Nuclear Medicine in the Acute Clinical Setting: Indications, Imaging Findings, and Potential Pitfalls

Abstract

Nuclear medicine imaging provides valuable functional information that complements information obtained with anatomic imaging techniques in the evaluation of patients with specific acute clinical manifestations. Nuclear medicine studies are most often used in conjunction with other imaging modalities and as a problem-solving tool. Under certain circumstances a nuclear medicine study may be indicated as the first-line imaging modality, as in the case of renal scintigraphy for transplant dysfunction in the early postoperative period. Nuclear imaging may be preferred when a conventional first-line study is contraindicated or when it is important to minimize radiation exposure. The portability of nuclear imaging offers particular advantages for the evaluation of critically ill patients whose clinical condition is unstable and who cannot be safely transported out of the intensive care unit. The ability to visualize physiologic and pathophysiologic processes over relatively long time periods without adding to the patient's radiation exposure contributes to the high diagnostic sensitivity of several types of nuclear medicine studies. Viewing the acquired images in the cine mode adds to the value of these studies for diagnosing and characterizing dynamic abnormalities such as intermittent internal bleeding and bile or urine leakage. In this pictorial review, the spectrum of nuclear medicine studies commonly performed in the acute care setting is reviewed according to body systems and organs, with detailed descriptions of the indications, technical considerations, findings, and potential pitfalls of each type of study. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.332125098/-/DC1.

Nuclear medicine and the emergency department patient: an illustrative case-based approach

“…Cholescintigraphy (HIDA scan) is commonly performed in the setting of suspected acute cholecystitis, where it provides a very high negative predictive value once the gallbladder is seen filling with radiotracer [3,19].…”

“…In the setting of suspected biliary leak, a variety of imaging modalities, including ultrasound, CT, MRI and endoscopic retrograde cholangiopancreatography (ERCP) can be used [3,[19][20][21][22][23]. Although one could argue that ERCP provides a chance for correcting the underlying abnormality, this is only the case for a limited set of leak locations.…”

“…111-185 MBq of the tracer is administered intravenously and dynamic images are acquired over at least 60 min [3,[19][20][21][22][23]. Dynamic acquisition can be continued as required.…”

“…While radiologist are usually familiar with the more common imaging including radiographs, computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US) procedures, many are not aware of the significant contributions nuclear medicine can make in the management of patients in acute care [1][2][3][4][5][6][7]. While other radiologic imaging methods depict anatomy and rely on knowledge of normal patterns to recognize abnormal ones, nuclear medicine evaluates organ and physiologic functions.…”

Basic Premises to Molecular Imaging and Radionuclide Therapy – Part 1

“…Radiocompounds labelled with technetium-99m are the most diffuse radiotracers used in clinical practice; due to their ability to perform in widely used studies, as gated-SPECT with myocardial perfusion agents, bone scans, thyroid scintigraphy and so forth [46][47][48][49][50][51]. In conjunction with traditional examinations, nethertheless there is a role, shared by iodine-123 radiotracers, already available in the clinical setting.…”