Search

Purpose: This study compared the sensitivity of two commercial computer-aided detection (CAD) systems in identifying noncalcified pulmonary nodules on low-dose multidetector computed tomography (MDCT) scans by using a double reference standard., Materials and Methods: Three chest low-dose MDCT scans of patients who had undergone lung cancer screening were retrospectively analysed using two distinct commercial CAD systems: LungCAD VC10A, Siemens Medical Solutions (CAD1) and LungVCAR, GE Healthcare (CAD2). The exact location of each finding suggested by each system was recorded by an independent reader according to spatial coordinates (x, y, z). Two panels of experienced thoracic radiologists from two different institutions independently established two reference standards (RS1, RS2) by identifying the true positive findings with spatial coordinates without using CAD. Sensitivity of the two CAD systems, defined by lesionlevel analysis, was tested and sensitivities compared., Results: RS1 identified 34 noncalcified pulmonary nodules, whereas RS2 identified 54. The total number of findings detected by the two CAD systems was 684. CAD1 correctly identified 13/34 nodules (sensitivity 38%) for RS1 and 17/54 (sensitivity 30%) for RS2, whereas CAD2 correctly identified 11/34 nodules (sensitivity 35%) for RS1 and 13/54 (sensitivity 23%) for RS2. Comparison between the two CAD systems did not show a statistically significant difference in terms of sensitivity (p<0.05) for both RS1 (p=0.42) and RS2 (p=0.33)., Conclusions: The two commercial CAD systems had similar sensitivity in detecting noncalcified pulmonary nodules on low-dose MDCT of the chest.

Purpose: To identify characteristic computed tomographic (CT) and computer-derived features of hamartomas manifesting as small pulmonary nodules., Methods: Individuals with a diagnosis of hamartoma were identified among participants in the International Early Lung Cancer Action Program and were included if there thin section CT images that included the entire nodule. The CT findings were reviewed to determine the nodule consistency (solid, part-solid, nonsolid), nodule diameter (average of length and width), shape (round, lobulated, neither) and edge (smooth, not smooth). Computer measures of nodule compactness, sphericity, surface regularity and gradient (change in gray-scale between the nodule and the surrounding parenchyma) were determined. Volume doubling time (VDT) was also determined for those with at least two scans with similar imaging acquisitions., Results: A total of 21 cases of hamartomas that had histologic or cytologic confirmation were identified. The median age was 60 and 12 (57%) were men. Average diameter was 10.7 mm (5-20.7 mm). All were solid in consistency and were described by the radiologist as having either round or lobulated shape with a smooth edge. None had pathognomonic radiologic findings for hamartoma. Computer measures demonstrated that all were compact and spherical, with a regular surface and a sharp margin between the nodule and surrounding parenchyma. Of nine on whom the VDT could be calculated, eight had VDTs longer than 450 days., Conclusion: Both radiologist and computer derived features of small hamartomas suggest a consistent presentation for these lesions which may be helpful in distinguishing them from other types of nodules., (Copyright © 2011. Published by Elsevier Inc.)

We present a case of a urothelial neoplasm arising within a direct bladder hernia in the inguinal canal. Bladder hernias are rarely found preoperatively and are exceptional sites of neoplasm. Spiral computed tomography with gaseous insufflation of the bladder demonstrated the bladder hernia and the extension of the neoplasm in the inguinal canal more accurately than other computed tomographic techniques with nonopacified and iodinated urine.

The evaluation of mural invasion (T) in primary urinary bladder carcinoma is important in the planning of an appropriate surgical or radiochemotherapeutic strategy. Previous investigators using computed tomography (CT) have evaluated the bladder filled with urine, urine opacified with iodinated contrast material, or air insufflation. The purpose of this trial was to establish which of these three techniques was the most accurate by comparing data obtained in postoperative staging (pT). Sixty-five patients with primary bladder cancer were enrolled, all of whom were studied by spiral CT with these three techniques. Patients were assigned to four stage groups: Ta-T1, T2-T3a, T3b, and T4. The results demonstrated total accuracies of 95% for the air-insufflated bladder, 90.5% for opacified urine, and 87% for noncontrast studies. In conclusion, the air-insufflated bladder is the more accurate technique in the evaluation of the T parameter in primary bladder cancer, especially in the first and third stage groups.

Spiral CT allows rapid data acquisition in an entire anatomical region during a single breath-hold and permits to obtain 2D and 3D reconstructions with good diagnostic accuracy. We investigated the capabilities of spiral CT reconstructions in demonstrating esophageal cancers. Spiral CT was performed in 10 patients with esophageal cancers and in 3 patients who underwent endoprostheses placement with surgical or interventional procedures. Bidimensional (MPR, CPR, MIP) and three-dimensional reconstructions with Shaded Surface Display (SSD) were obtained at the end of each exam. In the analysis of the results, CT reconstructions were compared with previous barium esophagography. Some of the main semiologic patterns were considered: tumor visualization, longitudinal extent of the neoplasm and its relationships with adjacent structures. MPRs were obtained in 9 patients and allowed to visualize the esophageal lumen with a filling defect, the neoplastic mass and its longitudinal and extraluminal extent. SSD reconstructions was obtained in 7 patients and allowed a good assessment of longitudinal neoplasm extent in 6 patients. Neoplastic mass visualization and extraluminal tumor extent were difficult to assess in all cases. MIP reconstructions were obtained in all patients and demonstrated longitudinal neoplasm extent with good accuracy. Neo-plastic tissue was visualized only indirectly through the filling defect of the esophageal lumen. MIP allowed to define, in 5 patients, the relationships of the neoplasms with adjacent vascular structures after the intravenous administration of contrast agent. In conclusion, we consider that Spiral CT reconstructions can be useful for a more accurate staging of esophageal cancers.

Thirty-three patients with ovarian carcinoma who had no evidence of metastases or ascites demonstrated on computed tomography (CT) with and without contrast agent were examined with CT after injection of approximately 3000 cc of a 2.4% solution of nonionic contrast media into the peritoneum. After intraperitoneal injection with CT (IPC CT), 22 were diagnosed as having intraperitoneal metastases. Of these, 19 were found to be true positives and 3 false negatives. Three other patients diagnosed as normal were found to have metastases. In all patients the peritoneum was well outlined and generally any metastases smaller than 1 cm were demonstrated. It was possible to identify compartmentalization of the peritoneum and to determine the location of the lesion to be in the peritoneum or the extraperitoneal space. This information is necessary in the planning of chemotherapy, particularly endoperitoneal chemotherapy. Tiny metastases to the omentum or adherent loops of small bowel could not be seen well.