Gd(DTPA)2--enhanced, and Quantitative MR Imaging in Articular Cartilage

PURPOSE: Early degeneration of articular cartilage is accompanied by a loss of glycosaminoglycan (GAG) and the consequent change of the integrity. The purpose of this study was to biochemically quantify the loss of GAG, and to evaluate the Gd(DTPA)2--enhanced, and T1, T2, rho relaxation map for detection of the early degeneration of cartilage. MATERIALS AND METHODS: A cartilage-bone block in size of 8mmx10 mm was acquired from the patella in each of three pigs. Quantitative analysis of GAG of cartilage was performed at spectrophotometry by use of dimethylmethylene blue. Each of cartilage blocks was cultured in one of three different media: two different culture media (0.2 mg/ml trypsin solution, 1mM Gd (DTPA)2- mixed trypsin solution) and the control media (phosphate buffered saline (PBS)). The cartilage blocks were cultured for 5 hrs, during which MR images of the blocks were obtained at one hour interval (0 hr, 1 hr, 2 hr, 3 hr, 4 hr, 5 hr). And then, additional culture was done for 24 hrs and 48 hrs. Both T1-weighted image (TR/TE, 450/22 ms), and mixed-echo sequence (TR/TE, 760/21-168ms; 8 echoes) were obtained at all times using field of view 50 mm, slice thickness 2 mm, and matrix 256x512. The MRI data were analyzed with pixel-by-pixel comparisons. The cultured cartilage-bone blocks were microscopically observed using hematoxylin & eosin, toluidine blue, alcian blue, and trichrome stains. RESULTS: At quantitation analysis, GAG concentration in the culture solutions was proportional to the culture durations. The T1-signal of the cartilage-bone block cultured in the Gd(DTPA)2- mixed solution was significantly higher (42% in average, p0.05). However the focal increase in T1 relaxation time at superficial and transitional layers of cartilage was seen in Gd(DTPA)2- mixed culture. Toluidine blue and alcian blue stains revealed multiple defects in whole thickness of the cartilage cultured in trypsin media. CONCLUSION: The quantitative analysis showed gradual loss of GAG proportional to the culture duration. Microimagings of cartilage with Gd(DTPA)2--enhancement, relaxation maps were available by pixel size of 97.9x195 micrometer. Loss of GAG over time better demonstrated with Gd(DTPA)2--enhanced images than with T1, T2, rho relaxation maps. Therefore Gd(DTPA)2--enhanced T1-weighted image is superior for detection of early degeneration of cartilage.

The relationship of radiological findings and pathological types of primary lung cancer

The present study was intended to define the relationship of radiological findings and pathological types ofprimary lung cancer. The 85 cases were selected after confirmation of the cell types by bronchoscopic biopsy,cervical lymph node or thoracotomy biopsy and lung resection. Results of the study were presented below. 1.Primary lung cancer is frequently developed after 4th decade and males were affected more frequently than femaleswith ratio of 2 to 1. 2. The frequencies of pathologic cell types of lung cancer were presented as follows.Squamous cell carcinoma 40% Adenocarcinoma 25% Undifferentiated cell carcinoma 30% Alveolar cell carcinoma 5% 3.The findings of plain chest radiograph were presented as follows. In squamous cell carcinoma, hilar enlargement orhilar mass is the most frequent finding (53%) with atelectasis(26%) or obstructive pneumonitis(26%). Inadenocarcinoma, pleural effusion is accompained about half of cases (53%). In undifferentiated cell carcinoma,hilar mass with mediastinal widening and pleural effusion is frequent finding.