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Objectives: Myocardial perfusion scintigraphy (MPS) is an important diagnostic test for detecting of coronary artery stenosis (CAS); however, tissue attenuation can lead to a difference in accuracy. We evaluated the diagnostic accuracy of attenuation-corrected (AC) and non-attenuation-corrected (NC) MPS for the detection of CAS. Methods: We retrospectively recruited patients who underwent invasive coronary angiography within 10 months after Tc-99m sestamibi MPS. The AC and NC perfusion images were analyzed separately, and each myocardial segment was scored based on relative uptake from 0 to 4. The summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) were calculated. The diagnostic performances were analyzed using the area under the curve (AUC) of the receiver operating characteristic curve. Results: From 117 patients, significant coronary stenosis was present in 66 patients (56%). The SSS and SRS obtained from NC-images were higher than those from AC, supporting the presence of attenuation artifacts in NC images. The AUC of SSS and SDS were significantly higher than those of SRS in both AC- and NC-images, but no significant difference was found between the AUC of SSS, and those of SDS. The optimal cut-offs were >12 for AC-SSS, >15 for NC-SSS, >4 for AC-SDS and >3 for NC-SDS. There was no statistically significant difference in the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy among AC-SSS, NC-SSS, AC-SDS, and NC-SDS. Conclusion: NC-based Tc-99m-sestamibi MPS promised comparable accuracy to AC images by using different cut-off values for diagnosis.

Background. Some studies have reported the effectiveness of [18F]PI-2620 as an effective tau-binding radiotracer; however, few reports have applied semiquantitative analysis to the tracer. Therefore, this study’s aim was to perform a semiquantitative analysis of [18F]PI-2620 in individuals with normal cognition and patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Methods. Twenty-six cognitively normal (CN) subjects, 7 patients with AD, and 36 patients with MCI were enrolled. A dynamic positron emission tomography (PET) scan was performed 30–75 min postinjection. PET and T1-weighted magnetic resonance imaging scans were coregistered. The standardized uptake value ratio (SUVr) was used for semiquantitative analysis. The P-Mod software was applied to create volumes of interest. The ANOVA and post hoc Tukey HSD were used for statistical analysis. Results. In the AD group, the occipital lobe had a significantly higher mean SUVr ( 1.46 ± 0.57 ) than in the CN and MCI groups. Compared with the CN group, the AD group showed significantly higher mean SUVr in the fusiform gyrus ( 1.06 ± 0.09 vs. 1.49 ± 0.86 ), inferior temporal ( 1.07 ± 0.07 vs. 1.46 ± 0.08 ), parietal lobe, lingual gyrus, and precuneus regions. Similarly, the AD group demonstrated a higher mean SUVr than the MCI group in the precuneus, lingual, inferior temporal, fusiform, supramarginal, orbitofrontal, and superior temporal regions. The remaining observed regions, including the striatum, basal ganglia, thalamus, and white matter, showed a low SUVr across all groups with no statistically significant differences. Conclusion. A significantly higher mean SUVr of [18F]PI-2620 was observed in the AD group; a significant area of the brain in the AD group demonstrated tau protein deposit in concordance with Braak Stages III–V, providing useful information to differentiate AD from CN and MCI. Moreover, the low SUVr in the deep striatum and thalamus could be useful for excluding primary tauopathies.

Microscopic polyangiitis (MPA) is an autoimmune systemic vasculitis with predominantly small vessel involvement. The American College of Rheumatology (ACR) and the European Alliance of Associations of Rheumatology (EULAR) recently published a new classification criteria for MPA. 1 Diagnosis of MPA is difficult because clinical presentations of the disease are often non-specific. Major manifestations of MPA include renal, pulmonary, skin, gastrointestinal and neurologic manifestations. 2 Here we present a case of a woman with MPA who presented with prolonged fever and skin lesions. Fluoine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG-PET/CT) showed abnormal diffuse renal uptake in the cortex; therefore, guiding the site for biopsy and leading to the final diagnosis of MPA. | C A S E REP ORTA 79-year-old woman with underlying hypertension and dyslipidemia presented with a fever lasting for 3 months. During the first month of her febrile illness, she developed erythematous papules on her hands and feet, which subsequently turned into pustules and later spontaneously resolved. A skin biopsy revealed dermal abscesses with non-specific changes and inflammation of the dermis.No evidence of immunoglobulin deposit was detected from the skin biopsy. Her febrile illness persisted and the patient underwent extensive investigation including chest radiographs, echocardiography, whole spine magnetic resonance imaging and computed tomography angiography of the whole aorta, which did not show cause of the fever. She also had blood test positive for perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) and anti-myeloperoxidase (anti-MPO). The blood test for cytoplasmic ANCA (cANCA) and antiproteinase 3 (anti-PR3) were negative and her eosinophil count was 0.1 × 10 9 cells/L. Her erythrocyte sedimentation rate was 58 mm/h and her serum creatinine was 3.37 mg/dL, equivalent to estimated glomerular filtration rate of 19.5 mL/min/1.73 m 2 . Since there was no definable source of fever, she was classified as having fever of unknown origin (FUO) and she was referred for a whole-body F-18 FDG-PET/CT to identify the potential cause of fever. The FDG-PET/ CT was performed with the routine procedure with low-dose noncontrast CT. The kidney showed abnormal increased FDG uptake in bilateral renal cortices without abnormality in size, parenchymal