Imaging characterization of non-hypersecreting adrenal masses. Comparison between MR and radionuclide techniques.

AIM: In patients with non-hypersecreting adrenal masses, tumor characterization is clinically relevant to establish the appropriate treatment planning. The aim of this study was to comparatively characterize such adrenal lesions using MR and radionuclide techniques. METHODS: Thirty patients with non-hypersecreting unilateral adrenal tumors underwent both MR and adrenal scintigraphy. MR was performed using SE T1- (pre- and post-gadolinium DTPA) and T2-weighted images as well as in- and out-phase chemical-shift imaging (CSI). MR qualitative and quantitative (signal intensity ratios) evaluation was performed. Radionuclide studies consisted of iodine-131 nor-cholesterol (n=20), iodine-131 MIBG (n=15) and fluorine-18 FDG PET (n=11) scans. Histology (n=16), biopsy (n=3) or clinical-imaging follow-up (n=11) demomstrated 13 adenomas, 3 cysts, 2 myelolipomas, 4 pheochromocytomas (pheos), 4 carcinomas, 1 sarcoma and 3 metastases. Comparative imaging analysis was focused on adenomas, pheos and malignant tumors. RESULTS: Qualitative MR evaluation showed: signal T2-hyperintensity in 46% of adenomas and in 100% of pheos and malignant tumors, no gadolinium enhancement in 92% of adenomas and definite signal intensity loss on CSI in 100% of such tumor lesions, gadolinium enhancement in 100% of pheos and in 63% of malignancies and no absolute change of signal intensity on CSI in 100% of both pheos and malignancies. Quantitative MR analysis demonstrated: significantly higher signal T2-hyperintensity of pheos compared to adenomas and malignancies as well as significantly higher enhancement after gadolinium in pheos compared to adenomas and malignancies (p<0.03). Radionuclide studies showed significantly increased nor-cholesterol uptake only in adenomas (n=13), significant MIBG accumulation only in pheos (n=4) and FDG activity only in malignant adrenal lesions (n=8). CONCLUSION: MR techniques may provide some presumptive criteria to characterize non-hypersecreting adrenal masses, such as no gadolinium enhancement and definite signal intensity loss on CSI in adenomas or quantitatively measured T2-hyperintensity and gadolinium enhancement in pheos. On the other hand, radionuclide modalities offer more specific findings in this setting since nor-cholesterol and MIBG scans are respectively able to reveal benign tumors such as adenoma and pheochromocytoma, while FDG imaging allows identification of malignant adrenal lesions. Adrenal scintigraphy is recommended in those patients, when MR images are uncertain or inconclusive

advanced adrenal imaging comparison between radionuclide and mr techniques

Citation: Maurea S, Mainenti PP, Ponsiglione A, Salvatore M (2015) Advanced Adrenal Imaging: Comparison between Radionuclide and MR Techniques. J Adv Radiol Med Image 1(1): 103 Volume 1 | Issue 1 Journal of Advances in Radiology and Medical Imagin

Non-contrast cardiac computed tomography can accurately detect chronic myocardial infarction: Validation study

BackgroundThis study evaluates whether non-contrast cardiac computed tomography (CCT) can detect chronic myocardial infarction (MI) in patients with irreversible perfusion defects on nuclear myocardial perfusion imaging (MPI).MethodsOne hundred twenty-two symptomatic patients with irreversible perfusion defect (N = 62) or normal MPI (N = 60) underwent coronary artery calcium (CAC) scanning. MI on these non-contrast CCTs was visually detected based on the hypo-attenuation areas (dark) in the myocardium and corresponding Hounsfield units (HU) were measured.ResultsNon-contrast CCT accurately detected MI in 57 patients with irreversible perfusion defect on MPI, yielding a sensitivity of 92%, specificity of 72%, negative predictive value (NPV) of 90%, and a positive predictive value (PPV) of 77%. On a per myocardial region analysis, non-contrast CT showed a sensitivity of 70%, specificity of 85%, NPV of 91%, and a PPV of 57%. The ROC curve showed that the optimal cutoff value of LV myocardium HU to predict MI on non-contrast CCT was 21.7 with a sensitivity of 97.4% and specificity of 99.7%.ConclusionNon-contrast CCT has an excellent agreement with MPI in detecting chronic MI. This study highlights a novel clinical utility of non-contrast CCT in addition to assessment of overall burden of atherosclerosis measured by CAC

Prevalence of interstitial pneumonia suggestive of COVID-19 at 18F-FDG PET/CT in oncological asymptomatic patients in a high prevalence country during pandemic period: a national multi-centric retrospective study

Purpose: To assess the presence and pattern of incidental interstitial lung alterations suspicious of COVID-19 on fluorine-18-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) ([18F]FDG PET/CT) in asymptomatic oncological patients during the period of active COVID-19 in a country with high prevalence of the virus. Methods: This is a multi-center retrospective observational study involving 59 Italian centers. We retrospectively reviewed the prevalence of interstitial pneumonia detected during the COVID period (between March 16 and 27, 2020) and compared to a pre-COVID period (January\u2013February 2020) and a control time (in 2019). The diagnosis of interstitial pneumonia was done considering lung alterations of CT of PET. Results: Overall, [18F]FDG PET/CT was performed on 4008 patients in the COVID period, 19,267 in the pre-COVID period, and 5513 in the control period. The rate of interstitial pneumonia suspicious for COVID-19 was significantly higher during the COVID period (7.1%) compared with that found in the pre-COVID (5.35%) and control periods (5.15%) (p&nbsp;&lt; 0.001). Instead, no significant difference among pre-COVID and control periods was present. The prevalence of interstitial pneumonia detected at PET/CT was directly associated with geographic virus diffusion, with the higher rate in Northern Italy. Among 284 interstitial pneumonia detected during COVID period, 169 (59%) were FDG-avid (average SUVmax of 4.1). Conclusions: A significant increase of interstitial pneumonia incidentally detected with [18F]FDG PET/CT has been demonstrated during the COVID-19 pandemic. A majority of interstitial pneumonia were FDG-avid. Our results underlined the importance of paying attention to incidental CT findings of pneumonia detected at PET/CT, and these reports might help to recognize early COVID-19 cases guiding the subsequent management

Radiopharmaceuticals to in vivo characterize adrenal incidentalomas: the integrated role of radionuclide and radiological techniques.

To illustrate the role of radiopharmaceuticals in characterizing non-hypersecreting adrenal masses, 56 patients with non-hypersecreting unilateral adrenal tumors detected on CT and/or MR underwent adrenal scintigraphy. Radionuclide studies (n=83) included nor-cholesterol (n=24), metaiodobenzylguanidine (MIBG) (n=23), deoxyglucose (FDG) (n=26) and somatostatin analogs (SAs) (n=10) scans. Histology (n=32) or biopsy (n=24) were obtained. Lesions were 19 adenomas, 4 cysts, 1 myelolipoma, 1 neurinoma, 2 ganglioneuromas, 5 pheochromocytomas, 4 pseudotumors, 6 carcinomas, 2 sarcomas, 1 fibro-histiocytoma and 11 metastases. For nor-cholesterol, sensitivity, specificity and accuracy were 100%, 71% and 92%, respectively; positive predictive value (PPV) was 89%, while negative predictive value (NPV) was 100%. For MIBG, sensitivity, specificity and accuracy were 100%, 94% and 96%, respectively; PPV was 83%, while NPV was 100%. For FDG, sensitivity, specificity and accuracy were 100%, 100% and 100%, respectively; PPV and NPV were 100%; furthermore, in 7 patients with malignant adrenal tumors, FDG imaging scan was able to reveal extra-adrenal tumor sites (n=29). For SAs, sensitivity, specificity and accuracy were 80%, 100% and 90%, respectively; PPV was 100%, while NPV was 83%. In non-hypersecreting adrenal masses, nuclear imaging using specific labeled radiopharmaceuticals such as nor-cholesterol, MIBG, FDG ans SAs may provide functional information for tissue characterization. Nor-cholesterol and MIBG scans are able to identify benign tumors such as adenoma and pheochromocytoma respectively, while FDG and Sas imaging allow the recognition of malignant adrenal lesions. Thus, adrenal scintigraphy is recommended for tumor diagnosis in non-hypersecreting adrenal masses and, hence, for appropriate treatment planning of such patients, particularly when CT and/or MR findings are uncertain as well as inconclusive for lesion characterization