3T MRI bests 1.5T for spine visualization
The visualization of anatomic structure at 3T MRI is much more accurate than at 1.5T MRI, according to a study published in the April issue of the American Journal of Roentgenology.
Jian Zhao, MD, and colleagues from the department of radiology at the University of California, San Francisco, sought to compare image quality of the spine and visualization of spine abnormalities at 3T and 1.5T, as well as to evaluate differences in quantitative assessment of normal and neoplastic vertebral bone marrow. The researchers performed 109 MR exams of the spine at 1.5T and 3T in the same patients within a time interval of less than three months. Two radiologists analyzed the visualization of anatomic and pathologic structures. Normal and pathologic bone marrow was assessed on T1-weighted fast spin-echo sequences.
For all anatomic structures evaluated, the investigators found that the image quality was rated significantly higher at 3T than at 1.5T, with 71.6 percent of the studies overall being superior at 3T. The contrast between normal and pathologic bone marrow was significantly larger at 3T (mean, 0.33) than at 1.5 T (0.27).
The highest accuracy was found using muscle signal at 3 T to differentiate between normal and pathologic bone marrow. "Using muscle as a calibration standard at 3T showed the highest accuracy value of 89 percent versus 80.5 percent at 1.5T, whereas accuracies of the disk were 78.1 percent at both 3T and 1.5T," they wrote.
As an internal standard on T1-weighted FSE images, skeletal muscle can be used to differentiate between infiltrative and normal bone marrow with higher accuracy at 3T than at 1.5T, according to Zhao and colleagues, concluding that these standards can also be used at 3T.
"These findings are important in particular because increased susceptibility effects at 3T caused by trabecular bone induce signal loss in normal bone marrow. These internal standards are useful and can serve as simple tools to guide the practicing radiologist in differentiating normal and abnormal bone marrow on MRI," the authors wrote.
Jian Zhao, MD, and colleagues from the department of radiology at the University of California, San Francisco, sought to compare image quality of the spine and visualization of spine abnormalities at 3T and 1.5T, as well as to evaluate differences in quantitative assessment of normal and neoplastic vertebral bone marrow. The researchers performed 109 MR exams of the spine at 1.5T and 3T in the same patients within a time interval of less than three months. Two radiologists analyzed the visualization of anatomic and pathologic structures. Normal and pathologic bone marrow was assessed on T1-weighted fast spin-echo sequences.
For all anatomic structures evaluated, the investigators found that the image quality was rated significantly higher at 3T than at 1.5T, with 71.6 percent of the studies overall being superior at 3T. The contrast between normal and pathologic bone marrow was significantly larger at 3T (mean, 0.33) than at 1.5 T (0.27).
The highest accuracy was found using muscle signal at 3 T to differentiate between normal and pathologic bone marrow. "Using muscle as a calibration standard at 3T showed the highest accuracy value of 89 percent versus 80.5 percent at 1.5T, whereas accuracies of the disk were 78.1 percent at both 3T and 1.5T," they wrote.
As an internal standard on T1-weighted FSE images, skeletal muscle can be used to differentiate between infiltrative and normal bone marrow with higher accuracy at 3T than at 1.5T, according to Zhao and colleagues, concluding that these standards can also be used at 3T.
"These findings are important in particular because increased susceptibility effects at 3T caused by trabecular bone induce signal loss in normal bone marrow. These internal standards are useful and can serve as simple tools to guide the practicing radiologist in differentiating normal and abnormal bone marrow on MRI," the authors wrote.