Learning Objectives: On successful completion of this activity, participants should be able to describe (1) the rationale and the aims of conjoint endovascular mapping and 99m Tc-macroaggregated albumin ( 99m Tc-MAA) hepatic perfusion imaging before liver radioembolization; (2) how to integrate the information gathered during the angiographic procedure with the SPECT/CT hepatic perfusion study to generate an interpretation relevant to clinical management; (3) various sites of 99m Tc-MAA activity outside the liver parenchyma and their potential origin in order to avoid nontargeted radioembolization; and (4) pitfalls in 99m Tc-MAA hepatic perfusion imaging and how to avoid them.Financial Disclosure: Dr. Darcy is a consultant/advisor for Angiodynamics and Boston Scientific, is a meeting participant/lecturer for W.L. Gore; and is involved in scientific studies/trials sponsored by Bard and W.L. Gore. Dr. Saad is a proctor for Sirtex Medical Ltd. The authors of this article have indicated no other relevant relationships that could be perceived as a real or apparent conflict of interest. CME Credit: SNMMI is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing education for physicians. SNMMI designates each JNM continuing education article for a maximum of 2.0 AMA PRA Category 1 Credits. Physicians should claim only credit commensurate with the extent of their participation in the activity. For CE credit, participants can access this activity through the SNMMI Web site (http:// www.snmmi.org/ce_online) through November 30, 2015.Endovascular mapping and conjoint 99m Tc-macroaggregated albumin ( 99m Tc-MAA) hepatic perfusion imaging provide essential information before liver radioembolization with 90 Y-loaded microspheres in patients with primary and secondary hepatic malignancies. The aims of this integrated procedure are to determine whether there is a risk for excessive shunting of 90 Ymicrospheres to the lungs; to detect extrahepatic perfusion emerging from the injected vascular territory, which might lead to nontargeted radioembolization; to reveal incomplete coverage of the liver parenchyma involved by the tumor, which may be related to anatomic or acquired variants of the arterial vasculature; and to aid in calculation of the 90 Y-microsphere dose to be delivered to the liver. This pictorial essay presents an integrated comprehensive review of the anatomic, angiographic, and nuclear imaging aspects of planned liver radioembolization. The relevant anatomy of the liver, including the standard and the variant arterial vasculature, will be shown using digital subtraction angiography, SPECT/CT, contrast-enhanced CT, and anatomic illustrations. Technical details that will optimize the imaging protocols and important imaging findings will be discussed. From the angio suite to the g-camerathe goal of this review is to help the reader better understand how the technical details of the angiographic procedure are reflected in the imaging findings of the 99m Tc-MAA hepatic per...

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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.

A healthy patient presented with painful skin lesions on the anterior surface of her legs. Erythema nodosum was diagnosed but all the usual causes were ruled out. The finding of bilateral enlarged axillary lymph nodes with necrosis and granulomas led to the diagnosis of infection, an unusual cause of erythema nodosum. Imaging also revealed splenomegaly and small para-aortic lymph nodes. Up to one quarter of the patients with cat-scratch disease present atypically, a considerably higher prevalence than previously reported. A comprehensive review of the literature (PubMed, since inception, all languages) revealed a remarkable array of unusual presentations which are summarised and briefly discussed.

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