Value of semiquantitative analysis for clinical reporting of 123I-2-ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)nortropane SPECT studies.

UNLABELLED: Clinical (123)I-2-ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)nortropane ((123)I-FP-CIT) SPECT studies are commonly performed and reported using visual evaluation of tracer binding, an inherently subjective method. Increased objectivity can potentially be obtained using semiquantitative analysis. In this study, we assessed whether semiquantitative analysis of (123)I-FP-CIT tracer binding created more reproducible clinical reporting. A secondary aim was to determine in what form semiquantitative data should be provided to the reporter. METHODS: Fifty-four patients referred for the assessment of nigrostriatal dopaminergic degeneration were scanned using SPECT/CT, followed by semiquantitative analysis calculating striatal binding ratios (SBRs) and caudate-to-putamen ratios (CPRs). Normal reference values were obtained using 131 healthy controls enrolled on a multicenter initiative backed by the European Association of Nuclear Medicine. A purely quantitative evaluation was first performed, with each striatum scored as normal or abnormal according to reference values. Three experienced nuclear medicine physicians then scored each striatum as normal or abnormal, also indicating cases perceived as difficult, using visual evaluation, visual evaluation in combination with SBR data, and visual evaluation in combination with SBR and CPR data. Intra- and interobserver agreement and agreement between observers and the purely quantitative evaluation were assessed using κ-statistics. The agreement between scan interpretation and clinical diagnosis was assessed for patients with a postscan clinical diagnosis available (n = 35). RESULTS: The physicians showed consistent reporting, with a good intraobserver agreement obtained for the visual interpretation (mean κ ± SD, 0.95 ± 0.029). Although visual interpretation of tracer binding gave good interobserver agreement (0.80 ± 0.045), this was improved as SBRs (0.86 ± 0.070) and CPRs (0.95 ± 0.040) were provided. The number of striata perceived as difficult to interpret decreased as semiquantitative data were provided (30 for the visual interpretation; 0 as SBR and CPR values were given). The agreement between physicians' interpretations and the purely quantitative evaluation showed that readers used the semiquantitative data to different extents, with a more experienced reader relying less on the semiquantitative data. Good agreement between scan interpretation and clinical diagnosis was seen. CONCLUSION: A combined approach of visual assessment and semiquantitative analysis of tracer binding created more reproducible clinical reporting of (123)I-FP-CIT SPECT studies. Physicians should have access to both SBR and CPR data to minimize interobserver variability.

Value of 18F-fluorodeoxyglucose uptake in positron emission tomography/computed tomography in predicting survival in multiple myeloma.

PURPOSE: We assessed the role of the maximum standardized uptake value (SUV(max)) of bone marrow and the extramedullary lesion with the highest SUV(max) in positron emission tomography/computed tomography (PET/CT) of newly diagnosed multiple myeloma (MM) patients in predicting overall survival (OS). METHODS: A total of 61 newly diagnosed patients (55 MM and 6 plasmacytoma) were enrolled in the study [37 men and 24 women with a median age of 57 years (range 28-80 years)]. The SUV(max) of bone marrow and the extramedullary lesion in PET/CT was correlated with the levels of ß(2)-microglobulin, C-reactive protein (CRP), albumin, creatinine, per cent of bone marrow plasma cells, serum free light chain (FLC) ratio, International Staging System (ISS) score and Durie-Salmon stage. RESULTS: The extramedullary lesion with the highest SUV(max) showed significant correlation with bone marrow fluorodeoxyglucose (FDG) uptake (p = 0.027) and near significant correlation with ISS (p = 0.048). Bone marrow SUV(max) correlated significantly with the per cent of bone marrow plasma cell count (p = 0.024), CRP (p = 0.012) and ISS (p = 0.013). In stage III MM the mean values of SUV(max) in extramedullary lesions were significantly higher than stages I and II (6.23 ± 6.32 vs 2.85 ± 3.44, p = 0.023). The serum FLC ratio did not show any correlation with SUV(max) of lesions and bone marrow (p > 0.05). Forty-four MM patients with FDG-positive lesions in PET/CT showed inferior 5-year estimated survival (61.73%) when compared to 11 patients without FDG-positive lesions, all of whom were alive (p = 0.01). In multivariate analysis an extramedullary lesion with the highest SUV(max) was the only independent predictor of OS (p = 0.03). CONCLUSION: PET/CT allows identification of high-risk myeloma patients, and extramedullary lesions with the highest SUV(max) independently predict inferior OS.

Comparison of diagnostic performances of three different software packages in detecting coronary artery disease.

PURPOSE: Quantification of myocardial perfusion scintigraphy is frequently performed to assist physicians in detecting coronary artery disease (CAD). Software packages provide automated quantification of perfusion data. We aimed to compare the three commonly used software packages, Emory Cardiac Toolbox (ECT v2 and ECT v3), 4D-MSPECT (4DM v2 and 4DM v4) and Quantitative Perfusion SPECT (QPS v3 and QPS v4). METHODS: We selected 283 patients who had a myocardial perfusion scintigraphy with (201)Tl followed by coronary angiography within 3 months. Summed stress score (SSS), summed difference score (SDS), total stress defect extent (TDE) and regional stress defect extent values were obtained from programs. A ≥70% stenosis in coronary arteries and their major branches was considered positive for CAD. A subgroup of patients was used to form an institutional normal database for QPS and 4DM. Receiver-operating characteristic (ROC) analysis to detect CAD was performed. RESULTS: Mean SSS ± SD (vendor) for ECT v3, QPS v4 and 4DM v4 were 9.2 ± 7.1, 10.1 ± 6.8 and 5.5 ± 6.1, respectively. Area under the curve (AUC) values of SSS ROC analysis were 0.738 ± 0.031 for QPS v3, 0.755 ± 0.030 for QPS v4, 0.758 ± 0.030 for ECT v2, 0.778 ± 0.029 for ECT v3 and 0.771 ± 0.030 for 4DM v4. The AUC values for TDE were 0.755 ± 0.030 for QPS v4, 0.769 ± 0.030 for ECT v3 and 0.775 ± 0.029 for 4DM v4. The differences were not significant for both SSS and TDE. Differences of AUC between regional stress defect extent values of programs and AUC of SSS between institutional and vendor normal databases were not significant. CONCLUSION: The diagnostic performances of programs to detect CAD are similar. However, there are differences in the magnitudes of the quantitative values produced by the programs.

An open-source framework of neural networks for diagnosis of coronary artery disease from myocardial perfusion SPECT.

BACKGROUND: The purpose of this study is to develop and analyze an open-source artificial intelligence program built on artificial neural networks that can participate in and support the decision making of nuclear medicine physicians in detecting coronary artery disease from myocardial perfusion SPECT (MPS). METHODS AND RESULTS: Two hundred and forty-three patients, who had MPS and coronary angiography within three months, were selected to train neural networks. Six nuclear medicine residents, one experienced nuclear medicine physician, and neural networks evaluated images of 65 patients for presence of coronary artery stenosis. Area under the curve (AUC) of receiver operating characteristics analysis for networks and expert was .74 and .84, respectively. The AUC of the other physicians ranged from .67 to .80. There were no significant differences between expert, neural networks, and standard quantitative values, summed stress score and total stress defect extent. CONCLUSIONS: The open-source neural networks developed in this study may provide a framework for further testing, development, and integration of artificial intelligence into nuclear cardiology environment.