Editor's Choice - Management of the Diseases of Mesenteric Arteries and Veins: Clinical Practice Guidelines of the European Society of Vascular Surgery (ESVS).

A classification is a hierarchy of objects that conforms to the following principles: 1. The classes (groups with members) of the hierarchy have a set of properties or rules that extend to every member of the class and to all of the subclasses of the class, to the exclusion of all other [unrelated] classes. A subclass is itself a type of class wherein the members have the defining class properties of the parent class plus some additional property(ies) specific for the subclass.

What is a Classification

OBJECTIVE. Developments in MRI techniques have increased the role of MRI in assessment of the pelvis in women. The aims of this review are a short overview of pelvic MRI with an emphasis on diffusion-weighted MRI (DWI) and presentation of a practical approach that includes the pearls and pitfalls of DWI. CONCLUSION. DWI provides indispensable information in the evaluation of gyneco-logic malignancies. Prudent application of this technique requires knowledge of the optimal protocols and pitfalls in interpretation.

https://www.ajronline.org/doi/pdf/10.2214/AJR.12.9713

Pearls and pitfalls in MRI of gynecologic malignancy with diffusion-weighted technique.

Our intention is to demystify the MR quantification of hepatic iron (i.e., the liver iron concentration) and give you a step-by-step approach by answering the most pertinent questions. The following article should be more of a manual or guide for every radiologist than a classic review article, which just summarizes the literature. Furthermore, we provide important background information for professional communication with clinicians. The information regarding the physical background is reduced to a minimum. After reading this article, you should be able to perform adequate MR measurements of the LIC with 1.5-T or 3.0-T scanners. KEY POINTS: • MRI is widely accepted as the primary approach to non-invasively determine liver iron concentration (LIC). • This article is a guide for every radiologist to perform adequate MR measurements of the LIC. • When using R2* relaxometry, some points have to be considered to obtain correct measurements-all explained in this article.

/pdf/practical-guide-to-quantification-of-hepatic-iron-with-mri-2bpax8vmpk.pdf

Practical guide to quantification of hepatic iron with MRI

Awareness of radiation protection and dose levels of imaging procedures among medical students, radiography students, and radiology residents at an academic hospital: Results of a comprehensive survey

To investigate and compare the knowledge of radiation dose and risk incurred in common radiology examinations among radiology residents, fellows, staff radiologists and technologists. A questionnaire containing 17 multiple choice questions was administered to all residents, technologists, fellows and staff radiologists of the department of medical imaging through the hospital group mailing list. A total of 92 responses was received. Mean score was 8.5 out of 17. Only 48 % of all participants scored more than 50 % correct answers. Only 23 % were aware of dose from both single-view and two-view chest X-ray; 50–70 % underestimated dose from common studies; 50–75 % underestimated the risk of fatal cancer. Awareness about radiation exposure in pregnancy is variable and particularly poor among technologists. A statistically significant comparative knowledge gap was found among technologists. Our results show a variable level of knowledge about radiation dose and risk among radiology residents, fellows, staff radiologists and technologists, but overall knowledge is inadequate in all groups. There is significant underestimation of dosage and cancer risk from common examinations, which could potentially lead to suboptimal risk assessment and excessive or unwarranted studies posing significant radiation hazard to the patient and radiology workers. • Knowledge of radiation dose and risk is poor among all radiology workers. • Significant knowledge gap among technologists compared to residents, fellows and staff radiologists. • Significant underestimation of radiation dose and cancer risk from common examinations.

/pdf/radiation-awareness-among-radiology-residents-technologists-2dgyo4lhgg.pdf

Radiation awareness among radiology residents, technologists, fellows and staff: where do we stand?

Focal nodular hyperplasia (FNH) and hepatocellular adenomas (HCAs) constitute benign hepatic neoplasms in adults HCAs are monoclonal neoplasms characterised by an increased predilection to haemorrhage and also malignant transformation On the other hand, FNH is a polyclonal tumour-like lesion that occurs in response to increased perfusion and has an uneventful clinical course Recent advances in molecular genetics and genotype-phenotype correlation in these hepatocellular neoplasms have enabled a new classification system FNHs are classified into the typical and atypical types based on histomorphological and imaging features HCAs have been categorised into four subtypes: (1) HCAs with HNF-1α mutations are diffusely steatotic, do not undergo malignant transformation, and are associated with familial diabetes or adenomatosis (2) Inflammatory HCAs are hypervascular with marked peliosis and a tendency to bleed They are associated with obesity, alcohol and hepatic steatosis (3) HCAs with β-catenin mutations are associated with male hormone administration and glycogen storage disease, frequently undergo malignant transformation and may simulate hepatocellular carcinoma on imaging (4) The final type is unclassified HCAs Each of these except the unclassified subtype has a few distinct imaging features, often enabling reasonably accurate diagnosis Biopsy with immunohistochemical analysis is helpful in difficult cases and has strong implications for patient management • FNHs are benign polyclonal neoplasms with no risk of haemorrhage or malignancy
 • HCAs are benign monoclonal neoplasms classified into four subtypes based on immunohistochemistry
 • Inflammatory HCAs show an atoll sign with a risk of bleeding and malignant transformation
 • HNF-1α HCAs are steatotic HCAs with minimal complications and the best prognosis
 • β-Catenin HCA shows variable MRI features and a high risk of malignancy

https://link.springer.com/content/pdf/10.1007%2Fs13244-015-0399-8.pdf

Current updates on the molecular genetics and magnetic resonance imaging of focal nodular hyperplasia and hepatocellular adenoma.

Inflammatory myofibroblastic tumour (IMFT) is a relatively uncommon neoplasm with unpredictable malignant potential known to occur anywhere in the body. IMFT involving the omentum is a very rare entity with less than 15 cases reported so far. We report a case of omental IMFT in a 15-year-old girl who presented with multiple peritoneal masses on imaging and the diagnosis was confirmed on histopathology. In addition to its uncommon location, its presentation as multiple masses is extremely uncommon. This uncommon presentation as multifocal masses needs to be distinguished from other causes of peritoneal carcinomatosis.

Omental inflammatory myofibroblastic tumour mimicking peritoneal carcinomatosis.

Non-neoplastic hepatic vascular diseases: spectrum of CT and MRI appearances.

Detection and quantification of hepatic iron with dual-echo gradient recalled echo (GRE) has been proposed as a rapid alternative to other magnetic resonance imaging (MRI) techniques. Co-existing steatosis and T1 weighting are limitations. This study assesses the accuracy of routine dual-echo GRE. Between 2010 and 2013, 109 consecutive patients underwent multi-echo (ME) MRI and dual-echo GRE for quantification of hepatic iron. Liver iron concentration (LIC) was calculated from ME-MRI. Relative signal intensity (RSI) and fat signal fraction (FSF) were calculated from dual-echo GRE. Four radiologists subjectively evaluated dual-echo GRE (±subtraction). Diagnostic accuracy was compared between techniques and correlated with biopsy using Fisher’s exact test, Spearman correlation and regression. The sensitivity of visual detection of iron ranged from 48 to 55 %. Subtraction did not increase sensitivity (p < 0.001). Inter-observer variability was substantial (κ = 0.72). The specificity of visual detection of iron approached 100 % with false-positive diagnoses observed using subtraction. LIC showed a higher correlation with histopathological iron grade (r = 0.94, p < 0.001) compared with RSI (r = 0.65, p = 0.02). Univariate regression showed an association between RSI and LIC (B = 0.98, p < 0.001, CI 0.73-1.23); however, the association was not significant with multi-variate regression including FSF (p = 0.28). Dual-echo GRE has low sensitivity for hepatic iron. Subtraction imaging can result in false-positive diagnoses. • Routine liver MRI studies cannot effectively screen patients for iron overload.
 • Concomitant hepatic steatosis and iron limits diagnostic accuracy of routine liver MRI.
 • Dual-echo GRE subtraction imaging causes false-positive diagnoses of iron overload.
 • Dedicated MRI techniques should be used to diagnose and quantify iron overload.

Diagnostic accuracy of dual-echo (in- and opposed-phase) T1-weighted gradient recalled echo for detection and grading of hepatic iron using quantitative and visual assessment.

Subramaniyan Ramanathan

Papers

Radiation awareness among radiology residents, technologists, fellows and staff: where do we stand?

Current updates on the molecular genetics and magnetic resonance imaging of focal nodular hyperplasia and hepatocellular adenoma.

Omental inflammatory myofibroblastic tumour mimicking peritoneal carcinomatosis.

Non-neoplastic hepatic vascular diseases: spectrum of CT and MRI appearances.

Diagnostic accuracy of dual-echo (in- and opposed-phase) T1-weighted gradient recalled echo for detection and grading of hepatic iron using quantitative and visual assessment.