High-Resolution Microscopy-Coil MR Imaging of Skin Tumors: Techniques and Novel Clinical Applications.

High-resolution magnetic resonance (MR) imaging performed with a microscopy coil is a robust radiologic tool for the evaluation of skin lesions. Microscopy-coil MR imaging uses a small surface coil and a 1.5-T or higher MR imaging system. Simple T1- and T2-weighted imaging protocols can be implemented to yield high-quality, high-spatial-resolution images that provide an excellent depiction of dermal anatomy. The primary application of microscopy-coil MR imaging is to delineate the deep margins of skin tumors, thereby providing a preoperative road map for dermatologic surgeons. This information is particularly useful for surgeons who perform Mohs micrographic surgery and in cases of nasofacial neoplasms, where the underlying anatomy is complex. Basal cell carcinoma is the most common nonmelanocytic skin tumor and has a predilection to manifest on the face, where it can be challenging to achieve complete surgical excision while preserving the cosmetic dignity of the patient. Microscopy-coil MR imaging provides dermatologic surgeons with valuable preoperative anatomic information that is not available at conventional clinical examination.

The celiac axis revisited: anatomic variants, pathologic features, and implications for modern endovascular management.

The celiac axis (CA) and its branches are critically important arteries that supply blood to the vital solid and hollow abdominal viscera of the foregut. There are many potential anatomic configurations, with up to half the population having a variation from the classic pattern of the CA bifurcating into the hepatosplenic trunk and left gastric artery. These configurations result from permutations in the fusion of the paired dorsal aortas during the first trimester. Despite the short length of the CA, it is affected by a wide range of pathologic conditions, including mesenteric ischemia due to intrinsic occlusion (secondary to causes such as atherosclerosis or thromboembolic events) and extrinsic compression from masses or the median arcuate ligament. Symptoms of mesenteric ischemia are nonspecific and include postprandial abdominal pain and weight loss; thus, the underlying pathologic condition may be found only when being sought specifically. More unusual pathologic conditions include dissection, aneurysms, and vascular malformations. Awareness of the pathologic conditions that affect the CA is important for both diagnostic and interventional radiologists. Early recognition and treatment of CA disease may prevent catastrophic hemorrhage and bowel infarction. Both endovascular and surgical approaches to treatment are greatly enhanced by correct identification of arterial anatomic variants; catheter angiography, computed tomographic angiography, and magnetic resonance angiography can facilitate detection of these variants. Knowledge of the different anatomic permutations is essential to guide endovascular procedures, such as hemorrhage control, transarterial interventional oncologic therapy, and treatment of visceral artery aneurysms. Online supplemental material is available for this article.

Development and Preliminary Validation of a Digital Overlay-based Learning Module for Semiquantitative Evaluation of Magnetic Resonance Imaging Lesions in Osteoarthritis of the Hip.

OBJECTIVE: To develop and validate a knowledge transfer (KT) module aimed at enhancing feasibility and reliability of semiquantitative assessment of bone marrow lesions (BML) and synovitis-effusion using the Hip Inflammation Magnetic Resonance Imaging Scoring System (HIMRISS). METHODS: Three radiologists naive to the HIMRISS method reviewed the manuscript describing the method and then scored MRI scans from 16 patients with hip OA obtained at baseline and 8 weeks after intraarticular injection of corticosteroid. Readers then reviewed a KT module comprising an instructional presentation and 8 reference DICOM (digital imaging and communications in medicine) cases scored by 3 readers with expertise in the HIMRISS method, and then used electronic overlay software to score scans from 23 patients with OA. The same format was followed with a second group of 3 readers naive to HIMRISS using a KT module revised to incorporate the overlay with a Web-based DICOM viewer to enhance feasibility. Interobserver reliability was assessed with the intraclass correlation coefficient (ICC). RESULTS: In both exercises, reliability for baseline scores was excellent for femoral BML, very good for acetabular BML, and good for synovitis-effusion (overall ICC = 0.91, 0.89, 0.62, respectively) even without prior calibration using the KT module. However, reliability for detecting change was substantially worse than for expert readers, especially for acetabular BML and synovitis-effusion (overall ICC = 0.59 vs 0.19, and 0.42 vs 0.25, respectively). Reliability improved for detection of change in these lesions, especially after reader calibration with the revised KT module. CONCLUSION: Development and validation of a systematic method for KT may enhance external validation of certain imaging instruments.