Quantification of epicardial adipose tissue in obese patients using an open-bore MR scanner.

BACKGROUND: Our aim was to evaluate the reproducibility of epicardial adipose tissue (EAT) volume, measured on scans performed using an open-bore magnetic resonance scanner. METHODS: Consecutive patients referred for bariatric surgery, aged between 18 and 65 years who agreed to undergo cardiac imaging (MRI), were prospectively enrolled. All those with cardiac pathology or contraindications to MRI were excluded. MRI was performed on a 1.0-T open-bore scanner, and EAT was segmented on all scans at both systolic and diastolic phase by two independent readers (R1 with four years of experience and R2 with one year). Data were reported as median and interquartile range; agreement and differences were appraised with Bland-Altman analyses and Wilcoxon tests, respectively. RESULTS: Fourteen patients, 11 females (79%) aged 44 (41-50) years, underwent cardiac MRI. For the first and second readings, respectively, EAT volume was 86 (78-95) cm3 and 85 (79-91) cm3 at systole and 82 (74-95) cm3 and 81 (75-94) cm3 at diastole for R1, and 89 (79-99) cm3 and 93 (84-98) cm3 at systole and 92 (85-103) cm3 and 93 (82-94) cm3 at diastole for R2. R1 had the best reproducibility at diastole (bias 0.3 cm3, standard deviation of the differences (SD) 3.3 cm3). R2 had the worst reproducibility at diastole (bias 3.9 cm3, SD 12.1 cm3). The only significant difference between systole and diastole was at the first reading by R1 (p = 0.016). The greatest bias was that of inter-reader reproducibility at diastole (-9.4 cm3). CONCLUSIONS: Reproducibility was within clinically acceptable limits in most instances.

Low-Calorie Ketogenic Diet with Continuous Positive Airway Pressure to Alleviate Severe Obstructive Sleep Apnea Syndrome in Patients with Obesity Scheduled for Bariatric/Metabolic Surgery: a Pilot, Prospective, Randomized Multicenter Comparative Study.

Obstructive sleep apnea syndrome (OSAS) and obesity are frequently associated with hypertension (HTN), dyslipidemia (DLP), and insulin resistance (IR). In patients with obesity and OSAS scheduled for bariatric surgery (BS), guidelines recommend at least 4 weeks of preoperative continuous positive airway pressure (CPAP). Low-calorie ketogenic diets (LCKDs) promote pre-BS weight loss (WL) and improve HTN, DLP, and IR. However, it is unclear whether pre-BS LCKD with CPAP improves OSAS more than CPAP alone. We assessed the clinical advantage of pre-BS CPAP and LCKD in patients with obesity and OSAS. Seventy patients with obesity and OSAS were randomly assigned to CPAP or CPAP+LCKD groups for 4 weeks. The effect of each intervention on the apnea-hypopnea index (AHI) was the primary endpoint. WL, C-reactive protein (CRP) levels, HTN, DLP, and IR were secondary endpoints. AHI scores improved significantly in both groups (CPAP, p=0.0231; CPAP+LCKD, p=0.0272). However, combining CPAP and LCKD registered no advantage on the AHI score (p=0.863). Furthermore, body weight, CRP levels, and systolic/diastolic blood pressure were significantly reduced in the CPAP+LCKD group after 4 weeks (p=0.0052, p=0.0161, p=0.0008, and p=0.0007 vs baseline, respectively), and CPAP+LCKD had a greater impact on CRP levels than CPAP alone (p=0.0329). The CPAP+LCKD group also registered a significant reduction in serum cholesterol, LDL, and triglyceride levels (p=0.0183, p=0.0198, and p<0.001, respectively). Combined with CPAP, LCKD-induced WL seems to not have a significant incremental effect on AHI, HTN, DLP, and IR but lower CRP levels demonstrated a positive impact on chronic inflammatory status.

US-elastography in the differential diagnosis of benign and malignant thyroid nodules.

BACKGROUND: Ultrasound (US)-elastography is a newly developed imaging technique for the reconstruction of tissue stiffness by measuring the degree of tissue's deformation in response to the application of an external force. This technique has previously been shown to be useful in the differential diagnosis between benign and malignant tumors. METHODS: The objective of this study was to assess the diagnostic accuracy of US-elastography in the differential diagnosis of thyroid cancer, using the cytologic/histopathologic analysis as the reference standard. A total of 67 consecutive patients with thyroid nodules who were referred to the Thyroid Unit at the Policlinico MultiMedica were enrolled in this prospective study between January and December 2006. Eighty-six nodules in these patients were examined by US B-mode, US color-power-Doppler, and US-elastography. Nodules were subjected to fine-needle aspiration biopsy and patients with a reading of malignant or indeterminate had thyroid surgery. The final diagnosis was based on the cytology reading in those who did not have surgery and the histopathology reading in those who had surgery. US-elastography scores were based on four classes of tissue stiffness (class 1 for soft nodules; class 2 and 3 for nodules with an intermediate degree of stiffness; class 4 for anelastic lesions). RESULTS: Seventeen nodules were malignant and 69 were benign. Sensitivity and specificity of the US-elastography for thyroid cancer diagnosis were 94.1% (16/17) and 81% (56/69), respectively. The positive and negative predictive values were 55.2% (16/29) and 98.2% (56/57), respectively. The accuracy of the technique was 83.7%. CONCLUSION: US-elastography is a promising technique that, combined with other US modalities, is easy and rapid to perform and can help to identify thyroid nodules that are likely to be malignant. An important limitation is probably lack of sensitivity for follicular thyroid carcinoma.