Rationale and Objectives The educational value of the daily resident readout, a vital component of resident training, has been markedly diminished due to a significant decrease in imaging volume and case mix diversity. The goal of this study was to create a “simulated” daily readout (SDR) to restore the educational value of the daily readout. Materials and Methods To create the SDR the following tasks were performed; selection of cases for a daily worklist for each resident rotation, comprising a combination of normal and abnormal cases; determination of the correct number of cases and the appropriate mix of imaging modalities for each worklist; development of an "educational" environment consisting of separate "instances" of both our Picture Archive Communication System and reporting systems; and the anonymization of all of the cases on the worklists. Surveys of both residents and faculty involved in the SDR were performed to assess its effectiveness. Results Thirty-two residents participated in the SDR. The daily worklists for the first 20 days of the SDR included 3682 cases. An average of 480 cases per day was dictated by the residents. Surveys of the residents and the faculty involved in the SDR demonstrated that both agreed that the SDR effectively mimics a resident's daily work on rotations and preserves resident education during the Coronavirus Disease 2019 crisis. Conclusion The development of the SDR provided an effective method of preserving the educational value of the daily readout experience of radiology residents, despite severe decreases in imaging exam volume and case mix diversity during the Coronavirus Disease 2019 pandemic.

BACKGROUND: The chromium-51-labeled posttransfusion recovery (PTR) study has been the goldstandard test for assessing red blood cell (RBC) quality. Despite guiding RBC storage development for decades, it has several potential sources for error. METHODS: Four healthy adult volunteers each donatedan autologous, leukoreduced RBC unit, aliquots were radiolabeled with technetium-99m after 1 and 6 weeks of storage, and then infused. Subjects were imaged by single-photon-emission computed tomography immediately and 4 hours after infusion. Additionally, from subjects described in a previously published study, adenosine triphosphate levels in transfusates infused into 52 healthy volunteers randomized to a single autologous, leukoreduced, RBC transfusion after 1, 2, 3, 4, 5, or 6 weeks of storage were correlated with PTR and laboratory parameters of hemolysis.RESULTS: Evidence from one subject imaged after infusion of technetium-99m-labeled RBCs suggests that, in some individuals, RBCs may be temporarily sequestered in the liver and spleen immediately following transfusion and then subsequently released back into circulation; this could be one source of error leading to PTR results that may not accurately predict the true quantity of RBCs cleared by intra-and/or extravascular hemolysis. Indeed, adenosine triphosphate levels in the transfusates correlated more robustly with measures of extravascular hemolysis in vivo (e.g., serum iron, indirect bilirubin, non-transferrin-bound iron) than with PTR results or measures of intravascular hemolysis (e.g., plasma free hemoglobin).CONCLUSIONS: Sources of measurement error are inherent in the chromium-51 PTR method. Transfusion of an entire unlabeled RBC unit, followed by quantifying extravascular hemolysis markers, may more accurately measure true posttransfusion RBC recovery. T he chromium-51-labeled posttransfusion recovery (PTR) method is currently the gold-standard test for assessing the quality of stored red blood cells (RBCs) for transfusion. 1 As per the US Food and ABBREVIATIONS: AUC = area under the curve; FDA = US Food and Drug Administration; PTR = posttransfusion recovery; SPECT = single-photon-emission computed tomography; VOIs = volumes of interest. From the

Radioactive iodine has been, in various forms, the mainstay of Nuclear Medicine. Iodine-123 is the most widely used iodine isotope for single photon imaging. Iodine-125 continues to be used in diverse applications from in vitro radioassay to in vivo estimation of various pathophysiologic correlates. Iodine-131 ( 131 I), useful for imaging as well as therapy, has contributed more than any other radionuclide to the growth and sustenance of Nuclear Medicine. Positron emission tomography (PET) is an indispensable tool in current clinical practice, spurred by the rapid and increasing availability of radiopharmaceuticals for in vivo imaging. Most clinical PET imaging utilizes fluorine-18; there is a need for positron emitters with longer half-lives, suitable for imaging larger molecules of interest. Iodine-124 ( 124 I) has approximately 23 % positron emission; its 4-day half-life lends itself to sequential imaging, and its dosimetry is comparable to iodine-131. Iodine can be easily attached to a variety of molecules without alteration of physico-chemical or biologic properties. PET with 124 I-labeled molecules enables longitudinal in vivo assessment of their distribution; such pharmacokinetic and biodistribution information has considerable utility in oncologic and non-oncologic applications. We will provide a clinical perspective on the physical and chemical characteristics of 124 I, as the iodide, as well as radiolabeled to a wide variety of molecules of interest.Radioiodination is accomplished based on the chemical and biologic nature of the ligand to be studied, and issues of relevance will be highlighted. We will conclude by describing the current and potential future clinical applications of 124 I-based tracers used for molecular imaging in diagnosis and therapy.

Primary hepatic lymphoma (PHL) is an extremely rare entity with scarce information in evidence-based literature. Few case reports have described the role of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) in the diagnosing and staging of PHL. We report the case of a 78-year-old man with PHL who initially presented with weight loss and nonspecific fatigue. FDG PET-CT proved to be a beneficial tool in arriving at the diagnosis of this patient with nonspecific clinical presentation and also in the staging of PHL. Physiological uptake of FDG in the liver can be a potential cause of misinterpretation in such cases. Hence, knowing the imaging hallmarks can increase the accuracy in PET image interpretation.

Background The role of imaging in the management of Rosai-Dorfman disease (RDD), a rare non-Langerhans cell histiocytosis, is not clearly defined. We present an analysis of FDG PET/CT findings obtained for initial disease characterization, follow-up evaluation, and treatment planning for this disease. Methods From an institutional pathology database (2001–2018), we identified RDD patients who underwent FDG PET/CT scans either as part of clinical care or when done as part of clinical trials. For all scans, sites of abnormal FDG uptake were assessed, and SUVmax was measured. Comparison of PET/CT findings was made with anatomic (CT/MRI-based) imaging, where available. Instances of changing treatment based on PET/CT were recorded. Results We reviewed 109 FDG PET/CT scans in 27 patients with RDD. Five of 27 patients had only nodal/cutaneous disease, whereas 22 patients had extranodal disease, most commonly in bone (n = 9) and central nervous system (n = 7). PET/CT identified sites of active disease in 24 of 27 patients. All identified bone and extraskeletal lesions, except for a brain lesion in 1 patient, were FDG-avid. In 6 of 20 patients (30%) with available prior CT or MRI, PET/CT demonstrated additional RDD lesions (bones: n = 5, pleura: n = 1) that were not apparent on anatomic imaging; 3 of these lesions were outside the CT field of view, and 3 were not recognized on CT. Overall, 13 of 109 PET/CT scans led to a change in management, affecting 41% (11/27) of patients. Conclusion FDG PET/CT was valuable in defining disease extent and optimizing treatment strategy in patients with RDD.

No abstract

Objective: To understand value of early rapid, quality-assurance (QA), post-therapy whole-body scan (Tx-WBS) in patients receiving peptide receptor radionuclide therapy (PRRT) in outpatient setting. Methods: Sixteen patients with metastatic neuroendocrine tumors received PRRT and underwent Tx-WBS after each cycle. Early imaging (3 hour post-injection) was favored. Planar-images obtained on dual-headed gamma camera (speed 30 cm/min) were visually assessed and qualitatively compared with pre-therapy diagnostic scans. Retention% and lesion/spleen (L/S) ratios were calculated. Results: Fifty three Tx-WBS were analyzed. No cutaneous contamination, extravasation or unexpected tracer distribution was observed. 46/53 (87%) Tx-WBS in 14/16 (88%) patients demonstrated uptake in metastatic lesions. No significant correlation was seen between L/S ratios and response on follow-up imaging. Qualitative assessment of follow-up images during four-cycles of PRRT provided preliminary estimate of disease course in 11/16 patients; with unexpected findings in 2. Conclusion: In daily practice, especially in outpatient setting, an early QA post-PRRT scan proved effective for validating successful treatment and allowing preliminary disease monitoring, at no additional cost.

Undescended parathyroid adenomas are rare, and they are easily missed during neck exploration surgery in patients with hyperparathyroidism. Few reports have described ectopic parathyroid adenomas along the carotid arteries at or near the carotid bifurcation. These may be missed on planar Tc-MIBI dual-phase scintigraphy because of overlapping submandibular gland activity. Our case demonstrates the potential advantage of SPECT/CT in parathyroid scintigraphy to overcome this limitation.