OBJECTIVE: We aimed to correlate the ability of these modalities to differentiate Probable AD and Possible AD using the clinical diagnosis as a gold standard. We also investigated the correlation of severity of amyloid deposit in the brain with the diagnosis of AD.
METHODS: A retrospective study of 47 subjects (17 Probable AD and 30 Possible AD) who were referred for PET/CT amyloid scans to our centre was conducted. Hypoperfusion in the temporo-parietal lobes on Tc99m-HMPAO SPECT and loss of grey-white matter contrast in cortical regions on PET/CT Amyloid scans indicating the presence of amyloid β deposit were qualitatively interpreted as positive for AD. SPECT and PET/CT were also read in combination (Combo reading). The severity of amyloid β deposit was semiquantitatively assessed in a visual binary method using a scale of Grade 0-4. The severity of amyloid β deposit was assessed in a visual binary method and a semi-quantitative method using a scale of Grade 0-4.
RESULTS: There was significant correlation of Tc99m-HMPAO SPECT, PET/CT amyloid findings and Combo reading with AD. The sensitivity, specificity, PPV and NPV were 87.5%, 73.7%, 58.3% and 93.3% (SPECT); 62.5%, 77.4%, 58.8% and 80.0% (PET/CT) and 87.5%, 84.2%, 70.0% and 30.0% (Combo reading) respectively. The grade of amyloid deposition was not significantly correlated with AD (Spearman's correlation, p=0.687).
CONCLUSION: There is an incremental benefit in utilizing PET/CT amyloid imaging in cases with atypical presentation and indeterminate findings on conventional imaging of Alzheimer's disease.
PURPOSE: This study aims to semiquantitatively evaluate the standardized uptake value (SUV) of 99mTc-methylene diphosphonate (MDP) radionuclide tracer in the normal vertebrae of breast cancer patients using an integrated single-photon emission computed tomography (SPECT)/computed tomography (CT) scanner.
OVERVIEW OF LITERATURE: Molecular imaging techniques using gamma cameras and stand-alone SPECT have traditionally been utilized to evaluate metastatic bone diseases. However, these methods lack quantitative analysis capabilities, impeding accurate uptake characterization.
METHODS: A total of 30 randomly selected female breast cancer patients were enrolled in this study. The SUV mean (SUVmean) and SUV maximum (SUVmax) values for 286 normal vertebrae at the thoracic and lumbar levels were calculated based on the patients' body weight (BW), body surface area (BSA), and lean body mass (LBM). Additionally, 106 degenerative joint disease (DJD) lesions of the spine were also characterized, and both their BW SUVmean and SUVmax values were obtained. A receiver operating characteristic (ROC) curve analysis was then performed to determine the cutoff value of SUV for differentiating DJD from normal vertebrae.
RESULTS: The mean±standard deviations for the SUVmean and SUVmax in the normal vertebrae displayed a relatively wide variability: 3.92±0.27 and 6.51±0.72 for BW, 1.05±0.07 and 1.75±0.17 for BSA, and 2.70±0.19 and 4.50±0.44 for LBM, respectively. Generally, the SUVmean had a lower coefficient of variation than the SUVmax. For DJD, the mean±standard deviation for the BW SUVmean and SUVmax was 5.26±3.24 and 7.50±4.34, respectively. Based on the ROC curve, no optimal cutoff value was found to differentiate DJD from normal vertebrae.
CONCLUSIONS: In this study, the SUV of 99mTc-MDP was successfully determined using SPECT/CT. This research provides an approach that could potentially aid in the clinical quantification of radionuclide uptake in normal vertebrae for the management of breast cancer patients.
METHODS: A single-arm multicenter prospective study was designed aiming to determine the safety and efficacy of ESMT. Patients of functional Canadian Cardiovascular Society class II-IV, despite stable and optimal medical management, with documented myocardial segments with reversible ischemia and/or hibernation on the basis of echocardiography/single-photon emission computerized tomography (SPECT) were enrolled from 2010 to 2012. A total of 111 patients were enrolled, 33 from Indonesia, 21 from Malaysia, and 57 from Philippines. Patients underwent nine cycles of ESMT over 9 weeks. Patients were followed up for 3-6 months after ESMT treatment. During follow-up, patients were subjected to clinical evaluation, the Seattle Angina Questionnaire, assessment of nitrate intake, the 6-min walk test, echocardiography, and SPECT.
RESULTS: The mean age of the population was 62.9±10.9 years. The summed difference score on pharmacologically induced stress SPECT improved from 9.53±17.87 at baseline to 7.77±11.83 at follow-up (P=0.0086). Improvement in the total Seattle Angina Questionnaire score was seen in 83% of patients (P<0.0001). Sublingual nitroglycerin use significantly decreased (1.14±1.01 tablets per week at baseline to 0.52±0.68 tablets per week at follow-up; P=0.0215). There were no changes in left ventricular function on echocardiography (0.33±9.97, P=0.93). The Canadian Cardiovascular Society score improved in 74.1% of patients.
CONCLUSION: This multicenter prospective trial demonstrated that ESMT is both a safe and an efficacious means of managing medically refractory angina.