Purpose:To evaluate the use of apparent diffusion coefficient (ADC) measurements based on diffusion-weighted MRI (DWI) to assess stage of liver disease. Materials and Methods:A total of 31 patients who underwent both a liver biopsy and DWI and 132 patients who only underwent DWI were enrolled. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). The 31 patients consisted of 21 patients with chronic hepatitis and 10 with cirrhosis (ChildPugh stage A in nine and stage B in one), and the 132 patients consisted of 56 patients with cirrhosis (Child-Pugh stage A in 41, stage B in 10, and stage C in five), 42 with chronic hepatitis, and 34 with normal liver function. The ADCs in the liver parenchyma were measured using DWI with relatively low b factors (b ϭ 0.01 and 128.01 seconds/mm 2 ) and were compared among the HAI scores and among patients with cirrhosis, chronic hepatitis, and normal liver function. Results:The ADCs decreased as the fibrosis score in the HAI increased, and the correlation was statistically significant (P Ͻ 0.0001). No relationship between the ADCs and the necroinflammation scores in the HAI was found. The ADCs decreased as the stage of liver disease progressed or as the Child-Pugh stage progressed, and these relationships were statistically significant (P Ͻ 0.0001).Conclusion: ADC measurements are potentially useful for the evaluation of fibrosis staging in the liver.

This study was performed to determine if there is a relationship between apparent diffusion coefficient (ADC) and cellularity of bone marrow of the posterior ilium. Four groups of various marrow cellularity underwent diffusionweighted echo-planar imaging: 1) adults with normal hypocellularity (21 patients); 2) adults with normal normocellularity (13 patients); 3) young children with normal hypercellularity (5 patients); and 4) adults with lymphomarelated hypercellularity (3 patients). In all adults, marrow cellularity was confirmed by uni-or bilateral bone marrow biopsies. In children, the iliac marrow was presumed hy- Index terms: MRI; bone marrow; diffusion-weighted EPI; marrow cellularity; ADC DIFFUSION-WEIGHTED MRI is a relatively new method to quantitatively image intravoxel incoherent motion (IVIM) in vivo, as introduced by Le Bihan et al (1). These motions include molecular diffusion of water and microcirculation of blood in the capillary network, perfusion (2). By means of a parameter termed apparent diffusion coefficient (ADC), quantification of IVIM is possible. The ADC calculation is based on the signal intensity of the original diffusion-weighted images with two different b factors. Diffusion-weighted MR imaging was recently introduced to evaluate vertebral bone marrow (3-5). Bauer et al (3) reported that pathologic compression fractures are of high signal intensity, whereas benign compression fractures are relatively hypointense. They speculated a decrease in the ADC, hypothesizing that hypercellularity by tumor cells reduced the extracellular space and mobility of water protons, resulting in increased signal intensity on diffusion-weighted images (3). Castillo et al (4) examined various vertebral metastases and found both low and high signal intensity in affected bone marrow on diffusion-weighted images with the same b-value, 165 seconds/mm 2 . They implied that in cases in which lesions are hypointense, the ADC remains normal despite tumor-related hypercellularity within a vertebra, leading to loss of signal on diffusion-weighted images.To our knowledge, Ward et al reported ADC of normal bone marrow for the first time, with a mean value of 0.15 ϫ 10 Ϫ3 mm 2 /second (5). Although it has been suggested that hypercellularity leads to a decrease or no change in ADC of bone marrow, this has not yet been verified. In this study, we sought to determine if there is a relation between ADC and cellularity of bone marrow, using in vivo data of various cellularity groups with histological confirmation. MATERIALS AND METHODS Patients and SubjectsThe study included four groups according to bone marrow cellularity: 1) adults with normal hypocellular marrow (21 patients, 15 men, 6 women; age range, 28 -86 years; mean age, 61.2 years); 2) adults with normal normocellular marrow (13 patients, 6 men, 7 women; age range, 43-78 years; mean age, 62.5 years); 3) young children with normal hypercellular marrow (5 patients, 3 boys, 2 girls; age range, 0 -3 years; mean age, 1.6 years); and 4) adults with lymphoma cell-pack...

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Low-attenuation hemangiomas and those that changed from homogeneous high to isoattenuation are atypical and difficult to differentiate from other neoplasms. Most early parenchymal enhancement is caused by associated arterioportal shunts.

Background. Male patients with oral and oropharyngeal cancer are known to have high risk of concomitant esophageal cancer developing. Thus, mass screening programs are pursued to detect such esophageal cancer early, and in a mass screening trial of patients with early oral and oropharyngeal cancer, the efficacy of Lugol dye endoscopy for detecting concomitant esophageal cancers has been evaluated. Methods. Lugol dye was used in an endoscopic screening of 101 patients with oral cancer and 26 with oropharyngeal cancer; all of the patients were men. Results. Among these 127 patients, eight (6.3%) clinical asymptomatic concomitant esophageal cancers were detected, and four of these eight cancers were found in the patients with oropharyngeal cancer. Five of these eight superficial lesions could not be detected by ordinary endoscopy or barium study. Conclusion. Our results show that Lugol dye endoscopy is indispensable for monitoring male patients with oral or oropharyngeal cancer to detect an early concomitant esophageal cancer. In addition, a higher frequency of concomitant esophageal cancer was seen in the patients with oropharyngeal cancer than in the patients with oral cancer. Cancer 1994; 73:2038–41.