The ability to distinguish between intra-abdominal and subcutaneous abdominal fat may be important in epidemiologic and clinical research. In this study anthropometric measurements were taken from 71 men and 34 women presenting for routine computed tomography (CT). Areas of abdominal fat were calculated from CT scans made at the level of the L4 vertebra. The amounts of intra-abdominal and subcutaneous abdominal fat could be accurately predicted from several circumferences, skinfold measurements, body mass index, and age (R2 ranged from 0.79 to 0.84). In addition, it was found that the area of intra-abdominal fat on the CT scan was related to the waist:hip circumference ratio (r = 0.75 in men, r = 0.55 in women) and to the waist:thigh circumference ratio (r = 0.55 in men, r = 0.70 in women). The correlations of the circumference ratios with the areas of subcutaneous fat were invariably lower.

Abstract. In this study we analyze MR-negative ma lignant lesions of the breast. A total of 204 patients with palpable and/or mammographie lesions were studied. The MR technique consisted of the turbo FLASH and MP-RAGE subtraction techniques. All patients underwent surgical biopsy and/or mastecto my and all specimens were examined by the correla tive radiologic-histologic mapping technique, A total of 208 lesions were evaluated; 145 turned out to be malignant and 63 proved to be benign. Six malignant lesions were misinterpreted as benign on MR imag ing; thus, suspicious contrast enhancement was pre sent in 96 % of the lesions detected by mammogra phy, US, or clinical examination. Especially 4 of the 17 ductal carcinoma in situ (DCIS) lesions were mis interpreted (23.5 %). Despite optimal technique, 6 malignant lesions were not identified by MR imaging. The highest prevalence of these MR occult lesions was in the group of DCIS. Although MR imaging has an important role in the evaluation of breast le sions and, primarily, in ruling out malignancy, one should be aware of the fact that false-negative MR findings do occur.

This report describes the use of an endorectal coil and a double spln-echo pulse sequence for localized 1H MR spec troscopy of the normal prostate in volunteers. The spectra showed well-resolved signals for citrate, (phospho)choline, and creatine protons. Additional signals were assigned to taurine and myoinositol protons. J modulation of the main and outer peaks of citrate could be monitored in vivo. Apparent relaxation times 7^ and Tz have been estimated for the methyl protons of cholines and creatine. An effective T^ relaxation time was estimated for the main peaks of the citrate multiple! Ratios of the integrals of these resonances have been evalu ated, and tissue contents of choline and creatine were esti mated using the H20 signal as an internal reference. Spectro scopic imaging experiments revealed a lower relative citrate signal in central parts of the prostate than in peripheral parts.

New diagnostic tests are mainly evaluated by determining the sensitivity and specificity of the test. These test characteristics were originally meant to be used in making diagnoses. For evaluative purposes their usefulness is weakened by their susceptibility to selection and their dependence on the cut-off points that are used for test positivity. The plotting of a receiver operating characteristic (ROC) curve might be a solution to these problems. Furthermore, the ROC curve yields a measure for the diagnostic power of the test expressed in one number instead of two, namely the area under the curve (AUC). Finally, the ROC curve and its AUC permit easy comparison of different tests and the performance of different interpreters of one test. The construction and use of ROC curves are described and illustrated with data of a case-referent investigation into the relationship between iron status parameters and the presence of acute myocardial infarction. The AUCs of ferritin and serum iron, 0.61 and 0.68 respectively, are too low to suggest meaningful usefulness in clinical practice.

Since the introduction, pelvic MRI has been considered the best non-invasive technique for primary staging of urinary bladder cancer. Before using MRI an understanding of normal and pathological MR images of the urinary bladder is essential. This review therefore describes the MR anatomy of the urinary bladder as well as the appearances of carcinoma. MRI plays an important clinical role in staging the primary tumour. In superficial tumours, clinical staging, which includes transurethral biopsy, is the best technique. For invasive tumours, MRI is superior to other techniques such as CT scanning, transvesical ultrasonography and clinical staging. A limitation of both MRI and CT scanning is their inability to recognize minimal tumour growth in the muscle layer of the bladder wall, or to differentiate between post-transurethral resection oedema and tumour. Therefore, in all patients with urinary bladder cancer staging should preferably start with MRI followed by clinical staging. Unfortunately, however, because of the high cost of this strategy, MRI has to be reserved for staging deeply invasive and superficial poorly differentiated tumours.