Visual and Quantitative Evaluation of Low-Concentration Bismuth in Dual-Contrast Imaging of Iodine and Bismuth Using Clinical Photon-Counting CT.

Simultaneous dual-contrast imaging of iodine and bismuth has shown promise in prior phantom and animal studies utilizing spectral CT. However, it is noted that in previous studies, Pepto-Bismol has frequently been employed as the source of bismuth, exceeding the recommended levels for human subjects. This investigation sought to assess the feasibility of visually differentiating and precisely quantifying low-concentration bismuth using clinical dual-source photon-counting CT (PCCT) in a scenario involving both iodinated and bismuth-based contrast materials. Four bismuth samples (0.6, 1.3, 2.5, and 5.1 mg/mL) were prepared using Pepto-Bismol, alongside three iodine rods (1, 2, and 5 mg/mL), inserted into multi-energy CT phantoms with three different sizes, and scanned on a PCCT system at three tube potentials (120, 140, and Sn140 kV). A generic image-based three-material decomposition method generated iodine and bismuth maps, with mean mass concentrations and noise levels measured. The root-mean-square errors for iodine and bismuth determined the optimal tube potential. The tube potential of 140 kV demonstrated optimal quantification performance when both iodine and bismuth were considered. Distinct differentiation of iodine rods with all three concentrations and bismuth samples with mass concentrations ≥ 1.3 mg/mL was observed across all phantom sizes at the optimal kV setting.

Know your way around acute unenhanced CT during global iodinated contrast crisis: a refresher to ED radiologists.

Due to a contrast shortage crisis resulting from the decreased supply of iodinated contrast agents, the American College of Radiology (ACR) has issued a guidance statement followed by memoranda from various hospitals to preserve and prioritize the limited supply of contrast. The vast majority of iodinated contrast is used by CT, with a minority used by vascular and intervention radiology, fluoroscopy, and other services. A direct consequence is a paradigm shift to large volume unenhanced CT scans being utilized for acute and post traumatic patients in EDs, an uncharted territory for most radiologists and trainees. This article provides radiological diagnostic guidance and a pictorial example through systematic review of common unenhanced CT findings in the acute setting.

Esophagectomy and Gastric Pull-through Procedures: Surgical Techniques, Imaging Features, and Potential Complications.

Esophagectomy takes the center stage in the curative treatment of local and local-regional esophageal cancer. It is a complex procedure with a high postoperative complication rate. When interpreting imaging studies, radiologists must understand the surgical techniques used and their potential complications. The most common surgical techniques are transthoracic esophagectomies, such as the Ivor Lewis and McKeown techniques, and transhiatal esophagectomy. Variations of these techniques include different choices of conduit (ie, stomach, colon, or jejunum) to serve in lieu of the resected esophagus. Postoperative imaging and accurate interpretation is vital in the aftercare of these patients. Chest radiographs, esophagrams, and computed tomographic images play an essential role in early identification of complications. Pulmonary complications and anastomotic leaks are the leading causes of postoperative morbidity and mortality secondary to esophagectomy. Other complications include technical and functional problems and delayed complications such as anastomotic strictures and disease recurrence. An esophagographic technique is described that is performed by using hand injection of contrast material into an indwelling nasogastric tube. Familiarity with the various types of esophagectomy and an understanding of possible complications are of utmost importance for radiologists and allow them to be key participants in the treatment of patients undergoing these complicated procedures.

Variations in use of "water soluble contrast challenge" for small bowel obstruction among academic radiologists: results of a national survey.

OBJECTIVE: To assess the frequency and indications for use of oral water-soluble contrast challenge as a diagnostic test for small bowel obstruction in four regions of the USA. MATERIALS AND METHODS: We distributed a 9-question web-based survey to the abdominal section heads of academic radiology departments throughout the USA (N = 97). The questions pertained to use of water-soluble contrast for management of small bowel obstruction. Descriptive statistics and Fisher's exact tests were used for data analysis. RESULTS: The overall response rate was 46%. Eighty percent of the responding hospitals had more than 500 beds in operation. Water-soluble contrast challenge was considered standard of care for management of non-operative small bowel obstruction in 60% of the responding radiology departments. The majority of the responding departments (41%) performed 2-8 contrast challenge studies per month on average. The most frequent indication for the study was distinguishing partial vs complete bowel obstruction. Eighty percent of the responding radiologists believed that the contrast challenge is useful for management of small bowel obstruction. Overall, there was no statistically significant difference in frequency and indication for use of water-soluble contrast challenge based on geographic location. CONCLUSION: The water-soluble contrast challenge was considered standard of care for non-operative management of small bowel obstruction in majority of the academic radiology departments represented in this survey. Surgeons were referring clinicians in every case. The most common clinical indication for the study was distinguishing partial versus complete small bowel obstruction.

Comprehensive review of typical and atypical pathology of the appendix on CT: cases with clinical implications.

Acute appendicitis is the most common abdominal surgical emergency in the United States with approximately 250,000 cases annually. Computed Tomography (CT) has emerged as the most accurate diagnostic test to triage these patients for emergent surgery. Although the radiology search pattern is prioritized to detect an inflamed appendix, not all appearances equate to a typical surgical appendicitis. There are a select set of atypical pathologies involving the appendix that have subtle differences on CT, but can have catastrophic complications if treated with emergent appendectomy. This paper will review the spectrum of CT appearances and clinical management for typical and atypical appendiceal pathologies.