Impairment of cardiac metabolism and sympathetic innervation after aneurysmal subarachnoid hemorrhage: a nuclear medicine imaging study.

INTRODUCTION: Although aneurysmal subarachnoid hemorrhage (SAH) is often complicated by myocardial injury, whether this neurogenic cardiomyopathy is associated with the modification of cardiac metabolism is unknown. This study sought to explore, by positron emission tomography/computed tomography, the presence of altered cardiac glucose metabolism after SAH. METHODS: During a 16-month period, 30 SAH acute phase patients underwent myocardial (18)F- fluorodesoxyglucose positron emission tomography ((18)F-FDGPET), (99m)Tc-tetrofosmin and (123)I-meta-iodobenzylguanidine ((123)I-mIBG) scintigraphy, respectively, assessing glucose metabolism, cardiac perfusion, and sympathetic innervation. Patients with initial abnormalities were followed monthly for two months for (18)F-FDG, and six months later for (123)I-mIBG. RESULTS: In this SAH population, acute cardiac metabolic disturbance was observed in 83% of patients (n = 25), and sympathetic innervation disturbance affected 90% (n = 27). Myocardial perfusion was normal for all patients. The topography and extent of metabolic defects and innervation abnormalities largely overlapped. Follow-up showed rapid improvement of glucose metabolism in one or two months. Normalization of sympathetic innervation was slower; only 27% of patients (n = 8) exhibited normal (123)I-mIBG scintigraphy after six months. Presence of initial altered cardiac metabolism was not associated with more unfavorable cardiac or neurological outcomes. CONCLUSIONS: These findings support the hypothesis of neurogenic myocardial stunning after SAH. In hemodynamically stable acute phase SAH patients, cardiomyopathy is characterized by diffuse and heterogeneous (18)F-FDG and (123)I-mIBG uptake defect. TRIAL REGISTRATION: Clinicaltrials.gov NCT01218191. Registered 6 October 2010.

Analysis of 18F-FDG PET diffuse bone marrow uptake and splenic uptake in staging of Hodgkin's lymphoma: a reflection of disease infiltration or just inflammation?

PURPOSE: (18)F-FDG PET has been successfully evaluated in the management of Hodgkin's lymphoma (HL) and the most recent international guidelines recommended (18)F-FDG PET for initial staging and final therapeutic assessment. However, (18)F-FDG PET diffuse bone marrow uptake (BMU) and splenic uptake (SU) are frequently observed at the initial imaging and remain difficult to analyse. The aim of this retrospective study was to evaluate the significance of (18)F-FDG diffuse BMU and SU in initial staging of HL. METHODS: A total of 106 patients (median age: 31 years, range: 9-81, 51 female, 55 male) underwent (18)F-FDG PET/CT for initial staging of HL. BMU level was assessed visually according to liver uptake (1 = below liver uptake, 2 = corresponding to liver uptake, 3 = above liver uptake) and semi-quantitatively using the maximum standardized uptake value (SUV(max)) measured in the sacral area. SU was assessed visually according to liver uptake (1 = below liver uptake, 2 = corresponding to liver uptake, 3 = above liver uptake). These data were compared with the patient's characteristics including sex, age, Ann Arbor staging, bulky disease (tumour burden > 10 cm), presence of B symptoms, bone foci on PET (n = 106), bone marrow involvement (BMI) on biopsy (n = 75), leukocyte count (n = 74), lactic dehydrogenase (LDH) (n = 87), C-reactive protein (CRP) (n = 83) and fibrinogen (n = 60). Univariate and multivariate analyses were performed. RESULTS: Multivariate analysis found an independent correlation between BMU visual grading and CRP level (p = 0.007). For semi-quantitative BMU evaluation, multivariate analysis found an independent correlation between sacral SUVs and CRP level (p = 0.032) and Ann Arbor stage (p = 0.005). No BMI was found in patients who presented with SUV(max) below 3.4. For splenic evaluation, multivariate analysis found an independent correlation between SU and splenic foci (p = 0.034). No statistical link was found between SU and inflammatory markers. CONCLUSION: Our study demonstrates that diffuse BMU at initial staging of HL could be due to bone marrow involvement but more likely to bone marrow inflammatory change and that diffuse SU in contrast is probably more associated with disease involvement than with inflammatory change.