Study results indicate that pre- and postcontrast imaging is necessary for delayed gadolinium-enhanced MR imaging evaluation of reparative cartilage after ACI.

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Magnetic resonance (MR) images of the liver were used to study 43 patients with relatively small hepatocellular carcinomas (HCCs) and 36 with other hepatic mass lesions. In 27 HCC patients, histologic findings were available. All focal lesions detectable by CT without contrast media were delineated with greater contrast by MR imaging. The rate of detection depended on tumor size, being 97.5% for HCCs greater than 2 cm in the longest axis and 33.3% for those less than 2 cm. MR imaging demonstrated the ring sign characteristic of encapsulated HCC twice as frequently as CT scans. Inversion recovery (IR) images depicted the internal structure of the HCC better than T2-weighted spin-echo images. Lesions were classified into four patterns of intensity: low, iso, high, and mixed. The latter three were relatively characteristic of HCC and related closely with steatosis of cancer tissue. HCCs with fibrosis tended to have long T1 values; those with steatosis had short T1 values. T1 and T2 relaxation times were useful in the differential diagnosis.

Purpose:To assess the apparent diffusion coefficient (ADC) value and diffusion tensor image (DTI) including fractional anisotropy (FA) of the noncancerous prostate and prostate cancer before and after carbon-ion radiotherapy (CIRT). Materials and Methods:Nine patients with biopsy-proven prostate cancer underwent 1.5T magnetic resonance (MR) examinations. One patient with benign prostatic hypertrophy and one healthy volunteer were also examined as references. The changes in ADC values and DTI of the entire prostate calculated from b-values of 0 and 700 (s/mm 2 ) were estimated between before and after CIRT.Results: ADC values of prostate cancer significantly increased after CIRT by paired t-test (P Ͻ 0.01) but those of noncancerous inner gland (IG) and peripheral zone (PZ) showed no significant change. By analysis of variance, significant differences in ADC values were observed among prostate cancer and noncancerous IG and PZ before CIRT (P Ͻ 0.05). After CIRT, those significant differences had disappeared. FAs showed no significant differences in any comparisons. DTI showed changes in the direction of the main axis of the tensor in prostate cancer after CIRT. Conclusion:There were changes in ADC and DTI in prostate cancer after CIRT. They may be useful for monitoring prostatic structural changes under radiotherapy.

In this study the dielectric properties are reported for human skin tissues over the frequency range 1-450 MHz at 36 degrees C. Healthy volunteers, collagen disease patients and dialysis patients are studied in order to investigate, primarily, the variability among (1) different regions of one individual, (2) the same region among different individuals and (3) skin conditions due to diseases. Considerable differences exist among the skin dielectric properties obtained from different regions of one individual body. Although region dependence is observed, larger variability is found even in the same skin region among individuals.