Usefulness of Contrast-Enhanced T1-Weighted Sampling Perfection with Application-Optimized Contrasts by Using Different Flip Angle Evolutions in Detection of Small Brain Metastasis at 3T MR Imaging: Comparison with Magnetization-Prepared Rapid Acquisition of Gradient Echo Imaging

• Published in: American journal of neuroradiology : AJNR 2009-05, Vol.30 (5), p.923-929
• Main Authors: Kato, Y, Higano, S, Tamura, H, Mugikura, S, Umetsu, A, Murata, T, Takahashi, S
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Algorithms; Biological and medical sciences; Brain; Brain Neoplasms - diagnosis; Brain Neoplasms - secondary; Contrast Media; Echo-Planar Imaging - methods; Gadolinium DTPA; Human viral diseases; Humans; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Imaging, Three-Dimensional - methods; Infectious diseases; Investigative techniques, diagnostic techniques (general aspects); Medical sciences; Middle Aged; Nervous system; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Reproducibility of Results; Sensitivity and Specificity; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A1506

Early accurate diagnosis of brain metastases is crucial for a patient's prognosis. This study aimed to compare the conspicuity and detectability of small brain metastases between contrast-enhanced 3D fast spin-echo (sampling perfection with application-optimized contrasts by using different flip angle evolutions [SPACE]) and 3D gradient-echo (GE) T1-weighted (magnetization-prepared rapid acquisition of GE [MPRAGE]) images at 3T. Sixty-nine consecutive patients with suspected brain metastases were evaluated prospectively by using SPACE and MPRAGE on a 3T MR imaging system. After careful evaluation by 2 experienced neuroradiologists, 92 lesions from 16 patients were selected as brain metastases. We compared the shorter diameter, contrast rate (CR), and contrast-to-noise ratio (CNR) of each lesion. Diagnostic ability was compared by using receiver operating characteristic (ROC) analysis. Ten radiologists (5 neuroradiologists and 5 residents) participated in the reading. The mean diameter was significantly larger by using SPACE than MPRAGE (mean, 4.5 +/- 3.7 versus 4.3 +/- 3.7 mm, P = .0014). The CR and CNR of SPACE (mean, 57.3 +/- 47.4%, 3.0 +/- 1.9, respectively) were significantly higher than those of MPRAGE (mean, 37.9 +/- 41.2%, 2.6 +/- 2.2; P < .0001, P = .04). The mean area under the ROC curve was significantly larger with SPACE than with MPRAGE (neuroradiologists, 0.99 versus 0.88, P = .013; residents, 0.99 versus 0.78, P = .0001). Lesion detectability was significantly higher on SPACE than on MPRAGE, irrespective of the experience of the reader in neuroradiology. SPACE should be a promising diagnostic technique for assessing brain metastases.