Hodgkin disease: clinical utility of CT in initial staging and treatment

One hundred seven consecutive new cases of Hodgkin disease were evaluated with chest radiography and computed tomography (CT) for initial staging. The data were evaluated with regard to five popular treatment protocols for Hodgkin disease. Thoracic CT scans were normal in 30 of 31 patients who had normal radiographs. In the remaining 76 patients, CT demonstrated 194 new sites of disease and disproved 25 suspected sites of disease. The use of CT scans changed the staging of disease in 20 patients, 16 of whom had extranodal extension. The effect of using CT findings on treatment depended on whether radiation therapy was used, and, if so, which treatment protocol was followed. The use of CT findings would have changed the treatment in 6.5%-62.7% of new cases of Hodgkin disease. The authors recommend that CT scans be obtained in all patients with Hodgkin disease, especially those with abnormal chest radiographs.     

The retrorenal colon in the supine and prone patient

Ninety patients underwent computed tomographic scanning in both the supine and prone positions to show the orientation of the retroperitoneal colon about the kidneys and allow evaluation of changes in colonic position and contents. The data were compared with data on 500 patients scanned only when supine. Particular attention was given to bowel found posterior to the kidneys (retrorenal colon): its frequency of occurrence on 500 scans of supine patients was 1.9%, but 10.0% in the 90 prone patients. Because most invasive renal procedures would not intersect with retrorenal colon located behind the lateral one-third of the kidney, the data were reevaluated after deletion of these patients, giving a frequency in prone patients of 4.7%. This was found exclusively at the level of the lower renal poles, and the involved colon was extensively distended with gas. Attention should be given at fluoroscopy to detect this unusual, posteriorly positioned, air-filled colon before any invasive renal procedure.     

MR angiography with two-dimensional acquisition and three-dimensional display. Work in progress

Magnetic resonance arteriograms of healthy volunteers and selected patients were produced with a new spoiled gradient-echo pulse sequence based on time-of-flight phenomena. The procedure involves sequential acquisition of many contiguous, thin (1.5-mm) axial two-dimensional sections. These volume data are then submitted to a raytracing projection program, which retrospectively yields multiple arbitrary projection angles rotating through any plane. Venous structures are suppressed with a presaturation slab superior to the current section. The slab location is advanced in concert with advancement of each new section location. The acquisition time varies from 6 to 13 minutes, depending on the number of sections acquired for three-dimensional display. This method obviates the subtraction of image data sets to suppress signals from stationary spins, is more sensitive to slow blood flow than three-dimensional methods of acquisition, and shows special promise for the study of extracranial vascular disease.     

A chromosome with five gamma-globin genes

Globin gene mapping of DNA from a Black newborn resulted in the detection of a chromosome with five gamma-globin genes. Based on results from digests with enzymes EcoRI and PstI, we concluded that the three genes between the 5'G gamma and 3'A gamma genes are G gamma genes with a possible 5' segment derived from A gamma. The high G gamma level in the fetal hemoglobin (Hb F) of the baby is consistent with this view. Family relationships were such that speculation as to the mechanism causing this quintuplication of the gamma-globin genes was not possible.     

Hearing improvement in patients with Fabry disease treated with agalsidase alfa

Aim : To describe the nature and prevalence of hearing loss in Fabry disease, and its response to enzyme replacement therapy (ERT) with agalsidase alfa. Methods : Fifteen male patients with Fabry disease were enrolled in a randomized, double-blind study and received placebo ( n = 8) or ERT ( n = 7) with agalsidase alfa for 6 months. This was followed by an open-label extension of 36 months thus far. Alongside this trial, an additional eight men and two women have so far received open-label ERT for between 6 and 30 months. Pure-tone audiometry, impedance audio-metry and otoacoustic emission testing were performed at 0 (baseline), 6, 18, 30 and 42 months. Results : Nine patients (36%) had bilateral and ten (40%) had unilateral high-frequency sensorineural hearing loss (SNHL). Three (12%) had unilateral middle ear effusions with conductive losses persisting beyond 6 months. Only five patients (20%) had normal hearing. The high-frequency SNHL deteriorated over the first 6 months in both placebo and active treatment groups by a median 6.3 dB ( p < 0.0001, Wilcoxon matched-pairs). This hearing loss subsequently improved above baseline by 1.5 dB at 18 months (p = 0.07), by 5.0 dB at 30 months ( p = 0.006) and by 4.0 dB at 42 months ( p = 0.01).
Conclusion : Significant hearing loss, usually high-frequency SNHL, is a common manifestation of Fabry disease in adults. α-Galactosidase A replacement therapy with agalsidase alfa appears to reverse the hearing deterioration in these patients. This improvement, however, is gradual, suggesting the need for long-term ERT.