Extrastriatal uptake related to dopaminergic dysfunction on 99mTc-TRODAT-1 brain SPECT in patient with atypical meningioma.

Extrastriatal accumulation on technetium-99m-([2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]- ethanethiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)])(99mTc)-TRODAT-1 is unexpected during nuclear medicine nigrostriatal pathway examinations on 99mTc-TRODAT-1 brain single photon emission computed tomography (SPECT). An 86-year-old female with a history of right hemiparesis, speech expressive difficulties, unstable gait, and bradykinesia on right side was reported. Technetium-99m -TRODAT-1 dopamine transporter SPECT revealed an incidental extrastriatal accumulation of radiotracer in the left anterior frontal region, accompanied by a photopenic area which resulted in the displacement of the left striatum with decreased dopaminergic neuronal function. The brain magnetic resonance imaging (MRI) revealed an invasive meningioma corresponding to the extrastriatal uptake on SPECT, accompanied by edema and mass effect. The patient received surgery and the histopathological results confirmed the diagnosis of atypical meningioma.This study emphasizes the importance of understanding the underlying causes of extrastriatal uptake from 99mTc-TRODAT-1 brain SPECT, which may indicate an invasive brain tumor.

Meta-analysis of the effectiveness of heparin in suppressing physiological myocardial FDG uptake in PET/CT.

BACKGROUND: The present meta-analysis aims to investigate the effectiveness of heparin administration in suppressing physiological myocardial 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET)/computed tomography (CT), as its role in this regard has not been well investigated. METHODS: PRISMA guidelines were used to interrogate the PubMed, Embase, Cochrane library, Web of Knowledge, and www.clinicaltrail.gov databases from the earliest records to March 2023. The final analysis included five randomized controlled trials (RCTs). Meta-analysis was conducted to compare the effectiveness of unfractionated heparin (UFH) administration versus non-UFH administration, and subgroup analysis based on fixed and variable fasting durations was conducted. Effect sizes were pooled using a random-effects model, and the pooled odds ratios (ORs) were calculated. RESULTS: Five eligible RCTs with a total of 910 patients (550 with heparin, 360 without heparin) were included. The forest plot analysis initially indicated no significant difference in the suppression of myocardial FDG uptake between the UFH and non-UFH groups (OR 2.279, 95% CI 0.593 to 8.755, p = 0.23), with a high degree of statistical heterogeneity (I2 = 91.16%). Further subgroup analysis showed that the fixed fasting duration group with UFH administration had statistically significant suppression of myocardial FDG uptake (OR 4.452, 95% CI 1.221 to 16.233, p = 0.024), while the varying fasting duration group did not show a significant effect. CONCLUSIONS: According to the findings of our meta-analysis, we suggest that intravenous administration of UFH can be considered as a supplementary approach to suppress myocardial FDG uptake.

Effective suppression of myocardial glucose uptake using predesigned low-carbohydrate boxed meals.

BACKGROUND: Dietary preparation protocols are an effective means to suppress physiological myocardial 18F-fluorodeoxyglucose (FDG) uptake. This study aimed to investigate the efficacy of various carbohydrate-restricted diets using predesigned boxed meals. METHODS: The patients were divided into four groups to undergo different preparatory protocols as follows: a minimum 15-hour fast alone, two meals of high-fat, low-carbohydrate diet (HFLCD), two meals of high-animal-protein, low-carbohydrate diet (HAPLCD), and two meals of high-plant-based-protein, low-carbohydrate diet (HPPLCD). Boxed meals were prepared to meet the required carbohydrate restrictions. Myocardial SUVmax and SUVmean were measured and the suppression rate was analyzed. RESULTS: The average myocardial SUVmax of fast alone, HFLCD, HAPLCD, and HPPLCD were 8.26 ± 5.85, 2.21 ± 1.50, 2.34 ± 1.88, and 4.10 ± 3.61, respectively, and the suppression rates were 36.6%, 93.3%, 93.3%, and 70%, respectively. The effectiveness of HFLCD, HAPLCD, and HPPLCD was all statistically superior to that of a 15-hour fast alone. SUVmax of HFLCD and HAPLCD showed no significant differences (p = 1), whereas HFLCD and HPPLCD had significant differences (p = .046). CONCLUSIONS: Using the predesigned boxed meals based on carbohydrate restriction, HFLCD, HAPLCD, and HPPLCD can be administered to patients with different dietary needs while providing a substantial reduction in physiological myocardial FDG uptake.

Real-World Testing of a Machine Learning-Derived Visual Scale for Tc99m TRODAT-1 for Diagnosing Lewy Body Disease: Comparison with a Traditional Approach Using Semiquantification.

Objectives: Abnormal dopamine transporter (DAT) uptake is an important biomarker for diagnosing Lewy body disease (LBD), including Parkinson's disease (PD) and dementia with Lewy bodies (DLB). We evaluated a machine learning-derived visual scale (ML-VS) for Tc99m TRODAT-1 from one center and compared it with the striatal/background ratio (SBR) using semiquantification for diagnosing LBD in two other centers. Patients and Methods: This was a retrospective analysis of data from a history-based computerized dementia diagnostic system. MT-VS and SBR among normal controls (NCs) and patients with PD, PD with dementia (PDD), DLB, or Alzheimer's disease (AD) were compared. Results: We included 715 individuals, including 122 NCs, 286 patients with PD, 40 with AD, 179 with DLB, and 88 with PDD. Compared with NCs, patients with PD exhibited a significantly higher prevalence of abnormal DAT uptake using all methods. Compared with the AD group, PDD and DLB groups exhibited a significantly higher prevalence of abnormal DAT uptake using all methods. The distribution of ML-VS was significantly different between PD and NC, DLB and AD, and PDD and AD groups (all p < 0.001). The correlation coefficient of ML-VS/SBR in all participants was 0.679. Conclusions: The ML-VS designed in one center is useful for differentiating PD from NC, DLB from AD, and PDD from AD in other centers. Its correlation with traditional approaches using different scanning machines is also acceptable. Future studies should develop models using data pools from multiple centers for increasing diagnostic accuracy.

The Value of 99mTc ECD SPECT With Statistical Image Analysis on Enhancing the Early Diagnosis of Primary Progressive Aphasia.

A 64-year-old woman with poor short-term memory was first suspected as early Alzheimer disease. Tc ECD brain SPECT was arranged for differential diagnosis. A small area of mild hypoperfusion was noted in the left temporal lobe on conventional display. Further statistical analysis of SPECT with an easy Z-score imaging system showed large areas of distinct hypoperfusion in left precentral and perisylvian cortical areas, compatible with typical pictures of nonfluent variant primary progressive aphasia (PPA), but no involvement in areas characteristic for Alzheimer disease. Further detailed neuropsychological examination and 6 months of clinical follow-up confirmed the final diagnosis of PPA.

Visualization of an Incidental Ectopic Gallbladder Location on 99mTc-MIBI Myocardial Perfusion Imaging With SPECT/CT.

An ectopically located gallbladder is rare and unusual. In this study, we described a case of a 52-year-old woman who underwent SPECT-myocardial perfusion imaging because of exertional dyspnea and chest tightness. The rest sinograms reveal 2 substantially increased tracer uptakes in the right chest. Subsequently, a SPECT/CT scan was performed to clarify the indeterminate findings on the SPECT-myocardial perfusion imaging. The coregistered SPECT/CT images depict intense focal activity in the right chest, which corresponds to the gallbladder on the CT scan, thus explaining the peculiar ectopic gallbladder finding.

Relationship of quantitative parameters of myocardial perfusion SPECT and ventricular arrhythmia in patients receiving cardiac resynchronization therapy.

BACKGROUND: Ventricular arrhythmia is the major cause of sudden cardiac death for patients with heart failure, including those receiving implantation of cardiac resynchronization therapy (CRT). The purpose of this study was to assess the value of myocardial perfusion SPECT (MPS) in predicting ventricular arrhythmia for patients with CRT. METHODS AND METHODS: Fifty-one patients (35 males, mean age 64 ± 12 years) who had received CRT for at least 6 months were enrolled for resting gated MPS. Three main quantitative parameters of MPS, including extent of myocardial scar, left ventricular ejection fraction (LVEF) and LV dyssynchrony (phase SD), were generated by Emory Cardiac Toolbox. Using the recorded ventricular arrhythmia in the device, including ventricular tachycardia (VT) and ventricular fibrillation (VF), as the primary end point, the value of quantitative parameters of MPS in predicting the development of VT/VF was assessed. RESULTS: Twenty (39 %) of the 51 patients developed VT/VF during the follow-up (15.3 ± 12.7 months). The patients with VT/VF had significantly lower LVEF (24 ± 12 vs. 36 ± 17 %, p < 0.005), larger scar areas (36 ± 19 vs. 22 ± 12 %, p < 0.05) and larger phase SD (57° ± 20° vs. 43° ± 17°, p < 0.01). When categorizing the patients by the median values of LVEF, scar and phase SD, univariate regression analysis showed that lower LVEF (<29 %), larger scar (>23 %) and larger phase SD (>50°) were related to the development of VT/VF (p = 0.006, 0.011 and 0.064, respectively). However, only LVEF was marginally significant as an independent predictor of VT//VF on multivariate regression analysis (p = 0.0573). Survival analysis with Kaplan-Meier curves showed that the survival probability for VT/VF in those with LVEF >29 %, scar areas <23 % and phase SD < 50° was significantly better than in the others (HR 5.16, 95 % CI 1.20-22.16) by log-rank test (χ (2) = 5.9894, p = 0.014). CONCLUSION: Lower LVEF, larger scar and/or more dyssynchrony assessed by MPS were related to the development of ventricular arrhythmia for patients with CRT, and further defibrillator implantation may be considered for these patients.

Quantitation of myocardial blood flow and myocardial flow reserve with 99mTc-sestamibi dynamic SPECT/CT to enhance detection of coronary artery disease.

PURPOSE: Conventional dual-head single photon emission computed tomography (SPECT)/CT systems capable of fast dynamic SPECT (DySPECT) imaging have a potential for flow quantitation. This study introduced a new method to quantify myocardial blood flow (MBF) and myocardial flow reserve (MFR) with DySPECT scan and evaluated the diagnostic performance of detecting coronary artery disease (CAD) compared with perfusion using invasive coronary angiography (CAG) as the reference standard. METHODS: This study included 21 patients with suspected or known CAD who had received DySPECT, ECG-gated SPECT (GSPECT), and CAG (13 with ≥ 50% stenosis in any vessel; non-CAD group: 8 with patent arteries or < 50% stenosis). DySPECT and GSPECT scans were performed on a widely used dual-head SPECT/CT scanner. The DySPECT imaging protocol utilized 12-min multiple back-and-forth gantry rotations during injections of (99m)Tc-sestamibi (MIBI) tracer at rest or dipyridamole-stress stages. DySPECT images were reconstructed with full physical corrections and converted to the physical unit of becquerels per milliliter. Stress MBF (SMBF), rest MBF (RMBF), and MFR were quantified by a one-tissue compartment flow model using time-activity curves derived from DySPECT images. Perfusion images were processed for GSPECT scan and interpreted to obtain summed stress score (SSS) and summed difference score (SDS). Receiver-operating characteristic (ROC) analyses were conducted to evaluate the diagnostic performance of flow and perfusion. RESULTS: Using the criteria of ≥ 50% stenosis as positive CAD, areas under the ROC curve (AUCs) of flow assessment were overall significantly greater than those of perfusion. For patient-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.91 ± 0.07, 0.86 ± 0.09, 0.64 ± 0.12, and 0.59 ± 0.13. For vessel-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.81 ± 0.05, 0.76 ± 0.06, 0.62 ± 0.07, and 0.56 ± 0.08, respectively. CONCLUSION: The preliminary data suggest that MBF quantitation with a conventional SPECT/CT system and the flow quantitation method is a clinically effective approach to enhance CAD detection.

Whole-body FDG PET/CT in diagnosis of internal mammary nodal metastasis of ovarian carcinosarcoma.

Internal mammary lymph node is rare metastatic site in ovarian neoplasm. In this study, we report an ovarian carcinosarcoma with peritoneal carcinomatosis initially. Annually, whole-body FDG PET/CT is indicated during 4 years. Tiny peritoneal nodules are found on the first-time FDG PET/CT imaging. A high grade of FDG-avid internal mammary nodal activity is shown on the secondary time of FDG PET/CT imaging. Pathologic result of excision biopsy demonstrates carcinoma metastasis. On the recent imaging, significant FDG-avid peritoneal and subphrenic carcinomatosis has happened again. After surgery and chemotherapy, the patient is still followed up in clinic.

FDG PET/CT delayed diuretic imaging technique for differentiating invasive pelvic cancer.

A 72-year-old woman was diagnosed as having a International Federation of Gynecology and Obstetrics (FIGO II) stage cervical cancer with diffuse uterus corpus invasion without evidence of rectal or urinary bladder invasion as determined by endoscopic examinations. Recently, 2 sharp elevations of serum tumor marker squamous cell carcinoma (SCC) were noted while she was receiving radiation therapy. Therefore, a PET/CT scan was performed using fluorodeoxyglucose (FDG) to restage the cervical cancer. FDG-avid cervical tumor was shown to extend into the anterior uterine wall by use of a diuretic imaging technique, which lowered tracer activity in the bladder and improved visualization of lower pelvic structures, which otherwise might have been obscured by urine-FDG activity.