Differences between gray matter and white matter water diffusion in stroke: diffusion-tensor MR imaging in 12 patients.

Purpose: To investigate differences in water diffusion between white matter and gray matter in acute to early subacute stroke with diffusion-tensor magnetic resonance (MR) imaging.

Materials And Methods: Twelve patients with unilateral middle cerebral arterial infarcts were examined with diffusion tensor-encoded echo-planar MR imaging 17 hours to 5 days after stroke onset. Isotropic diffusion coefficient (D) and diffusion anisotropy (A(sigma)) images were computed.

Quantitative diffusion-tensor anisotropy brain MR imaging: normative human data and anatomic analysis.

Purpose: To obtain normative human cerebral data and evaluate the anatomic information in quantitative diffusion anisotropy magnetic resonance (MR) imaging.

Materials And Methods: Quantitative diffusion anisotropy MR images were obtained in 13 healthy adults by using single-shot echo-planar MR imaging and a combination of tetrahedral and orthogonal gradient encoding (whole-brain coverage in about 1 minute). White matter (WM) anatomy was assessed at visual inspection, and values were measured in various brain regions.

The abdominal compartment syndrome: CT findings.

Objective: The abdominal compartment syndrome is a potentially fatal condition resulting from pathologic elevation of intraabdominal pressure. We evaluated preoperative abdominal CT scans of four patients with proven abdominal compartment syndrome to identify signs of increased intraabdominal pressure.

Conclusion: CT findings common to all four patients included tense infiltration of the retroperitoneum out of proportion to peritoneal disease, extrinsic compression of the inferior vena cava by retroperitoneal hemorrhage or exudate, and massive abdominal distention with an increased ratio of anteroposterior-to-transverse abdominal diameter (positive round belly sign; ratio > .

Tracking neuronal fiber pathways in the living human brain.

Functional imaging with positron emission tomography and functional MRI has revolutionized studies of the human brain. Understanding the organization of brain systems, especially those used for cognition, remains limited, however, because no methods currently exist for noninvasive tracking of neuronal connections between functional regions [Crick, F. & Jones, E.

A multiple echo pulse sequence for diffusion tensor imaging and its application in excised rat spinal cords.

A new imaging sequence for rapid determination of the apparent self-diffusion tensor of water was developed and tested on fixed excised rat spinal cords. To reduce the time required to determine the tensor, the sequence utilized a new single-shot approach with multiple spin echoes. An assumption of cylindrical symmetry in the sample was made, thus requiring the measurement of only four of the six unique elements of the tensor.