Article Figures & Data
Figures
- Fig 1.
SNR measurements obtained on a phantom for T1 values between 5 and 1000 ms for the 5-mm VIBE and MP RAGE reformations and the T1-weighted SE images.
- Fig 2.
Images of the posterior fossa in a patient with suspected metastatic disease. A, Two-dimensional T1-weighted SE image shows marked pulsation artifacts. Superimposition of the choroidal plexus in the fourth ventricle and the artifacts mimic a possible contrast-enhancing lesion (arrow). B, MP RAGE 5-mm reformation shows considerable ghost artifacts (arrows) impairing visualization of the pons and the cerebellum. C, VIBE 5-mm reformation shows no artifact.
- Fig 3.
Primary cerebral lymphoma. A–C, Interhemispheric contrast-enhancing lesion (arrow in A) is well visualized on both the 2D T1-weighted SE image (A) and the VIBE 5-mm reformation (B), but is less obvious on the MP RAGE 5-mm reformation (C).
Tables
Images SNR CNR GM WM GM-WM Lesion-GM Lesion-WM Source MP Rage 23.1 ± 5.2 27.8 ± 5.0 4.8 ± 1.5 16.3 ± 10.2 11.8 ± 10.3 VIBE 26.1 ± 5.4 32.0 ± 6.3 5.9 ± 2.2 20.2 ± 11.3 14.3 ± 12.0 P value .001 <.001 <.001 .002 .053 5-mm Reformations MP RAGE 73.8 ± 14.6 89.2 ± 15.1 15.4 ± 4.1 38.9 ± 26.3 25.1 ± 26.1 VIBE 77.5 ± 14.5 94.2 ± 16.3 16.8 ± 4.4 46.1 ± 26.4 30.0 ± 28.3 T1-weighted SE 96.1 ± 11.0 106.4 ± 10.1 10.2 ± 4.9 64.1 ± 37.9 54.1 ± 39.1 P value* <.001† <.001† <.001† <.001‡ <.001† Note.—Data are mean ratios ± SD.
↵* P values are based on analysis of variance.
↵† Paired Student t test demonstrated no significant difference between 5-mm VIBE and MP RAGE reformations.
↵‡ Student t test demonstrated a statistically significant difference between each pairing of images obtained with the three imaging methods.
Artifact T1-Weighted SE Images VIBE 5-mm Reformations MP RAGE 5-mm Reformations P Value* Gross patient motion 5.00 ± 0.0 4.98 ± 0.1 4.92 ± 0.2 0.039 Flow-related 3.73 ± 0.4 4.33 ± 0.6 4.02 ± 0.6 <0.001† Ringing (truncation) 4.25 ± 0.4 3.92 ± 0.4 3.83 ± 0.6 <0.001‡ Note.—Data are mean grade ± SD. Grading scheme: 1, unreadable, nondiagnostic study; 2, severe artifacts, but diagnostic study; 3, moderate artifacts; 4, mild artifacts; 5, not encountered.
↵* P values are based on analysis of variance.
↵† Wilcoxon signed rank test demonstrated a statistically significant difference between each pairing of images obtained with the three imaging methods.
↵‡ The Friedman nonparametric test showed significant differences between the three sequences considered together. However, the difference between MP RAGE and VIBE was not significant on the Wilcoxan signed rank sum test.
Conspicuity Level and Lesion Type T1-Weighted SE VIBE MP RAGE Best* Contrast-enhancing 12.5 (14/11) 8 (8/8) 2.5 (1/4) All hyperintense 20.5 (23/18) 10 (9/11) 3.5 (2/5) Intermediate* Contrast-enhancing 4 (5/3) 9 (10/8) 10 (8/12) All hyperintense 4.5 (5/4) 15 (18/12) 14.5 (11/18) Lowest* Contrast-enhancing 6.5 (4/9) 6 (5/7) 10.5 (14/7) All hyperintense 9 (6/12) 9 (7/11) 16 (21/11) Average rank† Contrast-enhancing 1.7 (1.6/1.9) 1.9 (1.9/2.0) 2.4 (2.4/2.4) All hyperintense 1.6 (1.6/1.9) 2.0 (1.9/2.0) 2.4 (2.6/2.2)
