Annular tears and disk herniation: prevalence and contrast enhancement on MR images in the absence of low back pain or sciatica.

Purpose: To evaluate the prevalence and radiologic findings of annular tear (especially of contrast material enhancement), bulging disk, and disk herniation on T2-weighted and gadolinium-enhanced T1-weighted magnetic resonance (MR) images in people without low back pain (LBP) or sciatica.

Materials And Methods: Thirty-six volunteers without LBP and/or sciatica (18 with no symptoms in their lifetime and 18 who were pain free for at least 6 months) were examined with sagittal and axial T2-weighted fast spin-echo (SE) and sagittal gadolinium-enhanced T1-weighted fast SE imaging. The prevalence and MR findings of bulging disk, focal protrusion, extrusion, and nonenhancing or enhancing annular tears were assessed.

Factors influencing distant tele-evaluation in cytology, pathology, conventional radiology and mammography.

The present paper summarizes our 1 year's experience with the use of static high resolution videophones (9600 bauds transmission rate, lossless compression, 512 x 512 spatial resolution). The images (n = 610) belong to regular videoconsultation in cytology (160 images), (160 images), pathology (226 images), conventional radiology (50 images) and mammographies (174 images). The results showed an exponential relationship between agreement with 'gold standards' (true diagnosis of the case based on pathology, surgery and follow-up) and the time of training on screen diagnosis (r = 0.

Previous experience in teleradiology could serve as a first lesson to telepathologists.

The author draws the following conclusions from twenty years of experience with teleradiology and in telemedicine in general. 1) Standardise now. Use existing standards, keep protocols open for other partners.

The rat liver cell nuclear imprint as a standard for DNA measurements.

Standards are used in DNA cytophotometry to determine the diploid reference value. Fixation and staining protocols have to be standardized because numerous sources of variation influence staining intensity of DNA. When Feulgen stained imprints of rat liver cell nuclei are used as an external DNA standard a significant difference of reference value of up to 60% between imprints, from the same liver and with all sources of variation minimized, is demonstrated.