We sought to study the accuracy of dual-energy computed tomographic angiography (DE-CTA) for the assessment of symptomatic peripheral arterial occlusive disease of the lower extremity by using the dual-energy bone removal technique compared with a commercially available conventional bone removal tool. Twenty patients underwent selective digital subtraction angiography and DE-CTA of the pelvis and lower extremities. CTA data were postprocessed with two different applications: conventional bone removal and dual-energy bone removal. All data were reconstructed and evaluated as 3D maximum-intensity projections. Time requirements for reconstruction were documented. Sensitivity, specificity, accuracy, and concordance of DE-CTA regarding degree of stenosis and vessel wall calcification were calculated. A total of 359 vascular segments were analyzed. Compared with digital subtraction angiography, sensitivity, specificity, and accuracy, respectively, of CTA was 97.2%, 94.1%, and 94.7% by the dual-energy bone removal technique. The conventional bone removal tool delivered a sensitivity of 77.1%, a specificity of 70.7%, and an accuracy of 72.0%. Best results for both postprocessing methods were achieved in the vascular segments of the upper leg. In severely calcified segments, sensitivity, specificity, and accuracy stayed above 90% by the dual-energy bone removal technique, whereas the conventional bone removal technique showed a substantial decrease of sensitivity, specificity, and accuracy. DE-CTA is a feasible and accurate diagnostic method in the assessment of symptomatic peripheral arterial occlusive disease. Results obtained by DE-CTA are superior to the conventional bone removal technique and less dependent on vessel wall calcifications.

In chronic B-cell leukemias, fluorescence in situ hybridization has greatly improved the ability to detect certain chromosomal aberrations, as cells in all phases of the cell cycle are analyzed. To obtain a comprehensive view of chromosomal gains and losses, we applied the recently developed technique of comparative genomic hybridization (CGH) to 28 patients with chronic B-cell leukemias. CGH results were compared with those obtained by chromosome banding analysis and interphase cytogenetics. In 19 of the 28 cases, chromosomal imbalances were detected, including amplified DNA sequences in three instances. The most common aberrations included gains of chromosomal material on 8q and 12 as well as losses of 6q, 11q, 13q, and 17p. In 13 cases, CGH revealed chromosomal gains and losses not detected by banding analysis. In 8 of these 13 cases, discrepancies were further investigated using other methods, and in all instances, the CGH findings were confirmed. A limitation of detecting small deleted regions by CGH was found in one example of 18p. In conclusion, our data show that the results of banding analysis in chronic B-cell leukemias often do not reflect the chromosomal changes in the predominant cell clone. This may be one explanation for the as yet poor correlation between cytogenetic findings and clinical course in this group of neoplasms.