Virtual Endoscopy Using Spiral CT in Patients with Carcinomas of the Hypopharynx and Larynx

PURPOSE: To compare the usefulness of virtual endoscopy using spiral CT with that of laryngoscopy in the detection and evaluation of laryngeal and pharyngeal carcinomas. MATERIALS AND METHODS: Twenty-four patients with pathologically proven laryngeal and pharyngeal carcinomas underwent laryngoscopy and virtual endoscopy using spiral CT. Eleven of the carcinomas were supraglottic, five were glottic, and eight were hypopharyngeal. Source images obtained by spiral CT were transmitted to an independent workstation and virtual endoscopic images were obtained using Navigator software. These were graded according to their quality (good, fair, bad), and were interpreted by two radiologists who were blinded to the conventional endoscopic findings. These latter were subsequently compared with the virtual endoscopic findings in terms of similarity to laryngoscopic examination and detectability of lesions. RESULTS: The overall image quality of virtual endoscopy was good in 16 cases (67%), fair in eight (33%), and bad in no case. Among the 11 supraglottic carcinomas, image quality was good in seven cases (64%), and fair in four (36%). In four of the five glottic carcinomas (80%) quality was good, and in one case (20%) it was fair, while among the eight hypopharyngeal carcinomas, quality was good in five cases (63%), and fair in three (37%). Overall, detection of the lesion was possible in 23 cases (96%). Due to the small size of the lesion, the CONCLUSION: Virtual endoscopy using spiral CT is a safe and noninvasive method, and also successfully detects laryngeal and pharygenal lesions, with good image quality. For the evaluation of laryngeal and hypopharyngeal carcinoma, its use may complement that of axial CT.

The Usefulness of CT and MR Virtual Colonoscopy in the Evaluation of Experimental Polyp Models

PURPOSE: The purpose of this study was to evaluate the diagnostic accuracy of CT and MR virtual colonoscopy using an experimental model of colonic polyposis. MATERIALS AND METHODS: Eleven pig colons ranging from 15 to 20cm in length were cleansed and a total of 99 variable sized polyps ranging from 3 to 15mm in diameter were created. The polyps were divided into three groups according to size: <5mm(n=23), 5-9mm(n=44), and ?10mm(n=32) in diameter. Each specimen was scanned using spiral CT and MRI. Each CT and MR virtual colonoscopy was independently evaluated by two radiologists blinded to the location, size and numbers of polyps, but aware that polyps were present. Interobserver agreement regarding the detection rate of the polyps during the two types of virtual colonoscopy was measured and the diagnostic accuracy of CT and MR virtual colonoscopy was compared. Results: In both CT and MR virtual colonoscopy, the detection rates determined by the two radiologists coincided in all three groups(p<0.05). The detection rates of polyps less than 5mm, between 5 and 9mm, and 10mm or larger in diameter were 74%(17/23), 89%(39/44), and 100%(32/32), respectively, in CT colonoscopy, and 61%(14/23), 89%(39/44), and 100%(32/32), respectively in MR colonoscopy. In polyps 5mm or larger, the results of the two types of virtual colonscopy coincided but in those less than 5mm in diameter, the results of MR virtual colonoscopy were slightly inferior to those of CT colonoscopy. Conclusion: Both CT and MR virtual colonoscopy provide high detection rates of colonic polyps 5mm or larger in diameter and these techniques can therefore be used to diagnose colonic mass lesions.

The Usefulness of CT and MR Virtual Colonoscopy in the Evaluation of Experimental Polyp Models

PURPOSE: The purpose of this study was to evaluate the diagnostic accuracy of CT and MR virtual colonoscopy using an experimental model of colonic polyposis. MATERIALS AND METHODS: Eleven pig colons ranging from 15 to 20cm in length were cleansed and a total of 99 variable sized polyps ranging from 3 to 15mm in diameter were created. The polyps were divided into three groups according to size: <5mm(n=23), 5-9mm(n=44), and ?10mm(n=32) in diameter. Each specimen was scanned using spiral CT and MRI. Each CT and MR virtual colonoscopy was independently evaluated by two radiologists blinded to the location, size and numbers of polyps, but aware that polyps were present. Interobserver agreement regarding the detection rate of the polyps during the two types of virtual colonoscopy was measured and the diagnostic accuracy of CT and MR virtual colonoscopy was compared. Results: In both CT and MR virtual colonoscopy, the detection rates determined by the two radiologists coincided in all three groups(p<0.05). The detection rates of polyps less than 5mm, between 5 and 9mm, and 10mm or larger in diameter were 74%(17/23), 89%(39/44), and 100%(32/32), respectively, in CT colonoscopy, and 61%(14/23), 89%(39/44), and 100%(32/32), respectively in MR colonoscopy. In polyps 5mm or larger, the results of the two types of virtual colonscopy coincided but in those less than 5mm in diameter, the results of MR virtual colonoscopy were slightly inferior to those of CT colonoscopy. Conclusion: Both CT and MR virtual colonoscopy provide high detection rates of colonic polyps 5mm or larger in diameter and these techniques can therefore be used to diagnose colonic mass lesions.

Utility of Multiplanar Reformation Images of Helical CT in the Evaluation of Pancreatic Diseases

PURPOSE: The purpose of this study is to assess the clinical utility of multiplanar reformation images of helical CT in the evaluation of pancreatic diseases. MATERIALS AND METHODS: Helical CT scans of the pancreas were obtained in 30 patients with pancreatic diseases. Helical CT was performed with 5mm collimation at 5mm/sec table speed during rapid injection of intravenous contrast agent using power injector. After scanning, helical volume data were reconstructed at 2mm interval and then multiplanar reformation of the pancreas and adjacent structures was done. In both prospective reconstructed axial images and multiplanar reformation images, detection of pancreatic lesion, extent of lesion, and vascular and bile ductal changes were analyzed with a grading system of 1,2, 3. RESULTS: The mean grade of detection of pancreatic lesions was 2.37 in the prospective axial image and 2.83 in multiplanar reformation image, extent of diseases was 2.40 in prospective axial image and 2.97 in multiplanar reformation image, and vascular and bile ductal changes was 2.00 in the prospective axial image and 2.97 in multiplanar reformation image. All the differences were statistically significant (P<0.0001). CONCLUSION: Multiplanar reformation images of helical CT are useful in the evaluation of pancreatic diseases and especially in the demonstratibn of complex anatomic relationships between the pancreas and surrounding structures.

MR Findings of Congenital Craniocerebral Anomaly: Correlation with Seizures and Developmental Delay

PURPOSE: To evaluate characteristic MR findings of craniocerebral anomaly and its relationship with neurologic manifestations. MATERIALS AND METHODS: We retrospectively reviewed MR images of 36 patients with craniocerebral anomaly diagnosed by MRI and clinical courses. We correlated the characteristic MR findings in 41 lesions with neurologic manifestastions focusing on seizures and developmental delay. RESULTS: Twenty-three patients with seizures consisted of 14 patients(60%) with neuronal migration disorders and seven(30%) with phakomatosis, among which 18 patients(78%) had generalized type of seizures. Locations of the lesions were the parietal lobes in 11 patients(52%) and the subependymal or periventricular regions in seven(33%). Two patients with tuberous sclerosis had the lesions in both parietal and subependymal areas. Nine patients had the signs of developmental delay that were seen in the four(44%) with schizencephaly, two (22%) with tuberous sclerosis, two(22%) with heterotopia, and one(ll %) with pachygyria. CONCLUSION: Neuronal migration anomaly was relatively common lesion that presented neurologic manifestations such as seizures and developmental delay. Generalized type of seizures was common. We were able to diagnose these anomalies using the MRI that helped establish therapeutic plans.