Associations of cardiovascular and diabetes-related risk factors with myocardial perfusion reserve assessed by 201Tl/99mTc-tetrofosmin single-photon emission computed tomography in patients with diabetes mellitus and stable coronary artery disease.

We aimed to examine the associations of cardiovascular risk factors with myocardial perfusion reserve (MPR) in patients with type 2 diabetes and stable coronary artery disease. The study patients were retrospectively identified from a database of patients with diabetes and stable coronary artery disease at Asan Medical Center (Seoul, Republic of Korea), covering the period from 2017 to 2019. The primary outcome variable was MPR assessed by dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT. Univariable and stepwise multivariable analyses were performed to assess the associations of cardiovascular risk factors with MPR. A total of 276 patients (236 men and 40 women) were included. The median global MPR was 2.4 (interquartile range 1.9-3.0). Seventy-five (27.2%) patients had an MPR < 2.0. Multivariable linear regression showed that smoking (ß = - 0.44, 95% confidence interval - 0.68 to - 0.21, P < 0.001), hypertension (ß = - 0.24, 95% confidence interval - 0.47 to - 0.02, P = 0.033), and summed difference score (ß = - 0.05, 95% confidence interval - 0.07 to - 0.03, P < 0.001) were independently associated with MPR. Abnormal MPR (< 2.0) was associated with a higher incidence of cardiac death or myocardial infarction (P = 0.034). MPR assessed by dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT was impaired in a large cohort of patients with diabetes. After adjusting for risk variables, including standard myocardial perfusion imaging characteristics, smoking, and hypertension were associated with MPR. Our results may aid in identifying patients with impaired MPR and stratifying patients with type 2 diabetes.

Predicting Vascularized Bone Graft Viability Using 1-Week Postoperative Bone SPECT/CT After Maxillofacial Reconstructive Surgery.

PURPOSE: We aimed to evaluate the performance of hybrid bone single-photon emission computed tomography (SPECT)/computed tomography (CT) in predicting bone graft viability after maxillary or mandibular reconstructive surgery with vascularized bone grafts. METHODS: We retrospectively reviewed 46 bone planar scintigraphy and SPECT/CT images of 45 adult patients taken at 1 week (5-8 days) after maxillary or mandibular reconstructive surgery with vascularized bone grafts. By visual analysis, two nuclear medicine physicians scored the uptake degrees of each bone graft segment compared with the calvarium uptake on planar bone scintigraphy and SPECT/CT, respectively (0 = absence of uptake, 1 = less uptake, 2 = similar uptake, and 3 = more uptake). The imaging results were compared with clinical follow-up for assessing bone graft viability. RESULTS: During follow-up, five bone graft segments were surgically removed and confirmed as nonviable-one had a score of 0, although the other four had a score of 1-3 on planar bone scintigraphy. All five bone graft segments were scored 0 on SPECT/CT and eventually confirmed as nonviable. All other graft segments with a score of > 1 on SPECT/CT were viable and uneventful. The anatomical CT information on SPECT/CT images was helpful in discriminating bone graft uptake from adjacent bone or soft tissue uptake. CONCLUSIONS: The absence of tracer uptake by the vascularized bone graft on bone SPECT/CT at 1 week after maxillary or mandibular reconstructive surgery can predict graft failure. Bone SPECT/CT can be used to predict vascularized bone graft viability postoperatively.

Is dual-phase SPECT/CT with 99mTc-sestamibi better than single-phase SPECT/CT for lesion localization in patients with hyperparathyroidism?

This study aimed to establish an optimal protocol for Tc-sestamibi parathyroid imaging for lesion localization in patients with hyperparathyroidism (HPT).We retrospectively enrolled 35 consecutive patients who underwent dual-phase (at 10 minutes and 120 minutes) Tc-sestamibi parathyroid scintigraphy with single-photon emission computed tomography (SPECT)/computed tomography (CT). Twenty seven patients had primary HPT, and 8 had secondary or tertiary HPT. Three nuclear medicine physicians independently analyzed the parathyroid images for lesion localization at 9 predefined parathyroid locations using the following 4 different image sets blinded to the clinical information:All SPECT or SPECT/CT image sets were analyzed with dual-phase planar images. The image results were compared with the histopathological results after surgery.Dual-phase SPECT/CT showed the highest positive rate of 85.7% in the patient-based analysis and 13.7% in the location-based analysis. Of 35 patients, surgical pathological results were available in 21 (16 adenomas in 16 primary HPTs and 16 hyperplasias in 5 secondary or tertiary HPTs). Dual-phase SPECT/CT showed the sensitivity values of 100% and 84.4% in the patient-based and location-based analysis, respectively, which were the highest sensitivity values among all image sets. In the primary HPT subgroup, dual-phase SPECT/CT showed the highest sensitivity value of 93.8% in the location-based analyses, whereas dual-phase SPECT, early SPECT/CT, and delayed SPECT/CT showed the sensitivity values of 62.5%, 81.3%, and 81.3%, respectively. In the secondary or tertiary HPT subgroup, dual-phase SPECT/CT also showed the highest sensitivity value of 75.0%, whereas early SPECT/CT, delayed SPECT/CT, and dual-phase SPECT showed the sensitivity values of 43.8%, 56.3%, and 68.8%, respectively.Compared with dual-phase SPECT or single-phase SPECT/CT, the dual-phase SPECT/CT imaging protocol for Tc-sestamibi scintigraphy showed the highest positive rate and sensitivity, and was optimal for parathyroid lesion localization.

Comparison of diagnostic sensitivity of [18F]fluoroestradiol and [18F]fluorodeoxyglucose positron emission tomography/computed tomography for breast cancer recurrence in patients with a history of estrogen receptor-positive primary breast cancer.

BACKGROUND: To compare the diagnostic sensitivity of [18F]fluoroestradiol ([18F]FES) and [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT) for breast cancer recurrence in patients with estrogen receptor (ER)-positive primary breast cancer. METHODS: Our database of consecutive patients enrolled in a previous prospective cohort study to assess [18F]FES PET/CT was reviewed to identify eligible patients who had ER-positive primary breast cancer with suspected first recurrence at presentation and who underwent [18F]FDG PET/CT. The sensitivity of qualitative [18F]FES and [18F]FDG PET/CT interpretations was assessed, comparing them with histological diagnoses. RESULTS: Of the 46 enrolled patients, 45 were confirmed as having recurrent breast cancer, while one was diagnosed with chronic granulomatous inflammation. Forty (89%) patients were ER-positive, four (9%) were ER-negative, and one (2%) patient did not undergo an ER assay. The sensitivity of [18F]FES PET/CT was 71.1% (32/45, 95% CI, 55.7-83.6), while that of [18F]FDG PET/CT was 80.0% (36/45, 95% CI, 65.4-90.4) with a threshold of positive interpretation, and 93.3% (42/45, 95% CI, 81.7-98.6) when a threshold of equivocal was used. There was no significant difference in sensitivity between [18F]FES and [18F]FDG PET/CT (P = 0.48) with a threshold of positive [18F]FDG uptake, but the sensitivity of [18F]FDG was significantly higher than [18F]FES (P = 0.013) with a threshold of equivocal [18F]FDG uptake. One patient with a benign lesion showed negative [18F]FES but positive [18F]FDG uptake. CONCLUSIONS: The restaging of patients who had ER-positive primary breast cancer and present with recurrent disease may include [18F]FES PET/CT as an initial test when standard imaging studies are equivocal or suspicious.

Value of the Filtration Fraction Assessed by Dynamic 99mTc-Diethylenetriaminepentaacetic Acid Renal Scintigraphy After Angiotensin-Converting Enzyme Inhibition for the Diagnosis of Renovascular Hypertension.

PURPOSE: This study aimed to determine the diagnostic value of the relative filtration fraction (RFF) assessed by dynamic 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) renal scintigraphy after angiotensin-converting enzyme (ACE) inhibition for renovascular hypertension (RVHT) diagnosis. METHODS: 99mTc-DTPA captopril renal scintigraphy performed in adolescents or adults (≥ 10 years) with suspected RVHT was retrospectively reviewed. The RFF of the affected kidney was qualitatively assessed as the relative glomerular filtration rate during the 2 to 3-min period compared with the relative perfusion during the first 60 s (qualitative RFF) and scored from 1 (definitely same) to 5 (definitely decreased). The quantitative RFF of the affected kidney was obtained by dividing the percentage of glomerular filtration rate by the percentage of renal perfusion. RESULTS: Overall, 173 patients (high probability, n = 15; and low probability, n = 158) were included based on conventional captopril renal scintigraphic criteria. An abnormal qualitative RFF was observed in 12 patients with high probability, and the diagnostic sensitivity was 80.0% (95% CI, 51.9-95.7). The RFF was normal in 152 patients with low probability, and the diagnostic specificity was 96.2% (95% CI, 91.9-98.6). The RFF was lower in patients with high probability than in those with low probability (0.79 ± 0.15 vs. 1.02 ± 0.11, P < 0.0001). CONCLUSIONS: The RFF assessed by dynamic 99mTc-DTPA renal scintigraphy after ACE inhibition can detect patients with high probability for RVHT. The RFF after ACE inhibition might be a useful diagnostic criterion especially when baseline scintigraphy is not available for evaluating ACE inhibition-induced changes.

Feasibility of dynamic stress 201Tl/rest 99mTc-tetrofosmin single photon emission computed tomography for quantification of myocardial perfusion reserve in patients with stable coronary artery disease.

PURPOSE: We evaluated the feasibility of dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT imaging using a cardiac camera equipped with cadmium-zinc-telluride detectors for the quantification of myocardial perfusion reserve (MPR). METHODS: Subjects with stable known or suspected coronary artery disease (CAD) who had undergone or were scheduled to undergo fractional flow reserve (FFR) measurement were prospectively enrolled. Dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT imaging was performed using a dedicated multiple pinhole SPECT camera with cadmium-zinc-telluride detectors. MPR was derived using Corridor4DM software. RESULTS: A total of 34 subjects were enrolled (25 men and 9 women; mean age 60.4 years). FFR was measured in 65 coronary arteries with intermediate lesions. The average global MPR was 2.58 ± 1.03. Global MPR was associated with the extent of CAD (P = 0.028) and global summed stress score (r = -0.60, P < 0.001). Regional MPR showed a significant correlation with diameter stenosis (r = -0.57, P < 0.001), minimum lumen diameter (r = 0.50, P < 0.001), summed stress score (r = -0.52, P < 0.001) and FFR (r = 0.52, P < 0.001). The area under the receiver operating characteristic curve of MPR for the diagnosis of functionally significant stenosis (FFR ≤0.8) was 0.79 (P < 0.001). The sensitivity and specificity of regional MPR were 67% and 83%, respectively, using a cut-off value of 2.0. CONCLUSION: Dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT imaging and quantification of MPR is feasible in patients with stable CAD. The preliminary results of this study in a small number of patients require confirmation in a larger cohort to determine their implications for bolstering the role of SPECT imaging in the diagnosis and risk prediction of CAD.

Altered Biodistribution of 99mTc-DPD on Bone Scan After Intravenous Iron Supplement.

We report a case with altered biodistribution of 99mTc-dicarboxypropane diphosphonate (99mTc-DPD) on whole body bone scan after intravenous iron supplement therapy. A 47-year-old male patient who had recently been detected with a hepatic mass suggestive of hepatocellular carcinoma underwent bone scan as staging work-up before surgery. Bone scan images at 3 h after injection of 99mTc-DPD demonstrated unusually increased blood pool activities in the heart, liver, and spleen with usual skeletal uptakes. The patient had been treated for severe anemia from hemorrhoid with two intravenous administration of ferric hydroxide carboxymaltose complex at approximately 22 h and 2 h prior to the 99mTc-DPD injection, which we consider as the most probable cause of altered biodistribution of 99mTc-DPD.