Commentary: A Radiologist's Guide to Peer-Reviewing Manuscripts.

ABSTRACT: Reviewers play an important role in the publishing of radiology articles. When done well, reviewers help editors identify which articles to accept and improve them through their recommendations. In this commentary, we provide a step-by-step guide to reviewing both original science and review articles.

US of the Inguinal Canal: Comprehensive Review of Pathologic Processes with CT and MR Imaging Correlation.

Ultrasonography (US) has a fundamental role in the initial examination of patients who present with symptoms indicating abnormalities of the inguinal canal (IC), an area known for its complex anatomy. A thorough understanding of the embryologic and imaging characteristics of the contents of the IC is essential for any general radiologist. Moreover, an awareness of the various pathologic conditions that can affect IC structures is crucial to preventing misdiagnoses and ensuring optimal patient care. Early detection of IC abnormalities can reduce the risk of morbidity and mortality and facilitate proper treatment. Abnormalities may be related to increased intra-abdominal pressure, which can result in development of direct inguinal hernias and varicoceles, or to congenital anomalies of the processus vaginalis, which can result in development of indirect hernias and hydroceles. US is also helpful in assessing postoperative complications of hernia repair, such as hematoma, seroma, abscess, and hernia recurrence. In addition, it is often the modality initially used to detect neoplasms arising from or invading the IC. US is an important tool in the examination of patients suspected of having undescended testes or posttraumatic testicular retraction and is essential for the examination of patients suspected of having torsion or infectious inflammatory conditions of the spermatic cord. Online supplemental material is available for this article. ©RSNA, 2016.

An exceptional case of xanthomatous infiltration of the musculoskeletal and integumentary systems.

Tendinous and subcutaneous xanthomas are most commonly associated with primary hyperlipidemia. Xanthomatosis caused by cholesterol deposition can be a high risk marker for cardiovascular disease related to premature atherosclerosis; thus, early recognition of this diagnosis may reduce mortality and morbidity. Achilles tendon involvement is most common, followed by the extensor tendons of the hand and elbow. We present an exceptional case of tendinous and tuberous xanthomas, with intraoperative and histologic correlation, in a 34-year-old female manifesting with xanthomatous deposits of nearly all ankle tendons, plantar aponeurosis, extensor tendons of the hands, and various locations within the integumentum. To the authors' knowledge, only four studies to date have focused specifically on imaging findings of multifocal xanthomas. Thus, the radiographic and MR imaging descriptions of xanthomas in this report further add to the existing literature by helping to identify imaging characteristics of this multifocal systemic disease. The diagnosis of this condition should alert the physician to the presence of a dyslipidemia that can be treated with dietary modifications and/or drug therapy.

Dual energy CT applications in oncological imaging.

Cancer is the second leading cause of death in the United States, killing more than 600.000 people each year.1 Despite several screening programs available, cancer diagnosis is often made incidentally during imaging studies performed for other reasons. Once the diagnosis is made, treatment assessment and surveillance of these patients heavily rely on radiological tools. Computed tomography (CT) in particular is one of the most commonly ordered modalities due to wide availability even in the most remote locations, and fast results. However, conventional CT often cannot definitively characterize a neoplastic lesion unless it was tailored toward answering a specific question. Furthermore, characterizing small lesions can be difficult with CT. An innovative technique called dual-energy CT (DECT) offers solutions to some of the challenges of conventional CT in oncological imaging.

Imaging human brown adipose tissue under room temperature conditions with (11)C-MRB, a selective norepinephrine transporter PET ligand.

INTRODUCTION: Brown adipose tissue (BAT) plays a critical role in adaptive thermogenesis and is tightly regulated by the sympathetic nervous system (SNS). However, current BAT imaging modalities require cold stimulation and are often unreliable to detect BAT in the basal state, at room temperature (RT). We have shown previously that BAT can be detected in rodents under both RT and cold conditions with (11)C-MRB ((S,S)-(11)C-O-methylreboxetine), a highly selective ligand for the norepinephrine transporter (NET). Here, we evaluate this novel approach for BAT detection in adult humans under RT conditions. METHODS: Ten healthy, Caucasian subjects (5 M: age 24.6±2.6, BMI 21.6±2.7kg/m(2); 5 F: age 25.4±2.1, BMI 22.1±1.0kg/m(2)) underwent (11)C-MRB PET-CT imaging for cervical/supraclavicular BAT under RT and cold-stimulated conditions (RPCM Cool vest; enthalpy 15°C) compared to (18)F-FDG PET-CT imaging. Uptake of (11)C-MRB, was quantified as the distribution volume ratio (DVR) using the occipital cortex as a low NET density reference region. Total body fat and lean body mass were assessed via bioelectrical impedance analysis. RESULTS: As expected, (18)F-FDG uptake in BAT was difficult to identify at RT but easily detected with cold stimulation (p=0.01). In contrast, BAT (11)C-MRB uptake (also normalized for muscle) was equally evident under both RT and cold conditions (BAT DVR: RT 1.0±0.3 vs. cold 1.1±0.3, p=0.31; BAT/muscle DVR: RT 2.3±0.7 vs. cold 2.5±0.5, p=0.61). Importantly, BAT DVR and BAT/muscle DVR of (11)C-MRB at RT correlated positively with core body temperature (r=0.76, p=0.05 and r=0.92, p=0.004, respectively), a relationship not observed with (18)F-FDG (p=0.63). Furthermore, there were gender differences in (11)C-MRB uptake in response to cold (p=0.03), which reflected significant differences in the change in (11)C-MRB as a function of both body composition and body temperature. CONCLUSIONS: Unlike (18)F-FDG, the uptake of (11)C-MRB in BAT offers a unique opportunity to investigate the role of BAT in humans under basal, room temperature conditions.

Using SUV as a guide to 18F-FDG dose reduction.

UNLABELLED: This article explores how one can lower the injected (18)F-FDG dose while maintaining validity in comparing standardized uptake values (SUVs) between studies. Variations of the SUV within each lesion were examined at different acquisition times. METHODS: Our protocol was approved by either the Human Investigation Committee or the Institutional Review Board. All 120 PET datasets were acquired continuously for 180 s per bed position in list mode and were reconstructed to obtain 30-, 60-, 90-, 120-, 150-, and 180-s-per-bed-position PET images with registration to a single set of nondiagnostic CT images. Qualitative assessment of the images was performed separately for correlation. The SUV measurements of each lesion were computed and normalized to the 180-s acquisition values to create a stabilization factor. These stabilization factors were used to demonstrate a predictable trend of stabilization over time. The variances of the stabilization factors over the entire dataset, composed of several tumor types over a range of sizes, were compared for each time point with the corresponding 150-s time point using a 2-sided F test, which has similar values to the 180-s time point. RESULTS: The variance of the data decreased with increasing acquisition time and with increasing dose but leveled off for sufficiently long acquisitions. CONCLUSION: Through the statistical analysis of SUVs for increasing acquisition times and visual evaluation of the plots, we developed and hereby propose an algorithm that can be used to seek the maximum reduction in administered (18)F-FDG dose while preserving the validity of SUV comparisons.

Targeted radionuclide therapy.

Targeted radiotherapy is an evolving and promising modality of cancer treatment. The killing of cancer cells is achieved with the use of biological vectors and appropriate radionuclides. Among the many advantages of this approach are its selectiveness in delivering the radiation to the target, relatively less severe and infrequent side effects, and the possibility of assessing the uptake by the tumor prior to the therapy. Several different radiopharmaceuticals are currently being used by various administration routes and targeting mechanisms. This article aims to briefly review the current status of targeted radiotherapy as well as to outline the advantages and disadvantages of radionuclides used for this purpose.