Journal of magnetic resonance imaging : JMRI
-
J Magn Reson Imaging · May 1998
Comparative StudyHepatic T2-weighted MRI: a prospective comparison of sequences, including breath-hold, half-Fourier turbo spin echo (HASTE).
The purpose of this study was to quantitatively compare the hepatic contrast characteristics of conventional spin-echo (CSE) and fast spin-echo (FSE) sequences with breath-hold T2-weighted images acquired with half-Fourier turbo spin echo (HASTE). Forty-five patients were examined with a phased-array surface coil. Nineteen patients had focal hepatic lesions, including eight malignant tumors, 10 cavernous hemangiomas, and one hepatic adenoma. ⋯ HASTE performed significantly poorer than CSE and FSE for liver-spleen CNR (P < .0001), liver SNR (P = .0002 for CSE and P < .0001 for FSE), and spleen SNR (P < .0001). Optimized FSE images with a short echo train length performed comparably to CSE images of equivalent TE. Liver-lesion CNR was suppressed on HASTE images, suggesting that long echo train length FSE sequences could diminish solid lesion detection compared to CSE and short echo train length FSE.
-
J Magn Reson Imaging · May 1998
The value of respiratory triggered T2-weighted turbo spin-echo imaging of the liver using a phased array coil.
The purpose of this study was to evaluate the value of the respiratory triggered turbo spin-echo (TSE) technique for T2-weighted MRI of liver lesions. Fifty-nine patients (32 men, 27 women; mean age, 63.3 years) with focal hepatic lesions were prospectively studied with MRI at 1.5 T with use of a body phased array coil. In the first 15 patients, breath-hold TSE, respiratory triggered TSE, and conventional nonrespiratory triggered TSE T2-weighted imaging were compared. ⋯ The lesion-liver and liver-spleen contrast-to-noise ratios for the respiratory triggered images were greater by 37% and 39%, respectively, than for the breath-hold T2-weighted TSE images. Qualitatively, the respiratory triggered images showed lower frequency of image artifact, better lesion conspicuity, and greatly superior depiction of intrahepatic structures compared with the breath-hold T2-weighted TSE images. The respiratory triggered T2-weighted TSE technique provides better quality liver images than the breath-hold TSE technique or nonrespiratory triggered technique within a reasonable acquisition time.
-
J Magn Reson Imaging · May 1998
Contrast-enhanced 3D MRA with centric ordering in k space: a preliminary clinical experience in imaging the abdominal aorta and renal and peripheral arterial vasculature.
The objective of this study was to determine the clinical utility of a contrast-enhanced, centric reordered, three-dimensional (3D) MR angiography (MRA) pulse sequence in imaging the abdominal aorta and renal and peripheral lower extremity arteries. Twenty-eight MRA studies were performed on 23 patients and four volunteers at 1.5 T using a 3D contrast-enhanced, centric reordered pulse sequence. In 20 patients, the abdominal aorta and renal arteries were imaged, and in seven patients, the lower extremity arteries were imaged. ⋯ Contrast-enhanced, centric reordered, 3D MRA can rapidly image the abdominal aorta and renal and accessory renal arteries, as well as peripheral lower extremity arteries, with high resolution. Accurate depiction of the vascular lumen at sites of stenosis is made because of the lack of spin dephasing effects, even with hemodynamically significant stenoses. Additional larger clinical trials are required with this promising technique.