T1-weighted Magnetic Resonance Imaging In Patients Research Articles

Pseudonormal Corticomedullary Differentiation of the Kidney Assessed on T1-weighted Imaging for Chronic Kidney Disease Patients with Cirrhosis.

We investigated whether corticomedullary differentiation (CMD) increased to a pseudonormal appearance on T1-weighted magnetic resonance (MR) images in patients with chronic kidney disease (CKD) with cirrhosis compared with patients with CKD without chronic liver disease. We assessed CMD on T1-weighted MR images of 32 patients with CKD with liver cirrhosis and 32 age-matched patients with CKD without liver cirrhosis, grading CMD visualization as good, moderate, or poor. We calculated quantitative CMD by the ratio of the signal intensity of the cortex to that of the medulla. The proportions of patients in each of the good, moderate, and poor groups differed significantly between those with and without liver cirrhosis (P = 0.048). In patients with CKD with liver cirrhosis, the estimated glomerular filtration rate (eGFR) differed between those with poor CMD and those with good or moderate CMD (P < 0.01) but not between those with good and those with moderate CMD. In patients with CKD without cirrhosis, the eGFR differed significantly among the good, moderate, and poor CMD groups (P < 0.05). We observed no significant correlation between CMD and eGFR in patients with and without cirrhosis (P < 0.05, r = 0.62). CMD of the kidney had a pseudonormal appearance on T1-weighted MR imaging in patients with CKD with cirrhosis.

Whole-body 3D T1-weighted MR imaging in patients with prostate cancer: feasibility and evaluation in screening for metastatic disease.

To develop and assess the diagnostic performance of a three-dimensional (3D) whole-body T1-weighted magnetic resonance (MR) imaging pulse sequence at 3.0 T for bone and node staging in patients with prostate cancer. MATERIALS AND METHODS This prospective study was approved by the institutional ethics committee; informed consent was obtained from all patients. Thirty patients with prostate cancer at high risk for metastases underwent whole-body 3D T1-weighted imaging in addition to the routine MR imaging protocol for node and/or bone metastasis screening, which included coronal two-dimensional (2D) whole-body T1-weighted MR imaging, sagittal proton-density fat-saturated (PDFS) imaging of the spine, and whole-body diffusion-weighted MR imaging. Two observers read the 2D and 3D images separately in a blinded manner for bone and node screening. Images were read in random order. The consensus review of MR images and the findings at prospective clinical and MR imaging follow-up at 6 months were used as the standard of reference. The interobserver agreement and diagnostic performance of each sequence were assessed on per-patient and per-lesion bases. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were significantly higher with whole-body 3D T1-weighted imaging than with whole-body 2D T1-weighted imaging regardless of the reference region (bone or fat) and lesion location (bone or node) (P < .003 for all). For node metastasis, diagnostic performance (area under the receiver operating characteristic curve) was higher for whole-body 3D T1-weighted imaging (per-patient analysis; observer 1: P < .001 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P = .006 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging; observer 2: P = .006 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P = .006 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging), as was sensitivity (per-lesion analysis; observer 1: P < .001 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P < .001 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging; observer 2: P < .001 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P < .001 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging). Whole-body MR imaging is feasible with a 3D T1-weighted sequence and provides better SNR and CNR compared with 2D sequences, with a diagnostic performance that is as good or better for the detection of bone metastases and better for the detection of lymph node metastases.

Whole Blood Manganese Correlates with High Signal Intensities on T1-Weighted MRI in Patients with Liver Cirrhosis

We examined whole blood (MnB), plasma (MnP) and urinary Mn (MnU) concentrations in 33 cirrhotics and 11 healthy controls to clarify: (1) whether, in chronic liver diseases, MnB or MnP reflects pallidal signal intensities in magnetic resonance imaging (MRI); and (2) which factors in chronic liver diseases correlate with pallidal signal intensities in T1-weighted MRI. Increased signal intensity in the pallidum was observed in 27 (81.8%) of 33 patients with liver cirrhosis in T1-weighted MRI. There was a significant correlation between MnB and pallidal index (PI) ( γ = 0.559, P < 0.01) in the patients. However, no significant correlation was observed between MnP and PI ( γ = 0.353, P > 0.05). According to a multiple linear regression, MnB reflected the signal intensities of T1-weighted MRI better than MnP or MnU. Child/Pugh score and total bilirubin level also correlated with PI. However, the hemoglobin level did not correlate with PI significantly.

Hyperintense basal ganglia on T1-weighted MR images in patients receiving parenteral nutrition.

Patterns of intracranial signal intensity on magnetic resonance (MR) images were studied in nine patients undergoing long-term total parenteral nutrition therapy. The duration of therapy ranged from 5 months to 11 years (mean, 5.3 years). Symmetric increased signal intensity on T1-weighted MR images (hyperintense relative to white matter) was observed in the basal ganglia of all patients, without corresponding abnormality on T2-weighted images. Analysis of signal-intensity characteristics and distribution pattern suggests that the basis for these changes may be deposition of intravenously administered paramagnetic trace elements, especially manganese, and/or an astrogliotic reaction to such deposition.