MIBG scintigraphy in differential diagnosis of Parkinsonism: a meta-analysis.

OBJECTIVE: Differential diagnosis between Parkinson's disease (PD) and other Parkinsonism using clinical criteria or imaging methods is often difficult. The purpose of this study is to systematically review and meta-analyze published data about the diagnostic performance of myocardial innervation imaging using (123)I-metaiodobenzylguanidine (MIBG) scintigraphy in differential diagnosis between PD and other Parkinsonism. METHODS: A comprehensive computer literature search of studies published through March 2011 regarding MIBG scintigraphy in patients with PD and other Parkinsonism was performed in PubMed/MEDLINE and Embase databases. Only studies in which MIBG scintigraphy was performed for differential diagnosis between PD and other Parkinsonism were selected. Pooled sensitivity, pooled specificity and area under the ROC curve were calculated to measure the accuracy of MIBG scintigraphy in differential diagnosis between PD and other Parkinsonism. RESULTS: Nineteen studies comprising 1,972 patients (1,076 patients with PD, 117 patients with other Lewy body diseases and 779 patients with other diseases) were included in this meta-analysis. The pooled sensitivity of MIBG scintigraphy in detecting PD was 88% (95% CI 86-90%); the pooled specificity of MIBG scintigraphy in discriminating between PD and other Parkinsonism was 85% (95% CI 81-88%). The area under the ROC curve was 0.93. CONCLUSIONS: In patients with clinically suspected PD, myocardial innervation imaging demonstrated high sensitivity and specificity. MIBG scintigraphy is an accurate test in this setting. Nevertheless, possible causes of false-negative and false-positive results should be kept in mind when interpreting the scintigraphic results.

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.

Recent developments in innervation imaging using iodine-123-metaiodobenzylguanidine scintigraphy in Lewy body diseases.

Radiolabeled metaiodobenzylguanidine (MIBG) is an analog of guanethidine and is taken up by the postganglionic presynaptic nerve endings. MIBG uptake in the heart correlates with adrenergic function, which can be reduced in Lewy body diseases. We described the recent developments in innervation imaging using (123)I-MIBG scintigraphy in Lewy body diseases including Parkinson's disease and dementia with Lewy bodies. Particularly, we underlined the role of MIBG scintigraphy in differential diagnosis of movement disorders. As described by recent studies, MIBG scintigraphy is a valuable diagnostic tool for differentiation between Lewy body diseases and parkinsonian syndromes or other movement disorders with parkinsonism. Furthermore, this method may provide a powerful differential diagnostic tool between dementia with Lewy bodies and Alzheimer's disease. We also reported the results of clinical investigations about the correlation between characteristics of Parkinson's disease and myocardial MIBG uptake.

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%.

Iodine-123 metaiodobenzylguanidine scintigraphy and iodine-123 ioflupane single photon emission computed tomography in Lewy body diseases: complementary or alternative techniques?

PURPOSE: To compare myocardial sympathetic imaging using (123)I-Metaiodobenzylguanidine (MIBG) scintigraphy and striatal dopaminergic imaging using (123)I-Ioflupane (FP-CIT) single photon emission computed tomography (SPECT) in patients with suspected Lewy body diseases (LBD). METHODS: Ninety-nine patients who performed both methods within 2 months for differential diagnosis between Parkinson's disease (PD) and other parkinsonism (n = 68) or between dementia with Lewy bodies (DLB) and other dementia (n = 31) were enrolled. Sensitivity, specificity, accuracy, positive and negative predictive values of both methods were calculated. RESULTS: For (123) I-MIBG scintigraphy, the overall sensitivity, specificity, accuracy, positive and negative predictive values in LBD were 83%, 79%, 82%, 86%, and 76%, respectively. For (123)I-FP-CIT SPECT, the overall sensitivity, specificity, accuracy, positive and negative predictive values in LBD were 93%, 41%, 73%, 71%, and 80%, respectively. There was a statistically significant difference between these two methods in patients without LBD, but not in patients with LBD. CONCLUSIONS: LBD usually present both myocardial sympathetic and striatal dopaminergic impairments. (123)I-FP-CIT SPECT presents high sensitivity in the diagnosis of LBD; (123)I-MIBG scintigraphy may have a complementary role in differential diagnosis between PD and other parkinsonism. These scintigraphic methods showed similar diagnostic accuracy in differential diagnosis between DLB and other dementia.

Management of epithelial ovarian cancer from diagnosis to restaging: an overview of the role of imaging techniques with particular regard to the contribution of 18F-FDG PET/CT.

Epithelial ovarian carcinoma is a major form of cancer affecting women in the western world. The silent nature of this disease results in late presentation at an advanced stage in many patients. It is therefore important to assess the role of imaging techniques in the management of these patients. This article presents a review of the literature on the role of (18)F-FDG-PET/CT in the different stages of management of epithelial ovarian cancer. Moreover, a comparison with other imaging techniques has been made and the relationship between (18)F-PET/CT and the assay of serum CA-125 levels has been discussed.