Approach to Acute Traumatic and Nontraumatic Diaphragmatic Abnormalities.

Acute diaphragmatic abnormalities encompass a broad variety of relatively uncommon and underdiagnosed pathologic conditions, which can be subdivided into nontraumatic and traumatic entities. Nontraumatic abnormalities range from congenital hernia to spontaneous rupture, endometriosis-related disease, infection, paralysis, eventration, and thoracoabdominal fistula. Traumatic abnormalities comprise both blunt and penetrating injuries. Given the role of the diaphragm as the primary inspiratory muscle and the boundary dividing the thoracic and abdominal cavities, compromise to its integrity can yield devastating consequences. Yet, diagnosis can prove challenging, as symptoms may be vague and findings subtle. Imaging plays an essential role in investigation. Radiography is commonly used in emergency evaluation of a patient with a suspected thoracoabdominal process and may reveal evidence of diaphragmatic compromise, such as abdominal contents herniated into the thoracic cavity. CT is often superior, in particular when evaluating a trauma patient, as it allows rapid and more detailed evaluation and localization of pathologic conditions. Additional modalities including US, MRI, and scintigraphy may be required, depending on the clinical context. Developing a strong understanding of the acute pathologic conditions affecting the diaphragm and their characteristic imaging findings aids in efficient and accurate diagnosis. Additionally, understanding the appearance of diaphragmatic anatomy at imaging helps in differentiating acute pathologic conditions from normal variations. Ultimately, this knowledge guides management, which depends on the underlying cause, location, and severity of the abnormality, as well as patient factors. ©RSNA, 2024 Supplemental material is available for this article.

Evaluation of the proximal coronary arteries in suspected pulmonary embolism: diagnostic images in 51% of patients using non-gated, dual-source CT pulmonary angiography.

PURPOSE: This retrospective study reports the frequency and severity of coronary artery motion on dual-source high-pitch (DSHP), conventional pitch single-source (SS), and dual-source dual-energy (DE) CT pulmonary angiography (CTPA) studies. METHODS: Two hundred eighty-eight consecutive patients underwent CTPA scans for suspected pulmonary embolism between September 1, 2013 and January 31, 2014. One hundred ninety-four at DSHP scans, 57 SS scans, and 37 DE scans were analyzed. Coronary arteries were separated into nine segments, and coronary artery motion was qualitatively scored using a scale from 1 to 4 (non-interpretable to diagnostic with no motion artifacts). Signal intensity, noise, and signal to noise ratio (SNR) of the aorta, main pulmonary artery, and paraspinal muscles were also assessed. RESULTS: DSHP CTPA images had significantly less coronary artery motion, with 30.1% of coronary segments being fully evaluable compared to 4.2% of SS segments and 7.9% of DE segments (p < 0.05 for all comparisons). When imaging with DSHP, the proximal coronary arteries were more frequently evaluable than distal coronary arteries (51% versus 11.3%, p < 0.001). Without ECG synchronization and heart rate control, the distal left anterior descending coronary artery and mid right coronary artery remain infrequently interpretable (7% and 9%, respectively) on DSHP images. CONCLUSIONS: DSHP CTPA decreases coronary artery motion artifacts and allows for full evaluation of the proximal coronary arteries in 51% of cases. The study highlights the increasing importance of proximal coronary artery review when interpreting CTPA for acute chest pain.

A review of dosimetric and toxicity modeling of proton versus photon craniospinal irradiation for pediatrics medulloblastoma.

BACKGROUND: Craniospinal irradiation (CSI) is the standard radiation therapy treatment for medulloblastoma. Conventional CSI photon therapy (Photon-CSI) delivers significant dose to surrounding normal tissue (NT). Research into pediatric CSI with proton therapy (Proton-CSI) has increased, with the aim of exploiting the potential to reduce NT dose and associated post-treatment complications. This review aims to compare treatment outcomes of pediatric medulloblastoma patients between Proton- and Photon-CSI treatments. MATERIAL AND METHODS: A search and review of studies published between 1990 and 2016 comparing pediatric (2-18 years) medulloblastoma Proton- and Photon-CSI in three aspects - normal organ sparing and target coverage; normal organ dysfunction and second malignancy risks - was completed. RESULTS: Fifteen studies were selected for review and the results were directly compared. Proton-CSI reported improved out-of-field organ sparing while target coverage improvements were inconsistent. Normal organ dysfunction risks were predicted to be lower following Proton-CSI. Secondary malignancy risks (SMRs) were generally lower with Proton-CSI based on several different risk models. CONCLUSIONS: Proton-CSI conferred better treatment outcomes than Photon-CSI for pediatric medulloblastoma patients. This review serves to compare the current literature in the absence of long-term data from prospective studies.