Diffusion-weighted MR imaging offers no advantage over routine noncontrast MR imaging in the detection of vertebral metastases.

BACKGROUND AND PURPOSE: Diffusion-weighted MR imaging of the spine has been used to differentiate benign from pathologic vertebral body compression fractures. We sought to determine the utility of diffusion-weighted MR imaging in the detection of vertebral metastases and to compare it with conventional noncontrast T1- and T2-weighted MR imaging. METHODS: Fifteen patients with metastases to the spine were studied using conventional MR imaging and diffusion-weighted imaging. Blinded review of all images was undertaken, and patients were categorized according to whether they had focal or multiple lesions. The signal intensity of the lesions was compared on T1-, T2- (fast spin-echo), and diffusion-weighted images. RESULTS: In five patients with focal disease, metastases were hypointense on T1-weighted images; hypointense (n = 2), isointense (n = 1), or hyperintense (n = 2) on T2-weighted images; and hypointense (n = 3) or hyperintense (n = 2) on diffusion-weighted images with respect to presumed normal bone marrow. In 10 patients with disease in multiple sites, all lesions were hypointense on T1-weighted images; hypointense (n = 2), isointense (n = 4), hyperintense (n = 2), or mixed (n = 2) on T2-weighted images; and hypointense (n = 5), hyperintense (n = 3), or mixed (n = 2) on diffusion-weighted images with respect to presumed normal bone marrow. CONCLUSION: As used in this study, diffusion-weighted MR imaging of the spine showed no advantage in the detection and characterization of vertebral metastases as compared with noncontrast T1-weighted imaging, but was considered superior to T2-weighted imaging.

Breath-hold 3D gradient-echo MR imaging of the lung parenchyma: evaluation of reproducibility of image quality in normals and preliminary observations in patients with disease.

This study evaluates the reproducibility and image quality of a three-dimensional (3D) gradient-echo sequence for imaging the lung parenchyma, with and without gadolinium administration, using a 2D spoiled gradient-echo sequence for comparison. Twenty patients without lung disease (normals) and five patients with lung disease (lung disease) underwent paired 2D and 3D gradient-echo sequences, without contrast (24 patients) and with contrast (18 patients). Images were retrospectively reviewed independently in a blinded fashion by two investigators. Artifacts and demonstration of central lung, peripheral lung, heart, pulmonary arteries, and esophagus were evaluated. Image quality of the central lung was rated as fair or good in 5 and 4 (reader one and two) patients with non-contrast 2D gradient-echo, 24 and 25 patients with non-contrast 3D gradient-echo, 3 and 1 patient(s) with contrast-enhanced 2D gradient-echo, and 19 and 19 patients with contrast-enhanced 3D gradient-echo imaging. Differences in image quality between 2D and 3D sequences were significant (P < 0.001). Heart-related phase artifacts were negligible in 2 and 0 patients with non-contrast 2D gradient-echo, 23 and 25 patients with non-contrast 3D gradient-echo, 0 and 0 patients with contrast-enhanced 2D gradient-echo, and 17 and 19 patients with contrast-enhanced 3D gradient-echo imaging. Differences in heart-related phase artifact in the central lung between 2D and 3D sequences were significant (P = 0.001). Infiltrates, lung cancer, and pulmonary metastasis were better shown on the gadolinium-enhanced 3D gradient-echo sequences than on the other sequences. Breath-hold 3D gradient-echo imaging results in good image quality and negligible image artifacts and is superior to 2D spoiled gradient-echo imaging. Preliminary results in patients with disease appear promising.

Simultaneous occurrence of subacute cutaneous lupus erythematosus and Sweet syndrome. A marker of Sjögren syndrome?

A 78-year-old man presented simultaneously with subacute cutaneous lupus erythematosus (SCLE) and Sweet syndrome (neutrophilic dermatosis). He was subsequently investigated for and found to have Sjögren syndrome. We believe that the simultaneous occurrence of the above cutaneous manifestations are very suggestive of and should prompt investigation for Sjögren syndrome.

The kinetics of migration of murine CD4 and CD8 lymphocytes in vivo.

Lymphocytes from the mesenteric lymph nodes (MLN) of mice were enriched for CD4+ and CD8+ T cell populations, labeled with (51Cr) sodium chromate, and transferred to the bloodstream of syngeneic recipients. The time course of migration of the labeled cells from the blood to the secondary lymphoid organs of the recipients was investigated. CD4+ and CD8+ subpopulations differed in their profile of appearance in different lymphoid organs. Computer assisted analysis of the observations was used to obtain quantitative estimates of the rate of clearance of the lymphocytes from the blood into the tissues, and the rate of departure of the cells from the tissues. In the spleen, CD4+ lymphocytes were cleared from the blood about one and one-half times faster than CD8+ lymphocytes, but the CD8+ cells were retained longer. Inguinal nodes (IN), MLN, and Peyer's patches (PP) showed a consistent ability to clear CD4+ cells from the blood at a rate approximately 2.5 x greater than that for CD8+ cells, but the retention of the lymphocytes in these tissues varied with lymphocyte phenotype and the organ concerned. CD4+ lymphocytes were retained longer in PP and MLN than in IN, whereas CD8+ cells were retained longer in IN and MLN nodes than in PP. We conclude that the rate of clearance of lymphocytes into secondary lymphoid organs from the blood varies in a regular way with T cell phenotype and that organ specific sorting of T subpopulations also proceeds after the cells are admitted to the tissues.