Clinical Utility Of Computed Tomography Research Articles

Diagnostic Validity of Computed Tomography for HLA-B27 Negative Ankylosing Spondylitis: A Retrospective Study of 209 Patients

Objective: Radiographic sacroiliitis is considered the hallmark of ankylosing spondylitis (AS). However, large interobserver variations make plain radiographic diagnosis of sacroiliitis notoriously difficult. The heterogeneity of HLA-B27 negative AS makes its diagnosis even more challenging. Several reports have shown that sacroiliitis tends to be underestimated using radiography, and that computed tomography (CT) facilitates AS diagnosis in patients with suspected spondyloarthritis. However, no studies have stressed the clinical utility of CT, particularly in the diagnosis of HLA-B27(-) AS. Methods: We retrospectively evaluated 209 HLA-B27(-) patients with chronic lower back pain and suspected AS. Radiography and CT reports were examined and outcomes were compared. Results: Among 408 sacroiliac (SI) joints examined using both radiography and CT, there was agreement between the two methods in the sacroiliitis grading of 82 (20.1%) SI joints. However, sacroiliitis grade using CT was higher in 276 (67.6%) SI joints and lower in 50 (12.3%) SI joints. CT evaluation of SI joints showed that 78.9% of patients met the radiographic sacroiliitis criteria of the modified New York criteria, while only 26% of patients satisfied the criteria for plain radiography. Surprisingly, 117 patients (57.3%), who did not meet the modified New York AS diagnosis criteria for plain radiography met the criteria for CT. Conclusion: CT was sensitive and useful in providing evidence for the diagnosis of AS. We suggest that HLA-B27(-) patients with equivocal plain radiography results and chronic inflammatory lower back pain be examined using CT.

Thoracic Applications of Dual Energy

Computed tomography (CT) is the core imaging modality for the evaluation of thoracic disorders. With the recently developed dual-energy CT (DECT) technique, the clinical utility of CT in the management of pulmonary diseases can be expanded. The most actively investigated principle of dual energy is material decomposition based on attenuation differences at different energy levels. This technique provides two key insights into lung physiology, that is, regional perfusion and ventilation. This functional information is obtained in addition to morphologic information because high-resolution thoracic anatomy is entirely preserved on dual-energy thoracic CT. The second major possibility offered by DECT is virtual monochromatic imaging that represents a new option for standard chest CT in daily routine. In this review, imaging principles and clinical applications of dual-energy thoracic CT are described. Knowledge of the applications of DECT may lead to wider use of this technique in the field of respiratory disorders.

Clinical utility of CT in children with persistent focal chest abnormality

To the Editors: We read with interest the article by Li et al . 1 on the contribution of computed tomography (CT) in determining aetiological diagnosis of noncystic fibrosis (CF) bronchiectasis, and in leading to a change in management. We carried out a prospective study in 50 children (26 males; median age: 7.45 yrs, range: 12 months to 17 yrs) with chronic cough for >3 months and persistent focal chest abnormality on at least two conventional chest radiographs (CCR) made at intervals of ≥3 months. We aimed to assess what additional information CT (alone or combined with clinical findings and further diagnostic tests) provides, and to determine whether gaining such new information influences the clinical management. Sweat test, leukocytes blood count and purified protein derivative test for tuberculosis, electrocardiogram and Doppler echocardiography were normal or negative in all cases. Seven patients were affected by primary ciliary dyskinesia (PCD), five had previously undergone oesophageal atresia repair, three had common variable immunodeficiency and two were affected by Down's …

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.