Masuo Hayashi

Japanese guideline for the oncology FDG-PET/CT data acquisition protocol: synopsis of Version 1.0.

This synopsis outlines the Japanese guideline Version 2.0 for the data acquisition protocol of oncology FDG-PET/CT scans that was created by a joint task force of the Japanese Society of Nuclear Medicine Technology, the Japanese Society of Nuclear Medicine and the Japanese Council of PET Imaging, and was published in Kakuigaku-Gijutsu 2013; 33:377–420 in Japanese. The guideline aims at standardizing the PET image quality among PET centers and different PET camera models by providing criteria for the IEC body phantom image quality as well as for the patient PET image quality based on the noise equivalent count (NEC), NEC density and liver signal-to-noise ratio, so that the appropriate scanning parameters can be determined for each PET camera. This Version 2.0 covers issues that were not focused on in Version 1.0, including the accuracy of the standardized uptake value (SUV), effect of body size together with adjustment of scanning duration, and time-of-flight (TOF) reconstruction technique. Version 2.0 also presents data acquired with new PET camera models that were not tested in Version 1.0. Reference values for physical indicators of phantom image quality have been updated as well.

Evaluation of breath-hold201Tl SPECT in the differential diagnosis of solitary pulmonary nodules

The aim of this study was to evaluate the usefulness of deep inspiration breath-hold SPECT (BrST, a method for201T1 SPECT) in the diagnosis of solitary pulmonary nodules (SPN).Methods: Ten patients with malignant lesions and five with benign lesions were enrolled in this study. Early SPECT acquisition was performed 15 min after injection of201T1, while delayed SPECT images were acquired 3 h after injection. The first 15-sec acquisition was done using the BrST technique, and the second with the conventional free breathing (FB) method. We performed this technique alternately, and therefore, the odd data were from BrST and the even data were from FB. We referred to the T/N ratio of the early images as the ER and to the T/N ratio of the delayed images as the DR. To semi-quantitatively evaluate the degree of retention in the lesion, the retention index (RI) was calculated.Results: The RI of BrST indicated greater accuracy than that of FB in the differential diagnosis of SPN. For the benign and malignant lesions, the RI of BrST was -3.07 ± 31.51 and 29.86 ± 25.01, respectively (p < 0.05). The sensitivity, specificity, and accuracy of BrST (80%, 80%, and 80%, respectively) were significantly higher than those of FB (p < 0.05).Conclusion: The BrST method is more accurate than that of the conventional FB method in the differential diagnosis of SPN.

Presence of Postsystolic Shortening Increases the Likelihood of Coronary Artery Disease: A Rest Electrocardiography-Gated Myocardial Perfusion SPECT Study

Postsystolic shortening (PSS), which is a delayed myocardial contraction that occurs after end-systole, has been considered an important diagnostic index of myocardial ischemia. Recent technological advancements in quantitative gated SPECT (QGS) software enables the left ventricular (LV) regional analysis and may be useful for PSS measurement. The purpose of this study was to evaluate whether PSS at the resting condition determined by QGS is useful to identify patients with coronary artery disease. Methods: The study comprised 146 patients (mean age ± SD, 71 ± 8 y; 98 men) with normal LV wall motion (mean LV ejection fraction ± SD, 72% ± 9%) who underwent both coronary angiography and resting 99mTc-tetrofosmin myocardial perfusion SPECT. The sum of the difference between post–end-systolic maximal LV thickening and end-systolic LV thickening, designated PSS index, was calculated from 17 LV myocardial segments using QGS. Results: The PSS index was significantly higher in patients with significant stenosis of the coronary artery than in the other patients (9.8 ± 10.2 vs. 5.6 ± 5.1; P < 0.01). A cutoff point of 6.0 of the PSS index had sensitivity, specificity, positive predictive value, and negative predictive values of 55%, 70%, 76%, and 47%, respectively, for the diagnosis of coronary artery disease. Multivariate logistic regression analysis demonstrated that a PSS index greater than 6.0 was an independent predictor for the presence of coronary artery disease (odds ratio, 2.46; 95% confidence interval, 1.1–5.4; P < 0.05). Conclusion: Among subjects with normal LV function, PSS index even in the resting condition determined using QGS may help to identify patients with coronary artery disease.