Experimental intracranial septic infarction: magnetic resonance enhancement.

Abstract

Intracranial brain abscess was produced in three monkeys by embolization of a small pledget of polyvinyl alcohol (PVA) soaked in a broth of Staphylococcus aureus. Imaging of the chronic stable abscess was performed on the General Electric 8800 CT unit (Milwaukee, Wis.) and a 1.4 T superconducting small bore imaging system. Magnetic resonance imaging included saturation recovery, inversion recovery, and spin echo techniques. MR imaging was also performed after paramagnetic enhancement using gadolinium-DPTA (Gd-DTPA). Our results show that paramagnetic enhancement with T1-weighted imaging adds specificity and enables rapid assessment of abnormalities of the blood-brain barrier. T2-weighted imaging without paramagnetic enhancement was very sensitive in defining areas of abnormality in the brain but in our experiment lacked specificity. T2-weighted imaging with Gd-DTPA demonstrated no obvious change in the appearance of the lesion. The combination of T1-weighted Gd-DTPA and T2-weighted imaging appeared complementary in our experiment, and these images correlated well with the pathologic findings.

Magnetic Resonance Imaging of Local Soft Tissue Inflammation Using Gadolinium-DTPA

“…As inflammatory tissues have a large extravascular space and increased vascular permeability, the concentration of extravascularly-distributed paramagnetics is predictably high in the inflammatory loci, increasing lesion intensities. Similar paramagnetic enhancement of the edematous tissue has been demonstrated in the ischemic heart (2), and in histologically different tumors (4,6,9,19,20,21).…”

“…This is primarily attributed to increased water content with a concomitant prolongation of relaxation times in inflammatory tissue (10,16). Since inflammation and edema are important contributors to various pathologic processes in the body, and the MRI differentiation of inflammation from malignancy or tissue necrosis is of clinical importance (6,9,10,17,23), an appropriate experimental model for characterizing inflammation using MRI would be useful.…”

Magnetic Resonance Imaging—a General Overview of Principles and Examples in Veterinary Neurodiagnosis

“…3), vcntriculitis, and hydrocephalus can be detected.4s Use of Gd-DTPA detccts damage to the bloodbrain barrier and may increase MRI sensitivity for evaluating intlammation . [49][50][51] Image patterns may be characteristic for some diseases. but microscopic diagnosis is gencrally still required.…”

Brain parenchymal infection in bone marrow transplantation patients: CT and MR findings.

“…On MR images and CT scans, brain parenchymal infections in immunocompetent patients are usually characterized by marked vasogenic edema and intense enhancement after IV administration of contrast material [1][2][3][4][5]. Earlier CT studies of brain parenchymal infection in immunocompromised patients showed diminished contrast enhancement [6].…”