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Portal vein thrombosis refers to complete or partial obstruction of the portal venous system, in the intrahepatic or extrahepatic venous tract or even in the splenic or superior mesenteric veins. This common and potentially fatal condition can develop in various clinical contexts, especially those of liver cirrhosis, hepatocellular carcinoma, and other solid tumors. Certain characteristics, such as the time since the onset of the thrombus (acute or chronic), its biology (hematic or tumoral), the presence of collateral vessels, and the magnetic resonance imaging aspects, are important components of a thorough, careful analysis, as well as informing decisions regarding the appropriate therapeutic strategy. Here, we present a brief review of the anatomy of the portal venous system and a systematic approach to analyzing the condition, using a mnemonic (ABCD, for age, biology, collaterals, and diffusion). We discuss the various imaging methods and illustrate our discussion with images selected from the case files archived at our facility. [ABSTRACT FROM AUTHOR]

Primary bone lymphoma is a rare neoplasm that can initially present as local pain, a palpable mass, and pathologic fracture. It can also be discovered as an incidental finding on an imaging examination. It is defined as a bone marrow tumor with no involvement of other sites, lasting at least six months. The diagnosis is confirmed by biopsy and immunohistochemical analysis. Although the imaging characteristics are nonspecific, there are certain findings that, when correlated with clinical and epidemiological aspects, can increase the level of suspicion of primary bone lymphoma. The classic imaging aspect is a bone lesion with a soft-tissue component that preserves the cortical layer more than would be expected given the invasive nature of the lesion. Magnetic resonance imaging is the best imaging method to evaluate the extent of involvement of adjacent compartments, whereas computed tomography depicts the cortical layer in greater detail, as well as being an important tool for biopsy guidance. Other imaging modalities are also discussed, such as X-ray, ultrasound, bone scintigraphy, and positron emission tomography/computed tomography. The aim of this paper is to describe the most common findings obtained with the various imaging methods used in patients with a confirmed diagnosis of primary bone lymphoma. [ABSTRACT FROM AUTHOR]

Objective: To determine whether evaluating the mean apparent diffusion coefficient (ADC) together with capsular contact (CC) adds value in the prediction of microscopic extracapsular extension (ECE) of prostate cancer. Materials and Methods: Between January 2012 and December 2016, 383 patients underwent multiparametric magnetic resonance imaging (mpMRI) of the prostate. A total of 67 patients were selected for inclusion. Two radiologists (observers 1 and 2), working independently, performed qualitative and quantitative analyses of ECE, macroscopic ECE, and microscopic ECE. A third radiologist assessed the correlation with the clinical data, and two experienced pathologists reviewed all histopathological findings. Results: Among the 67 patients, mpMRI showed lesions that were confined to the capsule in 44 (66.7%), had microscopic ECE in 12 (17.9%), and had macroscopic ECE in 11 (16.4%). There were no significant differences, in terms of the diagnostic accuracy, as measured by determining the area under the curve (AUC), of CC on T2-weighted images (CCT2), CC on diffusion-weighted imaging (CCDWI), and the mean ADC for the prediction of microscopic ECE, between observer 1 (AUC of 0.728, 0.691, and 0.675, respectively) and observer 2 (AUC of 0.782, 0.821, and 0.799, respectively). Combining the mean ADC with the CCT2 or CCDWI did not improve the diagnostic accuracy for either observer. There was substantial interobserver agreement for the qualitative evaluation of ECE, as demonstrated by the kappa statistic, which was 0.77 (0.66-0.87). The diagnostic accuracy (AUC) of the qualitative assessment for predicting microscopic ECE was 0.745 for observer 1 and 0.804 for observer 2, and the difference was less than significant. In a multivariate analysis, none of clinical or imaging parameters were found to be associated with ECE. Conclusion: For the detection of microscopic ECE on mpMRI, CC appears to have good diagnostic accuracy, especially if the observer has considerable experience. Adding the mean ADC to the CCT2 or CCDWI does not seem to provide any significant improvement in that diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Objective: To establish the prevalence of patellar chondropathy using 3T magnetic resonance imaging (MRI) and to correlate the findings with individual features such as gender, age, and body mass index. Materials and Methods: Data consisted of collecting 3T MRIs of patients' knees obtained between October 2016 and September 2017, comprising a period of 12 months. These MRIs were assessed by an experienced musculoskeletal radiologist who confirmed the presence of patellar chondropathy and, when present, rated the finding into the four grades ascribed by the International Cartilage Repair Society. Results: A total number of 291 patients were assessed during the period with 389 MRI scans. Of those patients, 308 (79.2%) were diagnosed with patellar chondropathy, while 81 (20.8%) were not. Chondropathy was more prevalent in the female gender, in subjects above 40 years of age, and in obese patients. When the results were weighed in International Cartilage Repair Society classification, the milder grades (1 and 2) were seen in younger men (< 30 years of age), while the more severe grades (3 and 4) were mostly present in females, those above 40 years of age, and in obese patients. Conclusion: There was a high prevalence of patellar chondropathy in patients who had undergone high-field knee MRIs (79.2%), being highest in the female gender and in subjects above 40 years of age. The most prevalent group was graded as 4 by the International Cartilage Repair Society classification. [ABSTRACT FROM AUTHOR]

Accessory ossicles are supernumerary and inconstant structures that are not caused by fractures. Derived from unfused ossification centers, accessory ossicles were first described by Vesalius in 1543. For centuries, they were believed to be asymptomatic. However, with advances in radiology techniques, many have been associated with painful syndromes. Although the original descriptions date from the sixteenth century, the subject is little discussed and, in some cases, controversial. The objective of this study was to describe the radiological aspects of a series of accessory ossicles and to review the evolution of their various descriptions, in order to revive discussion of the subject. [ABSTRACT FROM AUTHOR]

Although ultrasound is still the gold standard for the assessment of fetal malformations, magnetic resonance imaging (MRI) has gained great prominence in recent years. In situations in which ultrasound has low sensitivity, such as maternal obesity, abdominal scarring, and oligohydramnios, MRI has proven to be a safe and accurate method. Regarding fetal abdominal wall defects, MRI appears to be widely used in the prognostic assessment of gastroschisis with intestinal atresia or of complications of omphalocele, allowing better perinatal management and parental counseling. In addition, MRI allows the assessment of local invasion of fetal abdominal tumors, with significant prognostic value for the postnatal period. In this article, we review the main MRI findings in the evaluation of fetal abdominal wall defects and tumors. [ABSTRACT FROM AUTHOR]

The recent association between the increase in the number of neonates with microcephaly in northeastern Brazil and the outbreak of infection with the Zika virus, which has been occurring in the Americas, has been declared a public health emergency of international concern. The evidence that implicates the virus as the cause of this public health emergency has been demonstrated ever more consistently. This pictorial essay illustrates the imaging characteristics seen on computed tomography and magnetic resonance imaging scans of infants admitted to a rehabilitation hospital with a diagnosis of microcephaly and a maternal history of rash during pregnancy. [ABSTRACT FROM AUTHOR]