Single-photon Emission Computed Tomography Analysis Research Articles

Higher Validity, Lower Radiation: A New Ictal Single-Photon Emission Computed Tomography Framework.

To assess whether arterial spin labeling perfusion images of healthy controls can enhance ictal single-photon emission computed tomography analysis and whether the acquisition of the interictal image can be omitted. We developed 2 pipelines: The first uses ictal and interictal images and compares these to single-photon emission computed tomography and arterial spin labeling of healthy controls. The second pipeline uses only the ictal image and the analogous healthy controls. Both pipelines were compared to the gold standard analysis and evaluated on data of individuals with epilepsy who underwent ictal single-photon emission computed tomography imaging during presurgical evaluation between 2010 and 2022. Fifty healthy controls prospectively underwent arterial spin labeling imaging. The correspondence between the detected hyperperfusion and the postoperative resection cavity or the presumably affected lobe was assessed using Dice score and mean Euclidean distance. Additionally, the outcomes of the pipelines were automatically assigned to 1 of 5 concordance categories. Inclusion criteria were met by 43 individuals who underwent epilepsy surgery and by 73 non-surgical individuals with epilepsy. Compared to the gold standard analysis, both pipelines resulted in significantly higher Dice scores and lower mean distances (p < 0.05). The combination of both provided localizing results in 85/116 cases, compared to 54/116 generated by the current gold standard analysis and the ictal image alone produced localizing results in 60/116 (52%) cases. We propose a new ictal single-photon emission computed tomography protocol; it finds relevantly more ictal hyperperfusion, and halves the radiation dose in about half of the individuals. ANN NEUROL 2024;96:1160-1173.

Remote ischemic periconditioning suppresses cardiac sympathetic activation in acute myocardial infarction: a randomized controlled trial.

Remote ischemic periconditioning (RIPC) has demonstrated cardioprotective effects and improved clinical outcomes as an adjunct to emergent percutaneous coronary intervention (PCI) in patients with ST-elevation myocardial infarction (STEMI). However, whether RIPC affects the cardiac sympathetic nerve activity in patients with STEMI remains unclear. This study investigated the effects of RIPC on cardiac sympathetic nerve activity in patients with STEMI. We prospectively assigned patients with STEMI who underwent emergent PCI to receive RIPC or no procedure (control group) upon arrival at the cardiac catheterization laboratory. The primary endpoint was cardiac sympathetic nerve activity assessed through the washout rate (WR) in cardiac 123I-metaiodobenzylguanidine (123I-MIBG) imaging. Patients in the RIPC (n = 62) and control (n = 60) groups had similar demographic and clinical characteristics at baseline. Multivariable linear regression models revealed that the culprit lesion of the left anterior descending artery and hemoglobin level were significantly and independently associated with WR at discharge. WRs of the groups differed insignificantly at discharge. However, the RIPC group (n = 49) showed significantly lower WR than the control group (n = 47) at 1year after discharge (p = 0.027). In the single-photon emission computed tomography analysis at 1year after discharge, the RIPC group demonstrated significantly higher late uptake (p = 0.021) and lower WR (p = 0.013) in the nonculprit lesion, with a non-significant decrease in WR for the culprit lesion. RIPC can suppress augmented cardiac sympathetic nerve activity in patients with STEMI, particularly in nonculprit lesions.

Assessment of SPECT Image Reconstruction in Liver Scanning Using 99mTc/ EDDA/ HYNIC-TOC

Purpose: Given that the Single Photon Emission Computed Tomography (SPECT) image quality is defined experimentally, developing a specialized scanning technique for each procedure is necessary to increase the diagnosis accuracy. This study aims to determine the optimal algorithm for liver scan reconstruction using 99mTc/SPECT. Materials and Methods: The Filtered Back-Projection (FBP) reconstruction method was used in liver scanning using 99mTc-EDDA/HYNIC-TOC (Tektrotyd) for SPECT images of 30 patients which were acquired with a dual-head EvoExel detector system. Using different types of filters in SPECT imaging, various optimal results can be achieved in the processed images, such as artifact reduction, noise reduction, or signal enhancement and recovery. To evaluate the effect of different filters on image quality, Signal-to-Noise-Ratio (SNR), Contrast-to-Noise-Ratio (CNR), and contrast parameters were calculated. Results: Applying filters enhanced contrast in the images in most cases as well as CNR and SNR. Metz (power = 2), Shepp-Logan (Cut-off frequency = 0.67) and Metz (power = 2) filters increase the CNR, contrast and SNR in images more than the other filters, respectively. The maximum improvement for CNR, contrast and SNR was from 0.62 to 2.35, 0.99 to 1.31, and 8.48 to 14.70, respectively. Conclusion: Based on the results, the Hamming filter, due to providing high-quality images for visual analysis of liver SPECT, and the Butterworth filter, due to balancing the image quality and noise for quantitative analysis, are recommended.

Microstructural alterations in white matter and related neurobiology based on the new clinical subtypes of Parkinson's disease.

The advent of new clinical subtyping systems for Parkinson's disease (PD) has led to the classification of patients into distinct groups: mild motor predominant (PD-MMP), intermediate (PD-IM), and diffuse malignant (PD-DM). Our goal was to evaluate the efficacy of diffusion tensor imaging (DTI) in the early diagnosis, assessment of clinical progression, and prediction of prognosis of these PD subtypes. Additionally, we attempted to understand the pathological mechanisms behind white matter damage using single-photon emission computed tomography (SPECT) and cerebrospinal fluid (CSF) analyses. We classified 135 de novo PD patients based on new clinical criteria and followed them up after 1 year, along with 45 healthy controls (HCs). We utilized tract-based spatial statistics to assess the microstructural changes of white matter at baseline and employed multiple linear regression to examine the associations between DTI metrics and clinical data at baseline and after follow-up. Compared to HCs, patients with the PD-DM subtype demonstrated reduced fractional anisotropy (FA), increased axial diffusivity (AD), and elevated radial diffusivity (RD) at baseline. The FA and RD values correlated with the severity of motor symptoms, with RD also linked to cognitive performance. Changes in FA over time were found to be in sync with changes in motor scores and global composite outcome measures. Furthermore, baseline AD values and their rate of change were related to alterations in semantic verbal fluency. We also discovered the relationship between FA values and the levels of α-synuclein and β-amyloid. Reduced dopamine transporter uptake in the left putamen correlated with RD values in superficial white matter, motor symptoms, and autonomic dysfunction at baseline as well as cognitive impairments after 1 year. The PD-DM subtype is characterized by severe clinical symptoms and a faster progression when compared to the other subtypes. DTI, a well-established technique, facilitates the early identification of white matter damage, elucidates the pathophysiological mechanisms of disease progression, and predicts cognitively related outcomes. The results of SPECT and CSF analyses can be used to explain the specific pattern of white matter damage in patients with the PD-DM subtype.

Proposal for a Display Method for Myocardial Single Photon Emission Computed Tomography Based on Left Ventricular Volume.

Bull's eye view for the display of myocardial single-photon emission computed tomography (SPECT) 3-D perfusion maps does not reflect left ventricular (LV) volume, an important parameter. We created and evaluated a myocardial SPECT display method that reflects the LV volume.Using Digital Imaging and Communications in Medicine data, short-axis slices from the apex to the base were reconstructed and interpolated into 0.5-mm thickness. We obtained the radial lengths at 1° intervals throughout 360°, and calculated the length of the LV long axis and half circumference (1/2 circ). Myocardial perfusion was displayed as 2 ellipsoidal developments that exhibited the left anterior descending coronary artery (LAD) and non-LAD regions. We created a system that can display these processes on a personal computer. Myocardial SPECT data from 526 individuals without heart disease were analyzed. The long axis and 1/2 circ were compared with the body size, LV end-diastolic diameter (LVDd) obtained by echocardiography, and the end-diastolic volume (EDV) obtained by electrocardiogram-gated SPECT analysis. The 1/2 circle correlated with the LVDd and EDV. The images obtained allowed a diagnosis comparable to that made using the conventional coordinate display system.The new myocardial display reflects ischemia and LV volume within a single image, which cannot be achieved with conventional SPECT image display. Additional studies of this display system are required to allow its application to patients with heart disease.

Ictal Single Photon Emission Computed Tomography (SPECT) In Patients with Focal Aware Seizure without Ictal Electroencephalographic Changes: A Single Center Experience (P2-1.012)

<h3>Objective:</h3> N/A <h3>Background:</h3> There is currently limited literature on the localization value of ictal SPECT tracer injection during patient-reported typical focal aware seizures (auras) that lack electrographic changes. One study reported that ictal SPECT studies in isolated auras lack reliability, with concordant localization with the seizure onset zone obtained in 5%, and lateralization in 35% of cases. In another study, localizing information of self-injection of ictal SPECT was better in three patients and obviated the need for intracranial monitoring in one patient. We present a study in which tracer injection was administered for patient-reported typical focal aware seizures, where the subsequent analysis of ictal and interictal SPECT helped inform further management. <h3>Design/Methods:</h3> We performed a retrospective review of cases who underwent ictal SPECT between 2020 to 2022 at University of Kentucky hospital. Cases with radiotracer injection during patient-reported auras lacking electrographic changes were identified. Timing of injection from onset of reported aura, hyperperfusion changes on ictal SPECT, and the outcome of imaging on further management of refractory epilepsy were noted. <h3>Results:</h3> 20 patients underwent ictal SPECT, of which 7 met our inclusion criteria. None of the 7 cases had electrographic correlate with aura on scalp EEG. Time of tracer injection ranged from 1–17 seconds following onset of aura. The ictal SPECT changes correctly localized the seizure onset zone in five patients. This was followed by intracranial monitoring and subsequent temporal lobectomy in three patients, interventricular ablation of epileptogenic focus in one patient, and Responsive Neurostimulation implant in one patient. One patient was managed medically, and one is ongoing pre-surgical evaluation. <h3>Conclusions:</h3> Ictal SPECT with radiotracer injection during typical focal aware seizures (patient reported auras) without ictal electrographic changes is helpful in the localization of the seizure onset zone. Additional studies with larger sample size and outcome information are needed to assess accuracy of localization. <b>Disclosure:</b> Dr. Pervin has nothing to disclose. Dr. Khan has received personal compensation for serving as an employee of University of Kentucky. Dr. Clay has nothing to disclose. Riham El Khouli has nothing to disclose. Dr. Mirza has nothing to disclose. Dr. Mathias has received research support from My Epilepsy Society Non Profit Organization.

The diagnostic value of ictal SPECT-A retrospective, semiquantitative monocenter study.

Ictal single photon emission computed tomography (SPECT) can be used as an advanced diagnostic modality to detect the seizure onset zone in the presurgical evaluation of people with epilepsy. In addition to visual assessment (VSA) of ictal and interictal SPECT images, postprocessing methods such as ictal-interictal SPECT analysis using SPM (ISAS) can visualize regional ictal blood flow differences. We aimed to evaluate and differentiate the diagnostic value of VSA and ISAS in the Bonn cohort. We included 161 people with epilepsy who underwent presurgical evaluation at the University Hospital Bonn between 2008 and 2020 and received ictal and interictal SPECT and ISAS. We retrospectively assigned SPECT findings to one of five categories according to their degree of concordance with the clinical focus hypothesis. Seizure onset zones could be identified more likely on a sublobar concordance level by ISAS than by VSA (31% vs. 19% of cases; OR=1.88; 95% Cl [1.04, 3.42]; P=0.03). Both VSA and ISAS more often localized a temporal seizure onset zone than an extratemporal one. Neither VSA nor ISAS findings were predicted by the latency between seizure onset and tracer injection (P=0.75). In people who underwent successful epilepsy surgery, VSA and ISAS indicated the correct resection site in 54% of individuals, while MRI and EEG showed the correct resection localization in 96% and 33% of individuals, respectively. It was more likely to become seizure-free after epilepsy surgery if ISAS or VSA had been successful. There was no MR-negative case with successful surgery, indicating that ictal SPECT is more useful for confirmation than for localization. The results of the most extensive clinical study of ictal SPECT to date allow an assessment of the diagnostic value of this elaborate examination and emphasize the importance of postprocessing routines.

Diagnosis and Treatment in Unilateral Condylar Hyperplasia.

Unilateral condylar hyperplasia (UCH) is an uncommon disease involving progressive facial asymmetry. The aim of this research was to perform an analysis of the diagnosis and treatment of patients with UCH in a clinical series. An observational retrospective study was performed on subjects with progressive facial asymmetry in the lower third of the face; all the subjects were under treatment with condylectomy and orthodontics to improve occlusion and face balance. Variables such as age, sex, clinical type, SPECT (single photon emission computed tomography) intensity and a requirement for secondary surgery were included; the Shapiro Wilk test was performed to analyze the normality of the data and nonparametric analysis and the Kruskal-Wallis or Mann-Whitney tests were used to assess the association between the SPECT difference and the variables, where 2-tailed p values < 0.05 were considered to be statistically significant. Forty-nine patients between 10 and 45 y.o. (average age: 19.1 ± 7.4 y.o.) were included in the study. There were 41 female (83.6%) and 8 male (16.4%) subjects. The SPECT analysis comparing the right and left condyles with more than 10% in caption of the isotope was present in 46 subjects; the results obtained using SPECT were not statistically related to the age or sex of the sample (p = 0.277). The patients were classified into clinical types I, II and III, and no correlations could be confirmed between the clinical type and other variables. High condylectomy was conducted on all patients, among which 14 patients underwent a secondary surgery for orthognathic or cosmetic treatment, and was not related to the initial variables used in diagnosis (p = 0.98); interestingly, the second surgical treatment was more present in the clinical type I and in subjects under 16 years old with no statistical differences. Clinical analysis, medical records, 3D imaging and SPECT should be used as a complementary analysis in assessing the diagnosis of UCH and progressive facial asymmetry.

Assessing cardiac mechanical dyssynchrony in left bundle branch area pacing and right ventricular septal pacing using myocardial perfusion scintigraphy in the acute phase of pacemaker implantation.

Left bundle branch area pacing (LBBAP) has recently been reported to be a new, clinically feasible and safe physiological pacing strategy. The present study aims to investigate the usefulness of LBBAP in reducing mechanical dyssynchrony compared with right ventricular septal pacing (RVSP). A total of 39 LBBAP patients, 42 RVSP patients, and 93 healthy control participants were retrospectively evaluated. We compared phase analysis- (bandwidth, phase standard deviation [PSD], entropy) and regional wall motion analysis parameters. Wall motion analysis parameters included the time to the end-systolic frame (TES) assessed using single-photon emission computed tomography analysis. The maximum differences between segmental TES (MDTES), the standard deviation of TES (SDTES), and the TES difference between the lateral and septal segments (DTES-LS) were obtained. All phase analysis parameters were significantly smaller in the LBBAP group than in the RVSP group (bandwidth: LBBAP, 74 ± 31° vs. RVSP, 102 ± 59°, p = .009; PSD: LBBAP, 19 ± 6.7° vs. RVSP, 26 ± 15°, p = .007; entropy: LBBAP, 0.57 ± 0.07 vs. RVSP, 0.62 ± 0.11 p = .009). The regional wall motion analysis parameters were also smaller in the LBBAP group than in the RVSP group (MDTES:LBBAP, 17 ± 7.1% vs. RVSP, 25 ± 14%, p = .004; SDTES:LBBAP, 4.5 ± 1.7% vs. RVSP, 6.0 ± 3.5%, p = .015; DTES-LS: LBBAP, 4.1 ± 3.4% vs. RVSP, 7.1 ± 5.4%, p = .004). All phase analysis and wall motion analysis parameters were same in the LBBAP and control groups. LBBAP may reduce mechanical dyssynchrony and achieve greater physiological ventricular activation than RVSP.

Criteria-unfulfilled multiple system atrophy at an initial stage exhibits laterality of middle cerebellar peduncles

To elucidate clinically useful imaging characteristics of multiple system atrophy with predominant cerebellar ataxia (MSA-C) at the initial stage showing pure cerebellar ataxia but unfilling consensus criteria (MSA-pc), clinical and neuroradiological analyses on cerebral MRI and single-photon emission computed tomography (SPECT) for measuring regional cerebral blood flow (rCBF) were performed. Seven MSA-pc patients meeting the above condition at an initial evaluation were identified, and all the MSA-pc patients later developed autonomic dysfunction and finally fulfilled the criteria for probable or possible category of MSA-C. For comparison, two patients with spinocerebellar ataxia type 6 and three patients with idiopathic cerebellar ataxia who did not exhibit autonomic dysfunction for more than three years were enrolled in this study (non-MSA-pc). As non-ataxic controls without cerebellar involvement, seven patients with Parkinson's disease were also enrolled. As a result, MRI analysis clarified a smaller pontine area and significant laterality of middle cerebellar peduncle (MCP) width in MSA-pc in comparison to non-MSA-pc and controls. SPECT analysis revealed that pontine rCBF was reduced even at the initial stage of MSA-pc. Moreover, the laterality of cerebellar rCBF values and the laterality of MCP width in MSA-pc patients exhibited a significant positive correlation, indicating anatomical and functional laterality of afferent projections to cerebellum is a characteristic finding for MSA-pc. These neuroimaging characteristics could be clinically useful to consider the possibility of the criteria-unfulfilled MSA and promote an earlier intervention after obtaining a diagnosis of probable MSA-C.

Associations Between Regional Cerebral Blood Flow and Psychiatric Symptoms in Dementia With Lewy Bodies Without Parkinsonism.

Because dementia with Lewy bodies (DLB) has various psychiatric symptoms, early diagnosis in patients without parkinsonism is difficult. To reveal associations between regional brain perfusion and psychiatric symptoms in DLB patients without parkinsonism, we quantified brain perfusion using an automated brain perfusion single-photon emission computed tomography analysis program, FineSRT. We statistically analyzed the differences in brain perfusion between groups, divided by the presence or absence of psychiatric symptoms. In DLB patients with depression, there were significant brain perfusion increases in the left angular gyrus and right upper precuneus. In DLB patients with visual hallucinations, there were significant decreases in the left inferior parietal lobule, left superior temporal gyrus, and right primary visual cortex. In DLB patients with auditory hallucinations, there were significant increases in the right middle occipital and right inferior occipital gyri. Our findings provide clues about the pathomechanisms of psychiatric symptoms and may enable early diagnosis of DLB in the future.

SPECT analysis and language profile in Greek speaking patients with subtypes of frontotemporal dementia.

We aimed to examine if single photon emission computed tomography (SPECT) can discriminate between variants of frontotemporal dementia (FTD). As a secondary investigation we identify and establish the linguistic differences between those variants. Nine patients with semantic variant primary progressive aphasia (svPPA), 8 with non-fluent variant primary progressive aphasia (nfvPPA) and 17 with behavioral variant of frontotemporal dementia (bvFTD) were compared on Addenbrooke's cognitive examination-revised (ACE-R), auditory comprehension, oral expression and verbal fluency. All patients were also compared with healthy controls. Patients were evaluated using technetium-99m-hexamethylproyleneamine oxime (99mTc-HMPAO) brain SPECT as a measure of regional cerebral flow. Significant group differences between all patients and controls were found for ACE-R, auditory comprehension and oral expression. Semantic variant primary progressive aphasia patients performed higher in letter compared to category fluency with significant deficits in auditory comprehension and oral expression. Non-fluent variant primary progressive aphasia patients showed significant deficits in auditory comprehension but not oral expression while performed lightly worse in letter fluency compared to category. Behavioral variant of frontotemporal dementia patients showed deficits in auditory comprehension and oral expression and performed similar in category and letter fluency. Single photon emission computed tomography analysis revealed left frontotemporal hypoperfusion extending to the right frontotemporal region in svPPA patients. Non-fluent variant primary progressive aphasia patients presented left frontotemporal hypoperfusion with participation of the left parietal and right frontotemporal regions. Behavioral variant of frontotemporal dementia patients showed bilateral frontotemporal hypoperfusion compared to parietal and visual cortices. Our findings suggest that SPECT may assist in the discrimination of the FTD variants. We also confirmed that bvFTD patients share similar language deficits with svPPA patients.

Ischemic Burden Assessment Using Single Photon Emission Computed Tomography in Single Vessel Chronic Total Occlusion of Coronary Artery.

Studies evaluating the nature of ischemic burden of chronic total occlusion (CTO) vessels are still lacking. A total of 165 patients with single vessel CTO >2.5 mm in an epicardial coronary artery who underwent single photon emission computed tomography (SPECT) were enrolled in the study. Ischemic burden was calculated with the use of semi-quantitative SPECT analysis, and was defined as the summed difference score (SDS) divided by the maximal limit of the score (=SDS/68). The mean age of the participants was 59.5 years and the CTO of the left anterior descending coronary artery (LAD), left circumplex coronary artery (LCX), and right coronary artery (RCA) accounted for 93 (56.4%), 18 (10.9%), and 54 (32.7%) patients, respectively. The median ischemic burden of the total population was 8.8%, and it was highest in the LAD CTO (10.3%) compared with the LCX (5.9%) and RCA CTO (5.9%, p<0.001). High-ischemic burden (ischemic burden >10%) was observed in 66 patients (40.0%), and in 47 patients (50.5%) of the LAD CTO. Ischemic burden was different according to the CTO location only in LAD CTO. The statistically significant predictors for high-ischemic burden were hypertension, baseline ejection fraction >45%, LAD CTO, proximal CTO location, and de novo CTO. Japanese-CTO score and Rentrop scale collateral grade were not associated with high-ischemic burden. Only 40% of patients with single vessel CTO had ischemic burden >10%. For CTO vessels, measurement of ischemic burden using SPECT prior to revascularization may be helpful in identifying beneficial subjects.

Regional Cerebral Blood Flow Abnormalities in Neurosyphilis: A Pilot SPECT Study.

Objective: Clinical and radiological findings on neurosyphilis are fairly non-specific and there is a paucity of functional neuroimaging studies on neurosyphilis other than case reports and case series. The purpose of this study was to investigate brain perfusion abnormalities in patients with neurosyphilis.Methods: Four HIV-negative neurosyphilis patients and 4 healthy controls underwent clinical evaluation, brain technetium-99m ethyl cysteinate dimer (99mTc-ECD) single-photon emission computed tomography (SPECT) imaging, and neuropsychological assessments which included the Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Clinical Dementia Rating—Sum of Boxes (CDR-SOB), and Global Deterioration Scale (GDS). Voxel-wise differences in regional cerebral blood flow were compared between the two groups.Results: Neuropsychological test results indicated cognitive impairment in all patients. SPECT analysis revealed multifocal hypoperfusion predominantly in the frontal, insular, and posterior cingulate regions in neurosyphilis patients compared with healthy controls (family-wise error corrected p < 0.05).Conclusions: Together with previous findings, our results suggest that the hypoperfusion in the frontal, insular, and posterior cingulate regions may reflect cognitive impairments observed in neurosyphilis patients. Further studies with larger samples are needed to confirm our findings.

Prognostic Significance of Cardiac 123I-MIBG SPECT Imaging in Heart Failure Patients With Preserved Ejection Fraction

ObjectivesThe authors sought to elucidate the prognostic value of cardiac sympathetic nerve dysfunction as evaluated using iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) single-photon emission computed tomography (SPECT) imaging in patients with heart failure (HF) with preserved left ventricular ejection fraction (HFpEF). BackgroundCardiac sympathetic nerve dysfunction assessed by 123I-MIBG imaging is associated with poor outcomes in chronic HF patients with reduced left ventricular ejection fraction (HFrEF). However, no information is available on the prognostic vale of cardiac 123I-MIBG SPECT imaging in patients with HFpEF. MethodsWe studied 148 patients admitted for acute decompensated HF (ADHF) with nonischemic HFpEF and who underwent cardiac 123I-MIBG imaging at discharge. The cardiac 123I-MIBG heart-to-mediastinum ratio (H/M) was measured on the delayed planar image (late H/M). SPECT analysis of the delayed image was conducted, and the tracer uptake in all 17 regions on the polar map was scored on a 5-point scale by comparison with a sex-matched normal control database. The total defect score (TDS) was calculated by summing the score of each of the 17 segments. The primary endpoint was the association between TDS and cardiac events (the composite of emergent HF hospitalization and cardiac death). ResultsDuring a mean follow-up period of 2.4 ± 1.6 years, 61 patients experienced cardiac events. TDS was significantly associated with cardiac events after multivariate Cox adjustment (P < 0.0001). Patients with high TDS levels had a significantly greater risk of cardiac events than those with middle or low TDS levels (63% vs 40% vs 20%, respectively; P < 0.0001; HR: 4.69; 95% CI: 2.29 to 9.61; and HR: 2.46; 95% CI: 1.14 to 5.29). C-statistic of TDS was 0.730 (95% CI: 0.651 to 0.799), which was significantly higher than that of late H/M (0.607; 95% CI: 0.524 to 0.686; P = 0.0228). ConclusionsCardiac 123I-MIBG SPECT imaging provided useful prognostic information in nonischemic ADHF patients with HFpEF. (Clinical Trial: Osaka Prefectural Acute Heart Failure Syndrome Registry [OPAR]: UMIN000015246)

Radiomics analysis of myocardial perfusion SPECT images in patients with cardiomyopathy and heart failure

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI Grants Background Although myocardial perfusion heterogeneity due to focally damaged cardiomyocytes is observed in single−photon emission computed tomography (SPECT) imaging, a current perfusion defect scoring system does not allow us to provide sufficient diagnostic information for heterogeneity. Purpose The aim of this study was to perform radiomics analysis of myocardial perfusion SPECT (MPS) images to investigate the potential to detect myocardial perfusion heterogeneity. Methods Patients with hypertrophic cardiomyopathy (n = 3), heart failure (n = 9), and with a low likelihood of coronary artery disease (n =15) (Figure 1), who underwent a rest 99mTc-MIBI myocardial perfusion SPECT, were assessed using a LIFEx software. Four shape−based features, 6 histogram−based features, and 32 textural features were computed. The relevant features for the classification of the patients were selected using the Boruta algorithm, and hierarchical clustering of the selected features using the Spearman correlation coefficient was also performed for the feature reduction. The receiver operating characteristics (ROC) analysis was performed by the support vector machine to calculate the area under the ROC curve (AUC) for the selected features. Results Of 40 features, 17 were selected by the classification analysis, and these features were classified into 7 classes by the correlation analysis (Figure 2). The ROC AUCs for 7 features extracted from each class were 0.99, 0.97, 0.96, 0.92, 0.90, 0.86, and 0.83 for the contrast of NDGLDM, the entropy of histogram, ZLNU of GLZLM, the energy of GLCM, the energy of histogram, SZLGE of GLZLM, and the correlation of GLCM, respectively, as compared to 0.39 for a summed rest score. Conclusions Radiomics analysis successfully determined the myocardial perfusion heterogeneity in patients with cardiomyopathy and heart failure. It might be promising for the evaluation of myocardial damages that cannot be analyzed by the conventional scoring method.

An alternative method for radioactivity measurement in quantitative bone SPECT/CT imaging.

Bone scintigraphy with combined single-photon emission computed tomography (SPECT) and computed tomography (CT) has become widely used for the detection of bone metastases. However, calculation of the semi-quantitative standardized uptake value (SUV) requires measurement of the pre- and post-injection radioactivity of the radiopharmaceutical. This study aimed to compare measured and fixed input radioactivity values for quantitative SPECT/CT bone imaging to examine whether the fixed measurement method of radiopharmaceutical radioactivity could be used as an alternative method. Four different methods were used to quantify the Tc-99m hydroxymethylene diphosphonate input radioactivity: (A) measured pre- and post-injection radioactivity values; (B) measured pre-injection and fixed post-injection radioactivity values; (C) fixed pre-injection and measured post-injection radioactivity values; (D) fixed pre- and post-injection radioactivity values. All SPECT/CT acquisitions were analyzed using bone SPECT analysis software, and the semi-quantitative parameters (SUVpeak and SUVmean) were recorded and compared for each analytical method. Two semi-quantitative parameters showed significant differences between analytical methods A and B, A and D, and C and D. However, an additional subgroup analysis performed on patients whose median post-injection measured radioactivity value was <1.5 MBq showed no significant differences in parameters between all analytical methods. Measurement of the radiopharmaceutical radioactivity can be an alternative method because it reduces the volume of radioactivity post-injection. The simplified fixed measurement method of radiopharmaceutical radioactivity can be used as an alternative method in cases when measuring the radioactivity in quantitative bone SPECT/CT imaging is missed.

Usefulness of 2D-Perfusion Analysis for the Assessment of Unilateral Cervical Internal Carotid Artery Stenosis.

We investigated the usefulness of 2D-perfusion analysis for the evaluation of cerebral blood flow in unilateral cervical internal carotid artery stenosis. We conducted a 2D-perfusion analysis during cerebral angiography and 123I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) for unilateral cervical internal carotid artery stenosis without contralateral stenosis. The relationship between the ratio of the lesion side to the normal side in the parameters obtained by 2D-perfusion and the value calculated by stereotactic extraction estimation (SEE) analysis of SPECT was statistically examined. The ratios of the lesion side to the normal side regarding the peak arrival time (AT; time to peak [TTP]) of the contrast agent and the mean filling time (mean transit time [MTT]) of the contrast agent in 2D-perfusion significantly correlated with the area of Stage II and increase ratio (I.R) ≤30% in the SEE analysis (p = 0.002, 0.003). 2D-perfusion analysis can be used to estimate the extent of impaired cerebrovascular reserve (CVR) area in unilateral internal carotid artery stenosis.

Injection of prophylactic lorazepam versus antiseizure drugs on the localization value of ictal SPECT studies and treatment-emergent adverse events: A single-center prospective study

ObjectiveWe aimed to examine the impact of resumption of home antiseizure drugs alone (ASD−) compared with adjunct administration of scheduled intravenous (IV) lorazepam 2 mg every 6 h (ASD+) following ictal single-photon emission computed tomography (SPECT) injection on the localization value of SPECT studies and treatment-emergent adverse events (TEAEs). MethodsWe conducted a prospective study at Mayo Clinic inpatient epilepsy monitoring unit (EMU) between January 2018 and May 2020 in Jacksonville, Florida. The ASD− and ASD+ groups were compared for concordance of SPECT studies with the epilepsy surgical conference (ESC) consensus or intracranial electroencephalography (icEEG) findings as reference. Treatment-emergent adverse events, obtained from surveys at 24 h and one week postictal SPECT injection, were also compared between both groups. ResultsTwenty-two consecutive patients with temporal (eight patients, 36%) and extratemporal (14 patients, 64%) epilepsy were included: 12 ASD+ and 10 ASD−. The two groups were well matched with regard to clinical and ictal SPECT injection characteristics including the occurrence of seizure between ictal and interictal SPECT injections. The localization value of SPECT studies was similar in the two groups. Patients in the ASD+ group reported higher rates of dizziness and excessive sedation at 24 h (p-value = 0.008). Fourteen patients (64%) underwent icEEG monitoring. For the entire cohort, the localization concordance of SPECT analysis by statistical parametric mapping (SPM) was superior to raw ictal SPECT (p-value = 0.003) and subtraction ictal SPECT coregistered to magnetic resonance imaging (MRI) (SISCOM; p-value = 0.021). Eventually, seven patients (31.8%) underwent resective brain surgery of whom four (57.1%) became seizure-free (median follow-up = 22 months). ConclusionsOur findings suggest that resuming home ASDs without the addition of scheduled IV lorazepam following inpatient ictal SPECT injection is equally efficacious for seizure onset zone (SOZ) localization on SPECT studies, especially SPM. This approach is also associated with fewer transient TEAEs and lower financial cost with no difference in preventing seizure between ictal and interictal SPECT injections.

Quantitative bone SPECT analysis of mandibular condyles in an asymptomatic population: an approach to normal reference values

Bone scintigraphy is an extremely valuable technique in diagnosis and treatment planning for patients with condylar hyperplasia (CH). The main objective of this study was to develop an approach to determine normal activity values in the mandibular condyles, adjusted to age and sex, through quantitative analysis of bone single-photon emission computed tomography (SPECT) on a condyle-by-condyle basis and to compare these values with those of a control group comprising patients with confirmed CH. Technetium 99 m-methylene diphosphonate (99mTc-MDP) SPECT studies of the mandibular condyles were performed in patients with no mandibular pathology for quantitative analysis. Regions of interest were drawn on slices representing the upper, middle, and inferior thirds of each condyle and on the summation of transaxial slices representing the whole condyle (three-dimensional approach). The clivus was used for internal validation and the condyle to clivus ratios were calculated. These ratios were compared between ‘normal’ and ‘diseased’ condyles. A total 144 condyles in normal patients and 25 in confirmed CH patients were analysed. Differences between the ratios were evaluated through the coefficient of variation. In normal patients, the ratios to the clivus on the summed condyle image showed the lowest variability: range 0.3–1.28 (median 0.74). The quantile regression model showed significant differences with respect to sex, but not to age. The Mann–Whitney test showed significant differences in the ratios to clivus between normal and diseased condyles (P<0.0001).