Fat suppression is commonly used in magnetic resonance (MR) imaging to suppress the signal from adipose tissue or detect adipose tissue. Fat suppression can be achieved with three methods: fat saturation, inversion-recovery imaging, and opposed-phase imaging. Selection of a fat suppression technique should depend on the purpose of the fat suppression (contrast enhancement vs tissue characterization) and the amount of fat in the tissue being studied. Fat saturation is recommended for suppression of signal from large amounts of fat and reliable acquisition of contrast material-enhanced images. The main drawbacks of this technique are sensitivity to magnetic field nonuniformity, misregistration artifacts, and unreliability when used with low-field-strength magnets. Inversion-recovery imaging allows homogeneous and global fat suppression and can be used with low-field-strength magnets. However, this technique is not specific for fat, and the signal intensity of tissue with a long T1 and tissue with a short T1 may be ambiguous. Opposed-phase imaging is a fast and readily available technique. This method is recommended for demonstration of lesions that contain small amounts of fat. The main drawback of opposed-phase imaging is unreliability in the detection of small tumors embedded in fatty tissue.

In addition to the NYHA classification and to the percent of maximal predicted VO2, RVEF is an independent predictor of survival in patients with moderate CHF.

SUMMARYWe have investigated the following pulmonary related parameters in 22 patients with Crohn's disease who were free of clinical pulmonary symptoms and had normal chest roentgenograms and in 25 controls: serum angiotensin converting enzyme, pulmonary function tests, bronchoalveolar lavage (lymphocyte count and subpopulations, macrophage viability and superoxide anion release by macrophages) and pulmonary scannings. Serum angiotensin converting enzyme was lower in Crohn's disease (14-1±5 1) than in controls (25-2±4-7) (p18% alveolar lymphocytes). Bronchoalveolar lavage lymphocytes subpopulations were quite variable. Twelve of 17 Crohn's disease (71%) had an increase spontaneous and/or stimulated superoxide anion production by alveolar macrophages. Six of 12 Crohn's disease (50%) had an increase physiologic dead space in the upper part of their lung against one of 11 controls (9%). These data suggest that most patients with Crohn's disease have a latent pulmonary involvement.Systemic manifestations are frequent in inflammatory bowel disease, but classically the lung was regarded as rarely involved. 1 2 A few recent reports, however, have described pulmonary manifestations occuring in patients with inflammatory bowel disease: bronchial suppuration, or bronchiectasis,3-5 granulomatous lung disease,6 diffuse or localised interstitial fibrosis71-2 and sulphasalazine pneumonitis. 1321 The rarity of pulmonary clinical manifestations contrasts with striking abnormalities of pulmonary function tests described in patients with inflammatory bowel disease: reduced lung transfer factor, increased residual volume, or decreased forced expiratory volume in one second.22 26We have attempted to determine the actual frequency of pulmonary tests and bronchoalveolar abnormalities in patients with Crohn's disease and without clinical or radiological pulmonary abnormalities.27 28 Furthermore, we tried to clarify

The purpose of this cross-sectional study was to assess the extent of and mechanisms involved in bone loss in anorexia nervosa patients. We compared 113 anorexia nervosa patients (mean age 25 +/- 8 years, mean duration of disease 5.7 +/- 6.1 years) with 21 age-matched controls. Mean duration of amenorrhea was 3.2 +/- 4.7 years. We measured serum calcium and phosphate; bone remodeling markers (osteocalcin, bone-specific alkaline phosphatase [BSAP], serum crosslaps [CTX], and carboxyl-terminal telopeptide of type I collagen [ICTP]); follicle-stimulating hormone and luteinizing hormone levels; and estradiol (ultrasensitive assay), cortisol, urinary free cortisol, thyroid function, prolactin, and nutritional factors (insulin-like growth factor I [IGF-I], IGF binding protein 3 [IGFBP3]). In controls, only bone remodeling markers and nutritional factors were measured. Osteodensitometry was also performed on both patients and controls. Weight and body mass index (BMI) were significantly lower in anorexia nervosa patients than in controls (P < 0.0001). No significant differences were observed in biological indicators except for IGF-I, which was lower in anorexia nervosa patients (0.9 +/- 0.4 UI/mL) than in controls (1.5 +/- 0.4 UI/mL) (P < 0.0001). Densitometric measurements at three sites were significantly lower in anorexia nervosa patients and correlated with duration of disease and amenorrhea and with IGF-I at the hip only (P < 0.01). In the study population, osteoporosis was observed in 24 patients (21%) and osteopenia in 54 patients (48%). Patients with osteoporosis were significantly older and had longer disease and amenorrhea durations; lower weight and BMI; higher alkaline phosphatase, BSAP, and osteocalcin; and lower serum ICTP, IGF-I, and IGFBP3. All of these differences were significant and remained so even after multiple adjustments were made, except for IGF-I (P = 0.21). When multivariate analysis was performed, we found that age at onset of amenorrhea, weight, alkaline phosphatase, urinary free cortisol, and serum estradiol concentration accounted for 54% of the variance in spinal bone mineral density (BMD). Duration of amenorrhea, alkaline phosphatase, and weight explained 46.6% of the variance in femoral neck BMD. Duration of amenorrhea, IGF-I, and ICTP levels accounted for 38.6% of the variance observed in total hip BMD. The etiology of bone loss in patients with anorexia nervosa is multifactorial. Hypoestrogenia alone cannot account for this loss, and nutritional factors, IGF-I concentrations in particular, seem to play an important role.

Structural measurements derived from MR images of the calcaneus may be used in vivo to characterize trabecular bone architecture in men with osteoporosis.