Impact of attenuation correction and gated acquisition in SPECT myocardial perfusion imaging: results of the multicentre SPAG (SPECT Attenuation Correction vs Gated) study.

PURPOSE: In clinical myocardial single photon emission computed tomography (SPECT), attenuation artefacts may cause a loss of specificity in the identification of diseased vessels that can be corrected by means of gated SPECT (GSPECT) acquisition or CT attenuation correction (AC). The purpose of this multicentre study was to assess the impact of GSPECT and AC on the diagnostic performance of myocardial scintigraphy, according to patient's sex, body mass index (BMI) and site of coronary artery disease (CAD). METHODS: We studied a group of 104 patients who underwent coronary angiography within 1 month before or after the SPECT study. Patients with a BMI>27 were considered "overweight". Attenuation-corrected and standard GSPECT early images were randomly interpreted by three readers blinded to the clinical data. RESULTS: In the whole group, GSPECT and AC showed a diagnostic accuracy of 86.5% (sensitivity 82%, specificity 93%) and 77% (sensitivity 75.4%, specificity 81.4%), respectively (p<0.05). In women, when anterior ischaemia was matched with CAD, AC failed to show any increase in specificity (AC 63.6% vs GSPECT 63.6%) with evident loss of sensitivity (AC 72.7% vs GSPECT 90.9%). AC significantly improved SPECT specificity in the identification of right CAD in overweight men (AC 100% vs GSPECT 66.7%, p<0.05). CONCLUSION: AC improved specificity in the evaluation of right CAD in overweight men. In the other evaluable subgroups specificity was not significantly affected while sensitivity was frequently reduced.

Penile doppler ultrasound in patients with erectile dysfunction (ED): role of peak systolic velocity measured in the flaccid state in predicting arteriogenic ED and silent coronary artery disease.

INTRODUCTION: The use of the penile peak systolic velocity (PSV) measured in the flaccid state during penile color Doppler ultrasound (PCDU) examination has been questioned without substantial evidence. AIM: To assess the validity of PSV measured in the flaccid state during PCDU, in patients consulting for erectile dysfunction (ED). METHODS: A consecutive series of 1,346 (mean age 55.0 +/- 12.0 years) male patients was studied. MAIN OUTCOMES MEASURES: All patients underwent PCDU performed both in the flaccid state and dynamic (after prostaglandin E1 stimulation) conditions. A subset of 20 subjects with uncomplicated type 2 diabetes underwent diagnostic testing for silent coronary heart disease by means of adenosine stress myocardial perfusion scintigraphy (SPECT). In these subjects penile arterial flow was simultaneously assessed by PCDU before and after systemic adenosine administration. RESULTS: Flaccid PSV showed a significant (r = 0.513, P < 0.0001) correlation with dynamic PSV. Receiver operating characteristic (ROC) curve analysis demonstrated that when a threshold of 13 cm/seconds was chosen, flaccid PSV was predictive for dynamic PSV < 25 and <35 cm/seconds with an accuracy of 89% and 82%, respectively. Among the subset of patients who underwent SPECT, an impaired coronary flow reserve (ICFR) occurred in nine cases (45%). When the same threshold of <13 cm/seconds was chosen, PSV before SPECT was predictive of ICFR with an accuracy of 80% (area under the ROC curve = 0.798 +/- 0.10; P < 0.05). After adjustment for confounders, anxiety symptoms were related to dynamic PSV (Adj. r = -0.154, P < 0.05) but not to flaccid PSV. CONCLUSIONS: Our results show that flow in the cavernosal arteries can be routinely evaluated by PCDU in the flaccid state. Performing PCDU only in the flaccid state allows identifying subjects with pathological dynamic PSV with accuracy higher than 80%. Furthermore, our preliminary data suggest that the same examination could identify diabetic subjects with ICFR with an accuracy of 80%.

Somatostatin receptor scintigraphy for bronchial carcinoid follow-up.

PURPOSE: Somatostatin receptor scintigraphy (SRS) has been used to diagnose bronchial carcinoids (BC) and is a valuable tool for accurate staging of BC. The aim of this study was to evaluate the role of SRS in restaging BC and following patients after treatment. METHODS: Thirty-one patients (18 male, 13 female) with confirmed BC who were referred during the last 7 years were included. Patients were examined via chest radiograph (12 studies), chest or abdominal computed tomography (CT; 28 scans), chest magnetic resonance imaging (2 scans), and liver ultrasound (5 scans). RESULTS: Overall, in 22 patients (71%), SRS confirmed the data obtained by other diagnostic procedures (16 negative and 6 positive findings). In 6 patients, SRS showed focal lesions not previously demonstrated. In 2 patients, SRS resolved uncertain findings of CT. In 1 patient, SRS showed fewer lesions compared with CT. In 8 of 31 patients, important diagnostic information obtained by SRS was not revealed by any other imaging procedure. CONCLUSION: Our results indicate that SRS is a reliable, noninvasive method that could be considered the principal follow-up procedure in patients with BC.