OBJECTIVE: Our goal was to evaluate the image quality, contrast characteristics, and possible clinical utility of STIR images obtained using a fast SE (FSE) technique. MATERIALS AND METHODS: The signal and contrast characteristics of FSE STIR images were evaluated using a lipid/water phantom and normal volunteers. Based upon these results, optimal FSE STIR imaging parameters were chosen. Conventional STIR and FSE STIR images were then obtained (while maintaining an equal number of section locations between the two sequences) in a series of 14 patients with known musculoskeletal abnormalities. These images were compared side by side by two experienced MR radiologists for image quality and lesion detection. RESULTS: There were no statistically significant differences between the FSE STIR images and conventional STIR images in lesion detection, image quality, motion artifact, or final diagnosis. CONCLUSION: STIR imaging provides optimal contrast for detection of many pathologic abnormalities. This is especially true for musculoskeletal tumors and infection. The long imaging time and reduced number of sections obtainable with conventional SE (CSE) STIR sequences limit their routine use. Our results show that FSE STIR images of the musculoskeletal system can be obtained up to seven times more rapidly than CSE STIR images without compromising lesion detection or image quality.

Adipose Tissue↗

PubMedDate not supplied

Conspicuity of normal and pathologic female pelvic anatomy: comparison of gadolinium-enhanced T1-weighted images and fast spin echo T2-weighted images.

PURPOSE: Our goal was to compare the conspicuity of normal and pathologic female pelvic anatomy between gadolinium-enhanced T1-weighted images and fast SE (FSE) T2-weighted images. METHOD: In 48 consecutive female patients, pre- and postenhanced T1-weighted images were compared with FSE T2-weighted images acquired with a phased array coil. Normal zonal anatomy (ZA) and pathologic abnormalities in gadolinium-enhanced T1-weighted images were rated as increased, decreased, or without change in conspicuity as compared with FSE T2-weighted images. RESULTS: The normal ZA of the uterine corpus on T1-weighted images showed a decrease in conspicuity in 93% of patients and an increase in 7% compared with FSE T2-weighted images. Conspicuity of cervical ZA on T1-weighted images was decreased in 86%, increased in 6%, and without change in 8% as compared with FSE T2-weighted images. ZA of the vagina on T1-weighted images was decreased in 94% and increased in 6% as compared with FSE T2-weighted images. On T1-weighted images, ovarian anatomy delineation was decreased in 95% and increased in 5% as compared with FSE T2-weighted images. Conspicuity of malignant pathologic abnormalities on T1-weighted images was decreased in 81%, increased in 11%, and without change in 8% as compared with FSE T2-weighted images. In patients with benign disease, conspicuity on T1-weighted images was decreased in 92%, increased in none, and without change in 8% as compared with FSE T2-weighted images. The p value for all categories was < 0.0001. CONCLUSION: Conspicuity of both normal and pathologic anatomy was significantly decreased on enhanced T1-weighted images. The use of gadolinium cannot replace T2-weighted scans for delineation of anatomy and disease and should be reserved to cases in which standard imaging sequences are not sufficiently diagnostic.

Adolescent↗

PubMedDate not supplied

Temporal changes in sequential quantitative thallium-201 imaging following myocardial infarction in dogs: comparison of four- and twenty-four-hour infarct images.

Thallium-201 ((201)T1) myocardial perfusion imaging allows definition of zones of myocardial infarction and ischemia. The temporal changes in sequential quantitative (201)T1 infarct imaging was studied 4 and 24 hours in dogs subjected to closed-chest anterior wall myocardial infarction. A temporal decrease in (201)T1 imaged infarct areas was noted in 10 of 13 animals. In no animal did the infarct area increase. The imaged infarct area decreased by an average of 30% from 12.9 ± 6.2 cm(2) at 4 hours to 9.1 ± 5.1 cm(2) at 24 hours (p < 0.001), and involved 34 ± 16% of the total (201)T1 left ventricular distribution at 4 hours and 22 ± 14% at 24 hours (p < 0.001). The magnitude of temporal change in imaged infarct area was not predicted by initial image defect or final histopathologic infarct size. Thus, the results of (201)T1 infarct imaging in the early period of infarction are clearly dependent upon the time at which the procedure is performed.

Animals↗