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Purpose: Indeterminate renal masses are increasingly incidentally found on cross-sectional imaging. 99m Tc-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) scans can be used to identify oncocytomas and oncocytic renal neoplasms, including a subset of chromophobe renal cell carcinomas (chRCCs), which are viewed as false-positive., Procedure: Patients imaged with renal sestamibi scans between 2014 and 2023 were reviewed. Those patients with solitary tumors that were originally classified as chRCC were included in the analysis. Imaging with SPECT/CT from the liver dome down had been carried out 75 min after the administration of 925 MBq of 99m Tc-sestamibi. All available H&E and immunostained slides were re-reviewed and classified according to WHO 2022 criteria. Confirmatory immunohistochemical stains were performed in tumors considered morphologically suspicious for non-chRCC entities., Result: A total of 18 patients with solitary tumors were included in the final analysis. 13/18 (72.2%) tumors in this cohort remained classified as chRCC, with 4/18 (22.2%) being eosinophilic-variant chRCC. The reclassified tumors (5/18 [27.8%]) included 2/18 (11.1%) low-grade oncocytic tumor (LOT), 1/18 (5.5%) eosinophilic vacuolated tumor (EVT), and 2/18 (11.1%) unclassified low-grade oncocytic neoplasms. As such, only 2/9 (22.2%) qualitatively "hot" tumors were chRCC other than eosinophilic-variant and only 1/9 (11.1%) "cold" tumors was a histology other than chRCC., Conclusion: Based on current histopathologic classification methods, it is likely that the "false-positive" rate of uptake on renal sestamibi scans with chRCC has been over-stated. Further study is warranted to better refine the optimal utility of renal sestamibi scans for non-invasive risk stratification of indeterminate renal masses., (© 2024. The Author(s), under exclusive licence to World Molecular Imaging Society.)

Molecular imaging moves forward with the development of new imaging agents, and among these are new radiotracers for nuclear medicine applications, particularly positron emission tomography (PET). A number of new targets are becoming accessible for use in oncologic applications. In this review, major new radiotracers in clinical development are discussed. Prominent among these is the family of fibroblast-activation protein-targeted agents that interact with the tumor microenvironment and may show superiority to 2-deoxy-2-[18F]fluoro-d-glucose in a subset of different tumor histologies. Additionally, carbonic anhydrase IX (CAIX) inhibitors are directed at clear cell renal cell carcinoma, which has long lacked an effective PET imaging agent. Those CAIX agents may also have utility in hypoxic tumors. Pentixafor, which binds to a transmembrane receptor, may similarly allow for visualization by PET of low-grade lymphomas, as well as being a second agent for multiple myeloma that opens theranostic possibilities. There are new adrenergic agents aimed at providing a PET-visible replacement to the single-photon-emitting radiotracer meta-[123I]iodobenzylguanidine (MIBG). Finally, in response to a major development in oncologic chemotherapy, there are new radiotracers targeted at assessing the suitability or use of immunotherapeutic agents. All of these and the existing evidence for their utility are discussed., Competing Interests: Declaration of competing interest JDO: consulted briefly for Telix Pharmaceuticals. MGP: none listed. RAW: speaker honoraria from Novartis/AAA and PentixaPharm, advisory board work for Novartis/AAA and Bayer, funding from the German Research Foundation (453989101, 507803309), involved in [68Ga]Ga-Pentixafor PET Imaging in PAN Cancer (FORPAN, sponsored and planned by PentixaPharm). TH: funding from the German Research Foundation (453,989,101). SPR is a consultant for Precision Molecular, Lantheus, and Telix. SPR has equity in Precision Molecular and PlenaryAI, (Copyright © 2024 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.)

Anatomic imaging with contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) has long been the mainstay of renal mass characterization. However, those modalities are often unable to adequately characterize indeterminate, solid, enhancing renal masses - with some exceptions, such as the development of the clear-cell likelihood score on multi-parametric MRI. As such, molecular imaging approaches have gained traction as an alternative to anatomic imaging. Mitochondrial imaging with 99m Tc-sestamibi single-photon emission computed tomography/CT is a cost-effective means of non-invasively identifying oncocytomas and other indolent renal masses. On the other end of the spectrum, carbonic anhydrase IX agents, most notably the monoclonal antibody girentuximab - which can be labeled with positron emission tomography radionuclides such as zirconium-89 - are effective at identifying renal masses that are likely to be aggressive clear cell renal cell carcinomas. Renal mass biopsy, which has a relatively high non-diagnostic rate and does not definitively characterize many oncocytic neoplasms, nonetheless may play an important role in any algorithm targeted to renal mass risk stratification. The combination of molecular imaging and biopsy in selected patients with other advanced imaging methods, such as artificial intelligence/machine learning and the abstraction of radiomics features, offers the optimal way forward for maximization of the information to be gained from risk stratification of indeterminate renal masses. With the proper application of those methods, inappropriately aggressive therapy for benign and indolent renal masses may be curtailed., Competing Interests: Declaration of competing interest SPR is a consultant for, has equity in, and has received research funding from Precision Molecular, Inc. SPR and MAG are consultants for Lantheus. SPR and MAG are consultants for Telix. JDO has been a consultant for Telix., (Copyright © 2024 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.)

Abstract: With the increase in use of GLP-1 receptor agonists such as semaglutide (Ozempic, Wegovy, Rybelsus) in the population, nuclear medicine physicians should be aware of the possibility of nondiagnostic FDG PET scans due to these medications, which work partly by increasing insulin secretion. We demonstrate a case where a patient's use of such a medication presumptively led to muscular and myocardial uptake, complicating scan interpretation considerably. Clinicians should be aware of the presence of these drugs and their potential effect on biodistribution in FDG PET. Further study is needed to best understand the effects of these medications on FDG biodistribution., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: The proliferation of US FDA-approved prostate-specific membrane antigen (PSMA)-targeted positron emission tomography (PET) imaging agents as a means to evaluate prostate cancer patients, and the expanding knowledge of interpretive pitfalls, has led to the generation of multiple online training modules geared toward the reading of each individual agent, each taking different approaches to criteria for interpretation, which may contribute to the variability of reporting in clinical practice., Materials and Methods: The websites of the marketers of each FDA-approved agent [ 68 Ga-PSMA-11 (Illuccix; Telix Pharmaceuticals), 68 Ga-PSMA-11 (Locametz; Novartis Pharmaceuticals), 18 F-rh-PSMA-7.3 (Posluma; Blue Earth Diagnostics)], and the website of the Society of Nuclear Medicine and Molecular Imaging [ 18 F-DCFPyL (Pylarify)] were examined. All information pertaining to reader training, including videos, PDFs, and PowerPoint presentations, were reviewed., Results: Videos from each module covered interpretive approach and pitfalls and ranged in length from a total of 20 min up to 315 min. Each module provided a different approach to PSMA PET scan findings, and on a different number and breadth of interpretive tips and pitfalls (a total of approximately 12-30 in all)., Conclusions: Each of the four PSMA PET reader training modules covered important interpretive pitfalls. The lengths of the video portions of each module varied considerably, suggesting variable investments in time necessary to complete each module. The differences in the modules could contribute to inconsistency among readers depending on which module(s) they may have completed and which radiotracer(s) they are using., (© 2024 Wiley Periodicals LLC.)

Introduction: There is growing interest in the development and application of standardized imaging criteria (SIC), to minimize variability and improve the reproducibility of image interpretation in head and neck squamous cell carcinoma (HNSCC)., Methods: "Squamous cell carcinoma" AND "standardized interpretation criteria" OR "radiographic response assessment" were searched using PubMed and Google Scholar for articles published between 2009 and 2024, returning 56 publications. After abstract review, 18 were selected for further evaluation, and 6 different SICs (i.e., PERCIST, Porceddu, Hopkins, NI-RADS, modified Deauville, and Cuneo) were included in this review. Each SIC is evaluated in the context of 8 desired traits of a standardized reporting system., Results: Two SICs have societal endorsements (i.e., PERCIST, NI-RADS); four can be used in the evaluation of locoregional and systemic disease (i.e., PERCIST, Hopkins, NI-RADS, Cuneo), and four have specific categories for equivocal imaging results (i.e., Porceddu, NI-RADS, modified Deauville, and Cuneo). All demonstrated areas for future improvement in the context of the 8 desired traits., Conclusion: Multiple SICs have been developed for and demonstrated value in HNSCC post-treatment imaging; however, these systems remain underutilized. Selecting an SIC with features that best match the needs of one's practice is expected to maximize the likelihood of successful implementation.

Abstract: Adenoid cystic carcinoma (ACC) of the Bartholin gland is an exceedingly rare neoplasm. A 56-year-old woman with remote ACC resection (plus neoadjuvant chemoradiation and adjuvant chemotherapy) presented to an outside institution with shortness of breath. CT showed bilateral pulmonary nodules and mediastinal lymphadenopathy. With high clinical suspicion for metastatic disease, 18 F-FDG PET/CT was performed and showed scattered nodules with mild FDG uptake along with FDG-avid mediastinal, bilateral hilar, and bilateral cervical chain lymphadenopathy. Lung biopsy of a hypermetabolic nodule confirmed metastatic ACC., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Endometriosis is a common cause of infertility, pelvic pain, and dysmenorrhea and there are prior case reports of lesion detection using an 18F-fluoroestradiol (FES) tracer with positron emission tomography (PET). We aimed to further investigate the use of the FES tracer in the context of PET-magnetic resonance (PET-MR) imaging. We administered FES to 6 patients and then imaged them using a Siemens mMR PET-MR scanner. Each patient was taken to surgery within 30 days after imaging, and surgical visualization served as the gold-standard for diagnosis. PET did not prove to be as sensitive as MR (50% per-patient sensitivity versus 67% per-patient and 35% versus 48% per-lesion), and did not show any additional sites over and above MR. When MR was used to localize lesions on PET after imaging, there was insufficient evidence of an association between total tracer uptake and reported pain intensity (P=0.25). FES PET-MR offers no additional value to MR for endometriosis., Competing Interests: None., (AJNMMI Copyright © 2024.)

Abstract: Prostate cancer (PCa) is the most common noncutaneous malignancy in men. Until recent years, accurate imaging of men with newly diagnosed PCa, or recurrent or low-volume metastatic disease, was limited. Further, therapeutic options for men with advanced, metastatic, castration-resistant disease were increasingly limited as a result of increasing numbers of systemic therapies being combined in the upfront metastatic setting. The advent of urea-based, small-molecule inhibitors of prostate-specific membrane antigen (PSMA) has partially addressed those shortcomings in diagnosis and therapy of PCa. On the diagnostic side, there are multiple pivotal phase III trials with several different agents having demonstrated utility in the initial staging setting, with generally modest sensitivity but very high specificity for determining otherwise-occult pelvic nodal involvement. That latter statistic drives the utility of the scan by allowing imaging interpreters to read with very high sensitivity while maintaining a robust specificity. Other pivotal phase III trials have demonstrated high detection efficiency in patients with biochemical failure, with high positive predictive value at the lesion level, opening up possible new avenues of therapy such as metastasis-directed therapy. Beyond the diagnostic aspects of PSMA-targeted radiotracers, the same urea-based chemical scaffolds can be altered to deliver therapeutic isotopes to PCa cells that express PSMA. To date, one such agent, when combined with best standard-of-care therapy, has demonstrated an ability to improve overall survival, progression-free survival, and freedom from skeletal events relative to best standard-of-care therapy alone in men with metastatic, castration-resistant PCa who are post chemotherapy. Within the current milieu, there are a number of important future directions including the use of artificial intelligence to better leverage diagnostic findings, further medicinal chemistry refinements to the urea-based structure that may allow improved tumor targeting and decreased toxicities, and the incorporation of new radionuclides that may better balance efficacy with toxicities than those nuclides that are available., Competing Interests: Conflicts of Interest and Source of Funding: J.D.O. briefly consulted for Telix Pharmaceuticals. M.G.P. owns equity in Precision Molecular, Inc., receives royalties from Lantheus, and has technology licensed to Blue Earth Diagnostics. T.A.H. has grant funding to the institution from Clovis Oncology, GE Healthcare, Lantheus, Janssen, Novartis, Telix Pharmaceuticals, the Prostate Cancer Foundation, and the National Cancer Institute (R01CA235741 and R01CA212148). He received personal fees from Bayer, Cardinal Health, BlueEarth Diagnostics and Lantheus and received fees from and has an equity interest in RayzeBio and Curium. S.P.R. is a consultant for, has received research funding from, and owns equity in Precision Molecular, Inc.; he is a consultant for Progenics Pharmaceuticals, Inc., a wholly owned subsidiary of Lantheus; and he is a consultant for Blue Earth Diagnostics, Inc. For the remaining authors, none were declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Renal cell carcinoma (RCC) and urothelial carcinoma (UC) are two of the most common genitourinary malignancies. 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) can play an important role in the evaluation of patients with RCC and UC. In addition to the clinical utility of 18F-FDG PET to evaluate for metastatic RCC or UC, the shift in molecular imaging to focus on specific ligand-receptor interactions should provide novel diagnostic and therapeutic opportunities in genitourinary malignancies. In combination with the rise of artificial intelligence, our ability to derive imaging biomarkers that are associated with treatment selection, response assessment, and overall patient prognostication will only improve., Competing Interests: Disclosure LBS has received research funding from Precision Molecular, Inc. SN has received research funding and is a consultant for Precision Molecular, Inc. SPR owns equity in, has received research funding from, and is a consultant for Precision Molecular, Inc., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: Endometriosis is an estrogen-dependent disorder of menstruating primates where tissues similar to the inner lining of the uterus exist "ectopically" outside of the uterus. The ectopic endometrium, like the endometrium within the uterus, expresses estrogen receptors (ER) and progesterone receptors (PR) and undergoes hormone-dependent cell proliferation and bleeding each menstrual cycle. The goal of this study was to conduct abdominopelvic positron emission tomography (PET) scans with computed tomography (CT) imaging of rhesus macaques (Macaca mulatta) using radiotracers that target ER and PR [16α-[ 18 F]fluoroestradiol (FES) and 12-[ 18 F]fluoro-furanyl-nor-progesterone (FFNP)] in individuals with and without endometriosis. We also aimed to determine if menstrual cycle phase and/or the presence of endometriosis affected the uptake of these radiotracers., Procedures: Rhesus macaques with either clinically diagnosed endometriosis (n = 6) or no endometriosis (n = 4) underwent PET/CT scans with FES. A subset of the animals also underwent PET/CT scans with FFNP. Standard uptake values corrected for body weight (SUVs) were obtained for each radiotracer in target and background tissues (e.g., intestinal). We performed repeated measure analysis of variance tests to determine how uterine and background uptake differed with scan time, phase of the menstrual cycle, and disease state., Results: Abdominopelvic PET/CT could not resolve small, individual endometriotic lesions. However, macaques with endometriosis displayed higher uterine uptake compared to those without the disorder. Radiotracer uptake differed by menstrual cycle phase with increased uterine uptake of both radiotracers in the proliferative phase of the menstrual cycle. Background intestinal uptake of FFNP increased over time after infusion, but only during the proliferative phase., Conclusions: PET/CT with FES and FFNP support the concept that ER and PR levels are altered in individuals with endometriosis. This highlights the impact of the disease on typical reproductive tract function and may provide a novel pathway for the identification of individuals with endometriosis., (© 2023. The Author(s), under exclusive licence to World Molecular Imaging Society.)

This study aimed to assess the accuracy of intraprostatic tumor volume measurements on prostate-specific membrane antigen-targeted 18 F-DCFPyL PET/CT made with various segmentation methods. An accurate understanding of tumor volumes versus segmentation techniques is critical for therapy planning, such as radiation dose volume determination and response assessment. Methods: Twenty-five men with clinically localized, high-risk prostate cancer were imaged with 18 F-DCFPyL PET/CT before radical prostatectomy. The tumor volumes and tumor-to-prostate ratios (TPRs) of dominant intraprostatic foci of uptake were determined using semiautomatic segmentation (applying SUV max percentage [SUV%] thresholds of SUV30%-SUV70%), adaptive segmentation (using adaptive segmentation percentage [A%] thresholds of A30%-A70%), and manual contouring. The histopathologic tumor volume (TV-Histo) served as the reference standard. The significance of differences between TV-Histo and PET-based tumor volume were assessed using the paired-sample Wilcoxon signed-rank test. The Spearman correlation coefficient was used to establish the strength of the association between TV-Histo and PET-derived tumor volume. Results: Median TV-Histo was 2.03 cm 3 (interquartile ratio [IQR], 1.16-3.36 cm 3 ), and median TPR was 10.16%. The adaptive method with an A40% threshold most closely determined the tumor volume, with a median difference of +0.19 (IQR, -0.71 to +2.01) and a median relative difference of +7.6%. The paired-sample Wilcoxon test showed no significant difference in PET-derived tumor volume and TV-Histo using A40%, A50%, SUV40%, and SUV50% threshold segmentation algorithms ( P > 0.05). For both threshold-based segmentation methods, use of higher thresholds (e.g., SUV60% or SUV70% and A50%-A70%) resulted in underestimation of tumor volumes, and use of lower thresholds (e.g., SUV30% or SUV40% and A30%) resulted in overestimation of tumor volumes relative to TV-Histo and TPR. Manual segmentation overestimated the tumor volume, with a median difference of +2.49 (IQR, 0.42-4.11) and a median relative difference of +130%. Conclusion: Segmentation of intraprostatic tumor volume and TPR with an adaptive segmentation approach most closely approximates TV-Histo. This information might be used to guide the primary treatment of men with clinically localized, high-risk prostate cancer., (© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)

The discovery and clinical development of radiolabeled small-molecule ligands targeting prostate-specific membrane antigen (PSMA) has had a profound influence on the field of nuclear medicine. Such agents have been successfully deployed for both imaging and therapeutic applications. In particular, PSMA radioligand therapy (PRLT) has been shown to be a life-prolonging therapy for men with metastatic, castration-resistant prostate cancer and has also brought nuclear medicine physicians and nuclear radiologists into the forefront of direct patient care. In this review, we will discuss the clinical study data regarding the efficacy and toxicities related to PRLT, outline the key personnel that any center offering PRLT should have, offer salient clinical examples, and provide an overview of future directions for PRLT. As PRLT continues to evolve as a treatment modality, it is paramount that nuclear medicine physicians and nuclear radiologists understand the clinical context, management implications, and practical aspects so as to best deliver high-value care to patients., (Copyright © 2023 Elsevier Inc. All rights reserved.)

[ 18 F]DCFPyL is increasingly used for prostate-specific membrane antigen (PSMA) mediated imaging of men with biochemically recurrent prostate cancer (BRPCa). In this meta-analysis, which is updated with the addition of multiple new studies, including the definitive phase III CONDOR trial, we discuss the detection efficiency of [ 18 F]DCFPyL in BRPCa patients. PubMed was searched on 29 September 2022. Studies evaluating the diagnostic performance of [ 18 F]DCFPyL among patients with BRPCa were included. The overall pooled detection rate with a 95% confidence interval (95% CI) was calculated among all included studies and stratified among patients with PSA ≥ 2 vs. <2 ng/mL and with PSA ≥ 0.5 vs. <0.5 ng/mL. The association of detection efficiency with pooled PSA doubling time from two studies was calculated. Seventeen manuscripts, including 2252 patients, met the inclusion criteria and were used for data extraction. A previous meta-analysis reported that the pooled detection rate was 0.81 (95% CI: 0.77-0.85), while our study showed a pooled overall detection rate of 0.73 (95% CI: 0.66-0.79). An increased proportion of positive scans were found in patients with PSA ≥ 2 vs. <2 ng/mL and PSA ≥ 0.5 vs. <0.5 ng/mL. No significant difference was found in detection efficiency between those with PSA doubling time ≥ 12 vs. <12 months. Detection efficiency is statistically related to serum PSA levels but not to PSA doubling time based on available data. The detection efficiency of [ 18 F]DCFPyL in men with BRPCa has trended down since a previous meta-analysis, which may reflect increasingly stringent inclusion criteria for studies over time.

Clinical trials of combined IDO/PD1 blockade in metastatic melanoma (MM) failed to show additional clinical benefit compared to PD1-alone inhibition. We reasoned that a tryptophan-metabolizing pathway other than the kynurenine one is essential. We immunohistochemically stained tissues along the nevus-to-MM progression pathway for tryptophan-metabolizing enzymes (TMEs; TPH1, TPH2, TDO2, IDO1) and the tryptophan transporter, LAT1. We assessed tryptophan and glucose metabolism by performing baseline C11-labeled α-methyl tryptophan (C11-AMT) and fluorodeoxyglucose (FDG) PET imaging of tumor lesions in a prospective clinical trial of pembrolizumab in MM (clinicaltrials.gov, NCT03089606). We found higher protein expression of all TMEs and LAT1 in melanoma cells than tumor-infiltrating lymphocytes (TILs) within MM tumors ( n  = 68). Melanoma cell-specific TPH1 and LAT1 expressions were significantly anti-correlated with TIL presence in MM. High melanoma cell-specific LAT1 and low IDO1 expression were associated with worse overall survival (OS) in MM. Exploratory optimal cutpoint survival analysis of pretreatment 'high' vs. 'low' C11-AMT SUV max of the hottest tumor lesion per patient revealed that the 'low' C11-AMT SUV max was associated with longer progression-free survival in our clinical trial ( n  = 26). We saw no such trends with pretreatment FDG PET SUV max . Treatment of melanoma cell lines with telotristat, a TPH1 inhibitor, increased IDO expression and kynurenine production in addition to suppression of serotonin production. High melanoma tryptophan metabolism is a poor predictor of pembrolizumab response and an adverse prognostic factor. Serotoninergic but not kynurenine pathway activation may be significant. Melanoma cells outcompete adjacent TILs, eventually depriving the latter of an essential amino acid., Competing Interests: Funding for the LCCC1531 trial was provided by Merck & Co., Inc., (© 2023 The Author(s). Published with license by Taylor & Francis Group, LLC.)

Introduction: Peer learning and near-peer teaching have been described in many specialties, less so in Radiology. We present near-peer teaching whereby residents present a series of didactic sessions at the course outset in the form of "symposia" and perform a scholarly activity in the form of teaching. We aim to demonstrate how near-peer teaching in symposia front-loaded within an introductory radiology course can improve medical student satisfaction., Method: A total of 169 students were enrolled over a period of 3 years, 55 before (2017-2018) and 114 (2018-2020) after the introduction of the symposium. Anonymous course evaluations were collected from all students. In addition, 240 fourth-year medical students who also attended symposium lectures received satisfaction surveys in 2019 and 2020., Results: All (169/169, 100%) students taking the course evaluated it. Overall evaluation scores rose from 8.3/10 to 9.0/10 post-symposia. Among student satisfaction surveys, 89/240 (37%) specifically commented on symposia; 91% (80/89) of those found symposia very or extremely informative. 29/71 (41%) of all residents were able to participate in the symposia, 20/29 in multiple years throughout residency, allowing them to fulfill the Accreditation Council for Graduate Medical Education interpersonal and communication skills core competencies and meet scholarly activity requirements., Conclusion: Near-peer teaching in the form of resident-taught interactive didactics grouped in symposia can have a positive outcome on medical student satisfaction., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

Introduction: Currently, there is a lack of consensus on the fixed dosage of RAI to be administered for this purpose between the main guideline frameworks set forth by the American Thyroid Association (ATA), Society of Nuclear Medicine and Molecular Imaging (SNMMI), European Association of Nuclear Medicine (EANM) and the European Thyroid Association (ETA). In this retrospective study, we will investigate the effectiveness of using a standard dose of 15 mCi ±10% of RAI in the treatment of Graves'., Methods: A retrospective chart review was conducted for the period between 1 May 2014 and 2 September 2020, to identify patients diagnosed with hyperthyroidism due to Graves' disease. The patients were grouped based on outcome and assessed for the efficacy of the dosage of 15 mCi ±10% of RAI in a successful treatment., Results: Sixty-seven patients were identified that met the inclusion criteria between 1 May 2014 and 2 September 2020. Of the 67 RAI ablations; 60 patients became hypothyroid [60/67, (89.55%)], 2 euthyroid [2/67, (2.99%)] and 5 remained hyperthyroid [5/67, (7.46%)]., Conclusions: For the treatment of Graves' disease, the use of a standard low dose of 15 mCi ±10% has a high success rate without additional measurements or calculations beyond a standard planar image and 24-h uptake %. The adoption of a standard low dose of 15 mCi of I-131 across institutional guidelines would streamline dosage questions and eliminate the need to determine the weight of the thyroid for calculations in all RAI treatments for hyperthyroidism caused by Graves' disease., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

While the presence of incidental breast and lung masses on cardiac scans is well known, renal masses are often incidentally discovered as well on cardiac examinations, some of which are malignant. We searched the electronic medical record system over the past 18 years, since the system was installed, for patients with a cardiac rubidium-82 ( 82 Rb) rubidium PET/CT or technetium-99m ( 99m Tc) sestamibi SPECT/CT performed within 1 year of a renal-protocol CT or MR. Each PET/CT or SPECT/CT was examined for presence of a renal lesion on the attenuation-correction CT images. We found 43 SPECT/CT and 18 PET/CT studies which fit the desired criteria. Of these, 7 SPECT/CT studies and 2 PET/CT studies demonstrated the renal mass on at least one of the two sets of CT images (rest or stress); if not visible, most commonly the tumor was either out of the field of view or had already been removed. Of these, 6 SPECT/CT and 2 PET/CT studies demonstrated a malignancy. Cardiac SPECT/CT and PET/CT images demonstrate incidental renal masses with a non-negligible frequency, and CT images should be carefully examined., Competing Interests: None., (AJNMMI Copyright © 2022.)

Objective: The aim of this study was to determine whether quantitative methods could aid in the evaluation of post-treatment head and neck scans, particularly taking human papillomavirus status into account., Methods: Clinical readings of positron emission tomography/computed tomography scans as well as standardized uptake value (SUV)max (and other metrics) of nodes visible on PET conducted on a total of 172 patients with head and neck squamous cell cancer were examined. Locoregional recurrence at 2 years was assessed. In total 88 of these patients had close enough follow-up to determine whether individual nodes were positive or negative, and 233 nodes on these patients were compared to surgical pathology notes or follow-up (if no path was available)., Results: General negative predictive value (NPV) of complete response was 93% and an equivocal response was 89%; focusing on nodal recurrence, NPV was found to be 97% and positive predictive value (PPV) 46% if equivocal reads were treated as negative and NPV 98% and PPV 16% if equivocal reads were treated as positive. Using SUVmax of the hottest node with a cutoff of 3.4 gave NPV 97% and PPV 26%; a direct re-read (using 2 observers) gave NPV 98% and PPV 32% if equivocal reads were treated as negative, and NPV 99% and PPV 18% if equivocal reads were treated as positive. Using other first-order radiomics data such as SD and skewness did not improve this., Conclusions: Quantitative data such as SUVmax does not show additional value over qualitative evaluation of response to chemoradiation in head and neck tumors., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

We present a case of abnormal findings on a Tc99m-Sestamibi parathyroid scan, post COVID-19 vaccination. The patient is a 48-year-old female presenting for evaluation of hyperparathyroidism who received the mRNA-1273 Moderna (ModernaTX, Inc.) vaccine seven days prior to the scan. The patient is right hand dominant and reported no traumatic events, inflammation, infection, or extraneous use of the left arm. The patient did report "soreness" of the extremity starting approximately 24 hours post injection which continued to the time of the study., Competing Interests: None., (AJNMMI Copyright © 2022.)

Background  Chest tumors are often found incidentally on cardiac scans; we aimed to describe the findings of rubidium (Rb) in incidentally discovered extracardiac tumors. Materials and Methods  We reviewed a database of cardiac Rb scans performed over a period of 11 years and identified those with a previously unsuspected malignancy seen on the plane of section. We then measured maximum standard uptake value for each of the tumors, as well as background lung, liver, mediastinum, and body wall. In cases where fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) was available, we compared Rb results with FDG PET/CT. Results  We identified 63 patients meeting criteria including full visualization of a tumor of at least 1.0 cm with no prior treatment. Of these patients, 17 had breast, 36 had lung, and 10 had miscellaneous other tumors. We selected patients with either breast or lung tumors for further analysis. Overall uptake was relatively stable between rest and stress but lower than FDG PET/CT; it was generally low and similar to blood pool. There was a small but statistically significant correlation between estrogen receptor positivity and Rb uptake in breast tumors. There was a stable pattern of uptake in background tissues, with liver being greater than mediastinal blood pool, which in turn was more avid than lung, which was more avid than subcutaneous body wall tissues. Lung showed a noticeable tendency toward increased uptake in dependent regions, likely reflecting low-level atelectasis. Conclusion  Uptake was stable between rest and stress but low relative to FDG PET/CT; some correlations with receptors suggest it may be useful in molecular imaging., Competing Interests: Conflict of Interest None declared., (World Association of Radiopharmaceutical and Molecular Therapy (WARMTH). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

This article will familiarize neuroradiologists with the pathophysiology, clinical findings, and standard MR imaging and PET imaging features of multiple forms of dementia as well as new emerging techniques. Cases were compiled from multiple institutions with the goal of improved diagnostic accuracy and improved patient care as well as information about biomarkers on the horizon. Dementia topics addressed include the following: Alzheimer disease, frontotemporal dementia, cerebral amyloid angiopathy, Lewy body dementia, Parkinson disease and Parkinson disease variants, amyotrophic lateral sclerosis, multisystem atrophy, Huntington disease vascular dementia, and Creutzfeldt-Jakob disease., (© 2021 by American Journal of Neuroradiology.)

Breast imaging, with its unique patient-facing, multimodality, and multidisciplinary workflow, offers opportunities to engage medical students enrolled in a general radiology rotation and to highlight the role of the radiologist in patient care. At a time when breast radiologists face unprecedented challenges in delivering safe and efficient imaging services, however, accommodating larger numbers of medical students can overwhelm reading rooms, dilute meaningful learning experiences for the student, and place further demands on faculty. In order to meet the students' and clinician educators' needs, Neher's one-minute preceptor teaching strategy is used to create a high-yield learning environment in a short amount of time. In this model, the breast radiologist weaves together multiple impactful and varied learning experiences in only 8 to 12 total hours of structured student exposure during the 160-hour general radiology course. We describe our adaptation of this technique and the positive impact that a short breast imaging component had on our general radiology medical student rotation. This standardized curriculum is easily adaptable to a variety of learning styles. It contributes to medical students' understanding of the various facets of radiology through direct participation and exceeds education goals set forth by the Alliance of Medical Student Educators in Radiology. Students' evaluations of the general radiology rotation demonstrated a sharp uptick in the year following the adoption of the technique, and students' rotation final examination mean scores on the breast questions were higher for students who participated at least eight hours on service in the breast radiology clinic., (© Society of Breast Imaging 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: We aimed to determine at what size melanoma metastases become detectable by PET/CT., Methods: We reviewed a total of 293 whole-body PET/CT studies performed on 212 patients for staging of melanoma where there was an MRI within a month of the PET/CT. MR and PET/CT were reviewed independently by separate readers., Results: PET/CT revealed an overall incidental true-positive rate of 1% on a per-patient basis, consistent with other studies, with 'hot' lesions (more avid than brain parenchyma) visible at smaller sizes than 'cold' lesions., Conclusions: PET/CT can detect metastatic melanoma lesions over about 2 cm in size, with hot lesions generally visible at smaller sizes.

Background: Millennial digital learners value meaningful work, immediate feedback, collaborative communication and technology implementation. A student-produced digital imaging teaching case file-centric flipped curriculum offers these benefits. Our questions included: (i) is a cloud-based website platform supporting the online publication of student-selected and student-submitted teaching cases feasible; and (ii) what were the impressions of students of this educational intervention?, Methods: An open-source medical student-centric radiology website was created with limited-access cloud upload capability, with site analytics continuously recorded. Medical students submitted de-identified radiology cases on a topic of their choosing, for peer review and publication. By making the host site publicly accessible, we empowered students to list their publication(s) on resumes. Following six blocks of the 2018/19 academic year after implementation, an electronic survey was sent to the eligible medical student cohort who had were enrolled in a radiology elective in order to assess the effectiveness of the intervention (n = 107)., Results: The survey response rate was 52% (n = 56), of which 98% participated (n = 55) and 75% completed a teaching file (n = 42). The students assessed their ability to systematically review imaging, communicate pertinent clinical information, appropriately order imaging, correctly use the ACR Appropriateness Criteria ® , consider procedure costs, consider procedure risks, consider procedure benefits, evaluate effectiveness and identify who to direct questions to regarding correct study. Students reported answers on a seven-point Likert scale. Data scores ranged from 5.28 (agree) to 6.71 (strongly agree) across all categories., Conclusions: Our successful student-developed teaching file takes advantage of digital radiology and the educational tools favoured by millennials. This activity meets core competencies in self-directed and lifelong learning., (© 2019 John Wiley & Sons Ltd and The Association for the Study of Medical Education.)

There are a wide variety of diseases that affect the thyroid gland ranging from hyperplastic to neoplastic, autoimmune, or inflammatory. They can present with functional abnormality or a palpable structural change. Imaging has a key role in diagnosing and characterizing the thyroid finding for management. Imaging is also essential in the management of thyroid cancer. 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 include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment., (Copyright © 2019 American College of Radiology. Published by Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to analyze the uptake of rubidium in malignant tumors., Participants and Methods: Sixteen malignant lesions were included. Two radiologists compared each lesion to four references (subcutaneous fat, lung, mediastinal blood pool, and liver) at rest and stress and scored as 1-4. Maximum standardized uptake value (SUV) in each lesion and four references, as well as ratios of lesion SUV to SUV of each of the references, were calculated at rest and stress. We assessed an agreement for scores of reader 1 versus reader 2 (inter-reader) at rest and stress, scores at rest versus stress (intrapatient) for reader 1 and reader 2, and lesion SUV and respective ratios at rest and stress using paired t-test and Bland-Altman analyses., Results: Fifteen (94%) out of 16 lesions had a score of 3 or 4 at rest or stress or both by at least one reviewer. We did not find evidence of inter-reader bias at rest or stress or intrapatient (rest vs. stress) bias for either reader. SUV ranged from 1.0 to 8.1 at rest and from 0.7 to 6.7 at stress. There was an excellent agreement between ratios of lesion SUV to lung SUV at rest versus stress. On the extreme, there was a poor agreement between ratios of lesion SUV to liver SUV at rest versus stress. Otherwise, the agreement was good for the majority of the results, and moderate for a few others., Conclusion: Malignant tumors can be readily depicted and quantified on rubidium PET/CT. Further research is needed.

As F-fluciclovine (FACBC) becomes more popular, new incidental findings are discovered. We present here a case of a 71-year-old man with prostate cancer in whom an FACBC PET/CT showed uptake in the superior sagittal sinus, which was found to be simply due to a dilated superior sagittal sinus on subsequent MRI. Accumulation in the superior sagittal sinus is a variant that interpreters of FACBC PET/CT should be aware of.

This retrospective analysis identifies predictors of survival in a cohort of patients with meta-iodobenzylguanidine (MIBG)-positive stage IV pulmonary and gastroenteropancreatic neuroendocrine tumor (P/GEP-NET) treated with 131 I-MIBG therapy, to inform treatment selection and posttreatment monitoring. Methods: Survival, symptoms, imaging, and biochemical response were extracted via chart review from 211 P/GEP-NET patients treated with 131 I-MIBG between 1991 and 2014. For patients with CT follow-up ( n = 125), imaging response was assessed by RECIST 1.1 if images were available ( n = 76) or by chart review of the radiology report if images could not be reviewed ( n = 49). Kaplan-Meier analysis and Cox multivariate regression estimated survival and progression-free survival benefits predicted by initial imaging, biochemical response, and symptomatic response. Results: All patients had stage IV disease at the time of treatment. Median survival was 29 mo from the time of treatment. Symptomatic response was seen in 71% of patients, with the median duration of symptomatic relief being 12 mo. Symptomatic response at the first follow-up predicted a survival benefit of 30 mo ( P < 0.001). Biochemical response at the first clinical follow-up was seen in 34% of patients, with stability of laboratory values in 48%; response/stability versus progression extended survival by 40 mo ( P < 0.03). Imaging response (20% of patients) or stability (60%) at the initial 3-mo follow-up imaging extended survival by 32 mo ( P < 0.001). Additionally, multiple 131 I-MIBG treatments were associated with 24 mo of additional survival ( P < 0.05). Conclusion: Therapeutic 131 I-MIBG for metastatic P/GEP-NETs appears to be an effective means of symptom palliation. Imaging, biochemical, and symptomatic follow-up help prognosticate expected survival after 131 I-MIBG therapy. Multiple rounds of 131 I-MIBG are associated with prolonged survival., (© 2018 by the Society of Nuclear Medicine and Molecular Imaging.)

With the spread of positron emission tomography/magnetic resonance (PET/MR), the question of comparability of studies becomes important. We aim to determine whether PET/MR and PET/computed tomography (PET/CT) are comparable for the case of cervical cancer. Fifteen cervical cancer patients identified by either a radiation oncologist or an oncologic surgeon had both PET/MR and PET/CT performed for initial staging within 3 weeks. We then compared the results both quantitatively (measuring standardized uptake values [SUVs] on visible lesions) as well as qualitatively (having radiologists and nuclear medicine physicians interprets the results). While interpretations between PET/MR and PET/CT varied in many cases, SUVs of primary lesions were similar to within 25% in all but one case, and correlation coefficient was 0.92. Maximum SUV ranged between 4.9 and 25.2 for PET-MR and between 5.8 and 30.4 for PET-CT for primary tumors and between 1.5 and 18.8 for PET-MR and between 1.8 and 20.8 for PET-CT for nodes. However, clinical reads often varied significantly between PET/MR and PET/CT. This suggests that SUV is similar on PET/MR and PET/CT although the differing anatomic modalities available for correlation may make the difference in terms of qualitative interpretation., Competing Interests: There are no conflicts of interest.

Purpose: Epilepsy surgery is the most successful method of treating medically unresponsive epilepsy, but carries a risk of morbidity. PET/MR is an emerging technique that increases detection of focal lesions whose resection may result in symptom remission., Methods: Retrospective review of 74 focal epilepsy patients over a period of 3 years who had a PET/MR was performed following IRB permission and informed consent. 27 patients underwent surgery or RNS (responsive neurostimulator) placement., Results: Hybrid PET-MR identified new anatomic or functional lesions in 10 patients not identified with standalone 3 T MR. Of the 27 patients who underwent focal surgery (19) or RNS placement (8), 24 showed improvement (Engel's I-III), 2 did not (Engel's IV), and one had an RNS explanted due to infection. MR and PET were read by 2 separate neuroradiologists and nuclear medicine physicians, respectively. Modalities were evaluated in terms of ability to detect the correct lobe and side for a focal lesion whose resection improved symptoms. Prior standalone MR exhibited 71-77% sensitivity and 0% specificity (as there were only 2 nonresponders), MR associated with PET/MR had 68-71% sensitivity and 0-50% specificity (depending on whether a lesion was seen on one of the nonresponders), and PET had 68-71% sensitivity and 25-33% specificity. Using either PET or MR to identify a focal lesion, PET/MR had sensitivity of 78-82% and specificity 0-50%., Conclusions: PET-MR provides additional sensitivity when used as two combined modalities for detecting possible epileptic foci., (Copyright © 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

We aimed to determine the sensitivity and specificity of fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) for the spread of disease to inguinal lymph nodes in vulvar cancer. A retrospective review of vulvar cancer patients who underwent both inguinal nodal sampling and dissection as well as FDG PET-CT was performed, with 21 patients meeting criteria. The sensitivity and specificity of the FDG PET-CT imaging was performed using a combination of maximum standardized uptake value (SUV max ), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Using an SUV max cutoff of 4.5 or of two times the average liver uptake, we had a 100% sensitivity and 89% specificity for positive inguinal nodes. MTV and TLG did not add to sensitivity or specificity. We conclude that FDG PET-CT has good sensitivity for inguinal nodal spread in vulvar cancer, and either a quantitative or semiquantitative approach is effective., Competing Interests: There are no conflicts of interest.

Objectives: This study sought to evaluate the incremental value of quantifying the extent and severity of myocardial perfusion and 18 F-labeled fluorodeoxyglucose (FDG) abnormalities in predicting adverse outcomes among patients with suspicion for cardiac sarcoidosis (CS)., Background: Positron emission tomography (PET) with FDG is a key component of the noninvasive assessment of patients with suspected CS. However, the optimal method for image interpretation has not been defined., Methods: A retrospective analysis was performed of 203 patients who underwent perfusion and FDG-PET imaging to evaluate for CS. Imaging findings were scored by conventional 3-category methods (normal perfusion and metabolism, abnormal perfusion or metabolism, abnormal perfusion and metabolism) and by summed scores using the 17-segment model to represent extent and severity of disease. Heterogeneity of metabolism was quantified using the coefficient of variation (SD divided by the mean) of FDG uptake. Multivariable Cox models were developed to assess associations between imaging findings and adverse events (death, heart transplant, or ventricular arrhythmia requiring defibrillation)., Results: The indication for FDG-PET was ventricular arrhythmia in 69 (34%), heart block in 16 (8%), cardiomyopathy in 54 (27%), and other indications in 64 (32%). There were 63 patients who developed adverse events over a mean follow-up of 1.8 years. After robust adjustment, only the summed score in segments with a perfusion-metabolism mismatch and the coefficient of variation were important prognostically (p = 0.029 and p = 0.041, respectively)., Conclusions: Quantitative measures of extent and severity of perfusion-metabolism mismatch and coefficient of variation of FDG uptake provide an incremental prognostic advantage in patients undergoing FDG-PET for CS. These results support the use of a more detailed analysis of imaging findings, as is conventional in coronary artery disease., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: Cardiac single-photon emission computed tomography (SPECT) is often used to identify defects in myocardial perfusion due to atherosclerotic coronary artery disease. It was also used in studies to evaluate radiation therapy (RT)-associated cardiac abnormalities. In the current review, we aim to evaluate the rates of post-RT cardiac SPECT early perfusion abnormalities and relate this to the irradiated left ventricular volume., Methods: The studies cited in this systematic review were identified using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines., Results: Six studies between 1996 and 2016 fulfilled the inclusion criteria. The reported perfusion defects in these studies were seen in the apical and anterolateral aspects of the left ventricle. Three studies show correlation between the percent of the left ventricle within the RT-field and percent of patients with early perfusion defects on cardiac SPECT. In two studies that used cardiac sparing techniques (such as deep inspiration), that resulted in a low mean heart dose, no perfusion defects were noted., Conclusions: Data suggest that incidental irradiation of the heart in cases of left breast/chest wall RT can result in early post-RT perfusion defects on cardiac SPECT. There appears to be strong dose/volume dependence to the risk, and hence techniques to reduce cardiac exposure are recommended.

PET-magnetic resonance (MR) is a hybrid imaging modality that combines PET and MR. Evidence for this new modality is in the process of being developed, but both component modalities are well tested in the diagnosis and management of multiple myeloma. It allows advanced bimodality imaging of the whole body with an adaptable field of view and it can be used for monitoring plasma cell dyscrasias for progression to multiple myeloma, for assessing disease burden in patients with known multiple myeloma, for assessing response to therapy and relapse after remission, and for radiation therapy treatment planning., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Positron emission tomograph (PET)-magnetic resonance (MR) is a new modality combining PET and MR. In gynecologic cancers it can be used for staging of cervical and endometrial cancer, planning of radiation therapy in cervical cancer, assessing response to chemotherapy in ovarian cancer, and detection of recurrence in most gynecologic cancers. It is being explored for prostate cancer and other genitourinary cancers, but is still in experimental stages., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Hybrid PET/MR imaging systems have recently become available for clinical practice. The simultaneous physiologic and anatomic imaging offers the potential to reduce radiation dose and other advantages for pediatric patients. Issues more unique to pediatric imaging, however, must also be addressed, including imaging time and disease sensitivity. Combined with newer tracers and a concerted multidisciplinary effort, the approach has the potential to substantially improve the imaging of a variety of pediatric diseases., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Purpose: To evaluate early cardiac single photon computed tomography (SPECT) findings after left breast/chest wall postoperative radiation therapy (RT) in the setting of deep inspiration breath hold (DIBH)., Methods and Materials: We performed a prospective single-institution single-arm study of patients who were planned for tangential RT with DIBH to the left breast/chest wall (± internal mammary nodes). The DIBH was done by use of a controlled surface monitoring technique (AlignRT, Vision RT Ltd, London, UK). The RT was given with tangential fields and a heart block. Radiation-induced cardiac perfusion and wall motion changes were assessed by pre-RT and 6-month post-RT SPECT scans. A cumulative SPECT summed-rest score was used to quantify perfusion in predefined left ventricle segments. The incidence of wall motion abnormalities was assessed in each of these same segments., Results: A total of 20 patients with normal pre-RT scans were studied; their median age was 56 years (range, 39-72 years). Seven (35%) patients also received irradiation to the left internal mammary chain, and 5 (25%) received an additional RT field to supraclavicular nodes. The median heart dose was 94 cGy (range, 56-200 cGy), and the median V25 Gy was zero (range, 0-0.1). None of the patients had post-RT perfusion or wall motion abnormalities., Conclusions: Our results suggest that DIBH and conformal cardiac blocking for patients receiving tangential RT for left-sided breast cancer is an effective means to avoid early RT-associated cardiac perfusion defects., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: New multipinhole cadmium-zinc-telluride (CZT) cameras allow for faster imaging and lower radiation doses for single photon emission computed tomography (SPECT) studies, but assessment of prognostic ability is necessary., Methods and Results: We collected data from all myocardial SPECT perfusion studies performed over 15 months at our institution, using either a CZT or conventional Anger camera. A Cox proportional hazards model was used to assess the relationship between camera type, imaging results, and either death or myocardial infarction (MI). Clinical variables including age, sex, body mass index (BMI), and historical risk factors were used for population description and model adjustments. We had 2,088 patients with a total of 69 deaths and 65 MIs (122 events altogether). A 3% increase in DDB (difference defect burden) represented a 12% increase in the risk of death or MI, whereas a 3% increase in rest defect burden or stress defect burden represented an 8% increase; these risks were the same for both cameras (P > .24, interaction tests)., Conclusions: The CZT camera has similar prognostic values for death and MI to conventional Anger cameras. This suggests that it may successfully be used to decrease patient dose.

Introduction: Although positron emission tomography PET-MR imaging is emerging into clinical practice, many aspects of this imaging technique such as attenuation correction have yet to be validated for myocardial imaging. Thus, it is uncertain whether PET-MR FDG images provide clinical information which is comparable to PET-CT FDG images. The study goal was to systematically compare relative myocardial FDG concentrations obtained from cardiac PET-MR images to those derived from same day PET-CT images., Methods: Myocardial FDG images of 27 patients undergoing PET-CT imaging, followed by PET-MR imaging 42 ± 13 minutes later as part of a prospective oncology study were analyzed. Mean segmental standardized uptake measurements (SUVmean) were obtained in each of the 17 standard myocardial segments and normalized to the brightest segment., Results: Normalized segmental SUVmean values did not differ significantly between the PET-MR and PET-CT images (mean difference 0.002, P = .826). The specific segment was a marginally significant predictor of the differences (P = .057), with the largest difference in the anteroseptal basal segment., Conclusions: PET-MR, vis-à-vis PET-CT, does not significantly raise segmental uptake relative to the brightest segment, suggesting that PET-MR can be used similarly to PET-CT for applications where relative uptake is important.

Importance: Positron emission tomography/Computed tomography(PET/CT) is widely used for gynecologic cancers., Objective: To determine when PET/CT should be used for gynecologic cancers., Evidence Acquisition: PubMed was reviewed for articles on PET/CT of all gynecologic cancers. National Comprehensive Cancer Network, Society of Gynecologic Oncology, and American College of Radiology guidelines were reviewed., Results: Whole-body PET/CT is useful for (1) initial staging of cervical and endometrial cancer, posttherapy assessment, radiation therapy planning, and posttreatment surveillance of cervical cancer, and (2) assessment of recurrence of cervical, endometrial, or ovarian cancer in the presence of symptoms. It is also useful for staging and recurrence of uterine sarcomas, and for staging of vulvar and vaginal cancer., Conclusions: Positron emission tomography/Computed tomography is clinically valuable for a variety of gynecologic cancers., Relevance: PET/CT plays an important role in detection of initial disease and recurrence of gynecologic malignancies.

We present a case of carcinosarcoma of the prostate. Workup of urinary retention after a previously treated squamous cell carcinoma of the prostate led to a transurethral prostate resection revealing carcinosarcoma of the prostate, which on F-FDG PET/CT demonstrated moderate to high avidity of this atypical prostate cancer, with partial obstruction of the urinary system and lung metastases. While FDG PET is not avid for typical prostatic adenocarcinomas, it should be considered for evaluation of atypical prostate cancers.

Objective: The recent introduction of high-efficiency solid-state gamma cameras for myocardial perfusion single photon emission computed tomography has enabled lower patient radiation dose, faster imaging, and improved image quality. However, artifacts still complicate interpretation. Prone imaging is a common maneuver to reduce artifacts and increase accuracy for detection of coronary artery disease, but its effect on imaging relative to supine imaging has not been fully characterized in these new systems., Methods: In this IRB-approved, HIPAA-compliant retrospective study, 30 patients were reviewed, who underwent prone and supine imaging on the GE 530c multipinhole cadmium zinc telluride camera under both rest and stress conditions. Informed consent was waived. Perfusion was scored visually by two readers on a five-point scale according to the 17-segment model. Differences were assessed for significance using a multivariate linear effects model and restricted maximum likelihood method., Results: Prone positioning resulted in increased activity in the basal inferior (P<0.001), basal inferolateral (P=0.009), basal inferoseptal (P<0.001), and mid-inferior (P<0.001) segments when taking into account factors such as stress versus rest, perfusion scores of other segments, and reader., Conclusion: Prone imaging on the GE 530c camera increases measured tracer activity in the basal inferior, basal inferolateral, basal inferoseptal, and mid-inferior segments. Caution is advised when diagnosing myocardial ischemia in these territories, particularly if clinical data are unavailable.

Objective: To determine the prevalence of missed lesions for parathyroid 4-dimensional computed tomography (4D CT) and scintigraphy and to describe the factors leading to missed lesions for both modalities., Study Design: Case series with chart review., Setting: Single center, hospital based., Subjects and Methods: Forty patients undergoing 4D CT and scintigraphy before parathyroidectomy between July 2009 and October 2013 were included. Radiology reports and imaging were reviewed and correlated with operative notes to identify cases with missed lesions and the reasons for those misses. All lesions were then classified according to the following factors: multigland disease, lesion size, patient body weight, and multinodular goiter., Results: Of the 40 patients, 6 had multigland disease, resulting in 51 lesions; 12 and 29 lesions were missed on 4D CT and scintigraphy, respectively. The sensitivity for detection of all lesions was 76% for 4D CT and 43% for scintigraphy. Sensitivities for single-gland disease were 88% for 4D CT and 50% for scintigraphy. Sensitivities for multigland disease were 53% for 4D CT and 24% for scintigraphy. Rates of multigland disease in patients with missed lesions were 75% on 4D CT and 48% on scintigraphy, as compared with patients with detected lesions, 23% and 18%, respectively (P ≤ .04). Mean weight of lesions missed on 4D CT was 0.3 and 0.6 g in detected lesions (P = .15). Mean weight of lesions missed on scintigraphy was 0.4 and 0.8 g in detected lesions (P = .03)., Conclusion: 4D CT has higher sensitivity than scintigraphy. Missed lesions are more likely to occur with multigland disease for both modalities and in smaller lesions for scintigraphy., (© American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.)

Understanding the range and variability of normal, benign degenerative, and malignant (18)F sodium fluoride ((18)F NaF) positron emission tomography/computed tomography (PET/CT) uptake is important in influencing clinical interpretation. Further, it is essential for the development of realistic semiautomated quantification techniques and simulation models. The purpose of this study is to determine the range of these values in a clinically relevant patient population with prostate cancer. (18)F NaF PET/CT scans were analyzed in patients with prostate cancer (n = 47) referred for evaluation of bone metastases. Mean and maximum standardized uptake values [SUVs (SUVmean and SUVmax)] were made in normal background regions (n = 470) including soft tissues (liver, aorta, bladder, adipose, brain, and paraspinal muscle) and osseous structures (T12 vertebral body, femoral diaphyseal cortex, femoral head medullary space, and ribs). Degenerative joint disease (DJD; n = 281) and bone metastases (n = 159) were identified and quantified by an experienced reader using all scan information including coregistered CT. For normal bone regions, the highest (18)F NaF PET SUVmean occurred in T12 (6.8 ± 1.4) and it also showed the lowest coefficient of variation (cv = 21%). For normal soft tissues, paraspinal muscles showed very low SUVmean (0.70 ± 0.11) and also showed the lowest variability (cv = 16%). Average SUVmean in metastatic lesions is higher than uptake in benign degenerative lesions but values showed a wide variance and overlapping values (16.3 ± 13 vs 11.1 ± 3.8; P < 0.00001). The normal (18)F NaF PET uptake values for prostate cancer patients in normal background, benign degenerative disease, and osseous metastases are comparable to those reported for a general population with a wide variety of diagnoses. These normal ranges, specifically for prostate cancer patients, will aid in clinical interpretation and also help to establish the basis of normal limits in a semiautomated data analysis algorithm.

[(18)F] sodium fluoride (NaF) PET/CT is a current, clinically relevant method to assess bone metastases. Time-of-flight (TOF) PET provides better statistical data quality, which can improve either lower image noise or improve resolution, or both, depending on the image reconstruction. Improved resolution can improve quantitative measurements of standardized uptake value (SUV) in small structures. These quantitative differences may be important in both clinical interpretation and multicenter clinical trials where quantification is integral to assessing response to therapy. The purpose of this study is to determine if and by how much SUV quantitatively differs between TOF and conventional non-TOF reconstructions in [(18)F] NaF PET/CT. SUV measurements (mean and maximum) were compared in TOF and non-TOF [(18)F] NaF PET-CT reconstructions for 47 prostate cancer patients in normal regions including: soft tissue (n=282 total regions; liver, aorta, posterior abdominal fat, bladder, brain, and paraspinal muscles), and osseous structures (n=188; T12 vertebral body, femoral diaphyseal cortex, femoral head, and lateral rib). Comparisons were also made for benign degenerative changes (n=281) and metastases (n=159). TOF and non-TOF SUVs were assessed with paired t-test and linear correlations. Normal soft tissue showed lower SUVmean for TOF compared to non-TOF in liver, brain, and adipose. All osseous structures showed higher SUVmean for TOF compared to non-TOF including normal regions, degenerative joint disease, and metastases. For all metastatic lesions, the average SUVmean increased by 2.5%, and in degenerative joint disease it increased by 3.5% on TOF reconstructions. Smaller lesion size was a significant factor influencing this increase in SUVmean. TOF SUVmean values are higher in osseous structures and lower in background soft tissue structures. While these differences are statistically significant, the magnitudes of these changes are relatively modest. Smaller osseous lesions may have higher contrast and higher SUVmean values with TOF reconstruction compared to non-TOF reconstructions. The differences in TOF vs. non-TOF images should be considered when evaluating response to therapy and in the design of multi-center clinical trials.

Background: Regadenoson is now widely used in single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). However, the prognostic value of abnormal stress perfusion findings with regadenoson vs adenosine are unclear. The aim of this study was to evaluate the prognostic value of regadenoson SPECT and to compare it to that of adenosine SPECT., Methods and Results: 3698 consecutive patients undergoing either adenosine or regadenoson SPECT were assessed at 1 year for the endpoints of cardiovascular death and a composite endpoint of cardiovascular death or MI. Weighted Cox proportional hazards regression modeling with the inverse probability weighted (IPW) estimators method adjusting to propensity for agent was used to account for differences in baseline characteristics. Patients undergoing adenosine SPECT MPI had a significantly higher prevalence of smoking history, diabetes, hypertension, and prior myocardial infarction (P < .05, all). At 1 year of follow-up, there were 154 cardiovascular deaths and 204 with the composite endpoint of cardiovascular death or MI. Using IPW adjustment to propensity for agent in a model with stress agent, summed stress score (SSS) remained a significant predictor of the composite endpoint of cardiovascular death or MI (HR 1.36 CI 1.28-1.46; P < .0001) as well as cardiovascular death (HR 1.38 CI 1.28-1.49; P < .0001). The interaction of SSS with agent was not significant. Similar findings were seen with summed difference score (SDS)., Conclusions: SSS derived from either adenosine or regadenoson SPECT MPI is a significant predictor of events and provides incremental prognostic information beyond basic clinical variables. We have shown for the first time that use of regadenoson vs adenosine as stress agent does not modify the prognostic significance of SSS. Similar findings were seen with SDS.