Diagnostic nuclear medicine in the ED

ACR Appropriateness Criteria® Acute Onset of Scrotal Pain-Without Trauma, Without Antecedent Mass: 2024 Update

Acute scrotum is a medical emergency that requires prompt accurate diagnosis to appropriately triage potentially surgical conditions. Numerous differential diagnoses with overlapping clinical presentations make this a diagnostic challenge. Ultrasound is the established first-line imaging modality for acute scrotal disease and can be used to diagnose most scrotal disorders promptly and with high accuracy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Emergency Imaging in Pregnancy and Lactation

The use of diagnostic imaging studies in the emergency setting has increased dramatically over the past couple of decades. The emergency imaging of pregnant and lactating patients poses unique challenges and calls upon the crucial role of radiologists as consultants to the referring physician to guide appropriate use of imaging tests, minimize risk, ensure timely management, and occasionally alleviate unwarranted trepidation. A clear understanding of the risks and benefits involved with various imaging tests in this patient population is vital to achieve this. This review discusses the different safety and appropriateness issues that could arise with the use of ionizing radiation, iodinated-, and gadolinium-based contrast media and radiopharmaceuticals in pregnant and lactating patients. Special considerations such as trauma imaging, safety concerns with magnetic resonance imaging and ultrasound, management of claustrophobia, contrast extravasation, and allergic reactions are also reviewed. The consent process for these examinations has also been described.

Sonographic diagnosis of acute cholecystitis in patients with symptomatic gallstones

PURPOSE

The aim of the retrospective study was to assess the diagnostic ultrasound (US) criteria for acute cholecystitis in patients admitted for symptomatic gallbladder stones.

METHODS

The medical records of 186 patients who had undergone cholecystectomy within 24 hours after an US examination were reviewed. Acute cholecystitis was defined on the basis of pathology findings. The correlation between standardized US signs and final diagnosis of acute cholecystitis was assessed with univariate and multivariate analyses. The diagnostic values of US based on the correlated signs were then calculated.

RESULTS

The prevalence of acute cholecystitis was 52.7% (95% confidence interval [CI], 42.8-64.2). Three US signs were found to be predictive of acute cholecystitis: gallbladder distension, wall edema, and pericholecystic fluid collection. When none of the US signs were registered, sonography proved to have a 72.4% (95% CI, 59.1-83.3) negative predictive value. When registering two or three signs, sonography had positive predictive values of 78% (95% CI, 56.3-92.5) and 100% (95% CI, 58.9-100), respectively. With just one sign, the positive predictive value was 57.6% (95% CI, 47.2-67.4), and such a finding was furthermore observed in only 53.2% of the cases.

CONCLUSIONS

The sonografic diagnosis of acute cholecystitis may be achieved by registering only three standardized US signs. Nevertheless, in patients admitted for symptomatic gallstones, US is of some utility in less than half of those patients.

Tele-nuclear medicine

This article presents a description of tele-nuclear medicine and, after outlining its history, a wide, representative range of its applications. Tele-nuclear medicine has benefited greatly from technological progress, which for several decades has provided greater data transfer rates and storage capacity at steadily decreasing cost. Differences in the practice of nuclear medicine between developed and developing countries arise mainly from disparities in their available infrastructure, funding and education levels of personnel involved. Consequently there are different emphases in their tele-nuclear medicine, which are elaborated. It is concluded that tele-nuclear medicine is important for all countries, but the emphasis on its application may differ between developed and developing nations, with an emphasis on distance learning in the latter.

Unexpected Tc-99m labelled erythrocyte scintigraphy finding of a patient with suspicion of active bleeding into renal haematoma

A 36-year-old male patient with suspicion of active bleeding into renal haematoma loge was sent to our clinic for Tc-99m labelled erythrocyte scintigraphy. Scintigraphy showed no active bleeding to renal haematoma but coexisting active haemorrhage of stomach which was confirmed as erosive bulbitis with further endoscopy.