Volume measurement with magnetic resonance imaging of hippocampus-amygdala formation in patients with anorexia nervosa.

The purpose of our work was to evaluate the volume of hippocampus-amygdala formation (HAF) in patients with anorexia nervosa (AN), being this structure a crucial target for the glucocorticoid action in the adaptative stress-response. AN patients have biochemical hypercortisolism associated to normal ACTH levels, but do not develop the characteristic clinical features of glucocorticoid hypersecretion. Furthermore, in these patients cortisol levels usually do not suppress after dexametasone challenge. Twenty AN females (aged 30.0+/-5.1) with 10.5+/-4.2 yr of disease underwent a brain magnetic resonance (MR) examination during the recovery phase; an age-matched control group (CG) of 20 healthy female volunteers was also studied. Two interleaved T1-weighted spin-echo sequences for 46 contiguous 2-mm coronal slices (pixel 0.98(2) mm) were used. The volumes of both right and left HAFs were calculated with manual contouring from the third ventricle to the Sylvian aqueduct. IGF-I, T3, gonadotropins, 24-h urine free cortisol, and BMI were obtained for both patients (on admission and on present evaluation) and CG. Mann-Whitney, Wilcoxon and Spearman tests were used. AN patients showed a significant (p=0.0001) reduction of total (right plus left) HAF volume (6.6+/-1.3 cm3) when compared with CG (8.9+/-1.1). No significant difference was found between right and left HAF in both patients and CG. In AN patients, no significant correlation was found between the HAF and all the hormonal parameters or BMIs, while a trend towards significance was observed with duration of the disease (r=-0.398; p=0.082). MR imaging demonstrated a significant volume reduction o

MR dynamic enhancement of breast lesions: high temporal resolution during the first-minute versus eight-minute study.

PURPOSE: To investigate the value of the early phase of MR enhancement of breast lesions. METHOD: To study 63 breast lesions (size 5-45 mm in diameter) in 56 patients, whole-breast and lesion-targeted precontrast T1 -weighted gradient-echo 2D sequences were acquired. After intravenous injection of Gd-DTPA (0.1 mmol/Kg), four targeted scans, each every 15 seconds during the first minute (1-m), and seven whole-breast scans, each every minute up to 8 minutes (8-m), were performed. The subtraction technique was used, and percent enhancement curves were obtained. The final diagnosis was obtained by histology for 36 lesions, including 28 malignancies, and by fine-needle aspiration cytology and at least 1-year negative follow-up for the remaining 27 benign lesions. RESULTS: Significant differences in enhancement between malignant and benign lesions were found using both techniques (p<0.0001). However the ratio between the median enhancement of malignant lesions and that of benign lesions was 6.7 (15 s), 4.8 (30 s), 4.6 (45 s), and 3.8 (60 s), descending from 4.3 to 2.5 from the second to the eighth minute. The overlap between the malignant and benign curves was 9% of the malignant range with the 1-m technique, and 50% with the 8-m technique. Three blinded observers obtained a 100% sensitivity with both techniques and a specificity of 94-97% with the 1-m technique and 83-89% with the 8-m technique. CONCLUSION: The first minute of Gd-enhancement allows a more prominent differentiation between malignant and benign breast lesions than the following times.

Magnetic resonance evaluation of autonomous thyroid nodules treated by percutaneous ethanol injection.

Magnetic resonance (MR) imaging was used to evaluate the effect of ultrasound-guided percutaneous ethanol injection (PEI) of autonomous thyroid nodules (ATNs). Nine patients affected with ATN (3.7-32.2 mL volume) underwent PEI (4-19 mL ethanol, subdivided in 3-6 weekly procedures). MR imaging (1.5 T) was performed before each alcoholization and 1 month after the last PEI procedure with the following parameters: T1- (550/12) and T2-weighted (2200/160) spin-echo images; 4-mm slices, 10% gap; coronal planes. A further seven patients with normal thyroid function, who had undergone PEI 6-18 months before, underwent an MR examination with the same parameters. The signal-to-noise ratio (S/N) of ATN and extranodular gland, as well as ATN volume, were evaluated on the T2-weighted images. On T1-weighted images, ATNs appeared mostly hypointense before treatment, with hyperintense areas during treatment, and were lightly hyperintense 6-18 months after treatment. S/N on T2-weighted images: extranodular gland 3.5-9.2; ATNs, before treatment 13.2-19.7, before the last procedure 7.7-11.6, 1 month after the last procedure 5.6-10.9; previously treated ATNs, 4.3-8.2. No significant volume reduction was observed with MR 1 month after the last procedure. The MR examination time was about 15 minutes. In conclusion, the effect of PEI on ATNs can be evaluated with an MR examination that is not very time consuming.