Biomedical subjects

I F Majesky

Publications and source records attributed to I F Majesky.

5 recordsLinked to original sources

PubMed1987

Computed tomography in advanced ovarian cancer: an evaluation of diagnostic accuracy.

The authors have investigated the diagnostic accuracy of computed tomography (CT) of the abdomen and pelvis in the assessment of patients prior to second-look laparotomy for advanced ovarian cancer. CT studies (read independently by three radiologists) and laparotomy findings were analyzed in 50 patients. Sensitivity varied from 0.30 to 0.65 among the radiologists, specificity from 0.44 to 0.89, positive predictive value from 0.50 to 0.73, and negative predictive value from 0.60 to 0.70. Receiver operator curve analysis of the data indicated poor performance of CT as a diagnostic test. The authors also examined some problems in interpreting their data and that of others in the literature, in particular, the influence of potential sources of bias.

Evaluation Studies as Topic↗

PubMed1986

Computed tomography in advanced ovarian cancer. Inter- and intraobserver reliability.

We have examined the reliability of computed tomography (CT) in the assessment of patients with advanced ovarian cancer. Three radiologists independently read the same set of 140 CT scans. Fifty percent of the films were reread by the same radiologist to assess intraobserver agreement. In addition we assessed variability among radiologists in reporting signs of disease such as a mass and ascites and the variability in reporting a change in signs in response to therapy. Intraobserver agreement on the identification of signs such as a mass and ascites and on overall response to therapy was moderate to excellent (Kappa 0.52-0.84). Agreement among observers on the same signs was not as good (Kappa 0.36-0.79).

Adult↗

PubMed1986

Magnetic resonance imaging of the mediastinum.

Seven normal volunteers and 69 patients with known disease in either the mediastinum or hila or both were imaged using a prototype magnetic resonance imager operating at 0.15T. Normal mediastinal and hilar structures were readily identified and mediastinal diseases were well demonstrated by magnetic resonance imaging (MRI). The value of MRI lies in the morphological demonstration of the presence and extent of disease.

Adult↗

PubMedDate not supplied

Observer variation in abdominal CT.

Observer performance in radiologic interpretation has traditionally been based upon Receiver Operating Characteristic (ROC) analysis. A statistical method that evaluates the reproducibility or consistency of radiologic interpretation is presented. Since this method is not based upon pathologic verification, it cannot be used to assess accuracy of interpretation and is therefore not a substitute for ROC analysis. Rather, it can either supplement ROC analysis or be of use in situations in which the latter is not feasible or practical.

Humans↗

PubMedDate not supplied

Assessment of acute radiation-induced pulmonary changes using computed tomography.

In a prospective study of acute radiation-induced pulmonary changes, CT scans of 54 patients were performed before and at preselected times during the 6 months following fractionated radiation therapy of the thorax. The CT films were evaluated independently by three diagnostic radiologists and 36 patients were scored as having postirradiation pulmonary findings. The average interobserver agreement for this scoring was approximately 85%. The end point was observed as an increase in lung density within the irradiated volume on a follow-up CT examination. All 36 patients demonstrated lung opacities in an irregular, homogeneous, or nonhomogeneous pattern within the radiation beam boundaries. In addition, the following characteristics were observed at various frequencies in these 36 patients: extension of the changes across anatomic tissue boundaries (50%), air bronchograms (25%), loss of lung volume (15%), and pleural thickening (15%). Confinement of the findings within the irradiated volume was the only specific characteristic of postirradiation changes. In two patients the changes appeared as sharply defined, nodular opacities and were considered to be atypical of radiation damage. These were subsequently confirmed to be metastases. Prospective assessment of an adequate number of patients has helped to establish the CT appearance of acute radiation-induced pulmonary effects and, hence, to minimize its confusion with malignancies and other abnormalities.

Adolescent↗