Assessment of bronchiectasis: comparison of HRCT and spiral volumetric CT.

OBJECTIVE: Our goal was to ascertain the sensitivity of spiral CT for the detection of bronchiectasis in comparison with high resolution CT (HRCT). MATERIALS AND METHODS: Thirty-one patients with a suspected clinical diagnosis of bronchiectasis were evaluated with spiral CT (slice thickness 5 mm, pitch 1, reconstruction index 2 mm, 1 s rotation) and HRCT (1.5 mm, interval 10 mm). Analysis of the presence, type, and severity of bronchiectasis was performed for each bronchopulmonary lobe. RESULTS: In 30 patients, 177 lobes were evaluated. At HRCT 14 patients showed signs of bronchiectasis in 32 lobes. Spiral CT confirmed the presence in 29 lobes. In one lobe spiral CT was false positive. The severity score was the same in 23 lobes, in 4 lobes higher at HRCT, and in 2 lobes higher at spiral CT. Spiral CT has a high sensitivity of 91% to detect bronchiectasis with a specificity of 99.3%. Spiral CT demonstrates adequately lack of tapering of the bronchus. CONCLUSION: In patients with suspected bronchiectasis, HRCT is the method of first choice based on greater sensitivity and lower radiation dose. However, spiral CT done for other indications is a reliable method for assessment of bronchiectasis. Inability of patients to hold their breath did not prove to interfere with diagnostic reliability.

Head and neck tumors, MRI versus CT: a technology assessment pilot study.

Thirty-three patients with head and neck tumors were evaluated with both magnetic resonance imaging (MRI) and high-resolution computed tomography (HRCT). Although CT and MRI of the head and neck are well-established clinical methods, reports assessing the relative value of both modalities are not available. Technology assessment was based on the determination of how often and to what extent MRI versus CT provided valuable diagnostic information, and whether this information influenced patient management. The diagnostic values were classified in five groups, ranging from confusing to unique information. Therapeutic values were classified in five groups ranging from disadvantageous therapy, to a favorable change of treatment. All benign tumors found in 14 patients showed positive diagnostic and therapeutic results with MRI (100%). In 19 cases of malignancy a positive yield of 84% was found in the diagnostic and therapeutic results. Two of six squamous cell carcinoma and one of two rhadbomyosarcomas had a negative therapeutic value. As MRI played a positive role in therapeutic management in 91% of the examinations, it is the method of choice for therapy planning and follow-up of head and neck neoplasm. However, when skull base infiltration is suspected, CT is preferred. MRI provides valuable information to support diagnosis of the disease.

Assessment of survey radiography and comparison with x-ray computed tomography for detection of hyperfunctioning adrenocortical tumors in dogs.

Results of abdominal survey radiography and x-ray computed tomography (CT) were compared in 13 dogs with hyperadrenocorticism histologically attributed to adrenocortical tumors. X-ray computed tomography enabled accurate localization of the tumor in all 13 dogs. Apart from 2 poorly demarcated irregular-shaped and mineralized carcinomas, there were no differences between adenoma (n = 3) and carcinoma (n = 10) on CT images. In 1 dog, invasion of the caudal vena cava by the tumor was suggested on CT images and was confirmed during surgery. Suspicion of adhesions between tumors of the right adrenal gland and the caudal vena cava on the basis of CT images was confirmed during surgery in only 2 of 6 dogs. Survey radiography allowed accurate localization of the tumor in 7 dogs (4 on the right side and 3 on the left). In 6 of these dogs, the tumor was visible as a well-demarcated soft tissue mass and, in the other dog, as a poorly demarcated mineralized mass. The smallest tumor visualized on survey radiographs had a diameter of 20 mm on CT images. Six tumors with diameter less than or equal to 20 mm were not visualized on survey radiographs. In 1 of these dogs, a mineralized nodule was found in the left adrenal region, without evidence of a mass. In a considerable number of cases, survey radiography can provide presurgical localization of adrenocortical tumors in dogs with hyperadrenocorticism; CT is redundant in these instances. In the absence of positive radiographic findings, CT is valuable for localization of adrenocortical tumors.