US and MR Imaging of Pectoralis Major Injuries.

During the past 2 decades, the frequency of pectoralis major muscle injuries has increased in association with the increased popularity of bench press exercises. Injury of the pectoralis major can occur at the muscle origin, muscle belly, musculotendinous junction, intratendinous region, and/or humeral insertion-with or without bone avulsion. The extent of the tendon injury ranges from partial to complete tears. Treatment may be surgical or conservative, depending on the clinical scenario and anatomic characteristics of the injury. The radiologist has a critical role in the patient's treatment-first in detecting and then in characterizing the injury. In this article, the authors review the normal anatomy and anatomic variations of the pectoralis major muscle, classifications and typical patterns of pectoralis major injuries, and associated treatment considerations. The authors further provide an instructive guide for ultrasonographic (US) and magnetic resonance (MR) imaging evaluation of pectoralis major injuries, with emphasis on a systematic approach involving the use of anatomic landmarks. After reviewing this article, the reader should have an understanding of how to perform-and interpret the findings of-US and MR imaging of the pectoralis major. The reader should also understand how to classify pectoralis major injuries, with emphasis on the key findings used to differentiate injuries for which surgical management is required from those for which nonsurgical management is required. Familiarity with the normal but complex anatomy of the pectoralis major is crucial for performing imaging-based evaluation and understanding the injury findings. ©RSNA, 2017 Online supplemental material is available for this article.

Recurrent non-surgical pneumoperitoneum due to jejunal diverticulosis.

BACKGROUND: The presence of free intraperitoneal gas usually warrants emergent surgery. In rare instances, however, non-surgical conditions such as jejunal diverticulosis can cause pneumoperitoneum and do not require intervention. OBJECTIVES: The objective of this article is to provide the computed tomography (CT) scan findings of jejunal diverticulosis causing pneumoperitoneum. The article will also discuss other non-surgical causes of spontaneous pneumoperitoneum to increase awareness and avoid unnecessary surgery. CASE REPORT: We describe a case of recurrent pneumoperitoneum due to jejunal diverticulosis in which the patient remained asymptomatic and free of complications with repeated evaluations in the emergency department over the course of 18 months. CONCLUSION: Although spontaneous pneumoperitoneum due to jejunal diverticulosis is a rare finding, when it does occur, this condition must be distinguished from other forms of pneumoperitoneum to avoid unnecessary surgery. CT scan findings of multiple rounded, variably sized jejunal outpouchings filled with oral contrast are helpful in diagnosing jejunal diverticulosis and confirming the decision for conservative management of the patient.

Hypothermia-treated neonates with hypoxic-ischemic encephalopathy: Optimal timing of quantitative ADC measurement to predict disease severity.

To determine the optimal time window for MR imaging with quantitative ADC measurement in neonatal HIE after hypothermia treatment, a retrospective review was performed on consecutive hypothermia-treated term neonates with HIE, with an initial and follow-up MR imaging within the first two weeks of life. Three neuroradiologists categorized each set of MR imaging as normal, mild, moderate or severe HIE based on a consensus review of the serial imaging. The lowest ADC values from the white matter, corpus callosum, and basal ganglia/thalamus were measured. The ADC values between mild-moderate and severe HIE were compared using a Student's t-test over a range of different time windows. A total of 33 MR imaging examinations were performed on 16 neonates that included three normal, four mild, five moderate, and four severe HIE. The time window of 3-10 days showed a statistically significant decrease in ADC value in severe HIE compared to mild-moderate HIE in all three locations, respectively: white matter 0.5 ± 0.22 versus 0.83 ± 0.27 ( p value 0.01), corpus callosum 0.69 ± 0.19 versus 0.91 ± 0.17 ( p value 0.01), and basal ganglia/thalamus 0.63 ± 0.16 versus 0.98 ± 0.06 ( p value <0.01). The range of 3-10 days is the optimal time window for MR imaging with quantitative ADC after hypothermia treatment.

Evaluation of the novel USPIO GEH121333 for MR imaging of cancer immune responses.

Tumor-associated macrophages (TAM) maintain a chronic inflammation in cancers, which is associated with tumor aggressiveness and poor prognosis. The purpose of this study was to: (1) evaluate the pharmacokinetics and tolerability of the novel ultrasmall superparamagnetic iron oxide nanoparticle (USPIO) compound GEH121333; (2) assess whether GEH121333 can serve as a MR imaging biomarker for TAM; and (3) compare tumor MR enhancement profiles between GEH121333 and ferumoxytol. Blood half-lives of GEH121333 and ferumoxytol were measured by relaxometry (n = 4 each). Tolerance was assessed in healthy rats injected with high dose GEH121333, vehicle or saline (n = 4 each). Animals were monitored for 7 days regarding body weight, complete blood counts and serum chemistry, followed by histological evaluation of visceral organs. MR imaging was performed on mice harboring MMTV-PyMT-derived breast adenocarcinomas using a 7 T scanner before and up to 72 h post-injection (p.i.) of GEH121333 (n = 10) or ferumoxytol (n = 9). Tumor R1, R2* relaxation rates were compared between different experimental groups and time points, using a linear mixed effects model with a random effect for each animal. MR data were correlated with histopathology. GEH121333 showed a longer circulation half-life than ferumoxytol. Intravenous GEH121333 did not produce significant adverse effects in rats. All tumors demonstrated significant enhancement on T1, T2 and T2*-weighted images at 1, 24, 48 and 72 h p.i. GEH121333 generated stronger tumor T2* enhancement than ferumoxytol. Histological analysis verified intracellular compartmentalization of GEH121333 by TAM at 24, 48 and 72 h p.i. MR imaging with GEH121333 nanoparticles represents a novel biomarker for TAM assessment. This new USPIO MR contrast agent provides a longer blood half-life and better TAM enhancement compared with the iron supplement ferumoxytol.

Spectral Doppler signature waveforms in ultrasonography: a review of normal and abnormal waveforms.

Doppler ultrasound is routinely used in the clinical setting to evaluate blood flow in many major vessels of the body. Spectral Doppler is used to display the normal and abnormal signature waveforms that are unique to each vessel. It is important for the sonographer and the radiologist to recognize both what is normal and what is abnormal in a spectral Doppler display. In this review, we briefly explain the physics behind Doppler ultrasound and some of the most common mathematical equations applied in a routine clinical examination. We also describe and demonstrate normal versus abnormal spectral Doppler signature waveforms of vessels in the neck, abdomen, pelvis, and fetus.