Evaluation of fat saturation and contrast enhancement on T1-weighted FLAIR sequence of the spine at 3.0 T.

PURPOSE: To evaluate T1-weighted fast spin echo (FSE) and fast T1-weighted fluid-attenuated inversion recovery (FLAIR) imaging, pre and post contrast administration, and assess the necessity of fat saturation regarding normal anatomical structures, degenerative and pathological vertebral body lesions of the spine at 3.0 T. METHODS AND MATERIALS: Spine magnetic resonance imaging studies of 59 consecutive patients (31 females, 28 males), aged 33-81 years (mean age 53 years) were reviewed. Qualitative and quantitative evaluation was performed by comparing T1-FSE and fast T1-weighted FLAIR after administration of a gadolinium (Gd)-based contrast agent (0.1 mmol/kg gadopentetate dimeglumine) with fat suppression (FS), detecting the sequence that provided better identification of the normal anatomical structures, as well as pathological findings. In a small sample of twelve patients, post-contrast T1-weighted images with and without FS were also included. RESULTS: On both quantitative and qualitative analysis between of T1-weighted FLAIR and T1-weighted FSE images, the FLAIR sequence with contrast administration and FS, demonstrated improved enhancement in all abnormalities, presented with minimal susceptibility artifacts, homogeneities in fat saturation for all FOV and minimal chemical shift artifacts. CONCLUSION: Based on the results of our qualitative and quantitative assessment of the cervical, thoracic and lumbar spine at 3.0T we concluded that fast T1-weighted FLAIR images with intravenous (iv) Gd and FS were superior to T1-weighted FSE images with iv Gd and FS, with respect to identification of normal anatomical structures and pathology.

T2 FLAIR artifacts at 3-T brain magnetic resonance imaging.

The purpose of this retrospective clinical study was to identify and evaluate the presence and frequency of T2 FLAIR artifacts on brain MRI studies performed at 3 T. We reviewed axial T2 FLAIR images in 200 consecutive unremarkable brain MRI studies performed at 3 T. All studies were reviewed for the presence of artifacts caused by pulsatile CSF flow, magnetic susceptibility and no nulling of the CSF signal. T2 FLAIR images introduce several artifacts that may degrade image quality and mimic pathology. Knowledge of these artifacts and increased severity and frequency at 3 T is of particular importance in avoiding a misdiagnosis.

Comparison of T1-weighted fast spin-echo and T1-weighted fluid-attenuated inversion recovery images of the lumbar spine at 3.0 Tesla.

BACKGROUND: T1-weighted fluid-attenuated inversion recovery (FLAIR) sequence has been reported to provide improved contrast between lesions and normal anatomical structures compared to T1-weighted fast spin-echo (FSE) imaging at 1.5T regarding imaging of the lumbar spine. PURPOSE: To compare T1-weighted FSE and fast T1-weighted FLAIR imaging in normal anatomic structures and degenerative and metastatic lesions of the lumbar spine at 3.0T. MATERIAL AND METHODS: Thirty-two consecutive patients (19 females, 13 males; mean age 44 years, range 30-67 years) with lesions of the lumbar spine were prospectively evaluated. Sagittal images of the lumbar spine were obtained using T1-weighted FSE and fast T1-weighted FLAIR sequences. Both qualitative and quantitative analyses measuring the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and relative contrast (ReCon) between degenerative and metastatic lesions and normal anatomic structures were conducted, comparing these sequences. RESULTS: On quantitative evaluation, SNRs of cerebrospinal fluid (CSF), nerve root, and fat around the root of fast T1-weighted FLAIR imaging were significantly lower than those of T1-weighted FSE images (P<0.001). CNRs of normal spinal cord/CSF and disc herniation/ CSF for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted FSE images (P<0.001). ReCon of normal spinal cord/CSF, disc herniation/CSF, and vertebral lesions/CSF for fast T1-weighted FLAIR images were significantly higher than those for T1-weighted FSE images (P<0.001). On qualitative evaluation, it was found that CSF nulling and contrast at the spinal cord (cauda equina)/CSF interface for T1-weighted FLAIR images were significantly superior compared to those for T1-weighted FSE images (P<0.001), and the disc/spinal cord (cauda equina) interface was better for T1-weighted FLAIR images (P<0.05). CONCLUSION: The T1-weighted FLAIR sequence may be considered as the preferred lumbar spine imaging sequence compared to T1-weighted FSE, as it has demonstrated superior CSF nulling, better conspicuousness of normal anatomic structures and degenerative and metastatic lesions, and improved image contrast.