role of performing stress in myocardial perfusion scintigraphy

One of the major limitations of myocardial scintigraphy is soft tissue attenuation, which could be interpreted as a true perfusion defects, particularly diaphragmatic and bowel attenuation of the inferior wall. The aim of this study was to evaluate the role of adding prone scan to the stress myocardial scintigraphy. Department of Radiology, Nuclear Medicine Section, King Faisal Specialist Hospital and Research Center. Retrospective study. Eighty-eight patients with coronary artery disease had myocardial perfusion scan and were reported with and without a prone scan during stress study. All patients in this study had a diagnostic coronary angiogram. Patients who had coronary angiogram within one month after the diagnostic cardiac scan were included. Patients who have been admitted to the hospital between the two procedures were excluded. Prone scan had improved the sensitivity [SN], specificity [SP], positive and negative predictive value [PPV, NPV] of the myocardial perfusion scintigraphy studies. Prone scan showed that SN, SP, PPV and NPV were, 91.7%, 70%, 78.6% and 87.5% compared to supine scan, which were 76.6%, 53.6%, 65.4% and 66.7%. In this study, we have found that the sensitivity and specificity had improved after the addition of prone stress scan in myocardial perfusion studies. Prone scan had helped in differentiating perfusion defects from attenuation artifacts, leading to improvement of detecting the true perfusion defects

Humeral head osteonecrosis in sickle cell disease

Sickle cell disease is the commonest cause of humeral head osteonecrosis worldwide. 144 shoulders in 72 patients with sickle cell disease were assessed clinically and radiographically. Our null hypothesis is that there is no correlation between the shoulder symptoms and the radiographic extent of osteonecrosis in such patients. The symptoms of each shoulder were scored using the UCLA shoulder scoring system. All shoulder x-rays were staged for humeral head osteonecrosis according to the modified Ficat and Arlet staging system. The Wilcoxin ranked sum test was used to correlate the data of the UCLA score with the data of the modified Ficat and Arlet stage. This gave a coefficient of 0.189. It is concluded that there is most likely no correlation between the shoulder symptoms and the radiographic stage of humeral head osteonecrosis in patients with sickle cell disease