Search

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 ​% and a success rate greater than 95 ​%, 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., Competing Interests: Declaration of competing interest All authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Context: Preoperative localization studies are standard practice in patients undergoing parathyroidectomy for primary hyperparathyroidism (pHPT). The most common modalities are neck ultrasound (US) and sestamibi scanning. However, the nature of pHPT is changing, with imaging increasingly yielding negative results. Numerous studies suggest unlocalized disease is associated with poor outcomes, calling into question whether such patients are best treated conservatively., Objective: This study aims to correlate parathyroidectomy outcomes with preoperative imaging in a single, high-volume institution., Methods: Data from a prospectively maintained departmental database of operations performed from 2017 to 2019 were analyzed. All patients undergoing first-time surgery for sporadic pHPT were included. Data collected included patient demographics, preoperative imaging, surgical strategy, and postoperative outcomes., Results: A total of 609 consecutive parathyroidectomies were included, with a median age of 59 years (range 20-87 years). The all-comer cure rate was 97.5%; this was 97.9% in dual localized patients (those with positive US and sestamibi), compared to 95.8% in the dual unlocalized group (those with negative US and sestamibi) (P = 0.33). Unilateral neck exploration was the chosen approach in 59.9% of patients with double-positive imaging and 5.7% of patients with double-negative imaging (otherwise, bilateral parathyroid visualization was performed). There was no significant difference in postoperative complications between patients undergoing unilateral or bilateral neck exploration., Conclusions: Patients with negative preoperative imaging who undergo parathyroidectomy are cured in almost 96% of cases, compared to 98% when the disease is localized. This difference does not reach statistical or clinical significance. These findings therefore support current recommendations that all patients with pHPT who are likely to benefit from operative intervention should be considered for parathyroidectomy, irrespective of preoperative imaging findings., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Primary hyperparathyroidism historically necessitated bilateral neck exploration to remove abnormal parathyroid tissue. Improved localization allows for focused parathyroidectomy with lower complication risks. Recently, positron emission tomography using radiolabeled 18F-fluorocholine demonstrated high accuracy in detecting these lesions, but its cost-effectiveness has not been studied in the United States., Methods: A decision tree modeled patients who underwent parathyroidectomy for primary hyperparathyroidism using single preoperative localization modalities: (1) positron emission tomography using radiolabeled 18F-fluorocholine, (2) 4-dimensional computed tomography, (3) ultrasound, and (4) sestamibi single photon emission computed tomography (SPECT). All patients underwent either focused parathyroidectomy versus bilateral neck exploration, with associated cost ($) and clinical outcomes measured in quality-adjusted life-years gained. Model parameters were informed by literature review and Medicare costs. Incremental cost-utility ratios were calculated in US dollars/quality-adjusted life-years gained, with a willingness-to-pay threshold set at $100,000/quality-adjusted life-year. One-way, 2-way, and threshold sensitivity analyses were performed., Results: Positron emission tomography using radiolabeled 18F-fluorocholine gained the most quality-adjusted life-years (23.9) and was the costliest ($2,096), with a total treatment cost of $11,245 or $470/quality-adjusted life-year gained. Sestamibi single photon emission computed tomography and ultrasound were dominated strategies. Compared with 4-dimentional computed tomography, the incremental cost-utility ratio for positron emission tomography using radiolabeled 18F-fluorocholine was $91,066/quality-adjusted life-year gained in our base case analysis, which was below the willingness-to-pay threshold. In 1-way sensitivity analysis, the incremental cost-utility ratio was sensitive to test accuracy, positron emission tomography using radiolabeled 18F-fluorocholine price, postoperative complication probabilities, proportion of bilateral neck exploration patients needing overnight hospitalization, and life expectancy., Conclusion: Our model elucidates scenarios in which positron emission tomography using radiolabeled 18F-fluorocholine can potentially be a cost-effective imaging option for primary hyperparathyroidism in the United States. Further investigation is needed to determine the maximal cost-effectiveness for positron emission tomography using radiolabeled 18F-fluorocholine in selected populations., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Preoperative parathyroid imaging guides surgeons during parathyroidectomy. This study evaluates the clinical impact of 18 F-fluorocholine positron emission tomography for preoperative parathyroid localization on patients with primary hyperparathyroidism., Methods: Patients with primary hyperparathyroidism and indications for parathyroidectomy had simultaneous 18 F-fluorocholine positron emission tomography imaging/magnetic resonance imaging. In patients who underwent subsequent parathyroidectomy, cure was based on lab values at least 6 months after surgery. Location-based sensitivity and specificity of 18 F-fluorocholine positron emission tomography imaging was assessed using 3 anatomic locations (left neck, right neck, and mediastinum), with surgery as the gold standard., Results: In 101 patients, 18 F-fluorocholine positron emission tomography localized at least 1 candidate lesion in 93% of patients overall and in 91% of patients with previously negative imaging, leading to a change in preoperative strategy in 60% of patients. Of 76 patients who underwent parathyroidectomy, 58 (77%) had laboratory data at least 6 months postoperatively, with 55/58 patients (95%) demonstrating cure. 18 F-fluorocholine positron emission tomography successfully guided curative surgery in 48/58 (83%) patients, compared with 20/57 (35%) based on ultrasound and 13/55 (24%) based on sestamibi. In a location-based analysis, sensitivity of 18 F-fluorocholine positron emission tomography (88.9%) outperformed both ultrasound (37.1%) and sestamibi (27.5%), as well as ultrasound and sestamibi combined (47.8%)., Conclusion: Long-term results in the first cohort in the United States to use 18 F-fluorocholine positron emission tomography for parathyroid localization confirm its utility in a challenging cohort, with better sensitivity than ultrasound or sestamibi., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Based on superior image quality, more accurate gated images, and lower radiation exposure to patients, Technetium-99m (Tc-99m) based tracers are preferred over Thallium-201 for SPECT myocardial perfusion imaging. The two Tc-99m tracers, sestamibi and tetrofosmin, have many similar characteristics but there are differences in blood and liver clearance rates, as well as the recommended time after injection for imaging to achieve optimal image quality. Because published peer-reviewed studies examining optimal times between injection and imaging are limited, it can be difficult to identify evidence-based opportunities to optimize imaging protocols. Using systematic literature review methods, this study was designed to identify and consolidate the available evidence on the use of sestamibi compared to tetrofosmin for variable injection to imaging times in regard to test efficiency, including test length and re-scan rates, and image quality, including overall quality and cardiac to extra-cardiac ratios. The composite of this data shows that earlier imaging with tetrofosmin is equivalent to later imaging with sestamibi when assessing subjective image quality or when quantifying heart-to-extra-cardiac ratios. Image quality and heart-to-extra-cardiac ratios comparing early versus later imaging with tetrofosmin were comparable if not equivalent to each other. The equivalency of the imaging quality occurs with 15 minutes (on average) earlier imaging compared to sestamibi and 30 minutes compared to standard time tetrofosmin. The subjective findings of equivalent image quality are also shown with objective measurements of heart-to-extra-cardiac ratios. In this review, the significantly shorter injection-to-acquisition times with tetrofosmin compared to sestamibi resulted in better efficiency and less waiting times for patients; in addition, significantly higher re-scan rates with sestamibi compared to tetrofosmin due to hepatic activity contributed to better throughput with tetrofosmin., (© 2020. The Author(s).)

There is a need for a sensitive, safe, and cost-effective tool for coronary assessment among asymptomatic post-operative children who have undergone arterial switch operation (ASO) for transposition of great arteries (TGA). Adenosine stress echocardiography may be useful in assessing major structures as well for coronary functional assessment. Twenty-six children [median age 6.0 years; IQR 4.9-7.1 years, (22 boys)], who had undergone ASO at a median age of 40 days (IQR 30-75 days), were prospectively included. Left ventricular ejection fraction (LVEF) was calculated in both rest and stress studies (140 µg/kg/min of adenosine IV over 4 min), along with assessment of regional myocardial wall motion. Coronary flow reserve (CFR) was also measured in the left anterior descending artery (LAD). Technetium 99m-MIBI [0.2mCi/kg] was injected after 2 min of adenosine infusion. Adenosine infusion had to be stopped in two children, due to transient atrioventricular (AV) block. The LVEF increased from 55.87 ± 7.27 to 61.20 ± 7.70% (p  < 0.001) with adenosine stress. No significant regional wall motion abnormality was seen in rest or stress. Distal LAD could not be visualized in four patients. Basal and peak coronary flow velocities were 41.51 ± 14.12 and 74.18 ± 6.01 cm/s. Mean CFR was 1.91 ± 0.51. Myocardial perfusion scintigraphy (MPS) was normal in all the patients. Four patients were lost to follow-up and remaining children did not develop any adverse events in the follow-up period of 64.5 ± 7.19 months. Adenosine stress echocardiography is feasible as the initial screening test in the assessment of asymptomatic post-operative children with ASO, at minimal to no inconvenience to the patient. The findings concurred with stress MPS.

Parathyroid exploration via a focused approach or bilateral neck exploration should be considered in the management of all types of hyperparathyroidism. Eutopic and ectopic, single or multiple glands can pose challenges to the surgeon and available preoperative imaging modalities may not be equally applicable or appropriate in all cases. We report an interesting case of parathyroid surgery where the patient presented with a rare ectopic adenoma in the form of a hyperparathyroid crisis.

Introduction: Reoperative parathyroidectomy for persistent and recurrent primary hyperparathyroidism is dependent on radiology. This study aimed to compare outcomes in reoperative parathyroidectomy at a single centre using a combination of traditional and newer imaging studies., Materials and Methods: Retrospective case note review of all reoperative parathyroidectomies for persistent and recurrent primary hyperparathyroidism over five years (June 2014 to June 2019; group A). Imaging modalities used and their positive predictive value, complications and cure rates were compared with a published dataset spanning the preceding nine years (group B)., Results: From over 2000 parathyroidectomies, 147 were reoperations (101 in group A and 46 in group B). Age and sex ratios were similar (56 vs 62 years; 77% vs 72% female). Ultrasound use remains high and shows better positive predictive value (76% vs 57 %). 99mTc-sestamibi use has declined (79% vs 91%) but the positive predictive value has improved (74% vs 53%). 4DCT use has almost doubled (61% vs 37%) with better positive predictive value (88% vs 75%). 18F-fluorocholine positron emission tomography-computed tomography and ultrasound-guided fine-needle aspiration for parathyroid hormone are novel modalities only available for group A. Both carried a positive predictive value of 100%. Venous sampling with or without angiography use has decreased (35% vs 39%) but maintains a high positive predictive value (86% vs 91%). Cure rates were similar (96% vs 100%). Group A had 5% permanent hypoparathyroidism, 1% permanent vocal cord palsy and 1% haematoma requiring reoperation. No complications for group B., Conclusion: Optimal imaging is key to good cure rates in reoperative parathyroidectomy. High-quality, non-interventional imaging techniques have produced a shift in the preoperative algorithm without compromising outcomes.

Coronary artery fistulas are abnormal vascular conduits, rarely related to atrioventricular conduction abnormalities. We report the case of a 52-year-old woman who presented with dyspnoea on exertion. Her ECG revealed advanced atrioventricular block and left bundle branch block. CT scans confirmed two fistulas, from the conus branch of right coronary artery and from the left anterior descending coronary artery, into the pulmonary artery. The patient underwent pacemaker implantation. To date, only nine patients with different degrees of heart blocks associated with coronary artery fistulas have been reported. Herein, we review and summarise previously reported cases of different degrees of heart blocks associated with coronary artery fistulas., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Primary hyperparathyroidism (HPT1) is the most frequent endocrinopathy in multiple endocrine neoplasia type 1 (MEN1). Its surgical management is challenging. We aimed to describe and compare the imaging findings of parathyroid ultrasound (US), sestaMIBI scintigraphy (sestaMIBI), and 18 F-fluorocholine (FCH) PET/CT in a series of MEN1 patients with HPT1., Methods: Retrospective analysis of a cohort of MEN1 patients with HPT1 assessed by parathyroid US, sestaMIBI scintigraphy and SPECT/CT, and FCH-PET/CT for potential surgery between 2015 and 2019., Results: Twenty-two patients with a confirmed diagnosis of MEN1 who presented with HPT1 and were assessed by the 3 imaging modalities were included. After imaging workups, 11 patients were operated on for the first time, 4 underwent a redo surgery, and 7 did not undergo an operation. The overall patient-based positivity rate of imaging was 91% (20 of 22) for parathyroid US and 96% (21 of 22) for both sestaMIBI and FCH-PET/CT. The 3 imaging modalities demonstrated negative findings in 1/22 patient who did not undergo surgery. Overall, 3 pathologic glands were not detected by any imaging technique. SestaMIBI and FCH-PET/CT both resulted in the same 3 false-positive results in ectopic areas with a significant uptake on two thymic carcinoid tumors and one inflammatory lymph node. FCH-PET/CT provided more surgically relevant data than sestaMIBI in 4/11 patients with initial surgery and in 1/4 patient who underwent redo surgery., Conclusions: Compared to sestaMIBI scintigraphy, FCH-PET/CT provides additional information regarding the number of pathologic parathyroid glands and their localization in MEN1 patients with HPT1.

We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available 99m Tc-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with 99m Tc-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with ~ 100 MBq [ 99m Tc]Tc-MIBI or ~ 150 MBq [ 99m Tc]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1 = "very poor" to 5 = "very good". Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time.

Background: This study aimed to compare the sensitivity of 99m Tc-MIBI SPECT/CT, 99m Tc-MIBI planar scintigraphy and ultrasonography (US) in patients with secondary hyperparathyroidism (SHPT), and to explore the factors that affect the sensitivity of 99m Tc-MIBI SPECT/CT., Methods: In this retrospective study, forty-six patients with SHPT who underwent 99m Tc-MIBI planar scintigraphy, 99m Tc-MIBI SPECT/CT and US were enrolled. They underwent surgery within 1 month. We compared the sensitivity of the different imaging methods based on the lesions according to the pathological results. The parathyroid lesions on 99m Tc-MIBI SPECT/CT images were divided into missed diagnosis group (MDG) and non-missed diagnosis group (NMDG). We compared the lesion to background ratio (LBR), maximum diameter, volume, the mean CT Hounsfield unit values (CT mean ) and location of lesions between MDG and NMDG., Results: The sensitivity of 99m Tc-MIBI SPECT/CT, 99m Tc-MIBI planar scintigraphy and US were 70.30% versus 48.48% versus 61.82%, respectively. The sensitivity of 99m Tc-MIBI SPECT/CT combined US was 79.39%, which was higher than 99m Tc-MIBI SPECT/CT with significant difference (P = 0.000). On 99m Tc-MIBI SPECT/CT images, the LBR, maximum diameter and volume of lesions in MDG was smaller than those in NMDG with significant difference (P < 0.001). The average LBR, maximum diameter and volume of lesions in MDG and NMDG were 3.42 ± 1.28, 9.32 ± 2.69 mm, 208.51 ± 163.22 mm 3 versus 6.75 ± 5.08, 15.03 ± 4.94 mm and 863.85 ± 1216.0 mm 3 , respectively., Conclusions: 99m Tc-MIBI SPECT/CT exhibited the highest sensitivity among the three methods. When 99m Tc-MIBI SPECT/CT combined with US, the sensitivity can be further improved. Lesions with lower MIBI uptake and smaller lesions on 99m Tc-MIBI SPECT/CT images were easily missed.

To compare the left ventricular (LV) phase dyssynchrony parameters obtained from Tc-99m Sestamibi SPECT (GSPECT) and F-18 FDG PET(GPET), as well as the prognostic values in patients with ischemic cardiomyopathy (ICM). Consecutive ICM patients referred for myocardial viability assessment were retrospectively evaluated and were followed-up for 21 ± 5 months. Phase parameter from both GSPECT and GPET were analyzed by QGS software, including histogram bandwidth (BW), standard deviation (SD) and entropy. Independent predictor for cardiac death was analyzed by Cox regression analysis. The estimated cardiac survival curve was analyzed by and was compared with the log-rank test. Eight-eight (mean age 56 ± 10, male 94%, LVEF SPECT 23 ± 10%) ICM patients were included for analysis. Moderate correlations were observed for BW (r = 0.65; p < 0.001), SD (r = 0.63; p < 0.001) and entropy (r = 0.73; p < 0.001) between GSPECT and GPET. Among all covariates, the extent of myocardial scar was significantly associated with the differences of SD (r = 0.22; p < 0.05) and entropy (r = - 0.7; p < 0.05), whereas the extent of myocardial viability was not (all p > 0.05). Entropy measured by GSPECT was the predictor for cardiac death (p = 0.037) while QRS duration was not. The cardiac survival of patients with a high entropy (≥ 59%) was significantly lower than that of patients with low entropy (< 59%) (p < 0.05). GSPECT and GPET-derived phase parameters were not interchangeable in ICM patients. Patients with LV dyssynchrony measured by gated SPECT were associated with a worse outcome.

Background: Secondary hyperparathyroidism (SHPT) usually requires parathyroidectomy when drug regimens fail. However, obtaining an exact preoperative map of the locations of the parathyroid glands is a challenge. The purpose of this study was to compare the diagnostic performance of US, dual-phase 99m Tc-MIBI scintigraphy, early and delayed 99m Tc-MIBI SPECT/CT in patients with SHPT., Methods: Sixty patients with SHPT who were undergoing dialysis were evaluated preoperatively by US, dual-phase 99m Tc-MIBI scintigraphy, early and delayed 99m Tc-MIBI SPECT/CT. Postoperative pathology served as the gold standard. The sensitivity, specificity, and accuracy were determined for each method. Spearman correlation analysis was used to analyse the correlation of hyperplastic parathyroid calcification with serum alkaline phosphatase (ALP) and parathyroid hormone (PTH)., Results: A total of 229 lesions in 60 patients were pathologically confirmed to be parathyroid hyperplasia, with 209 lesions in typical sites, 15 lesions in the upper mediastinum and 5 lesions in the thyroid. A total of 88.33% (53/60) of patients had four lesions. US, early and delayed 99m Tc-MIBI SPECT/CT had significantly higher sensitivity and accuracy than dual-phase 99m Tc-MIBI scintigraphy (P < 0.001). Furthermore, early 99m Tc-MIBI SPECT/CT had significantly higher sensitivity (P < 0.001) and accuracy (P = 0.001 and P < 0.001) than US and delayed 99m Tc-MIBI SPECT/CT. In patients with ectopic hyperplastic parathyroid glands, the sensitivity of early 99m Tc-MIBI SPECT/CT (90%) was significantly higher than that of US (55%) and dual-phase 99m Tc-MIBI scintigraphy (50%) (P < 0.05). The Spearman correlation results showed a significant albeit weak association between calcification and both serum PTH and ALP (P = 0.002)., Conclusion: The ability of early 99m Tc-MIBI SPECT/CT to detect hyperplastic parathyroid glands in patients with SHPT is superior to that of US, dual-phase 99m Tc-MIBI scintigraphy and delayed 99m Tc-MIBI SPECT/CT; furthermore, dual-phase 99m Tc-MIBI SPECT/CT is not essential.

Objective: Early identification of viable myocardium in ischemic cardiomyopathy (ICM) patients is essential for early intervention and better clinical outcome. 99mTechnetium (99mTc) sestamibi gated myocardial perfusion imaging (gMPI) is a well-established technique for myocardial viability evaluation. Detection of potentially viable segments is a predictor of hibernating myocardium. ICM patients with hibernation have a better prognosis after revascularization. We used a novel infusion technique to determine better viability detection preoperatively in challenging situations. Like thallium, does prolonged availability of sestamibi in circulation with additional low dose dobutamine steady infusion (DS Inf) facilitate improved myocardial viability?, Methods: A total of 58 ICM patients with infarct and left ventricular ejection fraction (LVEF) <45% underwent 99mTc sestamibi bolus injection followed by slow intravenous infusion single-photon emission computed tomography (SPECT) using a 2 day protocol. After acquiring the second set of 99mTc sestamibi infusion images, a third SPECT gMPI was performed during DS Inf., Results: A 17-segment myocardial model was used; 52 of 58 patients (548/986 segments) demonstrated perfusion defects (nonviable myocardium) on bolus study. Only 24 patients demonstrated viable segments by standard bolus imaging protocol. The slow MIBI infusion study demonstrated 158 viable segments (12 ICM patients), while combined infusion (99mTc sestamibi+DS Inf) exhibited an additional 6 patients with improved myocardial viability. Thus, 18 high risk patients benefited by this novel infusion technique to demonstrate viable myocardium on SPECT. There was a significantly higher sensitivity (p=0.05) and positive predictive value (p=0.01) in viability identification with the combined DS Inf technique. In dysfunctional segments, the rate of concordance for detecting viability between infusion and bolus techniques was 65%. Paired t test showed statistically significant improvement in viability detection with combined infusion compared to the bolus study (p=0.001)., Conclusion: This novel infusion technique was shown to be feasible and incremental in viability detection in ICM patients with severe left ventricular dysfunction. It is a robust tool to guide revascularization, in high risk ICM patients. This study also showed that patients with large transmural MI demonstrated no significant improvement in myocardial perfusion status using either protocol.

To test the utility of the Tc 99m -sestaMIBI myocardial perfusion stress test (MPS) over stress echo test (SEHO) in dyslipidemic patients with intermediate pre-test probability score. 56 dyslipidemic patients (42 males and 14 females) with a suspected/known ischaemic heart disease and intermediate pre-test probability score underwent MPS and SEHO. They were followed for 25.77 ± 6.19 months. The data about the new-onset cardiac events and possible coronary angiography (CA) were collected. MPS was positive in 80% of the patients, SEHO in 68% of the patients. Results of the SEHO and MPS showed a good correlation (p < 0.001, μ = 0.505). Both procedures had a good correlation with CA findings in the follow-up. Cardiac events occurred in 57% of the patients. The MPS result, SSS, SDS were significantly associated with the new-onset cardiac events (p < 0.05). The patients with higher SDS had more chance to get a cardiac event in the follow-up (ROC curve area = 0.719, p = 0.003). MPS sensitivity was 91%, specificity 56%; SEHO sensitivity 85% and specificity 61%. MPS may be useful in predicting a future cardiovascular event. It is sufficiently informative, objectified by quantification software, and with correspondingly reduced radiation doses it may be the method of choice in patients with intermediate pre-test probability score.

Objective: This study was an investigation of the role of left ventricular (LV) apical rotation seen in the early period after myocardial infarction (MI) in predicting infarct localization., Methods: A total of 124 patients with a ST-Segment elevation myocardial infarction (STEMI) diagnosis who underwent primary percutaneous coronary intervention (PCI) and 50 healthy volunteers with similar demographic characteristics were included in the study. The relationship between 2-dimenstional speckle tracking echocardiography (STE)-guided LV apical rotation angle measurements and technetium-99m sestamibi-single-photon emission computed tomography (SPECT)-guided infarct localization was evaluated. Conventional echocardiography and STE were performed on average 2 days after PCI, and gated SPECT myocardial perfusion imaging (MPI) was performed within an average of 60 days., Results: The apical rotation angle was lower in patients with an anterior MI compared with those who had an inferior MI and the control group (AntMI-InfMI: 6.51±2.4°, AntMI-Control: 13.20±2.5°, InfMI-Control: 14.3±2.1°; p value: 0.00, 0.00, 0.15, respectively). SPECT MPI analysis revealed the presence of an LV apical scar in all patients with acute anterior MI, but only 14 of those with inferior MI group (usually the inferoapical wall). The apical rotation angle recorded in patients with apical scar was lower than that of the patients without apical scar (7.6±2.8° and 14.5±2°, respectively; p=0.00). Receiver operating characteristic curve analysis yielded an area under the curve for apical rotation of 0.799 (p<0.01). The optimal cutoff value of 12.1° had a sensitivity of 78.3% and a specificity of 68.2% for predicting LV apical scar following STEMI., Conclusion: Detection of apical rotation angle decrease in the early period after STEMI may be useful in predicting extension of infarct scarring to the LV apex.

Aim: It has been postulated that gastro-oesophageal reflux disease (GORD) may trigger coronary ischaemia through viscerocardiac reflex vasoconstriction in subjects with ischaemic heart disease (IHD). Our aim was to estimate the prevalence of GORD in subjects with IHD who present with acute coronary syndrome (ACS) and to determine whether GORD may serve as a trigger for ischaemic events., Methods: Twenty patients with isolated reflux oesophagitis and 39 with acute coronary syndrome (ACS with concomitant GORD) were studied. Twenty-two subjects comprising normal volunteers and those who were admitted for minor surgical trauma were used as normal controls. All subjects underwent oesophago-gastroduodenal endoscopy (EGD) and acid instillation with hydrochloric acid (0.1 M), as well as nuclear imaging (sestaMIBI) with technetium 99 . Ischaemia was detected by ST depression using ECG monitoring for one hour during and immediately after EGD., Results: Of the 111 subjects with ACS, 39 (35.1%) had erosive GORD and comprised the study group. Subjects with ACS had more incidence of diabetes (p = 0.001), hypertension (p = 0.002), a history of smoking (p = 0.006) and elevated serum triglyceride levels (p = 0.008) compared to the GORD group. Risk-factor clustering in the form of the metabolic syndrome was more common in ACS subjects (44 vs 5%; p = 0.008). ST depression was documented in 8/39 (20.5%) patients in the ACS group and 5/20 (25%) in the GORD group (p = 0.958). Reversible perfusion defects on sestaMIBI scan were seen in 35.6% of the ACS subjects., Conclusions: Although GORD is common in subjects with ACS, we have not been able to show that GORD may serve as a trigger for ischaemia in these subjects.

Background Primary hyperparathyroidism is the third most common endocrine disorder for which surgical procedure called parathyroidectomy is the most effective treatment. Since the early 20th century, parathyroid surgery has improved extensively. With the advances in preoperative imaging and with understanding the causes of disease, new and minimally invasive surgical approaches overrode the standard bilateral exploratory operations. Directed parathyroidectomy is currently the standard technique for treatment of primary hyperparathyroidism worldwide. Conclusions Surgery is the only definitive treatment of primary hyperparathyroidism. The most appropriate type of surgical procedure depends on the number and localization of the hyperactive parathyroid glands, availability of modern imaging techniques, limitation of each type of procedure and expertise.

Hyperparathyroidism is a common endocrine disorder. The precise localization of causal parathyroid gland is crucial to guide surgical treatment. Several studies report the added value of 18F-fluorocholine (FCH) positron emission tomography-computed tomography (PET/CT) as second line imaging but rely on suboptimal first-line imaging using 99mTc-sestaMIBI dual phase scintigraphy. The aim of this study is to evaluate the percentage of successful parathyroid localization with FCH PET/CT after failure of a more sensitive first-line detection protocol associating neck ultrasonography and 99mTc-Pertechnetate/99mTc-sestaMIBI dual tracer subtraction scintigraphy.We included retrospectively 47 patients who underwent a FCH PET/CT as second line imaging for biologically proven primary hyperparathyroidism from November 2016 to October 2018 in Godinot Institute (Reims, France). 99mTc-Pertechnetate/99mTc-sestaMIBI dual tracer subtraction scintigraphy and neck ultrasonography were used as first-line imaging and failed to localize the causal parathyroid lesion in all cases.FCH PET/CT demonstrated at least 1 parathyroid target lesion in 29 patients (62%). 21/29 patients underwent surgery. Target lesions corresponded histologically to hyperfunctioning parathyroid glands for all 21 patients and surgery was followed by hyperparathyroidism biological resolution. Calcium serum levels were associated to FCH PET/CT positivity (P = .002) and a trend toward significance was seen for Parathyroid hormone (PTH) levels (P = .09).FCH PET/CT is a promising tool in second-line parathyroid imaging. Large prospective studies and cost-effectiveness analyses are needed to precise its role.

Purpose: Nuclear medicine myocardial perfusion imaging (MPI) in obese patients requires the administration of higher amounts of radioactivity, to compensate for the loss of photons due to the increased attenuation and scatter. The aim of the present study was to investigate whether an administered activity escalation protocol, proposed to yield the same effective dose irrespective of patient's weight, can also lead to images of comparable count density for all patients., Materials and Methods: 184 pharmacologically induced stress 99m-Tc MIBI and 99m-Tc tetrofosmin SPECT MPI examinations (123 males, 61 females) were included in this study. Body weight, BMI and chest circumference were collected for each patient. The administered activity was adjusted to body weight according to the IAEA protocol. Detector count rate (DCR) from the projection images and normal myocardial count rate (MCR) from the appropriately segmented reconstructed images, with and without attenuation correction, were recorded., Results: No statistically significant correlation was found between DCR and any anthropometric parameter. A weak correlation was observed between MCR and BMI and between MCR and chest circumference for male patients only, but even these correlations were eliminated after the application of attenuation correction. The anthropometric parameter that generally correlates more strongly with DCR/MBq and MCR/MBq was body weight for men and chest circumference for women., Conclusion: The IAEA activity escalation protocol used in this study leads to comparable image count densities, irrespective of body weight, for both men and women., (Copyright © 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

Background: Methionine uptake after myocardial infarction has been proven to reflect myocardial inflammation. The effect of postconditioning on the post-infarction inflammatory process, however, remains to be elucidated., Methods and results: In control (n=22) and postconditioning rats (n=23), the left coronary artery was occluded for 30 min, followed by reperfusion for 1, 3, 7, and 14 days. Postconditioning was performed immediately following the reperfusion. 14 C-methinine (0.74 MBq) and 201 Tl (14.8 MBq) were injected 20 and 10 min prior to sacrifice, respectively. One minute before sacrifice, 150-180 MBq of 99 m Tc-MIBI was injected immediately following the re-occlusion of the left coronary artery to verify the area at risk, and left ventricular triple-tracer autoradiography was performed. To examine the ventricular remodeling, echocardiography was performed 2 months after reperfusion in both groups (n=6 each). In the control rats, the methionine uptake ratios on days 1, 3, 7, and 14 were 0.74±0.12, 1.85±0.16, 1.48±0.10, 1.25±0.04, respectively. With postconditioning, methionine uptake was similar on day 3 (1.90±0.21), but was lower on day 7 (1.23±0.22, P<0.05) and day 14 (1.08±0.09, P<0.005). Echocardiography revealed that postconditioning reduced the ventricular end-diastolic (0.97±0.16 to 0.78±0.12 cm, P<0.05) and systolic (0.85±0.21 to 0.55±0.23 cm, P<0.05) dimensions and improved ventricular percentage fractional shortening (12±6.2 to 29±12 %, P=0.01)., Conclusions: 14 C-methinine imaging revealed that postconditioning accelerated resolution of inflammation and attenuated ventricular remodeling.

Introduction: Redo parathyroidectomy for persistent/recurrent primary hyperparathyroidism is associated with a higher risk of complications and should be planned only with convincing localisation. We assessed whether 18 fluorocholine positron emission tomography/computed tomography could identify parathyroid adenoma(s) in patients with persistent/recurrent primary hyperparathyroidism and negative conventional scans., Materials and Methods: A departmental database was used to identify patients with failed localisation attempts (sestamibi single photon emission computed tomography/computed tomography and/or computed tomography/magnetic resonance imaging and/or selective parathyroid hormone sampling) after previous unsuccessful surgery for primary hyperparathyroidism. 18 Fluorocholine positron emission tomography was performed in all patients and redo surgery offered to those with positive findings., Results: 18 Fluorocholine positron emission tomography incorporating arterial and portal phase enhanced computed tomography was performed in 12 patients with persistent/recurrent primary hyperparathyroidism (four men and eight women). Seven patients (58%) were cured after excision of adenomas located in ectopic positions ( n = 3) or in anatomical position ( n = 4). Five patients (42%) had persistent hypercalcaemia and repeat 18 fluorocholine scan confirmed that the area highlighted on preoperative scans was excised. The arterial phase enhancement of the computed tomography was significantly different between cured and not-cured patients ( P = 0.007). All seven cured patients had either a strong or weak enhancing pattern on computed tomography. Standardised uptake value at 60 minutes in patients with successful surgery (range 2.7-15.7, median 4.05) was higher than in patients with failed surgery (range 1.8-5.8, median 3.2) but was not statistically significant ( P = 0.300)., Discussion: 18 fluorocholine scanning can identify elusive parathyroid adenomas, including those that are ectopic, and is useful in the management of patients with persistent/recurrent primary hyperparathyroidism when first-line scans are negative. The grading of the arterial phase of computed tomography can help to differentiate between true adenomas and false positive targets (lymph nodes).

Purpose: Clinical symptoms and electrocardiographic changes in patients with Takotsubo syndrome can be similar to patients with myocardial infarction. The aim of the study was to assess the impact of SPECT/CT imaging on the diagnosis and management of Takotsubo syndrome (TTS)., Methods: Gated single photon emission computed tomography (SPECT)/CT after injection 99Tc-MIBI in resting conditions was performed in 27 patients with TTS using dual-head Symbia T6SPECT/CT hybrid device. CT data were used for attenuation correction of SPECT images and to assess the risk of coronary artery disease on the basis of coronary artery calcium score., Results: Abnormal myocardial perfusion was found in 20/27 patients. The mean defect size was 9.8 cm, the extent 11.7%, mean total perfusion defect was 10.36%, mean summed rest score (SRS) 6.71.Left ventricle ejection fraction was lower in patients with SRS at least 4 than in patients with SRS less than 4. Perfusion defect size, total perfusion defect, number of akinetic segments in echocardiography and number of segments with perfusion defect in SPECT were higher in the group with SRS at least 4. The applied attenuation correction algorithms did not change the result of our SPECT study., Conclusion: In the majority of patients with TTS perfusion in SPECT was normal or only minor perfusion defect was observed. Application of CT attenuation correction did not change the final result of myocardial perfusion imaging; therefore, the CT component of the SPECT/CT study performed for attenuation correction is not useful for TTS diagnosis.

Backgroud: This study compares the outcome of parathyroidectomy for primary hyperparathyroidism (PHPT) in patients whose adenomas' weights were at the extremes of the distribution curve. As the size of parathyroid adenomas influences the success rate of localization studies for PHPT, it is possible that a difference in cure rate could be observed between subgroups of patients., Materials and Methods: Data were retrieved from a prospective database maintained in a large university hospital., Results: From a cohort of 519 patients who underwent parathyroidectomy for PHPT, two subgroups of patients were identified based on the extreme 10% of the distribution curve for adenomas' weight: adenomas <300 mg ("dwarfs", n = 100, median 200 mg) and >3000 mg ("giants", n = 56, median 4300 mg). In comparison with giant adenomas, dwarf adenomas were associated with less severe hypercalcemia (median 2.84 versus 3.00 mmol/L, P < 0.001) and lower PTH (median 11.7 versus 25.6 pmol/L, P < 0.001). The occurrence of dwarf adenomas showed no trend during the study period (23/173 [13%] in 2000-2004 versus 36/217 [17%] in 2007-2011). Scan-directed parathyroidectomy was feasible in more patients with giant adenomas (59% versus 38%). Persistent disease was diagnosed in three patients with dwarf adenomas. Patients with giant adenomas had no recurrence during a follow-up of 40 mo even though eight patients had histological features suggestive of atypical/malignant tumors., Conclusions: Preoperative biochemistry is a poor predictor of adenomas' size even at the extremes of the distribution curve. Cure can be achieved in all patients with "dwarf" adenomas. Even in the presence of suspicious histological features, "giant" adenomas did not show malignant behavior., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: High background parenchymal uptake (BPU) on molecular breast imaging (MBI) has been identified as a breast cancer risk factor. We explored the feasibility of offering a short-term intervention of low-dose oral tamoxifen to women with high BPU and examined whether this intervention would reduce BPU., Methods: Women with a history of high BPU and no breast cancer history were invited to the study. Participants had an MBI exam, followed by 30 days of low-dose oral tamoxifen at either 5 mg or 10 mg/day, and a post-tamoxifen MBI exam. BPU on pre- and post-tamoxifen MBI exams was quantitatively assessed as the ratio of average counts in breast fibroglandular tissue vs. average counts in subcutaneous fat. Pre-tamoxifen and post-tamoxifen BPU were compared with paired t tests., Results: Of 47 women invited, 22 enrolled and 21 completed the study (10 taking 5 mg tamoxifen, 11 taking 10 mg tamoxifen). Mean age was 47.7 years (range 41-56 years). After 30 days low-dose tamoxifen, 8 of 21 women (38%) showed a decline in BPU, defined as a decrease from the pre-tamoxifen MBI of at least 15%; 11 of 21 (52%) had no change in BPU (within ± 15%); 2 of 21 (10%) had an increase in BPU of greater than 15%. Overall, the average post-tamoxifen BPU was not significantly different from pre-tamoxifen BPU (1.34 post vs. 1.43 pre, p = 0.11). However, among women taking 10 mg tamoxifen, 5 of 11 (45%) showed a decline in BPU; average BPU was 1.19 post-tamoxifen vs. 1.34 pre-tamoxifen (p = 0.005). In women taking 5 mg tamoxifen, 2 of 10 (20%) showed a decline in BPU; average BPU was 1.51 post-tamoxifen vs.1.53 pre-tamoxifen (p = 0.99)., Conclusions: Short-term intervention with low-dose tamoxifen may reduce high BPU on MBI for some patients. Our preliminary findings suggest that 10 mg tamoxifen per day may be more effective than 5 mg for inducing declines in BPU within 30 days. Given the variability in BPU response to tamoxifen observed among study participants, future study is warranted to determine if BPU response could predict the effectiveness of tamoxifen for breast cancer risk reduction within an individual., Trial Registration: ClinicalTrials.gov NCT02979301 . Registered 01 December 2016.

Ectopic parathyroid are most frequently found in the anterior mediastinum, in association with the thymus or the thyroid gland. Ectopic parathyroid glands are a major cause of persistent and recurrent Hyperparathyroidism. We report a case of 65-year-old female was referred from Surgical Endocrine department to the department of Cardiac Surgery on 20 September, 2017 in Bangabandhu Sheikh Mujib Medical University with parathyroid crisis due to an ectopic mediastinal parathyroid adenoma with her serum calcium and PTH markedly increased in short time. Computed tomography of the chest and lower neck showed an ovoid soft tissue density area measuring about 25×20×15mm in the anterior mediastinum. Technetium-99m-sestamibi (MIBI) scintigraphy scan showed positive and detected localized parathyroid adenoma/hyperplasia in superior mediastinum. Ectopic parathyroid adenoma resection was performed via median sternotomy approach. But after 4 hours patient developed the color change of the left arm due to acute left upper limb ischemia of unknown cause for which the patient was rushed to operation theatre suspecting it to be embolic occlusion and managed by both surgical and medical therapy.

Objectives: The study evaluated the automatic prediction of obstructive disease from myocardial perfusion imaging (MPI) by deep learning as compared with total perfusion deficit (TPD)., Background: Deep convolutional neural networks trained with a large multicenter population may provide improved prediction of per-patient and per-vessel coronary artery disease from single-photon emission computed tomography MPI., Methods: A total of 1,638 patients (67% men) without known coronary artery disease, undergoing stress 99m Tc-sestamibi or tetrofosmin MPI with new generation solid-state scanners in 9 different sites, with invasive coronary angiography performed within 6 months of MPI, were studied. Obstructive disease was defined as ≥70% narrowing of coronary arteries (≥50% for left main artery). Left ventricular myocardium was segmented using clinical nuclear cardiology software and verified by an expert reader. Stress TPD was computed using sex- and camera-specific normal limits. Deep learning was trained using raw and quantitative polar maps and evaluated for prediction of obstructive stenosis in a stratified 10-fold cross-validation procedure., Results: A total of 1,018 (62%) patients and 1,797 of 4,914 (37%) arteries had obstructive disease. Area under the receiver-operating characteristic curve for disease prediction by deep learning was higher than for TPD (per patient: 0.80 vs. 0.78; per vessel: 0.76 vs. 0.73: p < 0.01). With deep learning threshold set to the same specificity as TPD, per-patient sensitivity improved from 79.8% (TPD) to 82.3% (deep learning) (p < 0.05), and per-vessel sensitivity improved from 64.4% (TPD) to 69.8% (deep learning) (p < 0.01)., Conclusions: Deep learning has the potential to improve automatic interpretation of MPI as compared with current clinical methods., (Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objectives: This study sought to investigate whether patients with mental stress-induced myocardial ischemia will have high resting and post-mental stress high-sensitivity cardiac troponin I (hs-cTnI)., Background: Hs-cTnI is a marker of myocardial necrosis, and its elevated levels are associated with adverse outcomes. Hs-cTnI levels may increase with exercise in patients with coronary artery disease. Mental stress-induced myocardial ischemia is also linked to adverse outcomes., Methods: In this study, 587 patients with stable coronary artery disease underwent technetium Tc 99m sestamibi-single-photon emission tomography myocardial perfusion imaging during mental stress testing using a public speaking task and during conventional (pharmacological/exercise) stress testing as a control condition. Ischemia was defined as new/worsening impairment in myocardial perfusion using a 17-segment model., Results: The median hs-cTnI resting level was 4.3 (interquartile range [IQR]: 2.9 to 7.3) pg/ml. Overall, 16% and 34.8% of patients developed myocardial ischemia during mental and conventional stress, respectively. Compared with those without ischemia, median resting hs-cTnI levels were higher in patients who developed ischemia either during mental stress (5.9 [IQR: 3.9 to 8.3] pg/ml vs. 4.1 [IQR: 2.7 to 7.0] pg/ml; p < 0.001) or during conventional stress (5.4 [IQR: 3.9 to 9.3] pg/ml vs. 3.9 [IQR: 2.5 to 6.5] pg/ml; p < 0.001). Patients with high hs-cTnI (cutoff of 4.6 pg/ml for men and 3.9 pg/ml for women) had greater odds of developing mental (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.5 to 3.9; p < 0.001) and conventional (OR: 2.4; 95% CI: 1.7 to 3.4; p < 0.001) stress-induced ischemia. Although there was a significant increase in 45-min post-treadmill exercise hs-cTnI levels in those who developed ischemia, there was no significant increase after mental or pharmacological stress test., Conclusions: In patients with coronary artery disease, myocardial ischemia during either mental stress or conventional stress is associated with higher resting levels of hs-cTnI. This suggests that hs-cTnI elevation is an indicator of chronic ischemic burden experienced during everyday life. Whether elevated hs-cTnI levels are an indicator of adverse prognosis beyond inducible ischemia or whether it is amenable to intervention requires further investigation., (Copyright © 2018. Published by Elsevier Inc.)

Objective: To investigate the combined use of a nanocarbon (NC) suspension and low-dose 99m Tc-MIBI for parathyroid localization during surgery in patients with secondary hyperparathyroidism (sHPT)., Methods: Between March 2010 and September 2015, 40 patients with sHPT were enrolled in this study and were randomized to receive either low-dose 99m Tc-MIBI+NC (group I) or low-dose 99m Tc-MIBI (group II). Pre- and post-operative serum levels of intact PTH (iPTH), calcium and phosphorus between groups were compared and the intra-operative radioactive counts of the parathyroid glands were measured., Results: The post-operative iPTH level was significantly lower in patients of group I (24.2±31ng/L) than in those of group II (106±155ng/L) (P=0.03) while there were no significant differences in intra-operative parathyroid gland radioactive counts between the groups. The duration of the surgical procedure was shorter for patients of group I than patients of group II. There were no serious intra-operative or post-operative complications., Conclusion: The combined use of an NC suspension and 99m Tc-MIBI for patients with sHPT is strongly recommended for the localization of parathyroid glands during surgery and is likely to improve clinical outcomes for patients., (Copyright © 2018 Elsevier Inc. All rights reserved.)

(1) To evaluate the prognostic value of LV remodeling parameters in patients with LV aneurysm by gated SPECT (GSPECT), gated PET (GPET) and CMR; (2) to evaluate the impact of myocardial viability and LV remodeling on the long-term cardiac survival in patients with LV aneurysm. One hundred and twenty-six consecutive patients underwent GPET, GSPECT and CMR within two weeks, with a mean follow-up of 3.9 ± 1.5 years. End-diastolic volume (EDV, mL) and end-systolic volume (ESV, mL) measured by GPET, GSPECT and CMR and corrected for BSA; EDVI and ESVI were calculated. Patients were divided into three groups by aneurysmal viability [mismatch score (MMS) of aneurysm ≥2.0] and LV remodeling (ESVI by GPET > 60 mL/m 2 ). Group 1 (Viability -, LV remodeling -); Group 2 (Viability -, LV remodeling +) and Group 3 (Viability +, LV remodeling -/+). ESVI by GPET, MMS of aneurysm and summed rest score of aneurysm by multivariate regression analysis; as well as ESVI by GPET (HR 1.024, 95% CI 1.011-1.037, p = .0004), MMS of aneurysm (HR 1.284, 95% CI 1.051-1.577, p = .015) by interaction analysis were approved being independent predictors for cardiac death (p < .05). The long-term cardiac survival was significantly improved by revascularization in comparison with medical therapy in Group3 (p < .01), but did not significantly differ between Groups 1 and 2. ESVI by GPET showed a significant positive predictive value for cardiac death. Patients with viable myocardial aneurysm were most likely at increased risk for cardiac death and coronary revascularization was significantly associated with improved long-term cardiac survival. In contrast, the long-term cardiac survival of patients without LV remodeling and without aneurysmal viability was promising and, thus, could be treated by medical therapy.

Background: Interest in technetium-99m ( 99m Tc)-sestamibi imaging for neoadjuvant chemotherapy (NAC) response monitoring in locally advanced breast cancer (LABC) is increasing but remains matter of discussion. The present study conducted a meta-analysis of the diagnostic performance of 99m Tc-sestamibi to predict pathologic nonresponse to NAC for primary LABC., Materials and Methods: A systematic data search was performed. Studies with a minimum of 10 LABC patients that had evaluated 99m Tc-sestamibi imaging for NAC nonresponse using conventional planar scintimammography, breast-specific γ-imaging, and/or single photon emission computed tomography/computed tomography (SPECT/CT) were included. The histopathologic findings were the reference standard. The meta-analysis was performed using a mixed logistic regression model., Results: The search revealed 14 eligible studies with 529 patients. Of the 14 studies, 11 had evaluated scintimammography and 3 breast-specific γ-imaging. No studies examining SPECT or SPECT/CT were found. The overall estimated pooled sensitivity, specificity, and positive and negative likelihood ratios of 99m Tc-sestamibi imaging to predict nonresponsiveness to NAC were 70.3% (95% confidence interval [CI], 56.5%-81.3%%), 90.1% (95% CI, 77.5%-96.0%), 7.13 (95% CI, 3.08-16.53), and 0.33 (95% CI, 0.22-0.49), respectively. Only 3 studies (107 patients) evaluated 99m Tc-sestamibi imaging during NAC, reported an estimated pooled sensitivity of 87% (95% CI, 72%-100%) and specificity of 93% (95% CI, 85%-100%)., Conclusion: Only planar 99m Tc-sestamibi imaging has been investigated for NAC nonresponse in LABC but showed low sensitivity to predict pathologic nonresponse. However, most studies focused on the prediction of pathologic complete response after NAC. Although experience is limited, 99m Tc-sestamibi uptake during NAC seems highly sensitivity for the prediction of nonresponsiveness. Features such as SPECT/CT imaging, standardized quantification, relation to tumor subtypes, and proper timing have been insufficiently evaluated and require further investigation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

A middle-aged woman underwent Tc-sestamibi parathyroid scintigraphy because of parathyroid disease, and a focal pulmonary uptake of Tc-sestamibi was incidentally found on both planar and SPECT/CT images without corresponding pulmonary abnormality on the CT images. After 10 days, a subsequent parathyroid scintigraphy revealed no pulmonary accumulation. Therefore, the pulmonary intense Tc-sestamibi focus that once appeared in the first scan might be an artifact of iatrogenic microembolism from injection site.

To determine the prognostic value of a new, ultrafast, low dose myocardial perfusion SPECT (MPS) protocol in a cadmium-zinc telluride (CZT) camera. CZT cameras have introduced significant progress in MPS imaging, offering high-quality images despite lower doses and scan time. Yet, it is unknown if, with such protocol changes, the prognostic value of MPS is preserved. Patients had a 1-day 99 m-Tc-sestamibi protocol, starting with the rest (185-222 MBq) followed by stress (666-740 MBq). Acquisition times were 6 and 3 min, respectively. MPS were classified as normal or abnormal perfusion scans and summed scores of stress, rest, and difference (SSS, SRS and SDS), calculated. Patients were followed with 6-month phone calls. Hard events were defined as death or nonfatal myocardial infarction. Late revascularization was that occurring after 60 days of MPS. 2930 patients (age 64.0 ± 12.1 years, 53.3% male) were followed for 30.7 ± 7.5 months. Mean dosimetry was 6 mSv and mean total study time, 48 ± 13 min. The annual hard event and late revascularization rate were higher in patients with greater extension of defect and ischemia. SSS was higher in patients with hard events compared to those without events (2.6 ± 4.9 vs. 5.0 ± 6.3, p < 0.001), as well as the SDS (0.7 ± 1.9 vs. 1.7 ± 3.4, p < 0.00). The same was true for patients with or without late revascularization (SSS: 2.5 ± 4.7 vs. 6.6 ± 7.1; SDS: 0.6 ± 1.7 vs. 2.9 ± 3.8, p < 0.01). A new, faster, low-radiation, MPS protocol in a CZT camera maintain the ability to stratify patients with increased risk of events, showing that, in the presence of greater extension of defect or ischemia, patients presented higher rates of hard events and late revascularization.

Introduction Muscle perfusion is a physiologic process that can undergo quantitative assessment and thus define the range of normal values of perfusion indexes and perfusion reserve. The investigation of the microcirculation has a crucial role in determining the muscle perfusion. Materials and method The study included 30 examinees, 24-74 years of age, without a history of confirmed peripheral artery disease and all had normal findings on Doppler ultrasonography and pedo-brachial index of lower extremity (PBI). 99mTc-MIBI tissue muscle perfusion scintigraphy of lower limbs evaluates tissue perfusion in resting condition "rest study" and after workload "stress study", through quantitative parameters: Inter-extremity index (for both studies), left thigh/right thigh (LT/RT) left calf/right calf (LC/RC) and perfusion reserve (PR) for both thighs and calves. Results In our investigated group we assessed the normal values of quantitative parameters of perfusion indexes. Indexes ranged for LT/RT in rest study 0.91-1.05, in stress study 0.92-1.04. LC/RC in rest 0.93-1.07 and in stress study 0.93-1.09. The examinees older than 50 years had insignificantly lower perfusion reserve of these parameters compared with those younger than 50, LC (p=0.98), and RC (p=0.6). Conclusion This non-invasive scintigraphic method allows in individuals without peripheral artery disease to determine the range of normal values of muscle perfusion at rest and stress condition and to clinically implement them in evaluation of patients with peripheral artery disease for differentiating patients with normal from those with impaired lower limbs circulation.

Introduction: We aimed to evaluate whether the hyperemic myocardial blood flow (MBF) can be estimated using cadmium zinc telluride (CZT)-based single-photon emission computed tomography (SPECT) cameras with a single, rapid rest/stress dynamic scan. Dynamic contrast-enhanced (DCE) cardiac magnetic resonance imaging (MRI) was used as a reference modality for flow measurement., Materials and Methods: The proposed protocol included both the rest and stress acquisitions within a 24-min scan. Patients were first injected with 99mTc-Sestamibi at the resting state. Sixty minutes after the first injection, the subject was positioned via scintigraphy, after which the list-mode data acquisition was initiated and continued for 24 minutes. Five minutes after data acquisition was initiated, a stressed state was induced via dipyridamole infusion, after which a second dose of 99mTc-Sestamibi was injected. Dynamic SPECT images were reconstructed for all subjects, who also underwent T1-weighted cardiac DCE-MRI performed on days other than those of the SPECT studies. MBF values were estimated for the rest and stress MRI studies, and for the stress portion of the SPECT study. The SPECT-measured hyperemic MBF was compared with the MR-measured hyperemic MBF and coronary flow reserve (CFR), based on the regions of interest., Results: A total of 30 subjects were included in this study. The hyperemic MBF estimated from SPECT showed a strong correlation with the MR-measured hyperemic MBF (r2 = 0.76) and a modest correlation with the MR-measured CFR (r2 = 0.56). Using MR-measured CFR <1.3 as a cutoff for coronary stenosis, we found that the SPECT-measured hyperemic MBF served as a useful clinical index with 94% sensitivity, 90% specificity, and 93% accuracy., Conclusions: Hyperemic MBF can be measured with a rapid, single-scan rest/stress study with CZT-based SPECT cameras.

Quantitative 99m Tc-MIBI thyroid scintigraphy is a useful tool in differentiating malignant from benign thyroid nodules with indeterminate cytology. The aim of our report is to compare the diagnostic performance of different quantitative methods. We prospectively evaluated 20 patients affected by a thyroid nodule with a cytological diagnosis of class III or IV according to the Bethesda system. Planar images of the thyroid were acquired 10 and 60 minutes after 99m Tc-MIBI administration and two different quantitative methods applied (i.e. wash-out index, WOind; retention index, R.I.). All patients underwent lobectomy or thyroidectomy and final histological findings were matched with MIBI results obtained with both quantitative methods. Four out of 20 patients had a final histological result of differentiated thyroid cancer, while benign findings were found in the remaining cases. Overall sensitivity, specificity, accuracy, PPV and NPV were 100% in all for the WOind and 100%, 57.1%, 62.5%, 25% for the R.I., respectively. In conclusion 99m Tc-semiquantitative MIBI thyroid scintigraphy with WOind calculation is highly accurate in differential diagnosis of nodules with indeterminate cytology reading.

After dipyridamole infusion, electrocardiographic (ECG), blood pressure and heart rate (HR) changes were seen. We tried to investigate whether there is a relationship between hemodynamic, ECG and HR changes after dipyridamole infusion and gated myocardial perfusion SPECT findings. We studied 206 consecutive patients which underwent a 2-day protocol Dipyridamole Stress/Rest Tc99m-Sestamibi gated myocardial perfusion SPECT. Systolic blood pressure (SBP), diastolic blood pressure (DBP), HR and ECG were recorded. HR was mildly increased while SBP and DBP were mildly decreased after Dipyridamole infusion. There was only statistically significant difference between ECG changes as well as transient ischemic dilation (TID) ratio between normal scans and scans with ischemia (P = 0.02 and P = 0.01 respectively). There was correlation between these variables and summed stress score (SSS) and summed difference score (SDS). Patients with ischemia in their scans, 44.3% had ST depression after Dipyridamole infusion. Also ST depression most frequently was seen in patients with left anterior descending artery disease. From patients with abnormal scan + ST depression after Dipyridamole infusion (33 patient), 27 patient (81.81%) had ischemia. There was an association between TID ratio as well as ECG changes after Dipyridamole infusion and SSS, SDS and coronary artery territory abnormality. Difference between calculated left ventricular ejection fraction using stress and rest images had significant correlation with SSS and SDS. ST depression after Dipyridamole infusion and TID ratio had association with ischemia, SSS and SDS. So in equivocal Gated SPECT findings, they could be very useful for interpretation.

Background: Myocardial 18 F-deoxyglucose ( 18 F-FDG) uptake has been observed to be enhanced in patients with coronary artery disease (CAD) under fasting conditions. However, whether the increased 18 F-FDG is induced by myocardial ischemia and how to discriminate ischemic from physiological 18 F-FDG uptake have rarely been investigated., Methods: Under fasting conditions, 18 F-FDG PET imaging was performed in 52 patients with suspected CAD. Two 18 F-FDG imaging sessions were conducted within two hours after a single administration of 18 F-FDG (dual-time-point imaging), and with an intervention of an exercise test after the first imaging. Abnormal 18 F-FDG uptake was determined by the classification of the 18 F-FDG distribution pattern, and the changes of the 18 F-FDG distribution between the two PET imaging sessions were analyzed. 99m Tc-sestamibi was injected at peak exercise and myocardial perfusion imaging (MPI) was conducted after 18 F-FDG imaging. Coronary angiography was considered the reference for diagnosing CAD., Results: Overall, 54.8% (17/31) of CAD patients and 36.2% (21/58) of stenotic coronaries showed exercise-induced abnormal uptake of 18 F-FDG. Based on the classification of the 18 F-FDG distribution pattern, the sensitivity and specificity of exercise 18 F-FDG imaging to diagnose CAD was 80.6% and 95.2% by patient analysis, 56.9% and 98.0% by vascular analysis, respectively. Compared with MPI, 18 F-FDG imaging had a tendency to have higher sensitivity (80.6% vs 64.5%, P = 0.06) on the patient level., Conclusion: Myocardial ischemia can induce 18 F-FDG uptake. With the classification of the 18 F-FDG distribution pattern, dual-time-point 18 F-FDG imaging under fasting conditions is efficient in diagnosing CAD.

Background: Metastatic pulmonary calcification (MPC) is rarely reported in primary hyperparathyroidism, especially MPC develops quickly. We report such a case here with a literature review., Case Presentation: A 41-year-old woman presented with cough and dyspnea. Data from clinical, radiological, pathological, technetium ( 99m Tc)-methylene diphosphonate (MDP) bone scintillation imaging, and 99m Tc-methoxy isobutyl isonitrile (MIBI) thyroid imaging were studied. 99m Tc-MIBI thyroid imaging indicated hyperparathyroidism. Chest computed tomography (CT) scans showed rapidly progressive bilateral pulmonary multiple high-density shadows with mass consolidation and exudation in only five days. 99m Tc-MDP bone scintillation imaging indicated bilateral pulmonary calcifications. CT-guided lung biopsy showed multifocal irregularities of calcium deposition and calcified bodies in the pulmonary interstitium. The patient showed gradually clinical and radiological improvement after surgical removal of the parathyroid adenoma., Conclusion: Rapidly progressive MPC tends to be misdiagnosed as many primary pulmonary diseases. 99m Tc-MDP bone scintillation imaging and pulmonary biopsy could be performed to differentiate metastatic pulmonary calcification from other diseases. Surgical resection of the parathyroid gland is helpful for treatment of MPC in patients with primary hyperparathyroidism and is regularly recommended.

Background: Adenosine-assisted transthoracic Doppler-derived coronary flow reserve (TDE-CFR) reflects coronary vascular function. The prognostic and incremental value of left anterior descending coronary artery TDE-CFR above myocardial perfusion scintigraphy in patients with suspected myocardial ischemia has not yet been studied., Methods and Results: Three hundred seventy-one patients (mean age, 62.3±8.7 years; 46.8% males) referred to myocardial perfusion scintigraphy attributed to suspected myocardial ischemia were included in the study. The TDE-CFR result was blinded to the referring physician. Patients were followed up regarding major cardiovascular events, defined as cardiovascular death, myocardial infarction, or acute revascularization during a median follow-up time of 4.5 years. A TDE-CFR value of ≤2.0 was considered reduced. Major cardiovascular events occurred during follow-up in 60 patients (16.2%). A reduced TDE-CFR was detected in 76 patients (20.5%). Patients with reduced TDE-CFR had an event rate of 36.8% compared to 10.8% in patients with normal TDE-CFR (unadjusted hazard ratio, 4.63; 95% CI, 2.78-7.69; P <0.001). In a multivariate model, TDE-CFR remained a significant independent predictor of major cardiovascular events. The major cardiovascular events rate was 7.5% in patients without myocardial perfusion scintigraphy-detected myocardial ischemia and normal TDE-CFR (n=200), 24.2% in patients without ischemia but with reduced TDE-CFR (n=33), and 46.5% in patients with both myocardial perfusion scintigraphy-detected myocardial ischemia and a reduced TDE-CFR (n=43; P <0.001)., Conclusions: Coronary microvascular dysfunction, as determined by TDE-CFR, is a strong independent predictor of cardiovascular events and adds incremental prognostic value compared with myocardial perfusion scintigraphy. The current study supports routine assessment of CFR in patients with suspected ischemic heart disease., (© 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.)

Background: Surgical resection of the abnormal parathyroid glands is the only curative treatment for primary hyperparathyroidism (PHPT). Radioguided parathyroidectomy with technetium-99m (TC-99m) sestamibi has been successfully used in patients with PHPT. This study was designed to evaluate the results of a series of patients with PHPT who underwent minimally invasive radioguided parathyroidectomy (MIRP) using very low dose (1 mCi) of TC-99m sestamibi (MIBI) without application of intraoperative parathyroid hormone (PTH) assay or frozen section analysis., Methods: Eighty-seven patients with PHPT were prospectively studied from November 2012 to January 2015. Following neck ultrasound (US) and MIBI scan concordant for single gland disease, patients underwent MIRP using a handheld gamma probe. The technique involved injecting of 1 mCi MIBI in the operative room before the beginning of the intervention. All patients were followed up for a minimum of 6 months postoperatively., Results: MIRP was successfully performed in 86 out of 87 patients (98.85%). The Gamma probe was particularly useful in detection of ectopic parathyroid adenomas in upper mediastinum. Mean operative time was 23.95 ± 7.982 min and mean hospital stay was 1.44 ± 0.604 days. No major surgical complications were recorded., Conclusions: The MIRP technique using very low dose (1 mCi) of Tc-99m MIBI without intraoperative PTH assay and frozen section analysis resulted in excellent cure rate for PHPT. This technique involves a radiation exposure to patients and surgical staffs 20 times lower than conventional MIRP using 20 mCi Tc-99m MIBI. Besides, patients with PHPT due to ectopic parathyroid adenoma may especially benefit from MIRP., (Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Purpose To examine the relation between the lung elimination rate of inhaled technetium 99m ((99m)Tc)-sestamibi and immunohistochemical expression of bronchopulmonary multidrug resistance protein 1 (MRP1) and permeability glycoprotein (P-gp) and assess the repeatability of the inhaled (99m)Tc-sestamibi clearance technique. Materials and Methods (99m)Tc-sestamibi is a known substrate for P-gp and MRP1, which are established cellular drug efflux transporters. The elimination rate of (99m)Tc-sestamibi from the lungs after inhalation as an aerosol has been hypothesized to be regulated by expression of these transporters. Institutional ethics committee approval was received for this prospective study. Written informed consent was obtained from all participants. The clearance of inhaled (99m)Tc-sestamibi from the lungs of 13 patients due to undergo surgery for primary lung cancer (five of 13) or spontaneous pneumothorax (eight of 13) was estimated after dynamic imaging of the lungs during a period of 40 minutes. The time taken to clear 50% of inhaled sestamibi (T1/2) was compared with a semiquantitative immunohistochemical assessment (grade 0-3) of MRP1 and P-gp expression in the lung by using parametric and nonparametric tests. The study was repeated in five participants to assess the repeatability of the technique by using a Bland Altman analysis method. Results MRP1 expression was seen in 12 of 13 patients, while P-gp expression was seen in only two. The mean (99m)Tc-sestamibi elimination rate was faster in patients (n = 6) with low levels of MRP1 expression (grade 0-1) and mean T1/2 of 105 minutes ± 20 (standard deviation), compared with those with higher levels of MRP1 expression (grade 2-3, n = 7) and mean T1/2 of 149 minutes ± 28 (P = .008). Bland-Altman analysis revealed excellent agreement between test and retest values. Conclusion Inhaled (99m)Tc-sestamibi clearance study is a repeatable technique demonstrating significant correlation with MRP1 expression in the lungs. (©) RSNA, 2016.