Clinical Experience with 3.0 T MR for Cardiac Imaging in Patients: Comparison to 1.5 T using Individually Optimized Imaging Protocols

PURPOSE: To report our clinical experience with cardiac 3.0 T MRI in patients compared with 1.5 T using individually optimized imaging protocols. MATERIALS AND METHODS: We retrospectively reviewed 30 consecutive patients and 20 consecutive patients who underwent 1.5 T and 3 T cardiac MRI within 10 months. A comparison study was performed by measuring the signal-to-noise ratio (SNR), the contrast-to-noise ratio (CNR) and the image quality (by grading each sequence on a 5-point scale, regarding the presence of artifacts). RESULTS: In morphologic and viability studies, the use of 3.0 T provided increase of the baseline SNRs and CNRs, respectively (T1: SNR 29%, p < 0.001, CNR 37%, p < 0.001; T2-SPAIR: SNR 13%, p = 0.068, CNR 18%, p = 0.059; viability imaging: SNR 45%, p = 0.017, CNR 37%, p = 0.135) without significant impairment of the image quality (T1: 3.8 +/- 0.9 vs. 3.9 +/- 0.7, p = 0.438; T2-SPAIR: 3.8 +/- 0.9 vs. 3.9 +/- 0.5, p = 0.744; viability imaging: 4.5 +/- 0.8 vs. 4.7 +/- 0.6, p = 0.254). Although the image qualities of 3.0 T functional cine images were slightly lower than those of 1.5 T images (3.6 +/- 0.7 vs. 4.2 +/- 0.6, p < 0.001), the mean SNR and CNR at 3.0 T were significantly improved (SNR 143% increase, CNR 108% increase, p < 0.001). With our imaging protocol for 3.0 T perfusion imaging, there was an insignificant decrease in the SNR (11% decrease, p = 0.172) and CNR (7% decrease, p = 0.638). However, the overall image quality was significantly improved (4.6 +/- 0.5 vs. 4.0 +/- 0.8, p = 0.006). CONCLUSION: With our experience, 3.0 T MRI was shown to be feasible for the routine assessment of cardiac imaging.

Clinical Experience of 3T Breast MRI in Detecting the Additional Lesions in Breast Cancer Patients

PURPOSE: The purpose of this study was to evaluate the diagnostic accuracy of 3.0-T breast MRI for detecting additional breast cancer soon after the initial diagnosis of breast cancer. MATERIALS AND METHODS: From March to June 2009, 101 patients recently diagnosed breast cancer underwent breast MRI and surgery. Parameters analyzed on MRI were total extent of tumor, suspicious findings of multifocal, multicentric, or contralateral cancer. The diagnosis of MRI-detected cancer was confirmed by means of biopsy or surgical specimen evaluation after the localization. RESULTS: MRI showed 37 additional suspicious findings in 34 patients. Twenty nine findings were true-positive (29/37, 78.4%), including 16 cases of multifocality, 11 cases of multicentricity and 2 cases of contralateral cancer. Among these cancers, 13 (44.8%) were ductal carcinoma in situ (DCIS) and 16 (55.1%) were infiltrating cancer. Eight findings were false-positive (8/37, 21.6%) including 6 cases of benign disease and 2 cases of high-risk lesions. CONCLUSION: In women with recently diagnosed breast cancer, 3.0-T MR imaging showed additional suspicious findings in 33.7%. The sensitivity and specificity for detecting additional breast cancer was 100% and 89.3%, respectively.

Fluid Attenuated Inversion Recovery (FLAIR) Imaging of the Normal Brain: Comparisons between Under the Conditions of 3.0 Tesla and 1.5 Tesla

OBJECTIVE: The aim of this study was to evaluate the differences in normal brain MRI findings between under 3.0 Tesla (T) and 1.5T MRI conditions with the use of the fluid attenuated inversion recovery (FLAIR) sequences. MATERIALS AND METHODS: Eleven normal adults underwent imaging with the use of the FLAIR sequences on both 1.5T and 3.0T scanners. Two neuroradiologists compared the signal intensity (SI) of the centrum semiovale (CS), pulvinar thalami (PT) and normal iron deposit structures (IDSs) on the 3.0T and 1.5T FLAIR images, and they evaluated three MRI findings qualitatively: high SI of CS; low SI of PT; low SI of IDS. We also evaluated signal-to-noise ratios (SNRs) for the CS, PT, red nucleus and cerebellar dentate nucleus on the FLAIR images. RESULTS: Based on qualitative analyses, the 3.0T FLAIR images showed all three MRI findings for all cases. Low SI for the PT in seven cases (64%), high SI of the CS in one case (9%) and low SI of the cerebellar dentate nucleus in one case (9%) were visualized only on 3.0T FLAIR images. The mean SNRs of the PT, red nucleus and dentate nucleus in patients where 3.0T FLAIR imaging was performed were significantly lower as compared with the SNRs on 1.5T FLAIR images. The SNR of the CS was not significantly different between under the two magnetic field strengths (p > 0.05). CONCLUSION: We have demonstrated that normal, high and low SIs of the CS, PT and IDS on 3.0T FLAIR images were depicted more frequently and more prominently as compared with those on 1.5T FLAIR images in normal adult brains.