Pseudo fat-saturated appearance of magnetic resonance head and neck images in 2 cachectic patients.

Cachexia is a significant contributor to cancer mortality as it is responsible for up to 30% of cancer deaths. Magnetic resonance imaging offers a noninvasive approach to detect features of cachexia. T1-weighted images of cachectic patients have a "pseudo fat-saturated" appearance secondary to disappearance of subcutaneous and fascial fat throughout the body, as well as fat in the bone marrow. Orbital fat remains preserved until late disease. We present 2 cases with these classic imaging findings of cancer cachexia in the subcutaneous tissues of the head, neck, and spine. This imaging phenomenon is often misinterpreted by radiologists and may lead to delayed diagnosis or unnecessary repeat imaging.

Abbreviated Protocol Breast MRI.

OBJECTIVE. Patients with dense breast tissue are seeking supplemental screening because of the limited sensitivity of mammography. Abbreviated protocol (AP) breast MRI is attractive because it offers a higher cancer detection rate, shorter scan time, and lower cost than full MRI. This article explores the issues of balancing the benefits of AP MRI with safety concerns about gadolinium-based contrast agents, lack of standardization of protocols and field strengths, potential decrease in performance metrics, and potential for overdiagnosis. CONCLUSION. Important questions need to be addressed before AP MRI can be used routinely for breast cancer screening. Evidence is lacking from well-designed prospective trials that can confirm the accuracy and efficacy of AP MRI are comparable with those of other breast imaging modalities. Determining which patients benefit most from AP MRI will help shape future screening guidelines.

Magnetic Resonance Imaging of Human Olfactory Dysfunction.

Olfactory dysfunctions affect a larger portion of population (up to 15% with partial olfactory loss, and 5% with complete olfactory loss) as compared to other sensory dysfunctions (e.g. auditory or visual) and have a negative impact on the life quality. The impairment of olfactory functions may happen at each stage of the olfactory system, from epithelium to cortex. Non-invasive neuroimaging techniques such as the magnetic resonance imaging (MRI) have advanced the understanding of the advent and progress of olfactory dysfunctions in humans. The current review summarizes recent MRI studies on human olfactory dysfunction to present an updated and comprehensive picture of the structural and functional alterations in the central olfactory system as a consequence of olfactory loss and regain. Furthermore, the review also highlights recent progress on optimizing the olfactory functional MRI as well as new approaches for data processing that are promising for future clinical practice.

Preoperative detection of malignant liver tumors: Comparison of 3D-T2-weighted sequences with T2-weighted turbo spin-echo and single shot T2 at 1.5 T.

PURPOSE: To assess the performances of three-dimensional (3D)-T2-weighted sequences compared to standard T2-weighted turbo spin echo (T2-TSE), T2-half-Fourier acquisition single-shot turbo spin-echo (T2-HASTE), diffusion weighted imaging (DWI) and 3D-T1-weighted VIBE sequences in the preoperative detection of malignant liver tumors. METHODS: From 2012 to 2015, all patients of our institution undergoing magnetic resonance imaging (MRI) examination for suspected malignant liver tumors were prospectively included. Patients had contrast-enhanced 3D-T1-weighted, DWI, 3D-T2-SPACE, T2-HASTE and T2-TSE sequences. Imaging findings were compared with those obtained at follow-up, surgery and histopathological analysis. Sensitivities for the detection of malignant liver tumors were compared for each sequence using McNemar test. A subgroup analysis was conducted for HCCs. Image artifacts were analyzed and compared using Wilcoxon paired signed rank-test. RESULTS: Thirty-three patients were included: 13 patients had 40 hepatocellular carcinomas (HCC) and 20 had 54 liver metastases. 3D-T2-weighted sequences had a higher sensitivity than T2-weighted TSE sequences for the detection of malignant liver tumors (79.8% versus 68.1%; P < 0.001). The difference did not reach significance for HCC. T1-weighted VIBE and DWI had a higher sensitivity than T2-weighted sequences. 3D-T2-weighted-SPACE sequences showed significantly less artifacts than T2-weitghted TSE. CONCLUSION: 3D-T2-weighted sequences show very promising performances for the detection of liver malignant tumors compared to T2-weighted TSE sequences.

Imaging Assessment of Primary Prostate Cancer, Focused on Advanced MR Imaging and PET/CT

Imaging assessment of prostate cancer is one of the most difficult sections of oncology imaging. Detecting, localizing and staging of the primary prostate cancer by preoperative imaging are still challenging for the radiologist. Magnetic resonance (MR) imaging provides excellent soft tissue contrast and is widely used for solid organ imaging, but results of preoperative imaging of the prostate gland with conventional MR imaging is unsatisfactory. Positron emission tomography and computed tomography (PET/CT) is the cornerstone in oncology imaging, but some limitations prohibit the assessment of primary prostate cancer with PET or PET/CT. Recent studies to overcome these insufficient accuracies of imaging evaluation of primary prostate cancers with advanced MR techniques and PET and PET/CT are reported. In this article, we review the imaging findings of prostate cancer on variable modalities, focused on MR imaging and PET/CT.