable DL model compared to the gold standard of arthroscopy diagnosis., Conclusion: There are issues regarding the need for Explainable DL in CAD to increase confidence in its result while also highlighting the importance of the involvement of medical practitioners in system design. There is no funding for this work.

Objectives/hypothesis: To assess the ability of specific positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) features to detect extracapsular extension (ECE) in head and neck squamous cell carcinoma (HNSCC) patients., Study Design: Retrospective study in a tertiary certified university cancer institute., Methods: We performed a review of patients with advanced HNSCC at Bern University Hospital between 2014 and 2018. Patients with pretherapeutic PET/CT and/or MRI who underwent neck dissection were included, with 212 patients fulfilling inclusion criteria. Blinded evaluation of specific PET/CT and MRI features with respect to presence of ECE was performed. Histopathological examination of neck dissection specimens was used as the gold standard to determine ECE status., Results: Out of the 212 included patients, 184 had PET/CT, 186 MRI, and 158 both modalities. Overall clinical stage IV (odds ratio [OR]: 2.26, 95% confidence interval [CI]: 2.25-11.74), ill-defined margins in both PET/CT and MRI (OR: 3.48, 95% CI: 1.21-9.98 and OR: 2.14, 95% CI: 0.94-4.89, respectively), and a maximum standardized uptake value ≥ 10 (OR: 5.44, 95% CI: 1.21-9.98) were all significant independent predictors of ECE. When combined, these four features led to a cumulative score able to predict ECE status with an accuracy of 91.43%., Conclusions: The current findings indicate specific features in PET/CT and MRI are potential predictors of ECE status and may help in pretherapeutic stratification in HNSCC., Level of Evidence: 4 Laryngoscope, 131:E163-E169, 2021., (© 2020 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Radiological imaging methods used at a large scale in the assessment of hepatic lesions include: Ultrasound, computed tomography and magnetic resonance. To further characterize these lesions, specific contrast agents may be added, thus revealing the vascularity of the lesions., Discussion: This review focuses on gadoxetic acid, which is a hepatospecific contrast agent used in MRI. The aim of the review is to briefly explain the mechanism of GA enhancement, describe the enhancement patterns of some benign and malignant hepatic lesions and discuss possible advantages of GA over standard contrast agents., Conclusion: The role of GA in functional MR cholangiography and the idea of accessing liver function by measuring parenchymal enhancement will also be explained., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background and Purpose: Turbo spin-echo diffusion-weighted imaging (TSE-DWI) has not been used for evaluating pituitary lesions. We compared the usefulness of TSE-DWI and echo-planar (EP)-DWI for assessing normal pituitary structures and lesions., Materials and Methods: Our study included 41 consecutive patients (27 pituitary adenomas, 8 Rathke's cleft cysts, 4 craniopharyngiomas, 1 germinoma, 1 pituitary metastasis) who underwent conventional pre- and post-contrast magnetic resonance imaging (MRI) and TSE- and EP-DWI at 3T. Two observers independently performed qualitative assessment of normal pituitary structures and lesions on sagittal DWI and apparent diffusion coefficient (ADC) maps. One observer recorded ADC values of normal brain structures and pituitary lesions. Kappa (κ) statistics, Wilcoxon signed-rank test, intraclass correlation coefficient, Bland-Altman analysis, Pearson correlation coefficient and independent t-test were used for statistical analysis., Results: Interobserver agreement for qualitative evaluations was good to excellent (κ = 0.65-1.0). On both DWI and ADC maps, visualization of the pituitary gland, of the spatial relationship between the lesion and its normal surroundings, and the whole image quality were significantly better on TSE- than EP sequences (p < .01). In normal brain structures, the ADC value on TSE- and EP-sequences was significantly correlated (r = 0.6979, p < .05). The TSE-ADC value was significantly lower for pituitary adenomas than craniopharyngiomas (p < .05)., Conclusions: For the evaluation of normal pituitary structures and lesions, TSE-DWI is more useful than EP-DWI. The TSE-ADC value may help to differentiate between pituitary adenoma and craniopharyngioma., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The identification of breast tumor initiating cells (BTICs) is important for the diagnosis and therapy of breast cancers. This study was undertaken to evaluate whether the extra domain-B of fibronectin (EDB-FN) could be used as a new biomarker for BTICs and whether EDB-FN targeting superparamagnetic iron oxide nanoparticles (SPIONs) could be used as a magnetic resonance imaging (MRI) contrast agent for BTIC imaging in vitro and in vivo. BTICs (NDY-1) exhibited high EDB-FN expression, whereas non-BTICs (MCF-7, BT-474, SUM-225, MDA-MB-231) did not exhibit EDB-FN expression. Furthermore, Cy3.3-labeled EDB-FN specific peptides (APTEDB) showed preferential binding to the targeted NDY-1 cells. To construct an EDB-FN targeted imaging probe, APTEDB was covalently attached to a thermally cross-linked SPION (TCL-SPION) to yield APTEDB-TCL-SPION. In the in vitro MRI of cell phantoms, selective binding of APTEDB-TCL-SPION to NDY-1 cells was evident, but little binding was observed in MCF-7 cells. After the intravenous injection of APTEDB-TCL-SPION into the NDY-1 mouse tumor xenograft model, a significant decrease in the signal within the tumor was observed in the T2*-weighted images; however, there was only a marginal change in the signal of non-targeting SPIONs such as APTscramble-TCL-SPION or TCL-SPION. Taken together, we report for the first time that EDB-FN was abundantly expressed in BTICs and may therefore be useful as a new biomarker for identifying BTICs. Our study also suggests that APTEDB-TCL-SPION could be used as an MRI contrast agent for BTIC imaging.

Stem cells hold great promise for the treatment of multiple human diseases and disorders. Tracking and monitoring of stem cells in vivo after transplantation can supply important information for determining the efficacy of stem cell therapy. Magnetic resonance imaging (MRI) combined with contrast agents is believed to be the most effective and safest non-invasive technique for stem cell tracking in living bodies. Commercial superparamagnetic iron oxide nanoparticles (SPIONs) in the aid of transfection agents (TAs) have been applied to labeling stem cells. However, owing to the potential toxicity of TAs, more attentions have been paid to develop novel SPIONs with specific surface coating or functional moieties which facilitate effective cell internalization in the absence of TAs. This review aims to summarize the recent progress in the design and preparation of SPIONs as cellular MRI probes, to discuss their applications and current problems facing in stem cell labeling and tracking, and to offer perspectives and solutions for the future development of SPIONs in this field.

Entrapment neuropathies at the elbow are common in clinical practice and require an accurate diagnosis for effective management. Understanding the imaging characteristics of these conditions is essential for confirming diagnoses and identifying underlying causes. Ultrasound serves as the primary imaging modality for evaluating nerve structure and movement, while MRI is superior for detecting muscle denervation. Plain radiography and CT play a minor role and can be used for the evaluation of bony structures and calcifications/ossifications. Comprehensive knowledge of anatomical landmarks, nerve pathways, and compression sites is crucial for clinicians to accurately interpret imaging and guide appropriate treatment strategies for entrapments of ulnar, median, and radial nerves, and their branches. Critical relevance statement: Accurate imaging and anatomical knowledge are essential for diagnosing elbow entrapment neuropathies. Ultrasound is the preferred modality for assessing nerve structure and motion, while MRI excels in detecting muscle denervation and guiding effective management of ulnar, median, and radial nerve entrapments. Key Points: Ultrasound is the primary modality for assessing nerve structure and stability. Findings include nerve structural loss, isoechogenicity, thickening, and hyper-vascularization. MRI provides a comprehensive evaluation of the elbow and accurate muscle assessment. Imaging allows the identification of compressive causes, including anatomical variants, masses, or osseous anomalies. Awareness of anatomical landmarks, nerve pathways, and compression sites is essential. [ABSTRACT FROM AUTHOR]

Objective: To determine whether L5 nerve root morphology can assist in identification Lumbosacral Transitional vertebra. Study Design: Cross sectional study. Place and Duration of Study: Radiology Department, Combined Military Hospital, Multan Pakistan, Apr 2019 to Apr 2020. Methodology: Patients of both genders, 15 to 50 years age who underwent whole spine MRI were included in the study. Patients were referred from Combined Military Hospital Multan, from neighboring Combined Military Hospitals and Civil. Sagittal and axial T1WS and T2WS were performed along with coronal T2WS/FS sequences. Axial images were assessed for identification of L5 nerve root arising from LV5-SV1 level and hence vertebra was identified as LV5. Correlation was done with sagittal images for presence of Transitional vertebra, further confirmed by counting vertebral bodies from C2 vertebra upto sacrum using cross referencing tool. Results: A total of 135 patients were included in the study. Out of these, transitional vertebra was confidently labeled in 23 patients by nerve identification method which was confirmed on vertebral counting method. However, in four patients, L5 nerve root morphology was not clear and we had to rely on vertebral counting method for identification of transitional vertebra. Conclusion: Neuroanatomy and morphology of exiting L5 nerve roots can act as a reliable method for numbering of lumbosacral vertebra and identification of transitional vertebra. [ABSTRACT FROM AUTHOR]

To develop a radiomic nomogram based on multiparametric magnetic resonance imaging for the preoperative prediction of lymph node metastasis (LNM) in rectal cancer. This retrospective study included 318 patients with pathologically proven rectal adenocarcinoma from two hospitals. Radiomic features were extracted from T2-weighted imaging, diffusion-weighted imaging, and contrast-enhanced T1-weighted imaging scans of the training cohort, and the radsore model was then constructed. The combined model was obtained by integrating the Radscore and clinical models. The area under the receiver operating characteristic curve (AUC) was used to assess the diagnostic effectiveness of each model, and the best-performing model was used to develop the nomogram. The Radscore and clinical models exhibited similar diagnostic efficacy (DeLong's test, P > 0.05). The AUC of the combined model was significantly higher than those of the clinical and Radscore models in the training cohort (AUC: 0.837 vs. 0.763 and 0.787, P : 0.02120 and 0.02309) and the external validation cohort (AUC: 0.880 vs. 0.797 and 0.779, P : 0.02310 and 0.02471). However, the diagnostic performance of the three models was comparable in the internal validation cohort (P > 0.05). Thus, among the three models, the combined model exhibited the highest diagnostic efficiency. The calibration curve exhibited satisfactory consistency between the nomogram predictions and the actual results. DCA confirmed the considerable clinical usefulness of the nomogram. The radiomics nomogram can accurately and noninvasively predict LNM in rectal cancer before surgery, serving as a convenient visualization tool for informing treatment decisions, including the choice of surgical approach and the need for neoadjuvant therapy. [ABSTRACT FROM AUTHOR]

Background: To investigate the imaging features of hemangiomas in long tabular bones for better diagnosis.Methods: Twenty-four patients with long bone hemangiomas confirmed by pathology were enrolled. Nineteen patients had plain radiography, fourteen patients had computed tomography (CT) and eleven had magnetic resonance imaging (MRI). The hemangioma was divided into medullary [13], periosteal [6] and intracortical type [5].Results: Among 19 patients with plain radiography, eleven patients were medullary, three periosteal, and five intracortical. In the medullary type, the lesion was primarily osteolytic, including five cases with irregular and unclear rims and one lesion having osteosclerotic and unclear rims. In three patients with the periosteal type, the lesion had clear rims with involvement of the cortical bone in the form of bone defect, including two cases with local thickened bone periosteum and one case having expansile periosteum. Five intracortical hemangiomas had intracortical osteolytic lesions with clear margins. Among 14 patients with CT imaging, 8 cases were medullary, three periosteal, and three intracortical. Among 8 medullary hemangiomas, one had ground glass opacity, and seven had osteolytic, expansile lesions like soft tissue density with no calcification. In three periosteal cases, the lesion was osteolytic with thickened periosteum and narrowed medullary cavity. In three intracortical hemangiomas, the lesion was of even soft tissue density with no calcification. Among 11 patients with MRI imaging, seven were medullary, two periosteal, and two intracortical. Among 7 medullary lesions, six were of hypointense signal on T1WI and hyperintensesignal on T2 WI. In two periosteal cases, the periosteum was thickened, with one case being of equal signal, and the other having no signal. Two intracortical hemangiomas were both of slightly low signal on T1WI but hyperintense signal on T2WI.Conclusions: The long bone hemangiomas had characteristic cystic honeycomb-like presentations in plain radiograph. CT and MRI imagings are helpful for diagnosis of hemangiomas in long bone. [ABSTRACT FROM AUTHOR]

Aim: Comparison of the diagnostic value of ultrasonography (US) and magnetic resonance imaging (MRI) in the diagnosis of rotator cuff and biceps tendon pathologies. Material and methods: Shoulder US an MRI were performed in patients suffering from shoulder pain. The results of the two methods were retrospectively evaluated in a total of 105 cases. Magnetic resonance imaging findins were accepted as a reference. Results: In the biceps tendon, ultrasonography served as a method for correct diagnosis in 7 of the 8 cases with dislocation, in 1 of 3 cases with partial rupture, and i all 4 cases with full thickness rupture. In biceps tendon patholo- gies, the sensitivity nad the specifity of US were respectively 80% and 978%. And for supraspinatus tendon pathologies; 24 of 26 full thickness ruptures (92.3% sensitivity, 98.8% specifity), 30 of 37 partial ruptures (81% sensitivity, 95.6% specifity), 30 of 37 tendnosis' (83.3% sensitivity, 95.6% speifity) were diagnosed correctly with US. Conslusion: As a result, US is a reliable and especially reproducible method for evaluation and diagnosing of patients with shoulder pain. Furthermore, its diagnostic value is low in partial rotator cuff ruptures and in the partial ruptures of the intracapsular biceps tendon [ABSTRACT FROM AUTHOR]

Background 13C-Acetate labeled meals are widely used to determine meal emptying by means of analyzing resulting 13CO2 exhalation dynamics. In contrast to the underlying metabolic processes, only few 13C breath test meal emptying studies have focused on intragastric processes that may alter 13CO2 exhalation. This work assessed the effect of enhanced gastric secretion on the reliability of half emptying time ( t50) measurements by 13C-acetate breath test. Methods 13CO2 exhalation data were acquired in a double-blind, randomized, cross-over gastric emptying study in 12 healthy volunteers receiving either pentagastrin or placebo intravenously. The standard method proposed by Ghoos et al. was applied to calculate t50 ( t50_Ghoos) from 13CO2 exhalation data, which were compared and tested for agreement to meal half emptying times ( t50_MV) from concurrent recorded MRI (magnetic resonance imaging) volume data. In addition, the accumulated gastric secretion volumes during infusion as detected by MRI (AUC_SV60) were correlated with the corresponding cumulative percent 13C doses recovered (cPDR60). Key Results t50_Ghoos and t50_MV showed a linear correlation with a slope of 1.1 ± 0.3 ( r2 = 0.67), however, a positive offset of 136 min for t50_Ghoos. No correlation was detected between AUC_SV60 and cPDR60 ( r2 = 0.11). Both, breath test and MRI, revealed a prolonged t50 under pentagastrin infusion with median differences in t50_Ghoos of 45[28-84] min ( P = 0.002) and t50_MV of 39[28-52] min ( P = 0.002). Conclusions & Inferences This study suggests that 13CO2 exhalation after ingestion of a 13C-labeled liquid test meal is not affected by stimulated gastric secretion, but is rather reflecting the dynamics of meal or caloric emptying from the stomach. [ABSTRACT FROM AUTHOR]

Abstract: Background: Magnetic resonance imaging (MRI) for pediatric patients often requires deep sedation or anesthesia because they must remain completely immobile for a relatively long period to obtain high-quality images. Objective: The aim of this study was to compare the effectiveness of propofol IV or inhalation of sevoflurane anesthesia with the laryngeal mask airway (LMA) for children undergoing MRI. Methods: Children aged 2 to 6 years with American Society of Anesthesiologists'' physical status of I to II who were scheduled for MRI were enrolled in this study and randomly divided into 2 groups. The propofol group was administered propofol 4 mg/kg IV followed by infusion of 150 µg/kg · min-1. Patients in the sevoflurane group were induced with sevoflurane 8% by face mask and maintained with an air/oxygen mixture followed by sevoflurane 1.5%. Data recorded included age, weight, scan time, LMA insertion, removal, and recovery times, hemodynamic parameters, complications, pediatric anesthesia emergence delirium (PAED) scale score, child movement, and MRI interruption. A higher PAED score indicated a higher level of delirium. Results: Eighty-eight children were enrolled and randomized to treatment. Nine children were excluded from analysis due to protocol violations. After completion of the study, there were 37 children in the propofol group (male/female, 18/19; mean [SD] age, 42.1 months; weight, 15.2 [4.9] kg; scan time, 20.5 [4.6] min) and 42 in the sevoflurane group (male/ female, 15/27; mean [SD] age, 44.4 [26.1] months; weight, 15.1 [5.2] kg; scan time, 20.6 [4.8] min). No significant differences were found between the study groups with regard to age, weight, scan time, and hemodynamic parameters at baseline and during the study period. Mean LMA insertion, removal, and recovery times were significantly longer in the propofol group (4.8, 5.2, and 8.8 minutes, respectively) than in the sevoflurane group (3.3, 2.5, and 3.9 minutes, respectively) (P < 0.05). The mean PAED score in the propofol group was significantly lower than that in the sevoflurane group (mean [SD], 6.1 [4.0] vs 10.5 [3.7]; P < 0.05). The percentage of MRI interruption in the propofol group was significantly higher than that in the sevoflurane group (4 [11%] vs 0, respectively; P < 0.05). No episodes of hypotension or bradycardia occurred during the study, and alterations in the propofol infusion rate or sevoflurane concentration were not necessary. One child vomited in the sevoflurane group during the postoperative period. Conclusions: This small study found that sevoflurane, at the doses used in this study, provided shorter induction and faster recovery times than IV propofol for LMA anesthesia in these selected children undergoing MRI. The percentage of MRI interruption in the propofol group was significantly higher than that in the sevoflurane group. Sevoflurane was associated with a significantly higher score on the PAED scale, indicating greater emergence delirium. [Copyright &y& Elsevier]

The authors report a rare example of an isolated dissecting posterior inferior cerebellar artery (PICA) aneurysm with spontaneous resolution. A 41 year-old male suffered sudden dizziness, nausea and vomiting. An angiogram and magnetic resonance imaging (MRI) detected an isolated PICA dissection. The patient was treated conservatively and recovered without any apparent neurological deficit. MRI detected the self-resolution of the dissecting aneurysm. Dissecting PICA aneurysms, especially non-haemorrhagic lesions, have the possibility of spontaneous resolution resulting in a favorable outcome. The treatment strategy for this vascular lesion may be decided based upon neuroradiological changes on careful follow-up. [ABSTRACT FROM AUTHOR]

Although pituitary adenomas and Rathke’s cleft cysts have a shared ancestry, they rarely occur simultaneously. Only 32 reports involving a pituitary adenoma and a concomitant Rathke’s cleft cyst were identified upon review of the literature. Most initial presenting complaints include hormonal symptoms, visual disturbances, and headache. Next to growth hormone, Prolactin was the most commonly hypersecreted pituitary hormone. Rathke’s cleft cysts show variable position, size, and signal intensity on magnetic resonance imaging (MRI). Here, we report a patient with a growth hormone- secreting pituitary adenoma associated with a Rathke’s cleft cyst. The mass contained two different signal intensities on MRI. The lesion was successfully removed assisted by intraoperative MRI, when the presence of both lesions was confirmed. When a non-enhancing cyst-like structure is demonstrated on imaging in a patient with a pituitary adenoma, the possibility of a coexisting Rathke’s cleft cyst should be considered. [ABSTRACT FROM AUTHOR]

Image registration methods play a crucial role in computational neuroanatomy. This paper mainly contributes to the field of image registration with the use of nonlinear spatial transformations. Particularly, problems connected to matching magnetic resonance imaging (MRI) brain image data obtained from various subjects and with various imaging conditions are solved here. Registration is driven by local forces derived from multi-modal point similarity measures which are estimated with the use of joint intensity histogram and tissue probability maps. A spatial deformation model imitating principles of continuum mechanics is used. Five similarity measures are tested in an experiment with image data obtained from the Simulated Brain Database and a quantitative evaluation of the algorithm is presented. Results of application of the method in automated spatial detection of anatomical abnormalities in first-episode schizophrenia are presented. [ABSTRACT FROM AUTHOR]

Abstract: Magnetic resonance imaging (MRI) offers superb soft tissue contrast on T2-weighted images and allows direct multiplanar image acquisition. It can show the internal prostatic anatomy, prostatic margins, and the extent of prostatic tumors in much more detail than computed tomography (CT) images. The present article reviews some key prostatic and periprostatic radiologic landmarks that can be helpful for the radiotherapist using T2-weighted MRI as an adjunct to CT in treatment planning for prostate cancer. [Copyright &y& Elsevier]

In this study, cranial magnetic resonance imaging (MRI) findings were investigated in children with moderate and severe protein energy malnutrition (PEM) to determine cerebral abnormalities in malnutrition in childhood. A total of 20 children aged 3 months to 36 months were included in the study. Thirteen (65%) children had severe malnutrition and seven (35%) children had moderate malnutrition. Fifteen (75%) children had abnormal MRI findings: all of them had cerebral atrophy, and 10 (75%) children had cerebral atrophy plus ventricular dilatation. None of the children had abnormality in the brain stem or cerebellum. The authors did not find statistically significant differences between the groups when comparing the MRI findings for degree of malnutrition, head circumference, iron deficiency anemia, and serum albumin levels. In conclusion, the findings showed that most (75%) children with moderate/severe PEM had abnormal MRI findings. Therefore, it is suggested that children with PEM should be evaluated for cerebral atrophy. [ABSTRACT FROM AUTHOR]

A 54-year-old woman presented for cardiac evaluation of atypical chest pain. Workup included coronary angiography and a left ventriculogram, during which air was inadvertently injected, resulting in the development of an acute right hemisphere syndrome. Right carotid angiography was immediately performed, yielding only a delayed diffuse venous phase without focal vessel cutoffs. Within 60 minutes, the patient underwent hyperbaric oxygen therapy for the suspected cerebral air emboli. After removal from the chamber for technical reasons, she had a generalized tonic-clonic seizure, and further hyperbaric oxygen therapy was with-held. Initial computed tomography imaging obtained approximately 8 hours after symptom onset showed signs of early right hemispheric edema. Subsequent magnetic resonance imaging studies were markedly abnormal and suggestive of diffuse bilateral but predominantly right-sided parietal lobe edema with mildly positive diffusion-weighted imaging. Follow-up magnetic resonance imaging at 6 months was normal, and the patient's neurological examination returned to normal. [ABSTRACT FROM AUTHOR]

This report describes MRI findings of a rare case of biopsy-proven fatal cerebral infection with Chaetomium strumarium in a 28-year-old man with a history of i.v. drug abuse. Magnetic resonance imaging revealed rapidly progressing lesions with irregular peripheral enhancement, possible central haemorrhage and significant mass effect. Only six cases of cerebral infection with Chaetomium have been reported in the English literature. This is the first report in the radiology literature describing the imaging findings. The previously reported cases of cerebral infection by the Chaetomium species are also reviewed. [ABSTRACT FROM AUTHOR]

Primary double-chambered right ventricle is an uncommon congenital anomaly that presents with right ventricular outflow tract obstruction in childhood or adolescence. A search of the literature revealed only a few documented case reports with MRI findings. We present a case with mixed lesions, and with anomalous muscle bundles located both in the middle portion of the right ventricular sinus and at the subinfundibular level. [ABSTRACT FROM AUTHOR]

PURPOSE: Preoperative combined chemoradiotherapy is currently the main neoadjuvant therapy used to treat locally advanced middle and low rectal adenocarcinoma. A restaging work-up with magnetic resonance imaging was hoped to provide information about the effects related to combined chemoradiotherapy. The goal was to evaluate the correlation between pathologically verified tumor stages and clinical stages predicted by magnetic resonance imaging after combined chemoradiotherapy. METHODS: Between August 2000 and June 2003, 50 patients with biopsy-proven middle and lower rectal adeno carcinoma, with initial stage T3-T4 or N+, MO, were recruited in this series. Pelvic magnetic resonance imaging was used to stage the tumor before and after combined chemoradiotherapy. A protocol of the standard external radiation dose and oral combined uracil and 5-fluorouracil plus leucovorin was used. The results of magnetic resonance imaging restaging after combined chemoradiotherapy were correlated with the pathologic staging. RESULTS: The overall predictive accuracy in T stage was 52 percent, whereas overstaging and understaging occurred in 38 percent and 10 percent of patients, respectively. Most of the inaccurate T staging was a result of the overstaging of superficial tumors (T0-T2). In N stage, accurate staging was noted in 68 percent of all patients, whereas 24 percent were overstaged and 8 percent were under- staged. CONCLUSION: In restaging inadiated tumors, magnetic resonance imaging had the accuracy of 52 percent in T stage and 68 percent in N stage. Poor agreement between post-combined chemoradiotherapy magnetic resonance imaging and pathologic staging was observed in both T (k = 0.0 17) and N (k = 0.03 1) stages. Most of the inaccuracy in both T and N stages was caused by overstaging. The problem with magnetic resonance imaging was believed to be that it could not completely differentiate fibrosis from viable residual tumors. [ABSTRACT FROM AUTHOR]

The aim of the present study was to ascertain if in six young (23-35 years) and in six older (70-72 years) healthy men matched for comparable absolute and specific maximal force of the dominant elbow flexors, differences in isometric endurance, myoelectrical fatigability, and shortening velocity are still recognizable. To assess the specific force, the muscle cross sectional area (CSA) was determined from magnetic resonance imaging (MRI) scans. The performance of the elbow flexors was studied by assessing the isometric endurance times (ET) at different percentages of maximal isometric contraction (MVC), the average muscle fibre conduction velocity of action potentials (CV), and the median frequency (MDF) of the surface electromyogram (sEMG) of the biceps brachii. Finally, the torque-velocity curve was assessed by means of maximal isokinetic contractions at six fixed angular velocities. All data were expressed as the mean (SD). The results showed that: (1) the ET was longer in the older subjects at the highest levels of isometric contraction, independently from the absolute force; (2) the modifications of muscle fibre CV during isometric effort progressed less rapidly in the older than the younger groups, as did those of MDF; and (3) at the same angular velocity, the older subjects exerted less absolute force than the younger subjects. These results suggest an impairment of the neuromuscular system of older men, which is less powerful and less fatigable than that of young men. [ABSTRACT FROM AUTHOR]

The aim of this retrospective study was to assess and compare the diagnostic value of fine-needle cytology and MRI for the prediction of malignancy in parotid tumors. During an 11-year period, 148 patients underwent preoperative fine-needle aspiration cytology in our institution. Eighty-seven patients underwent a preoperative MRI study, and 54 had both MRI and cytology. The study compares results of cytology and MRI with histological reports. The sensitivity, specificity and accuracy for detecting malignant lesions were 87, 94 and 93% respectively for MRI, 81, 95 and 92% respectively for cytology and 100, 88 and 91% respectively for both studies combined. Fine-needle cytology provided better information than MRI concerning precise histological diagnoses. Conversely, the proportion of non-diagnostic smears reached 10%. Fine-needle cytology and MRI are simple, well-tolerated diagnostic means with an impact on the management of salivary gland tumors. The associated anatomic information obtained by MRI imaging makes it the test of first choice in an optimal medical environment. [ABSTRACT FROM AUTHOR]

The magnetic resonance imaging (MRI) findings of presumed cerebrovascular accident in 12 dogs are described. Fourteen lesions were seen, commonly (11 of 14) within the gray matter of the cerebellar hemispheres or vermis. Thirteen lesions were hyperintense on T2-weighted images (in 11 dogs) and one was hypointense. Eleven of 14 lesions were within the region supplied by the rostral cerebellar artery or one of its main branches and there was no, or minimal, mass effect. Contrast enhancement was only seen in six lesions and was mild in all. Gradient-echo images provided additional information in two dogs. The appearance of infarction in dogs with diffusion-weighted images (DWI) is similar to that in humans, and provided supportive evidence for the diagnosis of infarction in five dogs. The use of gradient-echo and DWI is recommended for the evaluation of suspected cerebrovascular accidents in dogs. Six of the 12 affected animals were spaniels or spaniel crosses, suggesting a possible breed predisposition. [ABSTRACT FROM AUTHOR]

We present an algorithm that automatically segments and classifies the brain structures in a set of magnetic resonance (MR) brain images using expert information contained in a small subset of the image set. The algorithm is intended to do the segmentation and classification tasks mimicking the way a human expert would reason. The algorithm uses a knowledge base taken from a small subset of semiautomatically classified images that is combined with a set of fuzzy indexes that capture the experience and expectation a human expert uses during recognition tasks. The fuzzy indexes are tissue specific and spatial specific, in order to consider the biological variations in the tissues and the acquisition inhomogeneities through the image set. The brain structures are segmented and classified one at a time. For each brain structure the algorithm needs one semiautomatically classified image and makes one pass through the image set. The algorithm uses low-level image processing techniques on a pixel basis for the segmentations, then validates or corrects the segmentations, and makes the final classification decision using higher level criteria measured by the set of fuzzy indexes. We use single-echo MR images because of their high volumetric resolution; but even though we are working with only one image per brain slice, we have multiple sources of information on each pixel: absolute and relative positions in the image, gray level value, statistics of the pixel and its three-dimensional neighborhood and relation to its counterpart pixels in adjacent images. We have validated our algorithm for ease of use and precision both with clinical experts and with measurable error indexes over a Brainweb simulated MR set. [ABSTRACT FROM AUTHOR]

We describe unusual brain MR imaging findings in a patient who is an HTLV-I carrier without myelopathy. T2-weighted MR images showed hyperintense signal abnormalities in the pyramidal tract, superior and middle cerebellar peduncles, and decussation of the superior cerebellar peduncles, in addition to subcortical white matter involvement. Diffusion-weighted images also showed hyperintense signal abnormalities in the same regions by T2 shine-through effect. [ABSTRACT FROM AUTHOR]

The present report describes two patients with glioblastoma multiforme with the tumour demonstrating low central apparent diffusion coefficient values similar to those found in cerebral abscesses. Although conventional MR images were fairly specific for tumour, the cases illustrate the need for exercising caution when using diffusion-weighted (DW) MR images for the differentiation of necrotic brain tumours from abscesses. The DW MR imaging information should always be integrated with the conventional spin-echo MR images. [ABSTRACT FROM AUTHOR]

Vertebral sarcoidosis is exceedingly rare with only a few cases reported in the published literature. The case of a 40-year-old man with vertebral sarcoidosis is presented, emphasizing the role of MRI and biopsy in confirming the diagnosis. A brief review of the published literature is also presented. [ABSTRACT FROM AUTHOR]

There have been several functional imaging studies using PET and SPECT to investigate posterior cortical atrophy (PCA). These studies have suggested dysfunction of corticocortical connections which is consistent with the occipitoparietal stream. However, there are no reports suggesting disturbance of the white matter that interconnects the temporal, parietal and occipital cortices. We measured fractional anisotropy (FA) in the genu and splenium of the corpus callosum and created color maps using diffusion tensor imaging (DTI), which is a relatively new MRI technique that allows visualization of the directionality of water diffusion, in a patient with PCA and compared these findings with those in 5 typical Alzheimer disease (AD) patients. The PCA patient was a 75-year-old man presenting with progressive complex visual disorder who satisfied the clinical diagnostic criteria for PCA. In 5 typical AD patients, the FA index in the splenium was higher than that in the genu; however, in the PCA patient, the FA index in the splenium was significantly lower than that in the genu. A DTI-based color map of the PCA patient showed reduction of anisotropy and fiber volume in the splenium. These findings suggest that the splenium of the corpus callosum secondarily degenerated due to neuronal degeneration of the temporal, parietal and occipital cortices and suggest that reduction of the FA in the splenium is one of the characteristics of PCA. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

This study was conducted to elucidate the effects of electroconvulsive therapy (ECT) on frontal white matter in late-life depressed patients. Diffusion tensor imaging was performed on 8 late-life depressed patients and 12 healthy age-matched controls. The patients were scanned before and after a course of ECT. Fractional anisotropy (FA) was determined in the frontal and temporal regions and the corpus callosum. A significant white matter FA reduction was found in widespread frontal and temporal brain regions in patients with depression before ECT treatment compared with controls. A significant increase in frontal white matter FA was seen following ECT treatment. A course of bilateral ECT ameliorated white matter integrity in frontal brain regions. This suggests a strong relationship with the antidepressant action of ECT. Copyright © 2004 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Summary Objective. To identify factors that favour spontaneous recovery in patients who suffered a spontaneous spinal epidural hematoma (SSEH). Methods. The literature was reviewed reguarding non-operative cases of SSEH (SSEHcons). Sixty-two cases from the literature and 2 of our own cases were collected, focusing on sex, age, medical history, position of the hematoma, segmental distribution and length of the hematoma, diagnostic imaging, neurological condition and outcome. Those data were analysed and compared with the data from a literature review of 474 cases operated on because of a SSEH (SSEHoper). Results. The mean length of the hematoma was significantly higher in SSEHcons, compared to SSEHoper (5.4 versus 4.2 vertebral segments; [standard error of the difference (SED) is 0.38 vertebral segments; 95% confidence limits for the difference are 0.45 to 1.95]). Also after exclusion of patients with coagulopathy, mean length of the hematoma was significantly higher in SSEHcons (4.7 versus 3.9 vertebral segments [SED is 0.39 vertebral segment; 95% confidence limits for the difference are 0.04 to 1.56]). Neurological signs and symptoms in SSEHcons were significantly less severe (P<0.005) and diagnosis was based on Magnetic Resonance Imaging (MRI) in the majority of cases (P<0.0005), when compared to SSEHoper. All other patient characteristics showed no correlation with spontaneous recovery. Conclusion. The recent increase of publications of SSEHcons has to be explained by the introduction of MRI in daily medical practice. As a result, more patients with a mild or benign clinical course are being diagnosed. In earlier times those patients would have escaped medical attention. The mean length of the hematoma in SSEHcons appears to be significantly higher compared to SSEHoper. This suggests that spontaneous regression of neurological symptoms may result from decompression of the neural structures by spreading of the (liquid) hematoma along the spinal epidural space in the early stages after haemorrhage. Based on the present review, there appear to be no factors which promote conservative treatment in SSEH. In the majority of cases with SSEH, the mainstay of treatment will remain surgical decompression of the neural structures and removal of the hematoma. The decision for conservative treatment has to be based on the severity of the neurological deficit and on the clinical course. Retrospectively, the length of the hematoma seems to give a clue to the spontaneous recovery which occurs in some cases of SSEH. Nevertheless, hematoma-length can not be used as a guide to treatment. [ABSTRACT FROM AUTHOR]

Background: We describe the computed tomographic (CT) and magnetic resonance imaging (MRI) findings of hepatic metastases caused by soft tissue angiosarcomas to clarify the relation between radiologic appearances and clinicopathologic features.Methods: CT and MR examinations of 13 patients with hepatic metastases of soft tissue angiosarcoma were retrospectively analyzed.Results: Contrast-enhanced CT images showed multiple hypoattenuating lesions relative to the adjacent liver parenchyma. Lesions contained peripheral areas of enhancement in eight patients (62%). Tumors showed cystic attenuation with fluid-fluid levels, which were suggestive of hemorrhage in five patients (38%). In one patient (8%) with cystic attenuation and fluid-fluid levels, lesions also contained marked enhanced nodular portions located centrally or peripherally. On T1-weighted MR images, all four liver tumors appeared heterogeneous and hypointense relative to adjacent liver parenchyma. Fluid-fluid levels were identified on T2-weighted MR images in five patients (38%). After an intravenous bolus of gadolinium-based contrast material was administered, slight peripheral enhancement was seen in three patients (75%).Conclusion: The common CT findings of metastatic angiosarcoma in our series were multiple hypoattenuating lesions often associated with nodular enhancement and cystic lesions with hemorrhagic change. [ABSTRACT FROM AUTHOR]

Summary¶Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos) is a rare space occupying lesion of the posterior fossa with some typical neuroradiological features which can be better diagnosed in the MRI era. This is the major CNS manifestation of Cowden disease. In recent years more publications underlined the association of these hamartomatous lesions. We add another patient with a dysplastic gangliocytoma of the cerebellum who also had a thyroid adenoma and fulfilled the criteria of having Cowden disease. A problem of surgical removal of these tumors is missing the borderline between tumor and healthy cerebellum tissue so that incomplete removal of the tumor is not rare. Surgical removal of these tumors in an open MRI unit would be a good indication. [ABSTRACT FROM AUTHOR]

Ovarian carcinoma is the most common cause of death from a gynecologic malignancy. The most important prognostic factors are the presence and magnitude of residual or recurrent disease after therapy. Recurrent ovarian malignancy usually manifests as pelvic masses in the surgical bed, peritoneal seeding, nodal recurrence and pleuropulmonary lesions, and liver metastasis. Pelvic recurrence involves the vaginal stump, parametria, urinary bladder, and/or bowel adjacent to the surgical bed. Peritoneal seeding presents as nodules on the peritoneal surface, most commonly around the liver or cul-de-sac, and mesenteric infiltration. Pseudomyxoma peritonei is the other form of peritoneal seeding. Nodal recurrence appears as enlarged paraaortic nodes, especially at the renal hilar level. Unusual manifestations include metastasis in the extrahepatic abdominal solid organs, bone metastasis, and abdominal wall lesion involving subcutaneous fat or muscle. Familiarity with the patterns and spectrum of imaging findings of recurrent ovarian malignancy will facilitate accurate diagnosis and prompt treatment. Correspondence to: S. H. Kim --> [ABSTRACT FROM AUTHOR]

A case report of a pituitary tuberculoma, with magnetic resonance imaging (MRI) features is described. The patient was treated with anti-tuberculous chemotherapy, and a follow-up MRI after 6 months showed good response. The relevant literature is briefly reviewed. [ABSTRACT FROM AUTHOR]

The imaging findings of multiple splenic inflammatory pseudotumors in a 45-year-old male are described. Peripheral ring enhancement on arterioportal phase and gradual enhancement from the periphery to the center on venous delay phase on contrast-enhanced dynamic magnetic resonance imaging were compatible with the pathologic findings. This result may aid in the preoperative diagnosis of these benign lesions. [ABSTRACT FROM AUTHOR]

Giant colonic diverticulum is a rare condition, and the usual site is the sigmoid colon. In this report, magnetic resonance imaging was performed in a patient with lower abdominal pain. The modality was useful for the evaluation of giant sigmoid colonic diverticulitis and the differential diagnosis. [ABSTRACT FROM AUTHOR]

A case with liver metastasis from papillary renal cell carcinoma (RCC) is presented, in which intratumoral fat was detected on dual-echo chemical shift magnetic resonance imaging (MRI). The preoperative chemical shift MR image of the primary RCC also suggested the presence of intratumoral fat. Liver metastasis from fat-containing RCC should be included in the differential diagnosis of fat-containing liver masses as observed on chemical shift MRI. [ABSTRACT FROM AUTHOR]

Spinal meningiomas of five or more vertebral segment long are very rare and also less common in younger patients. Under 50 years of age these tumors are more commonly genetical and have worse prognosis. A 25-year-old woman presented with back pain and progressive walking difficulty. An intradural extramedullary tumor extending from thoracal 9th to lumbar 2nd vertebral body was detected. The patient was operated and the tumor was totally removed. The histopathological diagnosis was angiomatous meningioma. Neurological symptoms and signs partially improved postoperatively. Interestingly, magnetic resonance imaging of this patient might easily be confused with ependymoma. Although we performed laminectomy and instrumentation, to maintain stability laminoplasty should be the first treatment modality for such a young patient. [ABSTRACT FROM AUTHOR]

We describe a rare case of a surgically proven myxoma arising within the masticator space probably from a pterygoid muscle. The lesion showed characteristic hyperintensity on T2-weighted images and did not enhance following gadolinium. [ABSTRACT FROM AUTHOR]