Search

The aim of this guideline is to provide recommendations for the implementation of an effective and efficient quality control (QC) programme for SPECT and PET systems in a preclinical imaging lab. These recommendations aim to strengthen the translational power of preclinical imaging results obtained using preclinical SPECT and PET. As for clinical imaging, reliability, reproducibility, and repeatability are essential when groups of animals are used in a longitudinal imaging experiment. The larger the variability of the imaging endpoint, the more animals are needed to be able to observe statistically significant differences between groups. Therefore, preclinical imaging requires quality control procedures to maintain reliability, reproducibility, and repeatability of imaging procedures, and to ensure the accuracy and precision of SPECT and PET quantification. While the Physics Committee of the European Association of Nuclear Medicine (EANM) has already published excellent procedure guidelines for Routine Quality Control Recommendations for Nuclear Medicine Instrumentation that also includes procedures for small animal PET systems, and important steps have already been made concerning preclinical quality control aspects, this new guideline provides a review and update of these previous guidelines such that guidelines are also adapted to new technological developments., (© 2024. The Author(s).)

Background: Qualification and interpretation standards are essential for establishing 99m Tc-SPECT MPI accuracy vs. alternative modalities., Methods: Rest-stress 99m Tc-SPECT phantom scans were acquired on 35 cameras. LV defects were quantified with summed stress (SSS) and difference scores (SDS) at 2 core labs. SDS ≥ 2 in the right coronary artery (RCA) was the qualifying standard. Twenty rest (R)-stress (S) patient images were acquired on qualified cameras and interpreted by core labs. Global scoring differences > 3 between labs or discordant clinical interpretations underwent review. Scoring, interpretation, image quality, and diagnostic parameter agreement were assessed., Results: Phantom scans: visual scoring confirmed RCA-ischemia on all cameras. Regional SSS, SDS agreement was moderate to very good: ICC-r = 0.57, 0.84. Patient scans: 90% of global SSS, 85% of SDS differences were ≤ 3. Regional SSS, SDS agreement: ICC-r = 0.87, 0.86, and global abnormal (SSS ≥ 4) and ischemic (SDS ≥ 2) interpretation: ICC-r = 0.90 were excellent. Clinical interpretation agreement was 100% following review. Image quality agreement was 70%. Automated metrics also agreed: ischemic total perfusion deficit ICC-r = 0.75, reversible perfusion defect, transient ischemic dilation, and S-R LV ejection fraction ICC-r ≥ 0.90., Conclusion: Quantitative scoring and interpretation of scans were highly repeatable with site qualification and clinical interpretation standardization, indicating that dual-core lab interpretation is appropriate to determine 99m Tc-SPECT MPI accuracy., (© 2020. American Society of Nuclear Cardiology.)

Objective: To provide evidence that cardiac I-123-metaiodobenzylguanidine sympathetic innervation imaging (MIBG) scintigraphy differentiates probable mild cognitive impairment with Lewy bodies (MCI-LB) from mild cognitive impairment due to Alzheimer disease (MCI-AD), we scanned patients with MCI and obtained consensus clinical diagnoses of their MCI subtype. We also performed baseline FP-CIT scans to compare the accuracy of MIBG and FP-CIT., Methods: We conducted a prospective cohort study into the accuracy of cardiac MIBG scintigraphy in the diagnosis of MCI-LB. Follow-up clinical assessment was used to diagnose MCI-AD (no core features of MCI-LB and normal FP-CIT), probable MCI-LB (2 or more core features, or 1 core feature with abnormal FP-CIT), or possible MCI-LB (1 core feature or abnormal FP-CIT). For the comparison between MIBG and FP-CIT, only core clinical features were used for diagnosis., Results: We recruited 95 people with mild cognitive impairment. Cardiac MIBG was abnormal in 22/37 probable and 2/15 possible MCI-LB cases and normal in 38/43 MCI-AD cases. The sensitivity in probable MCI-LB was 59% (95% confidence interval [CI], 42%-75%), specificity 88% (75%-96%), and accuracy 75% (64%-84%). The positive likelihood ratio was 5.1 and negative likelihood ratio 0.46. With symptom-only diagnoses, the accuracies were 79% for MIBG (95% CI, 68%-87%) and 76% for FP-CIT (95% CI, 65%-85%)., Conclusions: Cardiac MIBG appears useful in early disease, with an abnormal scan highly suggestive of MCI-LB. Validation in a multicenter setting is justified., Classification of Evidence: This study provides Class I evidence that cardiac MIBG distinguishes MCI-LB from MCI-AD., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background: Consistency of results between different readers is an important issue in medical imaging, as it affects portability of results between institutions and may affect patient care. The International Atomic Energy Agency (IAEA) in pursuing its mission of fostering peaceful applications of nuclear technologies has supported several training activities in the field of nuclear cardiology (NC) and SPECT myocardial perfusion imaging (MPI) in particular. The aim of this study was to verify the outcome of those activities through an international clinical audit on MPI where participants were requested to report on studies distributed from a core lab., Methods: The study was run in two phases: in phase 1, SPECT MPI studies were distributed as raw data and full processing was requested as per local practice. In phase 2, images from studies pre-processed at the core lab were distributed. Data to be reported included summed stress score (SSS); summed rest score (SRS); summed difference score (SDS); left ventricular (LV) ejection fraction (EF) and end- diastolic volume (EDV). Qualitative appraisals included the assessment of perfusion and presence of ischemia, scar or mixed patterns, presence of transient ischemic dilation (TID), and risk for cardiac events (CE). Twenty-four previous trainees from low- and middle-income countries participated (core participants group) and their results were assessed for inter-observer variability in each of the two phases, and for changes between phases. The same evaluations were performed for a group of eleven international experts (experts group). Results were also compared between the groups., Results: Expert readers showed an excellent level of agreement for all parameters in both phase 1 and 2. For core participants, the concordance of all parameters in phase 1 was rated as good to excellent. Two parameters which were re-evaluated in phase 2, namely SSS and SRS, showed an increased level of concordance, up to excellent in both cases. Reporting of categorical variables by expert readers remained almost unchanged between the two phases, while core participants showed an increase in phase 2. Finally, pooled LVEF values did not show a significant difference between core participants and experts. However, significant differences were found between LVEF values obtained using different software packages for cardiac analysis., Conclusions: In this study, inter-observer agreement was moderate-to-good for core group readers and good-to-excellent for expert readers. The quality of reporting is affected by the quality of processing. These results confirm the important role of the IAEA training activities in improving imaging in low- and middle-income countries.

Background: To determine diagnostic performance of non-invasive tests using invasive fractional flow reserve (FFR) as reference standard for coronary artery disease (CAD)., Methods: Medline, Embase, and citations of articles, guidelines, and reviews for studies were used to compare non-invasive tests with invasive FFR for suspected CAD published through March 2017., Results: Seventy-seven studies met inclusion criteria. The diagnostic test with the highest sensitivity to detect a functionally significant coronary lesion was coronary computed tomography (CT) angiography [88%(85%-90%)], followed by FFR derived from coronary CT angiography (FFR CT ) [85%(81%-88%)], positron emission tomography (PET) [85%(82%-88%)], stress cardiac magnetic resonance (stress CMR) [81%(79%-84%)], stress myocardial CT perfusion combined with coronary CT angiography [79%(74%-83%)], stress myocardial CT perfusion [77%(73%-80%)], stress echocardiography (Echo) [72%(64%-78%)] and stress single-photon emission computed tomography (SPECT) [64%(60%-68%)]. Specificity to rule out CAD was highest for stress myocardial CT perfusion added to coronary CT angiography [91%(88%-93%)], stress CMR [91%(90%-93%)], and PET [87%(86%-89%)]., Conclusion: A negative coronary CT angiography has a higher test performance than other index tests to exclude clinically-important CAD. A positive stress myocardial CT perfusion added to coronary CT angiography, stress cardiac MR, and PET have a higher test performance to identify patients requiring invasive coronary artery evaluation., (Copyright © 2019 Elsevier B.V. All rights reserved.)

One of the most commonly used imaging techniques for diagnosing pulmonary embolism (PE) is ventilation/perfusion (V/P) scintigraphy. The aim of this study was to evaluate the performance of the currently used imaging protocols for V/P single photon emission computed tomography (V/P SPECT) at two nuclear medicine department sites and to investigate the effect of altering important protocol parameters. The Monte Carlo technique was used to simulate 4D digital phantoms with perfusion defects. Six imaging protocols were included in the study and a total of 72 digital patients were simulated. Six dually trained radiologists/nuclear medicine physicians reviewed the images and reported all perfusion mismatch findings. The radiologists also visually graded the image quality. No statistically significant differences in diagnostic performance were found between the studied protocols, but visual grading analysis pointed out one protocol as significantly superior to four of the other protocols. Considering the study results, we have decided to harmonize our clinical protocols for imaging patients with suspected PE. The administered Technegas and macro aggregated albumin activities have been altered, a low energy all purpose collimator is used instead of a low energy high resolution collimator and the acquisition times have been lowered.

Objectives: This study sought to: 1) determine if the current training volume guidelines are reasonable for attaining competence for interpreting myocardial perfusion imaging (MPI); and if not, 2) identify potential thresholds for training volumes and competence., Background: There is a growing desire to adopt competency-based medical education (CBME). As such, the implementation of CBME will require new and novel methods of defining, measuring, and assessing clinical competence. The potential use of CBME in cardiac imaging has not been well studied., Methods: Consecutive MPI studies were interpreted independently by trainees, and expert readers reviewed the same studies. Studies were quantified using summed scores and % left ventricular (LV) ischemia and the kappa agreement between trainee and expert were measured every 50 cases. Agreement for all MPI and abnormal MPI cases was calculated., Results: A total of 24 trainees interpreted 9,668 MPI studies over 37 months. Agreement between trainees and expert readers increased with MPI case volumes but at different rates. The threshold for competence was set at 2 SDs below expert interobserver agreement. The average trainee surpassed this threshold for both summed stress score and %LV ischemia after 800 studies and after 400 abnormal MPI studies. Trainees learned at different rates and surpassed the competence threshold after different case volumes., Conclusions: The use of CBME within nuclear cardiology appears to be feasible. Our results suggest that current guidelines may be insufficient to ensure competence and would support the need to increase the MPI case volumes. The use of CBME principles would suggest that trainees may achieve competence at different rates and our results suggest a shift in focus from volume-based learning toward target agreement thresholds., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: In the current clinical practice, administered activity (AA) for pediatric molecular imaging is often based on the North American expert consensus guidelines or the European Association of Nuclear Medicine dosage card, both of which were developed based on the best clinical practice. These guidelines were not formulated using a rigorous evaluation of diagnostic image quality (IQ) relative to AA. In the guidelines, AA is determined by a weight-based scaling of the adult AA, along with minimum and maximum AA constraints. In this study, we use task-based IQ assessment methods to rigorously evaluate the efficacy of weight-based scaling in equalizing IQ using a population of pediatric patients of different ages and body weights., Methods: A previously developed projection image database was used. We measured task-based IQ, with respect to the detection of a renal functional defect at six different AA levels (AA relative to the AA obtained from the guidelines). IQ was assessed using an anthropomorphic model observer. Receiver-operating characteristics (ROC) analysis was applied; the area under the ROC curve (AUC) served as a figure-of-merit for task performance. In addition, we investigated patient girth (circumference) as a potential improved predictor of the IQ., Results: The data demonstrate a monotonic and modestly saturating increase in AUC with increasing AA, indicating that defect detectability was limited by quantum noise and the effects of object variability were modest over the range of AA levels studied. The AA for a given value of the AUC increased with increasing age. The AUC vs AA plots for all the patient ages indicate that, for the current guidelines, the newborn and 10- and 15-yr phantoms had similar IQ for the same AA suggested by the North American expert consensus guidelines, but the 5- and 1-yr phantoms had lower IQ. The results also showed that girth has a stronger correlation with the needed AA to provide a constant AUC for 99m Tc-DMSA renal SPECT., Conclusions: The results suggest that (a) weight-based scaling is not sufficient to equalize task-based IQ for patients of different weights in pediatric 99m Tc-DMSA renal SPECT; and (b) patient girth should be considered instead of weight in developing new administration guidelines for pediatric patients., (© 2019 American Association of Physicists in Medicine.)

Background/aim: The aim of the study was to prospectively compare I-131 postablation Whole Body scan (WBS) and Single Photon Emission Computerized Tomography/Computerized Tomography (SPECT/CT) scan on thyroid cancer patients., Patients and Methods: Overall, 58 patients with papillary thyroid carcinoma were submitted to total thyroidectomy and I-131 remnant ablation. Post-ablation WBS and SPECT/CT scans performed on the same day were compared. Results of SPECT/CT were confirmed by neck and upper mediastinum ultrasound scan and on specific cases by a fully diagnostic CT scan, other tests and definitive histology acting as the gold standard. A total of 36/58 patients were followed-up for 5 years to detect relapse., Results: Mac Nemar Chi square and Fisher's exact tests disclosed statistically significant differences between WBS and SPECT/CT scan, concerning cervical lymphadenopathy detection (p=0.031) and relapse prediction by NM stage (p=0.033), respectively; SPECT/CT was more accurate in both comparisons., Conclusion: In papillary thyroid carcinoma I-131 post-ablation SPECT/CT scan detects cervical lymphadenopathy and predicts relapse by NM stage more accurately than WBS., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: ECG-gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy combined with phase analysis allows for the assessment of left ventricular dyssynchrony. However, there are several software programs available thereby introducing variability in outcome and normal values. The aim of this systematic review was to evaluate the variability between different programs as currently available in literature with a focus on normal values., Methods: A systematic review was performed using the Embase, LILACS and Medline databases looking for articles reporting on normal values of the most used phase analysis parameters. The search resulted in 110 articles from Medline, 349 from Embase and one from LILACS. After exclusion of duplicate articles, 370 documents remained. Of these only 13 were deemed eligible for the systematic review., Results: Phase SD and bandwidth are the main parameters used in dyssynchrony analysis. Most articles reviewed here used the Emory Cardiac ToolBox (ECTb) to determine the phase analysis parameters values, which varied greatly among the four software tested. The bandwidth and phase SD calculated by the Quantitative Gated SPECT (QGS) tends to be smaller than that calculated by the ECTb. In relation to the bandwidth, ECTb and cardioREPO (cREPO) have higher values than the other software programs. The value of entropy obtained from 4DM is lower than those obtained from QGS and cREPO., Conclusion: We found that normal values of phase analysis can vary among software programs and can be different even when the same software is used.

Purpose: To determine whether the assessment of regional wall thickening (WT) in addition to myocardial perfusion from stress supine acquisitions could compensate for the lack of prone acquisition and the corresponding decrease in the diagnostic performance of SPECT myocardial perfusion imaging (MPI) in patients with known or suspected coronary artery disease (CAD)., Methods: The study group comprised 41 patients (123 vessels) with known or suspected CAD prospectively recruited for systematic prone and supine 201 Tl stress SPECT MPI. The diagnostic performance of SPECT MPI was determined for various image sets including nongated supine images (supine NG), nongated combined prone and supine images (prone and supine NG) and gated supine images, allowing WT evaluation from NG images in addition to perfusion (supine NG + WT) using invasive coronary angiography and fractional flow reserve as the gold standards., Results: The rate of false positives was significantly higher among the supine NG images (20.8%) than among either the prone and supine NG or the supine NG + WT images (3.3% and 2.7%, respectively, P < 0.05 vs. supine NG). Consequently, specificity was higher for the prone and supine NG images than for the supine NG images (96.1% vs. 76.1%, P < 0.01) and was highest for the supine NG + WT images (96.8%, P not significant vs. prone and supine NG), without significant differences in sensitivity (80.0%, 86.6% and 73.3%, respectively, P not significant for all comparisons)., Conclusion: The diagnostic performance of supine stress SPECT MPI is improved when WT assessment of ischaemic segments is used as an additional diagnostic criterion to values not significantly different from those with combined prone and supine acquisitions.

This study aimed to assess efficacy and limitations of regional cerebral blood flow imaging using single-photon emission computed tomography (rCBF-SPECT) in the diagnosis of Alzheimer's disease (AD) with amyloid-positron emission tomography (amyloid-PET). Thirteen patients, who underwent both rCBF-SPECT and amyloid-PET after clinical diagnosis of AD or mild cognitive impairment, were retrospectively identified. The rCBF-SPECTs were classified into 4 grades, from typical AD pattern to no AD pattern of hypoperfusion; amyloid-beta (Aβ) positivity was assessed by amyloid-PET. Four patients were categorized into a typical AD pattern on rCBF-SPECT, and all were Aβ+. The other 9 patients did not exhibit a typical AD pattern; however, 4 were Aβ+. The Mini-Mental State Examination score and Clinical Dementia Rating scale were not significantly different between Aβ+ and Aβ- patients. A typical AD pattern on rCBF-SPECT can reflect Aβ+; however, if not, rCBF-SPECT has a limitation to predict amyloid pathology.

We evaluated the reproducibility of I-ioflupane (I-FP-CIT) SPECT with shorter scan times using a CZT camera. One hundred ninety-nine I-FP-CIT SPECT scans obtained with standard scan time (30 minutes) were truncated to provide 24-, 18-, and 15-minute study simulations. Striatal binding ratios were automatically calculated and remained stable for all series. At 15 minutes, only 10 of 398 striata (2.5%) showed statistically significant different striatal binding ratios compared with reference series. These series were reviewed by 2 operators, and a perfect agreement was found for each patient. Therefore, CZT camera allows a 2-fold scan time reduction in I-FP-CIT SPECT.

Introduction: The added value of dopamine transporter SPECT (DAT-SPECT) for the diagnosis of "possible" multiple system atrophy of the cerebellar type (MSA-C) remains unknown., Methods: We reviewed retrospectively the charts of 128 consecutive patients with a clinical diagnosis of MSA-C who were seen between 2007 and 2016 at the French Reference Center for MSA. The main objective was to evaluate the proportion of patients for whom the diagnosis of "possible" MSA-C was made because of a positive DAT-SPECT., Results: Seventy-eight MSA-C patients had at least one DAT-SPECT. Fifty-nine of them were considered for the final analysis. In these, 22 had "possible" MSA-C and 23 "probable" MSA-C before DAT-SPECT, while 14 did not reach diagnosis criteria at that time. In those with "possible" MSA-C, DAT-SPECT was positive in 64%. In patients with "probable" MSA-C, 83% showed nigrostriatal denervation. Six out of 14 (43%) received a diagnosis of "possible" MSA-C because of positive DAT-SPECT. These patients had mean disease duration of 2.3 years at the time of DAT-SPECT compared to 3.5 years of the entire cohort of MSA-C patients with DAT-SPECT. Of the eight remaining, one had positive DAT-SPECT but also pons atrophy on magnetic resonance imaging, and seven progressed to "probable" MSA based on clinical features., Conclusion: Our results suggest that DAT-SPECT significantly contributes to the diagnosis of "possible" MSA-C (43% of patients not reaching consensus diagnosis criteria before DAT-SPECT). DAT-SPECT seems especially useful in patients with shorter disease duration, while a negative result does not exclude a diagnosis of MSA., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Direct invasive testing in the diagnosis of stable coronary artery disease (CAD) involves high costs and relevant risks. By comparison, single-photon emission computed tomography (SPECT) and cardiac magnetic resonance imaging (CMR) are noninvasive diagnostic tests. SPECT is currently the most widely used diagnostic technique, but new medical and economic evidence favours CMR. Guidelines do not recommend one technique in preference to the other, and their use in Switzerland is poorly documented, as a scoping study by the Swiss Medical Board reported. We aimed at a quantitative and qualitative analysis of the use of these diagnostic techniques in Swiss hospitals., Methods: We contacted nine Swiss hospitals to obtain the number of SPECT/CMR investigations used to diagnose stable CAD in 2014&ndash;2016 and submitted a questionnaire to investigate the advantages and limitations of the two imaging techniques. In addition, two experts in SPECT and CMR, respectively, at two university hospitals were interviewed, using open questions., Results: Data were obtained from 8 hospitals, and 22 questionnaires were returned. In Switzerland, both techniques have been implemented very differently in different hospitals, but the overall number of diagnostic procedures has increased. The questionnaires reported lower scores for CMR regarding the availability of the scans, contraindications and the suitability of the technique for the diagnosis of CAD. The experts described potential conflicts of interest in some institutions, depending on how the cardiology and radiology departments collaborated, and highlighted the debated results of studies comparing CMR with SPECT for the diagnosis of CAD. The main conclusion drawn from the interviews was the recommendation of a patient-centred evaluation., Conclusion: The use of SPECT versus CMR in Switzerland for the diagnosis of stable CAD is heterogeneous, but reflects the guidelines, which do not distinguish between the two diagnostic techniques. Expert opinions underlined that discussion should not be so much about the choice of the diagnostic modality but about how a clinical question in a patient can best be answered.

Objective: The quantitative values of the specific binding ratio (SBR) in [I]FP-CIT have been reported to change because of differences in apparatus, collection conditions, and image reconstruction. The aim of this study was to clarify the distribution of calculated SBR values by performing [I]FP-CIT single-photon emission computed tomography in a multicenter collaborative study using a phantom. A simple correction method was also devised that enables direct comparison of the SBR value calculated at one facility with those calculated at other facilities., Materials and Methods: Data were acquired at 14 facilities using the phantom adjusted to right striatum : left striatum : cerebral parenchyma (back ground)=8 : 4 : 1, and the SBR values were calculated.We devised a method to correct the SBR using the results of experiments with a known ratio phantom., Results: The SBR values considerably differed between facilities. The average SBR with a theoretical value of 7 and with a theoretical value of 3 in all facilities was 6.48±0.89 and 2.58±0.51, respectively. The range of SBRs with a theoretical value of 7 and a theoretical value of 3 was 3.18 and 1.59, respectively. We devised a simple method for calibrating the SBR value at the clinical examination of each facility to a directly comparable value., Conclusion: Direct comparison of the SBR with those of other facilities and sharing other facilities normal values is clinically difficult. We devised countermeasures that do not affect the diagnosis and developed a simple tool to calculate the standardized SBR.

Aims: The purpose of this study is to assess the economic cost differences and the associated treatment resource changes between the developing coronary artery disease (CAD) diagnostic tool fast strain-encoded cardiac imaging (Fast-SENC) and the current commonly used stress test single-photon emission computed tomography (SPECT)., Materials and Methods: A "payer perspective" model was created first, consisting of long-term and short-term components that used a hypothetical cohort of patients of average age (60.8 years) presenting with chest pain and suspected CAD to assess cost-impact. A cost impact model was then built that assessed likely savings from a "hospital perspective" from substituting Fast-SENC for a portion of SPECTs assuming an average number of annual SPECT tests performed in US hospitals., Results: In the payer model, using Fast-SENC followed by coronary angiography (CA) and percutaneous coronary intervention (PCI) treatment when necessary is less costly than the SPECT method when considering both direct and indirect costs of testing. Expected costs of the Fast-SENC were between $2,510 and $2,632 per correct diagnosis, while expected costs for the SPECT were between $3,157 and $4,078. Fast-SENC reduced false positives by 50% and false negatives by 86%, generating additional cost savings. The hospital model showed total costs per CAD patient visit of $825 for SPECT and $376 for Fast-SENC., Limitations: Limitations of this study are that clinical data are sourced from other published clinical trials on how CAD diagnostic strategies impact clinical outcome, and that necessary assumptions were made which impact health outcomes., Conclusion: The lower cost, higher sensitivity and specificity rates, and faster, less burdensome process for detecting CAD patients make Fast-SENC a more capable and economically beneficial stress test than SPECT. The payer model and hospital model demonstrate an alignment between payer and provider economics as Fast-SENC provides monetary savings for patients and resource benefits for hospitals.

Purpose: The aims of this study were to evaluate Tc-TRODAT-1 SPECT imaging patterns and to assess their correlation with disease severity in clinically diagnosed patients of Parkinson disease (PD)., Methods: The study included 241 patients with clinically diagnosed idiopathic Parkinson disease who underwent Tc-TRODAT-1 SPECT/CT scan. Binding ratios were calculated for each striatum, caudate, and putamen individually, by drawing region of interest. Occipital cortex region of interest was taken for background correction. Correlation of binding ratio with increasing clinical stage was derived, as described by modified Hoehn and Yahr scale., Results: Median binding ratio was least in the contralateral putamen for all stages of modified Hoehn and Yahr. A statistically significant negative correlation was found between increasing disease severity and binding ratio in all subregions of striatum. Patients were clinically categorized into postural instability and gait disorder group and tremor-dominant PD group. No significant asymmetry was found between the left and right striatum in patients belonging to postural instability and gait disorder group and in those with bilateral tremors without lateralization., Conclusions: Tc-TRODAT-1 SPECT is useful in early detection and in assessing disease severity of PD. A significant asymmetry with the contralateral side being affected more than the ipsilateral side can be attributed to tremor-dominant patients. The binding ratio of the ipsilateral striatum may serve useful as a marker of remaining functional dopaminergic neuronal reserve in the striatum.

The increasing implementation of advanced cardiovascular imaging in the form of cardiac PET/CT has had a significant impact on the management of cardiac sarcoidosis, which continues to evolve. This review summarizes the role of PET/CT imaging in sarcoidosis with a specific focus on (1) indications, (2) patient preparation, (3) test performance, (4) study interpretation, (5) clinical relevance of findings, (6) comparison to alternative imaging modalities, and finally (7) introduction of areas of anticipated development and research., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: We aimed to compare the myocardial ischemic burden assessed using semi-quantitative and quantitative analysis of computed tomography-myocardial perfusion imaging (CT-MPI) with that of single-photon emission computed tomography (SPECT)., Methods: From 2011 to 2013, 97 patients who underwent CT-MPI and SPECT were evaluated. The extent and severity of perfusion defects were assessed on a 5-point scale using a standard 16-segment model, and were expressed as summed stress score (SSS) and summed difference score (SDS). Receiver operating characteristic (ROC) curves for quantitative parameters were generated for the diagnosis of abnormal perfusion defect (SSS ≥ 4) and presence of ischemia (SDS ≥ 2) on SPECT., Results: On CT-MPI, 298 (19.2%) of the 1552 segments showed perfusion abnormalities during stress, whereas perfusion abnormalities were shown in 179 (11.5%) segments on SPECT-MPI. On a per-person basis, there was good agreement, with intraclass correlation coefficients of 0.78 for SSS and 0.72 for SDS. A significant reduction of attenuation in stress and myocardial perfusion reserve index, along with an increase in % defect volume of CT-MPI, were demonstrated as the degree of perfusion defect or ischemia on SPECT increased. On the ROC curves, % defect volume on CT-MPI demonstrated the highest area under the curve: 0.91 for abnormal perfusion defect and 0.89 (all p < 0.001) for the presence of ischemia on SPECT., Conclusions: Semi-quantitative analysis of CT-MPI showed good accordance with SPECT. A quantitative approach for CT-MPI, especially % defect volume, may provide additional value in the identification of myocardial perfusion abnormalities., Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT01696006., (Copyright © 2018. Published by Elsevier B.V.)

Objective: To investigate the influence of collimator hole shape, size, and material on the performance of the high-resolution SPECT camera to find the optimal collimator design using the GEANT4 application for the tomographic emission Monte Carlo platform., Methods and Materials: The geometry of the dual head camera equipped with a pixelated CsI(Na) crystal, lead hexagonal-hole collimator, and two flat-panel H8500 position-sensitive photomultipliers were accurately described in the GEANT4 application for the tomographic emission. The basic features of the scanner were calculated by using 2 mCi 99m Tc sources., Results: The simulated average spatial resolutions of lead hexagonal-, square-, and round-hole collimators were 2.68, 2.96, and 3.06 mm at 2.5 cm from the collimator surface, respectively. The sensitivity of the lead hexagonal-hole collimator was 10.86% and 18.84%, greater than that of the square and round holes, respectively, on the collimator surface. The measured averages of spatial resolution using gold were 16.14%, 11.39%, and 5.1% better than those of lead, tantalum, and tungsten hexagonal-hole collimators, respectively, at 2.5 cm from the collimator. The sensitivities of the tungsten, gold, tantalum, depleted uranium, and lead hexagonal-hole collimators were 0.74, 0.48, 1.127, 0.32, and 1.38 cps/μCi on the collimator surface, respectively., Conclusions: The hexagonal-hole collimator was preferred over the square- and round-hole collimators because of the optimum sensitivity and spatial resolution offered by its regular arrangement of apertures. Also, the lower-absorption and stopping-power materials such as lead revealed relatively better characteristics at specific sensitivity, whereas higher-absorption materials such as gold showed the best spatial resolution. The collimator with finer hole size had the superior spatial resolution and less sensitivity than larger holes., (Copyright © 2018. Published by Elsevier Inc.)

Aim: The aim of this study was to establish normal values for parotid gland (PG) and submandibular-sublingual salivary gland complex (SSC) uptake of 99m technetium pertechnetate ( 99m TcO 4 ) as a function of age, sex and circadian rhythm in mice., Methods: In 12 female (F) and 12 male (M) C57BL/6N mice, nine consecutive SPECT images of 10 min each were acquired as dynamic acquisitions beginning 5 min after intravenous injection of 80 MBq 99m TcO 4 . Each mouse was imaged in follow-up studies at 1, 3, 6, 12 and 24 months of age. In order to assess for physiologic changes related to circadian rhythm, animals were imaged during light (sleeping phase) as well as during night conditions (awake phase). The percentage tracer uptake of the injected activity is expressed as median %ID., Results: Maximum 99m TcO 4 uptake occurred earlier in PG at 11 min compared to SSC at 79 min (p < 0.001). No significant effect of circadian rhythm was observed in PG (p = 0.64) and SSC uptake (p = 0.27). With aging, 99m TcO 4 uptake significantly decreased for PG (p < 0.001) while it increased for SSC (p < 0.001). F (0.5) had a significantly higher PG uptake than M (0.3; p < 0.001) up to an age of 24 months. However, SSC uptake of F (4.6) was higher than that of M (3.8; p = 0.014) only at the age of 1 month. Thereafter, F (5.6) had lower SSC uptake than M (9.2; p < 0.001) from 3 months onwards. Normalizing %ID to gland volume showed that F had a significantly higher uptake (%ID/mm 3 ) in both PG (F 0.013; M 0.007; p < 0.001) and in SSC (F 0.110; M 0.075; p < 0.001)., Conclusion: Uptake patterns differed among PG and SSC with a significant impact of age and sex while circadian rhythm had no significant influence. Therefore, design of salivary gland studies in mice using 99m TcO 4 should consider age and sex as relevant factors., Competing Interests: The authors declare that they have no conflict of interest., (© Georg Thieme Verlag KG Stuttgart · New York.)

Objective: An indigenous polymethyl metacrylate (PMMA) phantom with a V-shaped slit and a correlated technique for semi-quantifying the minimum detectable difference (MDD) of single photon emission tomography (SPET) via gamma camera scanning are proposed and validated using four radionuclides., Materials and Methods: Radio-actinide solutions of gallium-67 ( 67 Ga), technetium-99m ( 99m Tc), iodine-131 ( 131 I) and thallium-201 ( 201 Tl) were diluted to 11c.c. and thoroughly injected into the continuous zig zag slit of the PMMA phantom. Either depth or edge of the slit between two lines of the V-shape was customized from deep or wide to change into shallow or narrow gradually. Thus, the quantified MDD could be easily evaluated, according to the revised Student's t-test evaluation. The revised Student's t-test was calculated by both full width at half maximum (FWHM) and edge width between two adjacent peaks that were acquired from the original data matrix of SPET. The derived MDD was indicated as for radionuclide, depth, width in mm: For 67 Ga, 2.9, 2.13, for 99m Tc, 2.5, 0.66, for 131 I, 4.7, 2.38 and for 201 Tl, 3.3, 2.00, respectively., Results: Technetium-99m had the highest and 131 I had the lowest MDD among the four radionuclides. Furthermore, two adjacent peaks of 67 Ga could be easily identified with fewer counts than for 201 Tl (depth, 2.9 vs. 3.3mm), but its MDD was poorer (width: 2.13 vs.2.00mm). The revised Student's t-test analysis proved to be an acceptable technique for the MDD identification., Conclusion: The proposed new combination of PMMA phantom with a V-slit and the revised Student's t-test proved to be instrumental in the MDD of SPET optimization analysis.

As therapeutic trials target early stages of Parkinson's disease (PD), appropriate patient selection based purely on clinical criteria poses significant challenges. Members of the Critical Path for Parkinson's Consortium formally submitted documentation to the European Medicines Agency (EMA) supporting the use of Dopamine Transporter (DAT) neuroimaging in early PD. Regulatory documents included a comprehensive literature review, a proposed analysis plan of both observational and clinical trial data, and an assessment of biomarker reproducibility and reliability. The research plan included longitudinal analysis of the Parkinson Research Examination of CEP-1347 Trial (PRECEPT) and the Parkinson's Progression Markers Initiative (PPMI) study to estimate the degree of enrichment achieved and impact on future trials in subjects with early motor PD. The presence of reduced striatal DAT binding based on visual reads of single photon emission tomography (SPECT) scans in early motor PD subjects was an independent predictor of faster decline in UPDRS Parts II and III as compared to subjects with scans without evidence of dopaminergic deficit (SWEDD) over 24 months. The EMA issued in 2018 a full Qualification Opinion for the use of DAT as an enrichment biomarker in PD trials targeting subjects with early motor symptoms. Exclusion of SWEDD subjects in future clinical trials targeting early motor PD subjects aims to enrich clinical trial populations with idiopathic PD patients, improve statistical power, and exclude subjects who are unlikely to progress clinically from being exposed to novel test therapeutics.

Purpose: Computed tomography (CT) attenuation correction of myocardial perfusion in single-photon emission computed tomography (SPECT) /CT systems is possibility of misregistration between emission and transmission scans. This study aimed to evaluate the influence of misregistration using a polar map of 17 segments model., Methods: Using the fusion software, we assessed the magnitude and direction of misregistration in 200 consecutive myocardial perfusion SPECT images with 99m Technetium ( 99m Tc) tetrofosmin. After registration, CT data was shifted by ±1, ±2, and ±3 pixels along the cephalad/caudal, dorsal/ventral, and left/right axes, respectively. The registered image was compared with the shifted image., Results: Misregistration between the SPECT and CT images occurred by 1-2 pixels in 127 cases (63.5%) and by 2 or more pixels in four cases (2%); the maximum misregistration was 1.2±0.4 pixels on average. The polar map scoring was most significantly affected by 3 pixel ventral shift. A ventral shift of 1 pixel affected the scores for the anterolateral and inferolateral segments, whereas a caudal shift of 1 pixel affected the scores for the anterior segment., Conclusion: Since the 17 segments model can evaluate the position more precisely than the five segments model, it is possible to evaluate up to 1 pixel misregistration.

The aim of this systematic review is to investigate the national diagnostic reference level (NDRL) methods for positron emission tomography/computed tomography (PET/CT) and single photon emission tomography/computed tomography (SPECT/CT) procedures. A search strategy was based on the preferred, reporting items for systematic review and meta-analysis (PRISMA). Relevant articles retrieved from Medline, Scopus, Web of Science, Embase, Cinahl, and Google Scholar published up to October 2017. The search yielded 1057 articles. Fourteen articles were included in the review after a screening process. Relevant information from the selected articles were summarised and analysed. Discrepancies were found between the methodologies utilised to establish and report both PET/CT and SPECT/CT NDRLs, e.g. patient sampling and administered activity. Further research should focus on reporting more NDRLs for hybrid PET/CT and SPECT/CT examinations, and establish a robust NDRL standard for the CT portion associated with PET/CT and SPECT/CT examinations. This review provides updated NDRL reommndations to deliver more comparable international radation doses for administered activity and CT dose across PET/CT and SPECT/CT clinics.

SPECT can be used to image dopamine transporter (DaT) availability in the human striatum, e.g. for diagnosis of Parkinson's disease (PD). As traditional SPECT provides limited resolution and sensitivity, we proposed a full ring focusing multi-pinhole SPECT system (G-SPECT-I (Beekman 2015 Eur. J. Nucl. Med. Mol. Imaging 42 S209)) which demonstrated a 2.5 mm reconstructed resolution in phantom scans. G-SPECT-I achieves data completeness in the scan region of interest by translating the patient bed with an xyz-stage and combining projections from all bed positions into image reconstruction using a scanning focus method (SFM). This paper aims to develop dedicated SFM parameters for performing a DaTscan with high effective sensitivity and appropriate sampling. To this end, the axial scanning length was restricted and transaxial bed trajectories with a reduced number of positions based on a convex hull data-completeness model were tested. Quantitative accuracy was assessed using full G-SPECT-I simulations of an Alderson phantom based on measured system matrices. For each sampling strategy, the specific binding ratio (SBR) and asymmetry index (AI) in the left and right striatum, as well as the Localized SBR (L-SBR) and the Localized AI (L-AI) in eight striatal sub-regions were calculated and compared to those of the reference scan which performs full brain oversampling using 112 bed positions. Results show that structures essential for PD diagnosis were visually and quantitatively barely affected even when using the lowest number of bed translations (i.e. 4). The maximum deviation from the reference was only 1.5%, 1.5%, 5.5% and 7.0% for the SBR, AI, L-SBR and L-AI, respectively, when 4 positions were used. Thus, it is possible to perform an accurate DaTscan with a confined axial scan region and a limited number of focused bed positions. This enables protocols for extremely fast dynamic SPECT scans with less than half-minute time frames, which can be useful for motion correction.

Purpose: Cardiac perfusion images in single-photon emission computed tomography (SPECT) can suffer from respiratory motion blur. We investigated a reconstruction approach for correcting respiratory motion in respiratory-binned acquisitions and assessed the benefit of this approach in both standard dose and reduced dose., Methods: We modeled the acquired data from different respiratory bins by a joint probability distribution which was parameterized with respect to a common reference bin. The acquired data from all the respiratory bins were then utilized simultaneously for determining the source distribution in the reference bin using maximum a posteriori (MAP) estimation. We evaluated this approach with simulated imaging data and ten sets of clinical acquisitions, and compared it with a postreconstruction motion correction approach developed previously. We quantified the accuracy of the reconstruction results both at standard dose and with imaging dose reduced by 50% and 75%, respectively., Results: The proposed motion-compensated reconstruction (MCR) approach led to improved reconstruction of the myocardium in terms of both noise level and LV wall resolution. Compared to traditional acquisition (without motion correction), the proposed approach reduced the mean squared error of the image intensity in the myocardium by 27.59%, 20.59%, and 12.05% at full, half-, and quarter dose, respectively; the LV resolution, quantified by the full width at half-maximum (FWHM), was improved by 17.34%, 14.35%, and 12.95% at full, half-, and quarter dose, respectively; in addition, the proposed approach also improved the perfusion defect detectability at both full dose and reduced dose. Furthermore, with motion correction, the reconstruction results obtained at half-dose were comparable to that obtained at full dose without correction. Similar improvements were also demonstrated in the clinical acquisitions at different dose levels., Conclusions: Respiratory motion correction in perfusion SPECT can improve the reconstruction of the myocardium at both standard and reduced dose. At half-dose, the results obtained with motion correction are comparable to that of traditional reconstruction obtained at full dose. MCR can be more accurate than postreconstruction correction., (© 2018 American Association of Physicists in Medicine.)

Recently, we proposed and optimized dedicated multi-pinhole molecular breast tomosynthesis (MBT) that images a lightly compressed breast. As MBT may also be performed with other types of collimators, the aim of this paper is to optimize MBT with fan beam and slit-slat collimators and to compare its performance to that of multi-pinhole MBT to arrive at a truly optimized design. Using analytical expressions, we first optimized fan beam and slit-slat collimator parameters to reach maximum sensitivity at a series of given system resolutions. Additionally, we performed full system simulations of a breast phantom containing several tumours for the optimized designs. We found that at equal system resolution the maximum achievable sensitivity increases from pinhole to slit-slat to fan beam collimation with fan beam and slit-slat MBT having on average a 48% and 20% higher sensitivity than multi-pinhole MBT. Furthermore, by inspecting simulated images and applying a tumour-to-background contrast-to-noise (TB-CNR) analysis, we found that slit-slat collimators underperform with respect to the other collimator types. The fan beam collimators obtained a similar TB-CNR as the pinhole collimators, but the optimum was reached at different system resolutions. For fan beam collimators, a 6-8 mm system resolution was optimal in terms of TB-CNR, while with pinhole collimation highest TB-CNR was reached in the 7-10 mm range.

The diagnosis of pulmonary embolism (PE) relies on clinical assessment, D-dimer test and diagnostic imaging. Modern CT pulmonary angiography (CTPA), ventilation/perfusion  single-photon emission computed tomography (SPECT) and SPECT/CT are rather equal in terms of sensitivity, specificity and inconclusive results for the diagnosis of PE, outper-forming planar lung scintigraphy. Furthermore, SPECT/CT and CTPA can both provide important information regarding differential diagnoses. Thus, the choice of primary diag-nostic modality relies on local expertise, availability and special circumstances like radiation dose, contraindications and the clinical urgency.

Purpose: The aim of this study was to investigate the optimal threshold for the functional lung (FL) definition of single-photon emission computed tomography (SPECT) lung perfusion imaging., Patients and Methods: Forty consecutive stage III non-small-cell lung cancer patients underwent SPECT lung perfusion scans and PET/CT scans for treatment planning, and the images were coregistered. Total lung and perfusion lung volumes corresponding to 10, 20, …, 60% of the maximum SPECT count were segmented automatically. The SPECT-weighted mean lung dose (SWMDx%) and the percentage of FL volume receiving more than 20 Gy (Fx%V20) of different thresholds were investigated using SPECT-weighted dose-volume histograms. Receiver-operator characteristic curves were used to identify SWMD and FV20 of different thresholds in predicting the incidence of radiation pneumonitis (RP)., Results: Eleven (27.5%) patients developed RP (grades 1, 2, 3, and 4 were 10.0, 7.5, 7.5, and 2.5%, respectively) after treatment. The largest area under the receiver-operator characteristic curve was 0.881 for the ability of SWMD to predict RP with 20% as the threshold and 0.928 for the ability of FV20 with 20% as the threshold., Conclusion: The SWMD20% and FV20 of FL using 20% of the maximum SPECT count as the threshold may be better predictors for the risk of RP.

Purpose To compare the diagnostic performance of stress myocardial computed tomography (CT) perfusion with that of stress myocardial magnetic resonance (MR) perfusion imaging in the detection of coronary artery disease (CAD). Materials and Methods All patients gave written informed consent prior to inclusion in this institutional review board-approved study. This two-center substudy of the prospective Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) multicenter trial included 92 patients (mean age, 63.1 years ± 8.1 [standard deviation]; 73% male). All patients underwent perfusion CT and perfusion MR imaging with either adenosine or regadenoson stress. The predefined reference standards were combined quantitative coronary angiography (QCA) and single-photon emission CT (SPECT) or QCA alone. Results from coronary CT angiography were not included, and diagnostic performance was evaluated with the Mantel-Haenszel test stratified by disease status. Results The prevalence of CAD was 39% (36 of 92) according to QCA and SPECT and 64% (59 of 92) according to QCA alone. When compared with QCA and SPECT, per-patient diagnostic accuracy of perfusion CT and perfusion MR imaging was 63% (58 of 92) and 75% (69 of 92), respectively (P = .11); sensitivity was 92% (33 of 36) and 83% (30 of 36), respectively (P = .45); and specificity was 45% (25 of 56) and 70% (39 of 56), respectively (P < .01). When compared with QCA alone, diagnostic accuracy of CT perfusion and MR perfusion imaging was 82% (75 of 92) and 74% (68 of 92), respectively (P = .27); sensitivity was 90% (53 of 59) and 69% (41 of 59), respectively (P < .01); and specificity was 67% (22 of 33) and 82% (27 of 33), respectively (P = .27). Conclusion This multicenter study shows that the diagnostic performance of perfusion CT is similar to that of perfusion MR imaging in the detection of CAD. © RSNA, 2017 Online supplemental material is available for this article.

Imaging of 99m Tc-labelled tracers is gaining popularity for detecting breast tumours. Recently, we proposed a novel design for molecular breast tomosynthesis (MBT) based on two sliding focusing multi-pinhole collimators that scan a modestly compressed breast. Simulation studies indicate that MBT has the potential to improve the tumour-to-background contrast-to-noise ratio significantly over state-of-the-art planar molecular breast imaging. The aim of the present paper is to optimize the collimator-detector geometry of MBT. Using analytical models, we first optimized sensitivity at different fixed system resolutions (ranging from 5 to 12 mm) by tuning the pinhole diameters and the distance between breast and detector for a whole series of automatically generated multi-pinhole designs. We evaluated both MBT with a conventional continuous crystal detector with 3.2 mm intrinsic resolution and with a pixelated detector with 1.6 mm pixels. Subsequently, full system simulations of a breast phantom containing several lesions were performed for the optimized geometry at each system resolution for both types of detector. From these simulations, we found that tumour-to-background contrast-to-noise ratio was highest for systems in the 7 mm-10 mm system resolution range over which it hardly varied. No significant differences between the two detector types were found.

The present study aimed to validate the absolute quantitative accuracy of a calibration method for single-photon emission computed tomography (SPECT) using cross-calibration factor (CCF)- and system sensitivity-based calibration methods. The CCF obtained with different reconstruction parameters was evaluated using a cylindrical phantom (diameter 20 cm, height 20 cm). SPECT images were acquired with a positron emission tomography/computed tomography (CT) phantom. Subsequently, they were reconstructed by using ordered subset expectation maximization with resolution recovery, scatter, and CT-based attenuation correction. All reconstructed SPECT counts were converted to activity concentrations based on the CCF and system planar sensitivity. We placed 12 circular regions of interest, 37 mm in diameter, on the phantom background, and the converted activity concentration and relative measurement error were assessed. The CCF obtained using a cylindrical phantom was affected by the iterative update number and post-smoothing filter function. The activity concentration calibrated using the CCF showed over- and underestimation. However, the activity concentration obtained from the system planar sensitivity was similar to that gained using the phantom. The values obtained using the system planar sensitivity were within 10% of the activity concentrations obtained with the phantom. These findings demonstrated that the calibration method using system planar sensitivity provides accurate quantification within 10% of the true activity concentration. Further clinical examination is required to validate the present results.

Aims: We studied the referral practice, reporting standards, and the impact of 123 ioflupane single photon emission computed tomogram dopamine transporters (DAT-SPECT) scans conducted for the diagnosis and clinical management of patients., Settings and Designs: The present study was a retrospective, non-interventional study., Materials and Methods: We assessed the DAT scan referral and the official reports available from the Nuclear Medicine Department of the Mater Misericordiae University Hospital over 1 year (2013). We also assessed the impact of the DAT scan result on the management of patients by analyzing patient records. The European Association of Nuclear Medicine Neuroimaging (EANM) 2010 and the Federal Drug Administration (FDA) 2012 guidelines were taken as the standard against which the quality of our DAT scans reporting was assessed., Statistical Methods: Microsoft Excel 2010 and graphpad software were used for statistical analysis., Results: Twenty five (56.2%) out of a total of 48 DAT scans were performed to confirm early Parkinson's disease, 5 (8.9%) were done to exclude drug-induced parkinsonism, and 8 (14.3%) to distinguish essential tremor from parkinsonism; 2 scans were performed to distinguish Lewy body diseases from Alzheimer's dementia, and 4 indications were outside the recommended guidelines. Twelve out of the 26 (46%) abnormal scans had bilateral abnormalities. Twenty one out of the 25 DAT scans proved the clinical diagnosis of degenerative parkinsonism to be correct., Conclusion: The overall compliance of the DAT imaging with the existing standard guidelines was good. DAT scan can be very useful in clinical practice because it influences the clinical diagnosis and management in 23% of the patients.

Purpose: Sentinel lymph node biopsy (SLNB) can be used for nodal staging in early cervical cancer. For this purpose, the tracers most commonly used are radiotracers based on technetium. For the last decade, indocyanine green (ICG) has been used as a tracer for SLNB in other malignancies with excellent results and, more recently, a combination of ICG and a radiotracer has been shown to have the advantages of both tracers. The aim of this study was to evaluate the role of ICG- 99m Tc-nanocolloid in SLN detection in patients with cervical cancer., Methods: This prospective study included 16 patients with cervical cancer. The hybrid tracer was injected the day (19-21 h) before surgery for planar and SPECT/CT lymphoscintigraphy. Blue dye was administered periorificially in 14 patients. SLNs were removed according to their distribution on lymphoscintigraphy and when radioactive, fluorescent and/or stained with blue dye. Nodal specimens were pathologically analysed for metastases including by immunochemistry., Results: Lymphoscintigraphy and SPECT/CT showed drainage in all patients. A total of 69 SLNs were removed, of which 66 were detected by their radioactivity signal and 67 by their fluorescence signal. Blue dye identified only 35 SLNs in 12 of the 14 patients (85.7%). All patients showed bilateral pelvic drainage. Micrometastases were diagnosed in two patients, and were the only lymphatic nodes involved., Conclusions: SLNB with ICG- 99m Tc-nanocolloid is feasible and safe in patients with early cervical cancer. This hybrid tracer provided bilateral SLN detection in all patients and a higher detection rate than blue dye, so it could become an alternative to the combined technique.

Purpose: A new method has been developed to calculate fractional flow reserve (FFR) from invasive coronary angiography, the so-called "contrast-flow quantitative flow ratio (cQFR)". Recently, cQFR was compared to invasive FFR in intermediate coronary lesions showing an overall diagnostic accuracy of 85%. The purpose of this study was to investigate the relationship between cQFR and myocardial ischemia assessed by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI)., Methods: Patients who underwent SPECT MPI and coronary angiography within 3 months were included. The cQFR computation was performed offline, using dedicated software. The cQFR computation was based on 3-dimensional quantitative coronary angiography (QCA) and computational fluid dynamics. The standard 17-segment model was used to determine the vascular territories. Myocardial ischemia was defined as a summed difference score ≥2 in a vascular territory. A cQFR of ≤0.80 was considered abnormal., Results: Two hundred and twenty-four coronary arteries were analysed in 85 patients. Overall accuracy of cQFR to detect ischemia on SPECT MPI was 90%. In multivariable analysis, cQFR was independently associated with ischemia on SPECT MPI (OR per 0.01 decrease of cQFR: 1.10; 95% CI 1.04-1.18, p = 0.002), whereas clinical and QCA parameters were not. Furthermore, cQFR showed incremental value for the detection of ischemia compared to clinical and QCA parameters (global chi square 48.7 to 62.6; p <0.001)., Conclusions: A good relationship between cQFR and SPECT MPI was found. cQFR was independently associated with ischemia on SPECT MPI and showed incremental value to detect ischemia compared to clinical and QCA parameters.

Importance: At present, the choice of noninvasive testing for a diagnosis of significant coronary artery disease (CAD) is ambiguous, but nuclear myocardial perfusion imaging with single-photon emission tomography (SPECT) or positron emission tomography (PET) and coronary computed tomography angiography (CCTA) is predominantly used for this purpose. However, to date, prospective head-to-head studies are lacking regarding the diagnostic accuracy of these imaging modalities. Furthermore, the combination of anatomical and functional assessments configuring a hybrid approach may yield improved accuracy., Objectives: To establish the diagnostic accuracy of CCTA, SPECT, and PET and explore the incremental value of hybrid imaging compared with fractional flow reserve., Design, Setting, and Participants: A prospective clinical study involving 208 patients with suspected CAD who underwent CCTA, technetium 99m/tetrofosmin-labeled SPECT, and [15O]H2O PET with examination of all coronary arteries by fractional flow reserve was performed from January 23, 2012, to October 25, 2014. Scans were interpreted by core laboratories on an intention-to-diagnose basis. Hybrid images were generated in case of abnormal noninvasive anatomical or functional test results., Main Outcomes and Measures: Hemodynamically significant stenosis in at least 1 coronary artery as indicated by a fractional flow reserve of 0.80 or less and relative diagnostic accuracy of SPECT, PET, and CCTA in detecting hemodynamically significant CAD., Results: Of the 208 patients in the study (76 women and 132 men; mean [SD] age, 58 [9] years), 92 (44.2%) had significant CAD (fractional flow reserve ≤0.80). Sensitivity was 90% (95% CI, 82%-95%) for CCTA, 57% (95% CI, 46%-67%) for SPECT, and 87% (95% CI, 78%-93%) for PET, whereas specificity was 60% (95% CI, 51%-69%) for CCTA, 94% (95% CI, 88%-98%) for SPECT, and 84% (95% CI, 75%-89%) for PET. Single-photon emission tomography was found to be noninferior to PET in terms of specificity (P < .001) but not in terms of sensitivity (P > .99) using the predefined absolute margin of 10%. Diagnostic accuracy was highest for PET (85%; 95% CI, 80%-90%) compared with that of CCTA (74%; 95% CI, 67%-79%; P = .003) and SPECT (77%; 95% CI, 71%-83%; P = .02). Diagnostic accuracy was not enhanced by either hybrid SPECT and CCTA (76%; 95% CI, 70%-82%; P = .75) or by PET and CCTA (84%; 95% CI, 79%-89%; P = .82), but resulted in an increase in specificity (P = .004) at the cost of a decrease in sensitivity (P = .001)., Conclusions and Relevance: This controlled clinical head-to-head comparative study revealed PET to exhibit the highest accuracy for diagnosis of myocardial ischemia. Furthermore, a combined anatomical and functional assessment does not add incremental diagnostic value but guides clinical decision-making in an unsalutary fashion.

Background: Cardiac 123 I-meta-iodobenzylguanidine (MIBG) uptake is quantified using the heart-to-mediastinum ratio (HMR) with an Anger camera. The relationship between HMR determined using D-SPECT with a cadmium-zinc-telluride detector and an Anger camera is not fully understood. Therefore, the present study aimed to define this relationship using images derived from a phantom and from patients., Methods: Cross-calibration phantom studies using an Anger camera with a low-energy high-resolution (LEHR) collimator and D-SPECT, and clinical 123 I-MIBG studies proceeded in 40 consecutive patients (80 studies). In the phantom study, a conversion coefficient (CC) was defined based on phantom experiments and applied to the Anger camera and the D-SPECT detector. The HMR was calculated using anterior images with the Anger camera and anterior planograms with D-SPECT. First, the HMR from D-SPECT was cross-calibrated to the Anger camera, and then, the HMR from both cameras were converted to the medium-energy general-purpose collimator condition (CC 0.88; ME88 condition). The relationship between HMR and corrected and uncorrected methods was examined. A 123 I-MIBG washout rate was calculated using both methods with and without background subtraction., Results: Based on the phantom experiments, the CC of the Anger camera with an LEHR collimator and of D-SPECT using an anterior planogram was 0.55 and 0.63, respectively. The original HMR from the Anger camera and D-SPECT was 1.76 ± 0.42 and 1.86 ± 0.55, respectively (p < 0.0001). After D-SPECT HMR was converted to the Anger camera condition, the corrected D-SPECT HMR became comparable to the values under the Anger camera condition (1.75 ± 0.48, p = n. s.). When the HMR measured using the two cameras were converted under the ME88 condition, the average standardized HMR from the Anger camera and D-SPECT became comparable (2.21 ± 0.65 vs. 2.20 ± 0.75, p = n. s.). After standardization to the ME88 condition, a systematic difference in the linear regression lines disappeared, and the HMR from both the Anger (StdHMR Anger ) and D-SPECT (StdHMR DSPECT ) became comparable. Additional correction using a regression line further improved the relationship between both HMR [StdHMR DSPECT  = 0.09 + 0.98 × StdHMR Anger (R 2  = 0.91)]. The washout rate closely correlated with and without background correction between both methods (R 2  = 0.83 and 0.65, respectively)., Conclusion: The phantom-based conversion method is applicable to D-SPECT and enables the common application of HMR irrespective of D-SPECT and the Anger camera.

Objective: The analysis of 99 mTc-ECD single-photon emission computed tomography (SPECT) images using the easy Z-score imaging system (eZIS) program is useful for the diagnosis of early AD in daily medical practice. However, it remains unclear whether eZIS analysis can identify the amnestic mild cognitive impairment (MCI) subjects with brain amyloid-β deposition. The aim of this study was to evaluate the usefulness of an eZIS analysis for predicting amnestic MCI subjects with brain amyloid β deposition., Patients and Methods: Twenty-three subjects with MCI (10 men and 13 women, mean age; 74.2 years) underwent brain perfusion SPECT and 11 C-Pittsburgh Compound B positron emission tomography (PiB-PET). MCI subjects were divided into PiB-positive and PiB-negative subgroups. SPECT data was analyzed using the Specific Volume of interest Analysis of the eZIS program. Three indicators (severity, extent, and ratio) were calculated automatically and compared between the two subgroups., Results: Five of 12 (41.7%) subjects in the PiB-positive subgroup and three of 11 (27.3%) subjects in the PiB-negative subgroup showed the abnormal value for each indicator. The frequency of subjects with abnormal ratio values was significantly higher in the PiB-positive subgroup compared to the PiB-negative subgroup (p=0.02), whereas that of subjects with abnormal values in severity and extent did not differ among the two subgroups. In particular, all subjects in the PiB-negative subgroup showed normal ratio values. Moreover, the subjects with abnormal values on two indicators, including ratio, or on all three indicators, showed PiB-positive., Conclusion: The analysis of brain perfusion SPECT using an eZIS program cannot identify the amnestic MCI subjects with brain amyloid-β deposition. However, abnormal three indicators or normal ratio values may be helpful SPECT findings for predicting the results of PiB-PET in the amnestic MCI subjects., (Copyright © 2017. Published by Elsevier B.V.)

Accurate quantitation of activity provides the basis for internal dosimetry of targeted radionuclide therapies. This study investigated quantitative imaging capabilities at sites with a variety of experience and equipment and assessed levels of errors in activity quantitation in Single-Photon Emission Computed Tomography (SPECT) and planar imaging. Participants from 9 countries took part in a comparison in which planar, SPECT and SPECT with X ray computed tomography (SPECT-CT) imaging were used to quantify activities of four epoxy-filled cylinders containing 133 Ba, which was chosen as a surrogate for 131 I. The sources, with nominal volumes of 2, 4, 6 and 23mL, were calibrated for 133 Ba activity by the National Institute of Standards and Technology, but the activity was initially unknown to the participants. Imaging was performed in a cylindrical phantom filled with water. Two trials were carried out in which the participants first estimated the activities using their local standard protocols, and then repeated the measurements using a standardized acquisition and analysis protocol. Finally, processing of the imaging data from the second trial was repeated by a single centre using a fixed protocol. In the first trial, the activities were underestimated by about 15% with planar imaging. SPECT with Chang's first order attenuation correction (Chang-AC) and SPECT-CT overestimated the activity by about 10%. The second trial showed moderate improvements in accuracy and variability. Planar imaging was subject to methodological errors, e.g., in the use of a transmission scan for attenuation correction. The use of Chang-AC was subject to variability from the definition of phantom contours. The project demonstrated the need for training and standardized protocols to achieve good levels of quantitative accuracy and precision in a multicentre setting. Absolute quantification of simple objects with no background was possible with the strictest protocol to about 6% with planar imaging and SPECT (with Chang-AC) and within 2% for SPECT-CT., (Copyright © 2016. Published by Elsevier GmbH.)

Background and Purpose: Venous oxygen saturation (SO 2 ) is measured in medical fields to assess tissue circulation insufficiency. This study aimed to elucidate the use of a cortical venous redness measurement to evaluate hemodynamic changes during revascularization surgery for patients with moyamoya disease., Methods: In this retrospective case-series analysis, we first quantitatively measured and correlated SO 2 and R intensity of 24-bit color digital red-green-blue pictures of blood samples from 3 volunteers. Subsequently, based on intraoperative digital pictures of 29 patients with moyamoya disease, we measured the R intensities of a cortical vein near the anastomosis site before and after anastomosis. Cerebral blood flow (CBF) at the site was measured using a single-photon emission computed tomography before and 1 to 3 days after surgery. Venous R intensity and CBF were measured twice by 4 raters, and their correlations were examined using generalized linear mixed effect model and linear regression analysis., Results: A strong linear correlation was found between blood R intensity and its SO 2 (coefficients, 0.522; 95% confidence interval, 0.364-0.680, using generalized linear mixed effect model). Venous R intensity before the anastomosis was not correlated with preoperative CBF (coefficients, 0.000352; 95% confidence interval, -0.000369 to 0.00107, by generalized linear mixed effect); however, the increases in venous R intensity after anastomosis were correlated with postoperative increases in CBF ( R 2 , 0.367; 95% confidence interval, 0.116-0.618 to 0.548; 95% confidence interval, 0.331-0.764, by linear regression analysis)., Conclusions: Cortical venous redness represented impaired CBF and could be a useful parameter for assessing hemodynamic changes during revascularization surgery., (© 2017 American Heart Association, Inc.)

Background: It was the primary purpose of our study to evaluate the inter- and intra-observer reliability of a standardized SPECT/CT algorithm for evaluating patients with painful primary total hip arthroplasty (THA). The secondary purpose was a comparison of semi-quantitative and 3D volumetric quantification method for assessment of bone tracer uptake (BTU) in those patients., Methods: A novel SPECT/CT localization scheme consisting of 14 femoral and 4 acetabular regions on standardized axial and coronal slices was introduced and evaluated in terms of inter- and intra-observer reliability in 37 consecutive patients with hip pain after THA. BTU for each anatomical region was assessed semi-quantitatively using a color-coded Likert type scale (0-10) and volumetrically quantified using a validated software. Two observers interpreted the SPECT/CT findings in all patients two times with six weeks interval between interpretations in random order. Semi-quantitative and quantitative measurements were compared in terms of reliability. In addition, the values were correlated using Pearson`s correlation. A factorial cluster analysis of BTU was performed to identify clinically relevant regions, which should be grouped and analysed together., Results: The localization scheme showed high inter- and intra-observer reliabilities for all femoral and acetabular regions independent of the measurement method used (semiquantitative versus 3D volumetric quantitative measurements). A high to moderate correlation between both measurement methods was shown for the distal femur, the proximal femur and the acetabular cup. The factorial cluster analysis showed that the anatomical regions might be summarized into three distinct anatomical regions. These were the proximal femur, the distal femur and the acetabular cup region., Conclusions: The SPECT/CT algorithm for assessment of patients with pain after THA is highly reliable independent from the measurement method used. Three clinically relevant anatomical regions (proximal femoral, distal femoral, acetabular) were identified.

Background: Considering the distinctive characteristics of CZT detectors, automatic quantification of ischemia using normal limits included with software package may deliver suboptimal results for CAD detection. The present study aims to evaluate the benefits of creating normal limits specific to a local population and laboratory protocol., Methods and Results: Two groups were selected from patients who had undergone a CZT MPI. Normal limits were generated with the QPS application based on the population with low likelihood of CAD. Using the vendor-supplied and the population-specific normal limits i-TPD and vessel-specific SDS results obtained for patients who had subsequently undergone coronary angiography were compared with coronary angiography data. A weak correlation was observed for low i-TPD (stress TPD minus rest TPD) and SDS values. Both databases gave similar values for the area under the ROC curve concerning i-TPD (0.75 to 0.74) and SDS results (0.72 to 0.75 for the LAD, 0.62 to 0.64 for the LCx, and 0.63 to 0.67 for the RCA). Sensitivity (60%), specificity (78%), and predictive positive (84%) and negative (52%) values were also similar with a diagnostic and prognostic threshold value., Conclusion: The use of a population-specific created database did not influence the diagnostic value of thallium-201 MPI QPS results using a CZT camera.

Objective: To establish a system for patient dosimetry audit and setting of local diagnostic reference levels (LDRLs) for nuclear medicine (NM) CT., Methods: Computed radiological information system (CRIS) data were matched with NM paper records, which provided the body region and dose mode for NMCT carried out at a large UK hospital. It was necessary to divide data in terms of the NM examination type, body region and dose mode. The mean and standard deviation dose-length products (DLPs) for common NMCT examinations were then calculated and compared with the proposed National Diagnostic Reference Levels (NDRLs). Only procedures which have 10 or more patients will be used to suggest LDRLs., Results: For most examinations, the mean DLPs do not exceed the proposed NDRLs. The bone single-photon emission CT/CT lumbar spine data clearly show the need to divide data according to the purpose of the scan (dose mode), with mean (±standard error) DLPs ranging from 51 ± 5 mGy cm (low dose) to 1086 ± 124 mGy cm (metal dose)., Conclusion: A system for NMCT patient dose audit has been developed, but there are non-trivial challenges which make the process labour intensive. These include limited information provided by CRIS downloads, dependence on paper records and limited number of examinations available owing to the need to subdivide data. Advances in knowledge: This article demonstrates that a system can be developed for NMCT patient dose audit, but also highlights the challenges associated with such audit, which may not be encountered with more routine audit of radiology CT.

Aims: High-energy resolution and sensitivity of novel cadmium-zinc-telluride (CZT) detector equipped SPECT systems facilitate simultaneous imaging of multiple isotopes and may enhance the detection of molecular/cellular signals. This may refine the detection of endocarditis. This study was designed to determine the feasibility and diagnostic accuracy of simultaneous imaging of inflammation with 111In-labeled white blood cells (WBCs) and myocardial perfusion with 99mTc-sestamibi, for localization of WBCs relative to the valve plane in suspected endocarditis., Methods and Results: A dedicated cardiac CZT camera (Discovery 530c, GE Healthcare) was employed. Anthropomorphic thorax phantom studies were followed by clinical studies in 34 patients with suspected infection of native valves (n = 12) or implants (n = 22). Simultaneous 111In-WBC/99mTc perfusion imaging was performed, and compared with standard 111In-WBC planar scintigraphy and SPECT-CT. Phantom studies ruled out significant radioisotope crosstalk. Downscatter on 99mTc images was not observed for 111In activity as high as 2.5*99mTc activity. In patients, image quality was superior for CZT imaging vs. conventional SPECT-CT and planar scintigraphy (P < 0.01). Cadmium-zinc-telluride dual isotope imaging improved reader confidence for detection of inflammatory foci. Diagnostic accuracy based on surgery or Duke Criteria during follow-up was highest for CZT imaging (P < 0.001)., Conclusion: Novel CZT SPECT technology improves the accuracy of molecular/cellular cardiac imaging. Simultaneous multi-isotope imaging with 111In and 99mTc is feasible and aids in the workup of suspected endocarditis., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Purpose: A robust method is required to standardise objective reporting of diagnostic 123 I-mIBG images in neuroblastoma. Prerequisites for an appropriate system are low inter- and intra-observer error and reproducibility across a broad disease spectrum. We present a new reporting method, developed and tested for SIOPEN by an international expert panel., Method: Patterns of abnormal skeletal 123 I-mIBG uptake were defined and assigned numerical scores [0-6] based on disease extent within 12 body segments. Uptake intensity was excluded from the analysis. Data sets from 82 patients were scored independently by six experienced specialists as unblinded pairs (pre- and post-induction chemotherapy) and in random order as a blinded study. Response was defined as ≥50 % reduction in post induction score compared with baseline., Results: In total, 1968 image sets were reviewed individually. Response rates of 88 % and 82 % were recorded for patients with baseline skeletal scores ≤23 and 24-48 respectively, compared with 44 % response in patients with skeletal scores >48 (p = 0.02). Reducing the number of segments or extension scale had a small but statistically negative impact upon the number of responses detected. Intraclass correlation coefficients [ICCs] calculated for the unblinded and blinded study were 0.95 at diagnosis and 0.98 and 0.99 post-induction chemotherapy, respectively., Conclusions: The SIOPEN mIBG score method is reproducible across the full spectrum of disease in high risk neuroblastoma. Numerical assessment of skeletal disease extent avoids subjective evaluation of uptake intensity. This robust approach provides a reliable means with which to examine the role of 123I mIBG scintigraphy as a prognostic indicator in neuroblastoma., Competing Interests: Compliance with ethical standards All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article does not contain any studies with animals performed by any of the authors. Informed consent Informed consent was obtained from all individual participants or legitimate representatives included in the study. Funding Charity Adam’s Hats supported the pilot study. The trial RDE database was supported by grants provided by Amgen International and Amgen UK. EC grant QLRI-CT-2002-01768 for the SIOPEN-R-NET project supporting national and international data management. Conflict of interest Lewington V declares that she has no conflict of interest. Poetschger U declares that she has no conflict of interest. Lambert B declares that she has no conflict of interest. Bar Sever Z declares that he has no conflict of interest. Castellani MR declares that she has no conflict of interest. Lynch T declares that he has no conflict of interest. Giammarile F declares that he has no conflict of interest. McEwan AJB declares that he has no conflict of interest. Shulkin B declares that he has no conflict of interest. Staudenherz A declares that he has no conflict of interest. Mario Drobics declares that he has no conflict of interest. Ladenstein R declares that she has no conflict of interest.

Rationale and Objectives: Although multiple studies have shown excellent accuracy statistics for noninvasive angiography by coronary computed tomographic angiography (CCTA), most studies comparing nuclear imaging to CCTA were performed on patients already referred for cardiac catheterization, introducing referral and selection bias. This prospective trial evaluated the diagnostic accuracy of 64-row CCTA to detect obstructive coronary stenosis compared to myocardial perfusion imaging (MPI), using quantitative coronary angiography (QCA) as a reference standard., Materials and Methods: Twelve sites prospectively enrolled 230 patients (49% male, 57.8 years) with chest pain. All patients underwent MPI and CCTA (Lightspeed VCT/Visipaque 320, GE Healthcare, Milwaukee, WI, USA) prior to invasive coronary angiography (ICA). All patients were evaluated, and those found to have either an abnormal MPI or CCTA were clinically referred for ICA. CCTAs were graded on a 15-segment American Heart Association model by three blinded readers for presence of obstructive stenosis (>50% or >70%); MPI was graded by two blinded readers using a 17-segment model for estimation of the % myocardium ischemic or with stress defects. ICAs were independently graded for % stenosis by QCA. The efficacies of MPI and CCTA were assessed including all vessel segments for per-patient and per-vessel analyses., Results: The prevalence of stenosis ≥50% by ICA was 52.1% (25 of 48). The sensitivity of CCTA was significantly higher than nuclear imaging (92.0% vs 54.5%, P < 0.001), with similar specificity (87.0% vs 78.3%) when obstructive disease was defined as ≥50%. CCTA provided superior sensitivity (92.6% vs 59.3%, P < 0.001) and similar specificity (88.9% vs 81.5%) using QCA stenosis ≥70%. For ≥50% stenosis, the computed tomographic angiography odds ratio for ICA disease was 51.75 (95% CI = 8.50-314.94, P < 0.001). For summed stress score ≥5%, the odds ratio for ICA CAD was 12.73 (95% CI = 2.43-66.55, P < 0.001). Using receiver operating characteristic curve analysis, CCTA was better at classifying obstructive coronary artery disease when compared to MPI (area = 0.85 vs 0.71, P < 0.0001)., Conclusions: This study represents one of the first prospective multicenter, controlled clinical trials comparing 64-row CCTA to MPI in the same patients, demonstrating superior diagnostic accuracy of CCTA over myocardial perfusion single photon emission computed tomography (MPS) to reliably detect >50% and >70% stenosis in stable chest pain patients., (Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)