MR of focal liver lesions: Comparison of breath‐hold and non‐breath‐hold hybrid rare and conventional spin‐echo T2‐weighted pulse sequences

Abstract

To compare liver lesion detection rates, tissue signal and noise data, and qualitative parameters for breath-hold (BH) and non-breath-hold (NBH) hybrid rapid acquisition with relaxation enhancement (RARE) and conventional spin-echo (CSE) T2-weighted (CSE-T2) MR sequences, 20 patients were imaged using all three sequences. Lesion detection rates were 73.5% for the CSE-T2 sequence and 81.1% and 88.6% for the BH-RARE and NBH-RARE sequences, respectively (P = .027). Mean lesion-to-liver signal-difference-to-noise ratio for the NBH-RARE sequence was 14.0 +/- 11.5, significantly greater than 9.8 +/- 7.8 obtained for the BH-RARE sequence (P = .050) and 9.0 +/- 6.2 obtained for the CSE-T2 sequence (P = .015). The NBH-RARE sequence demonstrated fewer artifacts and greater overall image quality compared to the CSE-T2 sequence. The NBH-RARE sequence is a useful alternative to the liver signal-difference-to-noise ratio and lesion detection rate and better overall image quality.

Detection of malignant hepatic tumors with ferumoxide-enhanced MR imaging: usefulness of multishot and single-shot fast spin echo sequences

“…Our quantitative results showed that the mean lesion-to-liver CNR with MS-FSE images was greater for metastases than for hepatocellular carcinoma. This observation may be explained as follows: first, the decrease in signal intensity caused by magnetization-transfer-contrast effect with MS-FSE sequence [27] may be less in metastases than in hepatocellular carcinoma, probably because internal tumor necrosis or abundant interstitial space in metastases contains more abundant free water compared with hepatocellular carcinoma. In contrast, the decrease in signal intensity due to a magnetization-transfer-contrast effect with fast SE sequence may be greater in hepatocellular carcinoma because tissue structures are often analogous between hepatocellular carcinoma and the surrounding liver parenchyma, resulting in lower lesion-to-liver CNR and lesion conspicuity.…”

Small Malignant Hepatic Tumor Detection in Gadolinium- and Ferucarbotran-Enhanced Magnetic Resonance Imaging: does Combining Ferucarbotran-Enhanced T2*-Weighted Gradient Echo and T2-Weighted Turbo Spin Echo Images have Additive Efficacy?

“…Despite the higher inherent lesion to liver contrast on the T2 * W-GRE, the better detection capability of the T2W-TSE for metastases could be explained by signal loss caused by a magnetization transfer effect, with the TSE sequence being lower in metastases than in HCC because tumor necrosis and abundant interstitial space in metastases generally contain more abundant free water compared with HCC (22, 23). There were 11 metastases (0.4-0.8 cm) that were not detected by either observer on the T2 * W-GRE set, but which were clearly revealed on the T2W-TSE set.…”

O valor da ressonância magnética na detecção de nódulos hepáticos utilizando-se diversas técnicas ponderadas em T2: existe consenso?

“…Carpenter et al não verificaram diferença estatisticamente significante na sensibilidade de detecção de lesões hepáticas utilizando seqüências RARE (FSE) com e sem apnéia, em 19 pacientes com 106 lesões (40) . Resultados semelhantes foram observados por Soyer et al (41,42) .…”