Virtual colonoscopy with magnetic resonance imaging: In vitro evaluation of a new concept

BACKGROUND & AIMS: Screening for colonic polyps is desirable. A new concept based on cross-sectional and endoscopic analysis of a magnetic resonance (MR) data set is presented. METHODS: Ex vivo autopsy colonic specimens, containing artificially placed polyps, were obtained and filled with a gadolinium-containing solution. Forty-four thin-section MR images were obtained in a 1.5-T MR scanner in 28 seconds. A three- dimensional endoscopic fly-through of these images was rendered. Fly- throughs and two-dimensional cross-sectional images were analyzed by two observers for the presence of polyps. RESULTS: The average sensitivity and specificity for the detection of polyps based on three- dimensional endoscopic MR colon imaging were 87% and 96%, respectively. Analysis of cross-sectional images showed an overall sensitivity and specificity of merely 57% and 84%, respectively. The difference in the interpretation of three-dimensional MR colonoscopy and two-dimensional cross-sections was statistically significant (P < 0.001). With three- dimensional MR colonoscopy, overall sensitivity for detection of polyps measuring < or =5 mm in length and diameter was 70%; for larger polyps, it increased to 95% (P < 0.01). CONCLUSIONS: The feasibility of an MR- based endoluminal assessment of the colon is shown. Minimal invasiveness, lack of radiation exposure, and high in vitro diagnostic accuracy warrant further investigation of this novel concept. (Gastroenterology 1997 Jun;112(6):1863-70)     

Cytogenetic studies in patients with secondary leukemia/dysmyelopoietic syndrome after different treatment modalities

Cytogenetic studies of 68 patients who developed secondary leukemia (SL)/dysmyelopoietic syndrome (DMS) after extensive chemotherapy and/or radiation therapy as well as patients who developed SL/DMS without such treatment showed that those patients who received radiation alone or with chemotherapy had more extensive numerical and structural abnormalities than those who received only chemotherapy. In terms of the specific chromosomal abnormalities, there are no differences between the various treatment groups. Hypodiploidy is the most common form of aneuploidy in these patients, with the most common numerical abnormality being the loss of chromosome 7. The most common structural abnormalities involved chromosomes 3 and 5. When compared with patients with de novo leukemia and DMS, the chromosomal abnormalities in these patients are more complex and extensive. Serial studies revealed that cytogenetic abnormalities do not precede the development of hematologic changes by significant time periods.     

Neurological disorders in Northern Tanzania: A 6-year prospective hospital-based case series

BackgroundThe burden of neurological disorders is large and altered by the HIV epidemic.ObjectivesWe describe the pattern of neurological disorders and their association with HIV infection in adult patients attending a consultant hospital in Northern Tanzania.MethodsIn this prospective cross-sectional study, we collected data on adult neurological referrals over a 6-year period between 2007–13. The odds of HIV infection, across neurological categories adjusted for age and sex, was calculated.ResultsOf 2037 participants, 54.8% were male and 45.2% were female. The median age of participants was 43 years. The results for HIV screening were available for 992/2037 (48.7%) patients, of whom 306 (30.8%) were seropositive. The most frequent neurological disorders were cerebrovascular disease (19.9%), paraplegia (13.6%), and peripheral neuropathies (8%). Taken together CNS infection accounted for 278/2037 (13.6%). The adjusted odds (aOR) of HIV infection was highest amongst infections; brain abscesses (aOR 107, 95% CI 35.1–470.4) and meningitis/encephalitis (aOR 40.1, 95% CI 13.6–172.9), but also raised in cerebrovascular disease, paraplegia, peripheral neuropathies, cranial nerve palsies, seizures, cerebllar disorders, movement disorders, motor neuron disease and headache.ConclusionThe main pattern of neurological disorders in Northern Tanzania is presented. The odds of HIV infection was highest in CNS infections and in a wide range of non-communicable neurological disorders.