Single-center study comparing computed tomography colonography with conventional colonoscopy.

AIM: To compare the results from computed tomography (CT) colonography with conventional colonoscopy in symptomatic patients referred for colonoscopy. METHODS: The study included 227 adult outpatients, mean age 60 years, with appropriate indications for colonoscopy. CT colonography and colonoscopy were performed on the same day in a metropolitan teaching hospital. Colonoscopists were initially blinded to the results of CT colonography but there was segmental unblinding during the procedure. The primary outcome measures were the sensitivity and specificity of CT colonography for the identification of polyps seen at colonoscopy (i.e. analysis by polyp). Secondary outcome measures included an analysis by patient, extracolonic findings at CT colonography, adverse events with both procedures and patient acceptance and preference. RESULTS: Twenty-five patients (11%) were excluded from the analysis because of incomplete colonoscopy or poor bowel preparation that affected either CT colonography, colonoscopy or both procedures. Polyps and masses (usually cancers) were detected at colonoscopy and CT colonography in 35% and 42% of patients, respectively. Of nine patients with a final diagnosis of cancer, eight (89%) were identified by CT colonography as masses (5) or polyps (3). For polyps analyzed according to polyp, the overall sensitivity of CT colonography was 50% (95% CI, 39%-61%) but this increased to 71% (95% CI, 52%-85%) for polyps > or = 6 mm in size. Similarly, specificity for all polyps was 48% (95% CI, 39%-58%) increasing to 67% (95% CI, 56%-76%) for polyps > or = 6 mm. Adverse events were uncommon but included one colonic perforation at colonoscopy. Patient acceptance was high for both procedures but preference favoured CT colonography. CONCLUSION: Although CT colonography was more sensitive in this study than in some previous studies, the procedure is not yet sensitive enough for widespread application in symptomatic patients.

Multiplanar reconstructed computed tomography images improves depiction and understanding of the anatomy of the frontal sinus and recess.

AIMS: The use of multiplanar reconstructed computed tomography (CT) images of frontal recess and sinuses was assessed with regard to depiction and understanding of anatomy and effect on surgical approach. MATERIALS AND METHODS: Three otorhinolaryngologists and one radiologist read CT scans of 43 patients referred for routine paranasal sinus scans. Spiral (helical) CT scans were obtained and coronal and parasagittal reconstructions were imaged. Three hundred forty-two readings were analyzed. The scans were assessed in the coronal plane and then in the parasagittal plane. The images were assessed for (i) Bent and Kuhn classification of frontal ethmoidal sinus air cells, (ii) size of frontal sinus ostium (assessed as unsure, normal, small, or large), (iii) use of parasagittal scans regarding additional understanding of the anatomy with particular reference as to how the agger nasi cell and frontal ethmoidal cells were arranged in a three-dimensional space, and (iv) if the parasagittal scan and subsequent three-dimensional picture created altered the surgical approach. The first two criteria were assessed in the coronal plane and then in the parasagittal plane. RESULTS: There was no statistically significant difference between the Bent and Kuhn classification of frontoethmoidal cells on coronal and reconstructed parasagittal images (t-test; p > 0.05). The parasagittal scans were significantly better than the coronal scans for identifying and assessing the size of the frontal sinus ostium (p < 0.001; chi-square test). Assuming an intraobserver change rate (repeat error) of 10% on CT scan observations, an exact binomial test was performed on S-PLUS, which showed that there was a significant (p < 0.001) proportion of observers who changed their rating after looking at the parasagittal scan. There also was significant improvement in observers' abilities to identify and classify the size of the frontal ostium as reflected by the number of observers who changed from being unsure on the coronal scans to sure on the parasagittal scans. Observers felt that the parasagittal scans improved their three-dimensional understanding of the anatomy of the frontal recess by 58% on a 10-point Lickert scale. In 55% of these observations, the surgical plan was altered by a mean of 70.2% on a 10-point Lickert scale based on additional information obtained by viewing the parasagittal scans. CONCLUSIONS: The three-dimensional understanding of the frontal recess is improved greatly by using both coronal and parasagittal reconstructed images as compared with coronal images alone. This had important implications on the planning of the surgery in the frontal recess.