Cem Hurcan

Appropriate interslice gap for screening coronal paranasal sinus tomography for mucosal thickening

The objective of this study was to establish the appropriate interslice gap for screening coronal paranasal sinus tomography to identify sinus mucosal thickening. We reviewed 100 coronal paranasal sinus tomographic scans (interslice gap, 2 mm) that had been performed at our institution between January 2004 and November 2004 to evaluate rhinosinusitis. Digital photographs of all slices from each tomographic scan were taken. The intervening slices were eliminated to form six different sets of interslice gaps of 4, 6, 8, 10, 16, and 20 mm. The remaining slices for each set were moved to corresponding folders created on a computer to catalog each interslice gap. The same specialist evaluated each folder of interslice gap. The paranasal sinuses, the ethmoid infundibulum, and the frontal recess were evaluated for mucosal thickening. The sensitivity, specificity, and accuracy of each interslice gap in detecting mucosal thickening were calculated by accepting the results of 2-mm-thick slices as the gold standard. The interslice gap of 2 mm was compared with that of other interslice gaps using the chi-square test for dependent groups (the McNemar test). The value of 20 mm interslice gap in detecting sinus mucosal thickening was found to be significantly low when compared with the interslice gap of 2 mm (P = 0.022). Using coronal paranasal sinus tomography, an interslice gap up to 16 mm may be used to detect sinus mucosal thickening.

Three-slice computerized tomography for the diagnosis and follow-up of rhinosinusitis

Plain sinus radiography is the imaging technique most frequently used to investigate suspected rhinosinusitis, but it has low diagnostic sensitivity. Contiguous paranasal computerized tomography (CT) gives detailed information about the pathology, anatomy and anatomical variations of the paranasal sinuses, but this method also has limitations. The cost of using this technique for all cases of suspected rhinosinusitis is prohibitive, and complete CT scans involve considerable radiation exposure. The aim of this study was to devise a CT protocol for diagnosing and following rhinosinusitis that is more economical and involves much less radiation exposure than contiguous CT. In this retrospective study, three physicians independently reviewed the contiguous coronal paranasal CT studies of 136 patients. The study population comprised the adult patients who were investigated for suspected chronic rhinosinusitis. All scans had been obtained at the second visit, after the patient had completed a 3-week course of medical treatment. For each case, the same three slices were selected to form the “three-slice CT” exam, and the same physicians independently evaluated this set. Using the results from the contiguous set as the gold standard, we calculated the sensitivity and specificity of three-slice CT for identifying rhinosinusitis. The sensitivity and specificity of three-slice CT for identifying inflammatory sinus disease were 95.1 and 92.6%, respectively. Three-slice CT is a valuable method for diagnosing and following rhinosinusitis cases, and would be cheaper and involve less radiation exposure than contiguous coronal CT. However, despite the high cost and greater radiation exposure, contiguous CT remains the gold standard for evaluating detailed sinus anatomy and disease progression.

Color Doppler Analysis of Vertebral Arteries Correlative Study With Angiographic Data

Objective. Color Doppler ultrasonography is the most widespread diagnostic procedure in obstructive disease of the arteries supplying the brain. To our knowledge, there are only a few correlative color Doppler ultrasonographic and angiographic studies of the vertebral arteries, especially in patients who have flow‐restrictive stenosis at the carotid bifurcation. The main purpose of this prospective study was to evaluate diameter, flow volume, and time‐averaged mean velocities of angiographically verified normal vertebral arteries without collateral flow. The second purpose was to try to establish a threshold value for the flow volume of the vertebral artery. Methods. One hundred twenty patients referred for carotid angiography with a normal vertebrobasilar system and with no patent posterior communicating arteries were investigated with color Doppler ultrasonography. Luminal diameter, time‐averaged mean velocity, peak systolic velocity, and flow volume values were calculated for each patient. The parameters were compared between sexes, in different age groups, in patients with carotid stenosis of 50% or less and greater than 50%, and in patients who had clinical signs of vertebrobasilar insufficiency versus those who had not. Results. We have found no significant difference in evaluated parameters with the degree of associated carotid stenosis or vertebrobasilar insufficiency. Diameter and flow volume values on the left side were higher than on the right side. Conclusions. We found similar flow volume values of vertebral arteries in both sexes and both groups of patients with carotid stenosis of 50% or less and greater than 50%. All parameters did not differ in patients with stenosis of 50% or less and greater than 50% and in patients with and without clinical signs of vertebrobasilar insufficiency.

The role of standing flexion-extension radiographs for spondylolisthesis following single level disk surgery.

Abstract Objectives: Spondylolisthesis is the forward displacement of a lumbar vertebra relative to the adjacent vertebra, occurs as result degeneration or surgery and is a special type of lumbar instability. There is no consensus about which radiologic modality or findings truly reflect the lumbar instability and the exact incidence after single level disk surgery is unknown. Methods: In this prospective study, we have included 90 patients who were operated by the same surgeon with single level disk herniation. We aimed at evaluating the post-operative lumbar spondylolisthesis, with flexion and extension lateral radiographs in addition to standard magnetic resonance imaging (MRI). Results: We have seen spondylolisthesis in six of 90 cases with standing lateral flexion-extension radiographs, which were undefinable with MRI. Pain intensity and functional-economic rating scale (Prolo scale) were unremarkable. Discussion: We have concluded that standing flexion-extension radiographs should be routinely combined in patients with failed back surgery syndrome and even if lumbar instability is clinically suspected, especially when conventional MR examination is normal. When the MR examination showed spondylolisthesis, standing flexion-extension radiographs could not give additional information.