Altered hepatic metabolic activity in patients with hepatic steatosis on FDG PET/CT.

OBJECTIVE: FDG PET studies frequently use the liver as an internal reference organ to assess the significance of FDG uptake in pathologic processes involving other organs. The purpose of this study was to assess whether hepatic steatosis has a significant effect on the standardized uptake value (SUV) of the liver. SUBJECTS AND METHODS: This prospective case-control study analyzed FDG PET/CT scans of patients with frank hepatic steatosis on the unenhanced CT portion of the study. Maximum SUVs (corrected for both body weight [SUV(bw)] and lean body mass [SUV(lbm)]) in 37 patients with hepatic steatosis were compared with those in 37 control patients without hepatic steatosis. RESULTS: Patients with hepatic steatosis had statistically significant smaller mean (± SD) values than did the control subjects for liver SUV(lbm) (1.91 ± 0.57 vs 2.17 ± 0.36), liver SUV(lbm)-mediastinum ratio (1.23 ± 0.19 vs 1.35 ± 0.19), and liver SUV(bw)-mediastinum ratio (1.24 ± 0.16 vs 1.39 ± 0.22). CONCLUSION: Hepatic steatosis results in a small statistically significant decrease in hepatic metabolic activity, as measured by FDG PET. However, because the degree of change is small, compared with healthy control subjects, this decrease is unlikely to have any clinical significance on the use of the liver as an internal reference organ.

Quality of Life, Dyspnea, and Functional Exercise Capacity Following a First Episode of Pulmonary Embolism: Results of the ELOPE Cohort Study.

BACKGROUND: We aimed to evaluate health-related quality of life (QOL), dyspnea, and functional exercise capacity during the year following the diagnosis of a first episode of pulmonary embolism. METHODS: This was a prospective multicenter cohort study of 100 patients with acute pulmonary embolism recruited at 5 Canadian hospitals from 2010-2013. We measured the outcomes QOL (by Short-Form Health Survey-36 [SF-36] and Pulmonary Embolism Quality of Life [PEmb-QoL] measures), dyspnea (by the University of California San Diego Shortness of Breath Questionnaire [SOBQ]) and 6-minute walk distance at baseline and 1, 3, 6, and 12 months after acute pulmonary embolism. Computed tomography pulmonary angiography was performed at baseline, echocardiogram was performed within 10 days, and cardiopulmonary exercise testing was performed at 1 and 12 months. Predictors of change in QOL, dyspnea, and 6-minute walk distance were assessed by repeated-measures mixed-effects models analysis. RESULTS: Mean age was 50.0 years; 57% were male and 80% were treated as outpatients. Mean scores for all outcomes improved during 1-year follow-up: from baseline to 12 months, mean SF-36 physical component score improved by 8.8 points, SF-36 mental component score by 5.3 points, PEmb-QoL by -32.1 points, and SOBQ by -16.3 points, and 6-minute walk distance improved by 40 m. Independent predictors of reduced improvement over time were female sex, higher body mass index, and percent-predicted VO2 peak <80% on 1 month cardiopulmonary exercise test for all outcomes; prior lung disease and higher pulmonary artery systolic pressure on 10-day echocardiogram for the outcomes SF-36 physical component score and dyspnea score; and higher main pulmonary artery diameter on baseline computed tomography pulmonary angiography for the outcome PEmb-QoL score. CONCLUSIONS: On average, QOL, dyspnea, and walking distance improve during the year after pulmonary embolism. However, a number of clinical and physiological predictors of reduced improvement over time were identified, most notably female sex, higher body mass index, and exercise limitation on 1-month cardiopulmonary exercise test. Our results provide new information on patient-relevant prognosis after pulmonary embolism.

The "pirate sign" in fibrous dysplasia.

Fibrous dysplasia commonly involves the skull in both its monostotic and polyostotic variants. We present two cases of fibrous dysplasia involving the sphenoid wing, which were strikingly similar in their bone scan appearance. Both patients demonstrated intense increased uptake of Tc-99m MDP in a pattern reminding us of a "pirate wearing an eyepatch." We propose that this characteristic appearance of fibrous dysplasia of the sphenoid wing be called the "pirate sign." A review of the literature revealed several other pathologic conditions that have been reported to involve the sphenoid bone and should be considered in the differential diagnosis of abnormal bone tracer uptake in this region.