Sonographic Evaluation of Breast Nodules: Comparison of Conventional, Real-Time Compound, and Pulse-Inversion Harmonic Images

OBJECTICE: To compare the use of conventional, real-time compound, and pulse-inversion harmonic imaging in the evaluation of breast nodules. MATERIALS AND METHODS: Fifty-two breast nodules were included in this study, conducted between May and December 2000, in which conventional, real-time compound, and pulse-inversion harmonic images were obtained in the same plane. Three radiologists, each blinded to the interpretations of the other two, evaluated the findings, characterizing the lesions and ranking the three techniques from grade 1, the worst, to grade 3, the best. Lesion conspicuity was assessed, and lesions were also characterized in terms of their margin, clarity of internal echotexture, and clarity of posterior echo pattern. The three techniques were compared using Friedman's test, and interobserver agreement in image interpretation was assessed by means of the intraclass correlation coefficient. RESULTS: With regard to lesion conspicuity, margin, and internal echotexture of the nodules, real-time compound imaging was the best technique (p < 0.05); in terms of posterior echo pattern, the best was pulse-inversion harmonic imaging (p < 0.05). Real-time compound and pulse inversion harmonic imaging were better than conventional sonography in all evaluative aspects. Interobserver agreement was greater than moderate. CONCLUSION: Real-time compound and pulse-inversion harmonic imaging procedures are superior to conventional sonography in terms of both lesion conspicuity and the further characterization of breast nodules. Real-time compound imaging is the best technique for evaluation of the margin and internal echotexture of nodules, while pulse-inversion harmonic imaging is very effective for the evaluation of the posterior echo patterns.

In Vitro of MR Imaging of the Resected Normal Gastric Wall: Radiologic-Histologic Correlation

PURPOSE: To evaluate normal human gastric wall layers in vitro using magnetic resonance*(MR) imaging, to correlate the results with the histologic findings, and to determine the optimal technique for evaluation of the gastric wall. MATERIALS AND METHODS: Forty-one normal resected gastric specimens obtained from 25 patients were dissected and placed in a polyethylene tube filled with normal saline. MR imaging with four MR sequences, T1-weighted FLASH*(T1FLASH), fat-saturated T1-weighted FLASH, T2-weighted TSE*(T2TSE), and True-FISP, was performed. The number of gastric wall layers and signal intensity of each layer were determined, and after correlating MR images with the histologic findings, the conspicuity of each layer*(mucosa, submucosa, and muscle), the distinction between each layer, and overall image quality were assessed. RESULTS: The gastric wall was shown by TIFLASH to have two (n=6, 14-6%), three (n=31, 75.6%) and four layers (n=4, 9.8%); by fat-saturated TIFLASH to have two (n=6, 14.6%) and three (n=35, 85.4%) ; by T2TSE to have three (n=24, 58.5%), four (n=11, 26.8%), and five (n=6, 14.6%); and by True-FISP to have one (n=2, 4.9%), two (n=8, 19.5%), three (n=23, 56%), four (n=4, 9.8%), and five (n=4, 9.8%) . The signal intensity of each layer at T1FLASH and fat-saturated T1FLASH was high-intermediate from the lumen in two-layer cases, high-low-high/intermediate in three-layer cases, and high-low-high-intermediate in four-layer cases. The signal intensity of each layer at T2TSE was intermediate/high-low-intermediate in three-layer cases, intermediate low-high-intermediate/low in four-layer cases, and low-high-low-high-low in five-layer cases. Three-layered gastric wall corresponded mostly to mucosa, submucosa, and muscle from the inner to outer layers, respectively. T1FLASH, fat-saturated T1FLASH, and T2TSE were superior to True-FISP in evaluating the gastric wall. T1FLASH and fat-saturated T1FLASH were the best sequences for demonstrating mucosa (p<0.05), and T2TSE was the best for submucosa and the distinction between this and muscle (p<0.05). Both T1FLASH and T2TSE provided the best overall image quality (p<0.05). CONCLUSION: In-vitro MR imaging is an excellent technique for the evaluation of layers of normal gastric wall. T2TSE is the sequence which best demonstrates the conspicuity of submucosa, the distinction between submucosa and muscle, and overall image quality.