Enhanced Differentiation of Amiodarone-Induced Thyrotoxicosis Types Using Semi-Quantitative 99mTc-MIBI Uptake Analysis: A Pilot Study.

BACKGROUND Technetium (99mTc)-labelled Methoxy-2-Isobutylisonitrile (MIBI) is a diagnostic lipophilic cationic radiotracer used to evaluate the cardiac, breast, thyroid, and parathyroid pathology. This study aimed to evaluate the role of MIBI combined with Tc-99m pertechnetate thyroid scintigraphy, thyroid ultrasonography, and measurement of thyrotropin, thyroid hormones, and autoantibodies to subtype amiodarone-induced thyrotoxicosis (AIT) and the contribution of semi-quantitative analysis of MIBI uptake. MATERIAL AND METHODS This cross-sectional study included 36 patients with AIT who underwent thyrotropin, thyroid hormone, and autoantibody analysis using chemiluminescent method, ultrasonography, pertechnetate, and MIBI thyroid scintigraphy with semi-quantitative uptake, including calculation of the target-to-background ratio (TBR) with 2 different background regions. The MIBI washout rate (WR) was analyzed in all groups. Statistical analysis was performed using descriptive statistics, correlations, and the receiver operating characteristic curve - area under the curve (ROC-AUC). The results were compared with the control group. RESULTS Based on visual and semi-quantitative analyses, patients were successfully categorized into AIT groups (AIT-1, AIT-2 and AIT-3) but the latter method enabled better differentiation of MIBI uptake between all groups. Additionally, ROC-AUC analysis determined cutoff values which enabled discerning between AIT-1 and AIT-2 groups, and AIT-1 and AIT-3 groups. WR showed no significant difference between all AIT groups and controls (P>0.05). CONCLUSIONS Visual MIBI analysis enabled differentiation between AIT-1 and 2 groups, but the method was substantially improved with semi-quantitative analysis, especially in defining AIT-3 group. However, multicenter collaboration with larger studies is needed to standardize the method and obtain more accurate and consistent results.

Relationship Between Infarct Artery, Myocardial Injury, and Outcomes After Primary Percutaneous Coronary Intervention in ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: The extent to which infarct artery impacts the extent of myocardial injury and outcomes in patients with ST-segment-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention is uncertain. METHODS AND RESULTS: We performed a pooled analysis using individual patient data from 7 randomized STEMI trials in which myocardial injury within 30 days after primary percutaneous coronary intervention was assessed in 1774 patients by cardiac magnetic resonance (n=1318) or technetium-99m sestamibi single-photon emission computed tomography (n=456). Clinical follow-up was performed at a median duration of 351 days (interquartile range, 184-368 days). Infarct size and outcomes were assessed in anterior (infarct vessel=left anterior descending) versus nonanterior (non-left anterior descending) STEMI. Median infarct size (percentage left ventricular myocardial mass) was larger in patients with anterior compared with nonanterior STEMI (19.7% [interquartile range, 9.4%-31.7%] versus 12.6% [interquartile range, 5.1%-20.5%]; P<0.001). Patients with anterior compared with nonanterior STEMI were at higher risk for 1-year all-cause mortality (6.2% versus 3.6%; adjusted hazard ratio [HR], 1.66 [95% CI, 1.02-2.69]; P=0.04) and heart failure hospitalization (4.4% versus 2.6%; adjusted HR, 1.96 [95% CI, 1.15-3.36]; P=0.01). Infarct size was a predictor of subsequent all-cause mortality or heart failure hospitalization in anterior STEMI (adjusted HR per 1% increase, 1.05 [95% CI, 1.03-1.07]; P<0.001), but not in nonanterior STEMI (adjusted HR, 1.02 [95% CI, 0.99-1.05]; P=0.19). The P value for this interaction was 0.04. CONCLUSIONS: Anterior STEMI was associated with substantially greater myonecrosis after primary percutaneous coronary intervention compared with nonanterior STEMI, contributing in large part to the worse prognosis in patients with anterior infarction.

Is intraoperative parathyroid monitoring during minimally invasive parathyroidectomy still justified?

Introduction: Primary hyperparathyroidism (PHPT) is the third most common endocrine disease. With parathyroidectomy, a cure rate of over 95% at initial surgery is reported. Localization of the abnormal parathyroid gland is critical for the operation to be successful. The aim of this study is to analyze data of patients with single gland disease (SGD) and positive concordant localization imaging undergoing minimally invasive parathyroidectomy (MIP) and intraoperative parathyroid hormone monitoring (IOPTH) to evaluate if IOPTH is still justified in patients with localized SGD. Methods: A retrospective database analysis of all minimally invasive operations with IOPTH for PHPT and positive concordant localization in ultrasound (US) and 99mTc-sestamibi scintigraphy (MIBI) between 2016-2021. When both US and MIBI were negative, patients underwent either choline or methionine PET-CT. The patients were also analyzed a second time without applying IOPTH. Results: In total, 198 patients were included in the study. The sensitivity of US, MIBI and PET-CT was 96%, 94% and 100%, respectively. Positive predictive value was 88%, 89% and 94% with US, MIBI and PET-CT, respectively. IOPTH was true positive in 185 (93.4%) patients. In 13 (6.6%) patients, no adequate IOPTH decline was observed after localizing and extirpating the assumed enlarged parathyroid gland. Without IOPTH, the cure rate decreased from 195 (98.5%) to 182 (92%) patients and the rate of persisting disease increased from 2 (1.0%) to 15 (7.5%) patients. Conclusion: Discontinuing IOPTH significantly increases the persistence rate by a factor of 7.5 in patients with concordantly localized adenoma. Therefore, IOPTH appears to remain necessary even for this group of patients.

Prospective study of dual-phase 99mTc-MIBI SPECT/CT nomogram for differentiating non-small cell lung cancer from benign pulmonary lesions.

OBJECTIVES: To establish and validate a technetium 99m sestamibi (99mTc-MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) nomogram for predicting non-small cell lung cancer (NSCLC). Comparing the diagnostic performance of early and delayed SPECT/CT nomogram, and compare the diagnostic performance of SPECT/CT radiomics models with single SPECT and CT radiomics models. METHODS: This prospective study included 119 lesions (NSCLC: n = 92, benign pulmonary lesions: n = 27) from 103 patients (mean age: 59.68 ± 8.94 years). Patients underwent dual-phase 99mTc-MIBI SPECT/CT imaging. They were divided into the training (n = 83) and validation (n = 36) cohorts. Logistic regression, support vector machine, random forest, and light-gradient boosting machine were applied to train and determine the optimal machine learning model. Then, combining radiomics score and clinical factors, establish nomograms for diagnosing NSCLC. RESULT: CYFRA21-1 was selected for constructing the clinical model. In early imaging, the areas under the curve (AUCs) of the clinical model, radiomics model, and nomogram were 0.571, 0.830, and 0.875, respectively. The nomogram performed better than the clinical model and similarly to the radiomics model (P=0.020, P=0.216), and there are no statistically significant differences in the predictive performance between the radiomics model and the clinical model (P=0.103). In delayed imaging, the AUC was 0.643, 0.888, and 0.893, respectively. The predictive performance of the nomogram was superior compared to the clinical model and comparable to the radiomics model (P=0.042, P=0.480), and the radiomics model also demonstrated superior diagnostic performance compared to the clinical model (P=0.049). Compared to early SPECT/CT results, the AUC values of the nomogram and radiomics models in the delayed phase were higher, although no statistical differences were found (P=0.831, P=0.568). In delayed imaging, the AUC of the radiomics models for CT and SPECT was 0.696 and 0.768, respectively, SPECT/CT radiomics exhibited significant differences compared with CT and SPECT alone (P=0.042, P=0.038). CONCLUSION: Dual-phase 99mTc-MIBI SPECT/CT nomograms and radiomics models can effectively predict NSCLC, providing an economically and non-invasive imaging method for diagnosing NSCLC, moreover, these findings provide a basis for early diagnosis and treatment strategies in NSCLC patients. Delayed-phase SPECT/CT imaging may offer greater practical value than early-phase imaging for diagnosing NSCLC. However, this novel approach necessitates further validation in larger, multi-center cohorts. CLINICAL RELEVANCE: Radiomics nomogram based on SPECT/CT for discriminating NSCLC from benign lung lesions helps to aid early diagnosis and guide treatment. KEY POINTS: Nomograms, based on dual-phase SPECT/CT, was constructed to discriminate between non-small cell lung cancer and benign lesions. SPECT/CT radiomics model has better predictive performance than SPECT and CT radiomics model.

Can a Carbonated Lemon Drink Reduce Extracardiac Activity in Myocardial Perfusion Imaging?

Myocardial perfusion imaging (MPI) provides physiologic and functional information about the heart muscle and its blood flow. Extracardiac radioactivity can interfere with visualization of the inferior wall of the myocardium, leading to poor-quality images, difficulties in interpretation, and delays in routine practice. This study aimed to identify the efficiency of having the patient consume a carbonated lemon drink to minimize the extracardiac radioactivity of 99mTc-sestamibi in comparison to 99mTc-tetrofosmin during MPI. Methods: This was a retrospective study that recruited 158 patients with known or suspected coronary artery disease referred to undergo 99mTc-sestamibi or 99mTc-tetrofosmin rest/stress single-day MPI. The patients were divided into 2 groups of mixed sexes and different ages. The first group comprised 78 patients injected with 99mTc-sestamibi, and the second group comprised 80 patients injected with 99mTc-tetrofosmin. For both groups, the patients drank 30 mL of fresh lemon juice diluted with 150 mL of soda water, and then we gave the patients about 100 mL of straight soda water, before imaging for both the rest and the stress phases. Results: Generally, in both groups, the 99mTc-tetrofosmin produced a good-quality image in comparison with the 99mTc-sestamibi. The mean rank of the total score for 99mTc-tetrofosmin (62.75) was less than that for 99mTc-sestamibi (96.68), and this difference was highly statistically significant (P = 0.000). There were statistically significant differences in the ratios and mean ranks for both groups in favor of 99mTc-tetrofosmin in patients having coronary artery disease. Conclusion: The use of a carbonated lemon drink minimizes extracardiac activity from both 99mTc-labeled MPI radiopharmaceuticals. This finding was more statistically significant for 99mTc-tetrofosmin MPI, providing better image quality and earlier imaging in both the rest and the stress phases because of faster hepatobiliary clearance.

Comparison of intraoperative imaging with a portable gamma camera with extemporaneous histology in minimally invasive surgery for primary hyperparathyroidism.

INTRODUCTION: The curative treatment of primary hyperparathyroidism (PPH) is surgical and today it can be performed by minimally invasive surgery (MIS) and also be radioguided (RG) if a radiopharmaceutical with affinity for the parathyroid tissue that can be detected with gamma-detector probes or with a portable gamma camera (PGC) is injected. AIM: The objective is to assess whether intraoperative scintigraphy (GGio) with PGC can replace intraoperative pathological anatomy (APio) to determine if the removed specimen is an abnormal parathyroid. MATERIAL AND METHOD: 92 patients underwent CMI RG--HPP with PGC after the administration of a dose of 99 mTc-MIBI. The information provided by the PGC in the analysis of the excised specimens is qualitatively compared (capture yes/no) with the result of the intraoperative pathological anatomy (APio). The Gold standard is the definitive histology. RESULTS: 120 excised pieces are evaluated with GGio and APio. There were 110 agreements (95TP and 15TN) and 10 disagreements (3FP and 7FN). Of the 120 lesions, 102 were parathyroid and 18 were non-parathyroid. There was good agreement between intraoperative scintigraphy imaging (GGio) and PA, 70.1% according to Cohen's Kappa index. The GGio presented the following values ​​of Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value, Positive Likelihood Ratio, Negative Likelihood Ratio and Overall Value of the Test (93.1%, 83.3%, 96.9%, 68.2%, 5.59, 0.08 and 0.92 respectively). CONCLUSION: GGio is a rapid and effective surgical aid technique to confirm/rule out the possible parathyroid nature of the lesions removed in PPH surgery, but it cannot replace histological study.

Imaging of Chromophobe Renal Cell Carcinoma with 99mTc-Sestamibi SPECT/CT: Considerations Regarding Risk Stratification and Histologic Reclassification.

PURPOSE: Indeterminate renal masses are increasingly incidentally found on cross-sectional imaging. 99mTc-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 99mTc-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.

Low-dose radio-guided parathyroidectomy: A non-inferiority systematic review and meta-analysis.

BACKGROUND: Performing MIRP procedure with a 20-fold less MIBI isotope dose allows lower radiation exposure risk for both patient and staff and reduce the overall cost of the procedure. The main goal of this systemic review and meta-analysis is to prove the non-inferiority of the very low dose MIRP compared to the standard dose. METHODS: We performed a systemic review and meta-analysis of three different electronic databases - PubMed, Web of Science and google scholar. Meta-extraction was conducted in accordance with PRISMA guidelines. RESULTS: Among 4750 studies imported for screening, only 13 studies were selected for the meta-analysis. Analyzed data from the 13 selected studies performed with low dose MIRP demonstrated a detection rate greater than 97 â€‹% and a success rate greater than 95 â€‹%, which is comparable to the cure rate required by current guidelines, as well as to data published by studies using the original high dose protocol. CONCLUSION: Very low dose MIRP is not inferior to the high dose original MIRP and may be used in separate day protocol routinely.

Clinical Impact of Assessment of Myocardial Flow Reserve in Identifying the Cause of Chest Discomfort. / Impacto Clínico da Avaliação da Reserva de Fluxo Miocárdico na Identificação da Causa do Desconforto Torácico.

BACKGROUND: Gamma cameras with cadmium-zinc telluride (CZT) detectors allowed the quantification of myocardial flow reserve (MBF), which can increase the accuracy of myocardial perfusion scintigraphy (MPS) to detect the cause of chest discomfort. OBJECTIVE: To assess the clinical impact of MBF to detect the cause of chest discomfort. METHODS: 171 patients with chest discomfort who underwent coronary angiography or coronary CT angiography also underwent MPS and MBF in a time interval of <30 days. The acquisitions of dynamic imaging of rest and stress were initiated simultaneously with the 99mTc injection sestamibi (10 and 30mCi, respectively), both lasting eleven minutes, followed by immediately acquiring perfusion images for 5 minutes. The stress was performed with dipyridamole. A global or per coronary territory MBF <2.0 was classified as abnormal. RESULTS: The average age was 65.9±10 years (60% female). The anatomical evaluation showed that 115 (67.3%) patients had coronary obstruction significant, with 69 having abnormal MPs and 91 having abnormal MBF (60.0% vs 79.1%, p<0.01). Among patients without obstruction (56 - 32.7%), 7 had abnormal MPS, and 23 had reduced global MBF. Performing MBF identified the etiology of the chest discomfort in 114 patients while MPS identified it in 76 (66.7% vs 44.4%, p<0.001). CONCLUSION: MBF is a quantifiable physiological measure that increases the clinical impact of MPS in detecting the cause of chest discomfort through greater accuracy for detecting obstructive CAD, and it also makes it possible to identify the presence of the microvascular disease.

FUNDAMENTO: Gama-câmaras com detectores de telureto-cádmio-zinco (CZT) permitiram a quantificação da reserva de fluxo miocárdico (RFM), podendo aumentar a acurácia da cintilografia miocárdica de perfusão (CMP) para detectar a causa do desconforto torácico. OBJETIVO: Avaliar o impacto clínico da RFM para detectar a causa do desconforto torácico. MÉTODOS: 171 pacientes com desconforto torácico que foram submetidos a coronariografia ou angiotomografia de coronárias também realizaram CMP e RFM num intervalo de tempo <30 dias. As aquisições das imagens dinâmicas de repouso e estresse foram iniciadas simultaneamente à injeção de 99mTc sestamibi (10 e 30mCi, respectivamente), ambas com duração de onze minutos, seguidas imediatamente pela aquisição das imagens de perfusão durante 5 minutos. O estresse foi realizado com dipiridamol. Uma RFM global ou por território coronariano <2,0 foi classificada como anormal. RESULTADOS: A idade média foi de 65,9±10 anos (60% do sexo feminino). A avaliação anatômica mostrou que 115 (67,3%) pacientes apresentavam obstrução coronariana significativa, sendo que, 69 apresentavam CMP anormal e 91 apresentavam RFM anormal (60,0% vs. 79,1%, p<0,01). Dentre os pacientes sem obstrução (56 ­ 32,7%), 7 tinham CMP anormais e 23 tinham RFM global reduzida. A realização da RFM identificou a etiologia do desconforto torácico em 114 pacientes enquanto a CMP identificou em 76 (66,7% vs. 44,4%, p<0,001). CONCLUSÃO: A RFM é uma medida fisiológica quantificável que aumenta o impacto clínico da CMP na detecção da causa do desconforto torácico através de uma maior acurácia para detecção de DAC obstrutiva e ainda possibilita identificar a presença de doença microvascular.

F18-Choline PET/CT or MIBI SPECT/CT in the Surgical Management of Primary Hyperparathyroidism: A Diagnostic Randomized Clinical Trial.

Importance: Whether F18-choline (FCH) positron emission tomographic (PET)/computed tomographic (CT) scan can replace Tc99m-sestaMIBI (MIBI) single-photon emission (SPE)CT/CT as a first-line imaging technique for preoperative localization of parathyroid adenomas (PTA) in patients with primary hyperparathyroidism (PHPT) is unclear. Objective: To compare first-line FCH PET/CT vs MIBI SPECT/CT for optimal care in patients with PHPT needing parathyroidectomy and to compare the proportions of patients in whom the first-line imaging method resulted in successful minimally invasive parathyroidectomy (MIP) and normalization of calcemia 1 month after surgery. Design, Setting, and Participants: A French multicenter randomized open diagnostic intervention phase 3 trial was conducted. Patients were enrolled from November 2019 to May 2022 and participated up to 6 months after surgery. The study included adults with PHPT and an indication for surgical treatment. Patients with previous parathyroid surgery or multiple endocrine neoplasia type 1 (MEN1) were ineligible. Interventions: Patients were assigned in a 1:1 ratio to receive first-line FCH PET/CT (FCH1) or MIBI SPECT/CT (MIBI1). In the event of negative or inconclusive first-line imaging, they received second-line FCH PET/CT (FCH2) after MIBI1 or MIBI SPECT/CT (MIBI2) after FCH1. All patients underwent surgery under general anesthesia within 12 weeks following the last imaging. Clinical and biologic (serum calcemia and parathyroid hormone levels) assessments were performed 1 and 6 months after surgery. Main Outcomes and Measures: The primary outcome was a true-positive first-line imaging-guided MIP combined with uncorrected serum calcium levels of 2.55 mmol/l or less 1 month after surgery, corresponding to the local upper limit of normality. Results: Overall, 57 patients received FCH1 (n = 29) or MIBI1 (n = 28). The mean (SD) age of patients was 62.8 (12.5) years with 15 male (26%) and 42 female (74%) patients. Baseline patient characteristics were similar between groups. Normocalcemia at 1 month after positive first-line imaging-guided MIP was observed in 23 of 27 patients (85%) in the FCH1 group and 14 of 25 patients (56%) in the MIBI1 group. Sensitivity was 82% (95% CI, 62%-93%) and 63% (95% CI, 42%-80%) for FCH1 and MIBI1, respectively. Follow-up at 6 months with biochemical measures was available in 43 patients, confirming that all patients with normocalcemia at 1 month after surgery still had it at 6 months. No adverse events related to imaging and 4 adverse events related to surgery were reported. Conclusions: This randomized clinical trial found that first-line FCH PET/CT is a suitable and safe replacement for MIBI SPECT/CT. FCH PET/CT leads more patients with PHPT to correct imaging-guided MIP and normocalcemia than MIBI SPECT/CT thanks to its superior sensitivity. Trial Registration: ClinicalTrials.gov Identifier: NCT04040946.

DNA damage and repair in patients undergoing myocardial perfusion single-photon emission computed tomography.

As patient exposure to ionizing radiation from medical imaging and its risks are continuing issues, this study aimed to evaluate DNA damage and repair markers after myocardial perfusion single-photon emission computed tomography (MPS). Thirty-two patients undergoing Tc-99m sestamibi MPS were studied. Peripheral blood was collected before radiotracer injection at rest and 60-90 min after injection. The comet assay (single-cell gel electrophoresis) was performed with peripheral blood cells to detect DNA strand breaks. Three descriptors were evaluated: the percentage of DNA in the comet tail, tail length, and tail moment (the product of DNA tail percentage and tail length). Quantitative PCR (qPCR) was performed to evaluate the expression of five genes related to signaling pathways in response to DNA damage and repair (ATM, ATR, BRCA1, CDKN1A, and XPC). Mann-Whitney's test was employed for statistical analysis; p < 0.05 was considered significant. Mean Tc-99m sestamibi dose was 15.1 mCi. After radiotracer injection, comparing post-exposure to pre-exposure samples of each of the 32 patients, no statistically significant differences of the DNA percentage in the tail, tail length or tail moment were found. qPCR revealed increased expression of BRCA1 and XPC, without any significant difference regarding the other genes. No significant increase in DNA strand breaks was detected after a single radiotracer injection for MPS. There was activation of only two repair genes, which may indicate that, in the current patient sample, the effects of ionizing radiation on the DNA were not large enough to trigger intense repair responses, suggesting the absence of significant DNA damage.

Esophageal schwannoma mimicking non-functional parathyroid adenoma on 99mTc-sestamibi imaging: a case report.

Technetium-99m sestamibi single-photon emission computed tomography/computed tomography (99mTc-sestamibi SPECT/CT) is a mainstay of the pre-operative localization of parathyroid lesions. We report here the case of a 30 year-old woman with a fortuitously discovered 2 cm cervical mass for which a parathyroid origin was originally suspected due to its retro-thyroidal localization and a personal history of nephrolithiasis. Normal serum calcium and parathyroid hormone (PTH) levels excluded primary hyperparathyroidism, raising suspicion of a non-functional parathyroid adenoma, and SPECT/CT imaging showed that the mass was 99mTc-sestamibi-avid. Fine-needle aspiration (FNA) was performed; cytology was non-diagnostic but the needle washout was negative for thyroglobulin, calcitonin and PTH, arguing against a thyroidal or parathyroidal origin of the mass. Core needle biopsy revealed a schwannoma, ostensibly originating from the recurrent laryngeal nerve; upon surgical resection, it was finally found to arise from the esophageal submucosa. This case illustrates the fact that endocrinologists, radiologists, nuclear medicine, head and neck, and other specialists investigating patients with cervical masses should be aware that schwannomas need to be considered in the differential diagnosis of focal 99mTc-sestamibi uptake in the neck region.

Molecular Breast Imaging Biopsy with a Dual-Detector System.

Purpose To develop a molecular breast imaging (MBI)-guided biopsy system using dual-detector MBI and to perform initial testing in participants. Materials and Methods The Stereo Navigator MBI Accessory biopsy system comprises a lower detector, upper fenestrated compression paddle, and upper detector. The upper detector retracts, allowing craniocaudal, oblique, or medial or lateral biopsy approaches. The compression paddle allows insertion of a needle guide and needle. Lesion depth is calculated by triangulation of lesion location on the upper detector at 0° and 15° and relative lesion activity on upper and lower detectors. In a prospective study (July 2022-June 2023), participants with Breast Imaging Reporting and Data System category 2, 3, 4, or 5 breast lesions underwent MBI-guided biopsy. After injection of 740 MBq technetium 99m sestamibi, craniocaudal and mediolateral oblique MBI (2-minute acquisition per view) confirmed lesion visualization. A region of interest over the lesion permitted depth calculation in the system software. Upper detector retraction allowed biopsy device placement. Specimen images were obtained on the retracted upper detector, confirming sampling of the target. Results Of 21 participants enrolled (mean age, 50.6 years ± 10.1 [SD]; 21 [100%] women), 17 underwent MBI-guided biopsy with concordant pathology. No lesion was observed at the time of biopsy in four participants. Average lesion size was 17 mm (range, 6-38 mm). Average procedure time, including preprocedure imaging, was 55 minutes ± 13 (range, 38-90 minutes). Pathology results included invasive ductal carcinoma (n = 1), fibroadenoma (n = 4), pseudoangiomatous stromal hyperplasia (n = 6), and fibrocystic changes (n = 6). Conclusion MBI-guided biopsy using a dual-head system with retractable upper detector head was feasible, well tolerated, and efficient. Keywords: Breast Biopsy, Molecular Breast Imaging, Image-guided Biopsy, Molecular Breast Imaging-guided Biopsy, Breast Cancer Clinical trial registration no. NCT06058650 © RSNA, 2024.

Ultrasonographic Detective Flow Imaging for Evaluating Parathyroid Adenoma in Patients with Primary Hyperparathyroidism.

BACKGROUND: Detective flow imaging (DFI) is a new imaging technology that displays low-velocity blood flow, which is difficult to visualize on conventional color Doppler ultrasonography (CDU). In this study, we compared the usefulness of DFI with that of CDU and methoxy-isobutyl-isonitrile (MIBI) scintigraphy for detecting parathyroid adenoma (PA) in patients with primary hyperparathyroidism (PHPT). METHODS: From March 2021 to March 2023, 87 PHPT patients underwent surgery, and 66 had a single PA. We performed preoperative conventional ultrasonography with CDU, MIBI scintigraphy, and DFI for 42 patients (5 males and 37 females; mean age: 61.6 ± 15.4 years). RESULTS: MIBI scintigraphy detected PA in 85.7% (36/42) patients, and both CDU and DFI detected PA in all patients. The rates of vascularity in PA detected by CDU and DFI were 71.4% (30/42) and 85.7% (36/42), respectively. Vascularity was detected by DFI in 6 patients who were negative for vascularity on MIBI scintigraphy. Furthermore, DFI detected blood supply in 6 of the 12 patients with undetectable blood supply on CDU. Fisher's exact test revealed that high or low blood flow, as determined by DFI, was significantly associated with detection of feeding vessels in PA by CDU (P < 0.001). CONCLUSIONS: DFI was useful for preoperative detection of PA blood flow.

Papillary Thyroid Cancer, Small Cell Lung Cancer, and Parathyroid Adenoma Synchronously Visualized on 99m Tc-MIBI SPECT/CT in a Patient With Hyperparathyroidism : Comparison With 18 F-FDG PET/CT.

ABSTRACT: 99m Tc-MIBI scintigraphy is a nuclear medicine imaging modality commonly used for the preoperative localization of parathyroid adenomas in patients with hyperparathyroidism. In addition, 99m Tc-MIBI can also be used for imaging various tumors due to its unique mechanism of intracellular accumulation. Here, we introduced a case of a single 99m Tc-MIBI SPECT/CT simultaneously visualized two different malignant tumors, such as papillary thyroid cancer and small cell lung cancer, along with a parathyroid adenoma in a patient with hyperparathyroidism. The clinical usefulness of 99m Tc-MIBI SPECT/CT was also explored by comparing it with 18 F-FDG PET/CT among the three tumors.

Incidentally detected follicular thyroid carcinoma mimicking parathyroid adenoma on Tc-99m MIBI scan: A case report.

RATIONALE: Primary hyperparathyroidism, though relatively prevalent among endocrine disorders, affecting 1% of the general population, often presents diagnostic challenges. Given its potential to precipitate severe complications including nephrolithiasis and fractures, timely diagnosis, and effective management are crucial. PATIENT CONCERNS: A 38-year-old woman with hypercalcemia was referred to the Department of Nuclear Medicine for a Tc-99m MIBI scan. DIAGNOSES: Tc-99m MIBI scan showed focal increased uptake in the left thyroid gland area, initially suggesting a parathyroid adenoma. Further examination using SPECT/CT revealed a nodular lesion within the left thyroid gland showing high Tc-99m MIBI uptake. INTERVENTIONS: Left thyroid lumpectomy confirmed the lesion as follicular thyroid carcinoma. On the second Tc-99m MIBI scan conducted after total thyroidectomy, a parathyroid adenoma was eventually detected in the right lower area, enabling the subsequent appropriate treatment, a right lower parathyroidectomy. OUTCOMES: Thirteen days after the parathyroidectomy, serum levels of total calcium and parathyroid hormone returned to normal. Furthermore, bone mineral density evaluated using DEXA remained within the expected range for her age even after 14 months. LESSONS: When interpreting the Tc-99m MIBI scan, it is essential to keep in mind that various tumors rich in mitochondria, such as thyroid carcinoma, could show a high uptake of Tc-99m MIBI.

Relationship between transient ischemic dilatation and changes in heart rate during gated SPECT acquisition in a low-risk population without perfusion defects.

OBJECTIVES: Transient ischemic dilatation (TID) in myocardial perfusion single photon emission computed tomography (SPECT) is considered a marker of poor prognosis. However, it has been suggested that some cases are due to apparent volumetric changes secondary to differences in heart rate (HR) at the time of acquisition. We assessed the correlation between transient dilatation and HR in low risk patients with no perfusion defects. METHODS: We retrospectively analyzed patients sent for 99mTc-MIBI SPECT using a 2-day protocol. We recorded the median HR during acquisition and the HR difference (HRD) between the rest and post-stress. We obtained the medium ventricular volume, end-diastolic volume (EDV), and end-systolic volume (ESV). We included patients in which TID using medium ventricular volume (TIDMV) was ≥1.2. TID was also calculated for the EDV and ESV (TIDEDV, TIDESV). We excluded patients with known coronary artery disease, perfusion defects, various ECG disorders, positive stress test, or ESV < 10 ml. RESULTS: From a total of 2006 patients, 63 (50 exercise, 13 dipyridamole) met the criteria for analysis (age 63.8 ±â€…9.7, 44 men). TIDMV was 1.29 ±â€…0.09 and HRD 9.8 beats per minute (BPM) (range -10 to 41). There was positive correlation between HRD and TIDMV ( r  = 0.51, P  < 0.001) and TIDEDV ( r  = 0.5, P  < 0.001), but not TIDESV ( r  = 0.23, P  = 0.07). Correlation was stronger when HRD was ≥10 BPM ( r  = 0.67, P  < 0.001). CONCLUSION: TID without perfusion defects should be interpreted with caution in the presence of HRD ≥ 10 BPM during post-stress acquisition.