Routine use of gadolinium is not warranted. Instead, gadolinium should be reserved for clinically suspected infection in or around a joint, and in cases refractory to medical or surgical treatment due to possible abscess formation.

When rabbits receive intravenous injections of sodium iodate, large expanses of the retinal pigment epithelium are destroyed. The adjacent capillary bed, the choriocapillaris, atrophies in response to the loss of the pigment epithelium and then regenerates. This provides a model of the permeability of regenerating and atrophic choriocapillaris, which we studied using intravenously injected horseradish peroxidase and catalase. Regenerating capillaries were permeable to peroxidase but not catalase. The permeability to peroxidase was probably due to endothelial fenestrations, since catalase (which is larger than peroxidase and does not penetrate endothelial fenestrae) was retarded at interendothelial junctional complexes, indicating that they were intact. Atrophic choriocapillaries were impermeable to catalase but displayed a heterogeneous permeability to peroxidase.This was correlated with the presence or absence of fenestrae; capillary profiles lacking fenestrae retained peroxidase in their lumina, whereas if fenestrae were present the tracer penetrated into the pericapillary space. The observations indicate that: (1) the permeability of the regenerating choriocapillaris is qualitatively similar to the mature choriocapillaris, and (2) the atrophic choriocapillaris undergoes changes in permeability that are primarily correlated with the loss of endothelial fenestrae. The observations provide a functional correlate – change in permeability – for structural changes in choriocapillaris endothelium (thickening, loss of fenestrae) in response to destruction of the retinal pigment epithelium, which has been postulated to exert a trophic effect on these capillaries.

Sagittal images usually receive the most scrutiny in the magnetic resonance evaluation of meniscal and anterior cruciate ligament tears. We assessed the relative contribution of the coronal view. All knee magnetic resonance examinations performed over a 2-year period that had surgical confirmation were reviewed with respect to the presence of meniscal and anterior cruciate ligament tears. The appearance of an attenuated but uninterrupted anterior cruciate ligament was also evaluated. The coronal and sagittal plane images were evaluated separately. The study included 68 medial menisci, 67 lateral menisci, and 71 anterior cruciate ligaments. The coronal view is especially useful in the evaluation of the lateral meniscus. An anterior cruciate ligament that appears attennated but uninterrupted should be considered intact. The anterior cruciate ligament may be evaluated on the coronal view. The coronal view should be regarded as similar to the lateral chest radiograph, which supplements, but does not replace, the frontal chest radiograph.