Hüseyin Akan

Comparison of computed tomography and magnetic resonance imaging in the diagnosis of parotid tumors

OBJECTIVE: The role of computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of parotid tumors was investigated. METHODS: Forty patients with the clinical suspicion of a parotid mass underwent both CT and MRI of the parotid region. Two radiologists independently assessed the CT and MRI results with respect to tumor localization, tumor margin characteristics, and infiltration of surrounding tissue. Histopathologic specimens were obtained in all cases and correlated with the radiologic findings. RESULTS: The sensitivity and specificity of CT and MRI were nearly the same for tumor location, tumor margin, and tumor infiltration. CONCLUSION: The 2 imaging techniques provided the same information with respect to the presurgical planning and contribute to the diagnosis and therapy planning of parotid tumors. (Otolaryngol Head Neck Surg 2003;129:726-32.)

Diagnostic Value of Ultrasonography in Temporomandibular Disorders

PURPOSE The purpose of this study was to determine the diagnostic value of ultrasonographic imaging (USI) in temporomandibular disorders. PATIENTS AND METHODS USI and magnetic resonance imaging (MRI) were performed in 182 temporomandibular joints (TMJs) of 91 patients who were referred for treatment. After a detailed clinical examination, patients who were clinically diagnosed with TMJ disc derangement were referred to the radiology department for MRI and USI examinations. USI and MRI diagnoses of disc displacement were compared, using clinical diagnosis as the golden standard. The overall agreement between USI and MRI results was evaluated. RESULTS Compared with the clinical diagnosis, MRI showed a sensitivity of 85%, specificity of 62%, and an accuracy of 80% in the detection of internal derangements. The positive predictable value, negative predictive value, and likelihood ratio were 88%, 54%, and 2.29, respectively. Compared with the clinical diagnosis, USI showed a sensitivity of 69%, specificity of 80%, and accuracy of 71% in the detection of internal derangements. The positive predictable value, negative predictive value, and likelihood ratio were 92%, 42%, and 3.45, respectively. Comparing the agreements between the MRI and USI diagnoses of internal derangement, the κ value was found to be 0.36, indicating poor reliability (P < .001). CONCLUSION USI, a noninvasive and dynamic imaging method, is a reliable method in evaluating the position of the disc in TMJ disc derangements. Better visualization of joint structures and more reliable results with higher sensitivity and accuracy can be achieved with high-resolution devices (≥12 MHz).

Effects of fixed functional appliance treatment on the temporomandibular joint

INTRODUCTION In this study, we tested the hypothesis that fixed functional appliance treatment in a group of Class II Division 1 patients with mandibular retrusion changes the condyle position in the glenoid fossa. METHODS Transverse computed tomography images were taken of the temporomandibular joint region in 60 children with Class II Division 1 malocclusion. Thirty randomly selected patients were treated with a fixed functional orthodontic appliance (Forsus nitinol flat-spring, 3M Unitek Corp, Monrovia, Calif) for 7 months; another 30 patients without treatment were used as controls. Computed tomography images taken at the beginning and end of fixed functional appliance treatment were used for estimating the condyle-glenoid fossa relationship, including the volumes of condyle, glenoid fossa, and anterior and posterior joint spaces. RESULTS Although the volumes of the condyle and glenoid fossa increased more in the study group than in the control group, the differences were not statistically significant. However, statistically significant differences were found between the groups in the volumes of the anterior and posterior joint spaces (P < 0.05). CONCLUSIONS When the volumes of the anterior and posterior joint spaces changed, the condyle was more posteriorly positioned in the glenoid fossa in the study group than in the control group.

Dependence of computed tomography volume measurements upon section thickness: An application to human dry skulls

Estimation of intracranial volume (ICV) using computed tomography (CT) scans has previously been described. However, we were not able to identify a gold standard study that analyzed the effect of section thickness on the estimation of ICV. Therefore, we conducted the present study, scanning five dry skulls in the coronal and axial planes using a multislice CT machine (Toshiba TSX‐101A, Aquilion 16 Slice, Tochigi, Japan). Consecutive sections of variable thicknesses of 2, 3, 5, 7, and 10 mm, respectively, were used to estimate ICV by means of the planimetry method of the Cavalieri principle. All estimations were done by the same observer. However, the estimated volumes did not concur with the actual volumes of the skulls as determined by the fluid displacement technique (P < 0.05). In fact, results revealed that the section thicknesses created over‐ or under‐projection effects for the estimated volumes. The results were analyzed to reveal the deviation principles of the estimates based on section thickness. Prediction formulas were calculated to estimate the deviation percentage of the ICV depending on section thickness and section plane. Ultimately, the results showed that the effect of section thickness on ICV estimates could not be overlooked, but that the values obtained could be corrected using the proposed prediction formulas presented in this study. Clin. Anat. 21:479–485, 2008.

Massive Pulmonary Emboli and CT Pulmonary Angiography

Background: Massive pulmonary embolism (PE) is a devastating form of PE which usually results in acute right ventricular failure and death within 1–2 h. Objectives: To retrospectively assess pulmonary vascular, cardiac, pleural, and parenchymal findings on CT pulmonary angiography (CTPA) in patients with a diagnosis of massive PE (systolic blood pressure <90 mm Hg, syncope and/or shock). Methods: In 33 consecutive patients with proven massive PE, hemodynamic severity was assessed by the extent of right ventricular dysfunction (RVD); diameter of the main pulmonary artery; the shape of the interventricular septum; and the extent of obstruction to the pulmonary arterial circulation (CT obstruction index). Results: Central pulmonary arteries were embolized in all patients. RVD was detected in all patients (94% of them had severe RVD); the diameter of the main pulmonary artery was wider than normal in 76% of the patients; the shape of the interventricular septum was abnormal in all patients, and the CT obstruction index was higher than or equal to 50% in 85% of the patients. Wedge-shaped pleural-based consolidation was the most common parenchymal abnormality (36%). Pleural effusions were seen in 26 patients (79%). Twenty-eight patients were alive, and only the use of thrombolytic therapy was found to be statistically significant. Conclusions: In patients with acute massive PE, embolization of the central pulmonary arteries, RVD and displacement of the interventricular septum are commonly seen with CTPA. A CT obstruction index of >50% is commonly observed in massive PE. There was no association between CTPA findings and survival.

Ultrasound assessment of increased capsular width in temporomandibular joint internal derangements: relationship with joint pain and magnetic resonance grading of joint effusion

OBJECTIVE The relationship between radiologic evidence of effusion in the temporomandibular joint (TMJ) and the occurrence of clinical symptoms (e.g., pain) is still unclear. Increased capsular width (CW) measured in ultrasonographic imaging (USI) of the TMJ was considered to be an indirect marker of TMJ effusion. The purpose of this study was to evaluate the relationship between the grades of magnetic resonance imaging (MRI)-depicted joint effusion (JE), increased CW measured in USI, and joint pain in TMJ internal derangement (ID) patients. STUDY DESIGN During a 4-year period, 91 patients clinically diagnosed with TMJ ID according to the Research Diagnostic Criteria for Temporomandibular Disorders classification were included in the study. Those with mainly myogenic complaints were excluded. In clinical examination, the severity of pain was assessed by visual analog scale (VAS, 0 to 10). All TMJs (n = 182) were evaluated to detect the presence of joint effusion by means of USI and MRI. MRI-depicted effusion was classified as no effusion, moderate effusion, and severe effusion. Receiver operating characteristic curve analysis was performed to depict the critical cutoff value for TMJ CW. USI sensitivity was evaluated by means of MRI effusion, and a cutoff value was depicted that was considered to be the threshold to discriminate the TMJs with and without effusion. The relationship between the joint pain and USI and MRI findings of effusion were evaluated with Friedman and Wilcoxon tests. RESULTS The average VAS scores of the TMJs without effusion was found to be 2.55, with moderate effusion 2.92, and with severe effusion 4.80. A significant positive correlation was found between the VAS scores and the intensity of MRI JE (P = .003). The most accurate cutoff value of CW is found to be 1.65 mm. The average VAS score with CW <1.65 was found to be 2.10 and the average VAS score with CW >1.65 was found to be 3.75. A significant positive correlation was found between the clinical pain scores and CW measured in USI (P = .001). CONCLUSIONS Both MRI-depicted effusion and USI assessment of CW were found to be related to the pain in TMJ ID patients.

Unilateral breast enlargement: a rare complication of subclavian vein catheterization for hemodialysis

Radiologic findings of an unusual uremic case of marked unilateral breast enlargement due to subclavian vein stenosis after subclavian catheterization for hemodialysis are presented.

Ascariasis of the gallbladder: radiological evaluation and follow-up

A 10-year-old boy presented with fever, jaundice, abdominal pain and vomiting. There was hepatomegaly and right upper quadrant tenderness. US identified a dilated gallbladder containing a moving, linear echogenic structure with a central anechoic lumen (Fig.1). Cholangitis secondary to ascariasis was diagnosed. US also showed multiple adult roundworms in the smallbowel lumen. Gallbladder ascariasis was also confirmed by CT and MRI. Ascaris eggs were detected in the faeces. Antibiotic treatment was given, but antiparasitic drugs were not prescribed. Three days later, US showed the Ascaris in the main hepatic duct; after another 4 days, the worm had disappeared from the biliary tree. After antiparasitic treatment had been given, the patient was discharged with no clinical or US abnormality. Adult roundworm invasion into the gallbladder is very rare and accounts for 2.1% of hepatobiliary ascariasis [1]. Worm migration can also result in biliary obstruction [2]. Biliary ascariasis is best shown by US identification of worms inside the biliary tree or gallbladder [3]. US findings include a nonshadowing, long, mobile echogenic strip with central anechoic tube [1]. Cholecystectomy, choledochotomy and other interventions have been used in the treatment of hepatobiliary ascariasis [4]. The motion of the Ascaris can be observed by US and this will indicate whether it is alive or not, an advantage of US over CT and MRI. US is also useful to monitor the progress of the worm in the hepatobiliary system. After the worm returns to the small bowel, it can be effectively treated with antiparasitic drugs. Thus, surgery, other interventions and their complications can be prevented by timing antiparasitic treatment in accordance with the findings of US monitoring.

Preoperative Embolization in Surgical Treatment of a Primary Hemangiopericytoma of the Rib : A Case Report

Primary hemangiopericytoma of the rib is extremely rare and only a few cases have been reported. A 62-yr-old man presented with an aching chest pain and dyspnea. Thoracic computed tomography revealed a homogenous mass expanding the right seventh rib. A diagnosis of hemangiopericytoma was established by percutaneous needle biopsy. Preoperative embolization of the feeding vessels of the tumor was performed in order to prevent perioperative bleeding. There was no significant bleeding during the surgery, where complete resection of the tumor with 7th to 9th ribs with a surgical margin of 5 cm was performed. Postoperative course was uneventful and there has been no recurrence for thirteen months. To our knowledge, there has been no report to apply a preoperative embolization of a primary hemangiopericytoma of the rib.

Investigation of the vertebrobasilar arterial system in vertigo by vestibulocochlear test, SPECT and angiography

OBJECTIVE Perfusion of the areas of cochleovestibular structures was investigated using Tc-99m HMPAO single photon emission computerized tomography (SPECT) in the young patients with vertigo presumed to have peripheral vestibular abnormalities and compared the results with cochleovestibular test results, and vertebrobasilar angiography findings. METHODS AND PATIENTS The study was performed on 20 patients with vertigo and 17 control subjects who had performed vertebral arteriography due to another disease. The patients with vertigo presumed to be on peripheral vestibular disorder were included in the study. Systemic and otorhinolaryngological examination were carried out. Audiovestibular function was evaluated in all patients and control subjects. Brain SPECT was performed with a one-head rotating gamma camera system from 64 projections into a 64x64 matrix, using low energy and high-resolution fan beam collimators with a sampling time of 30 s. The images taken from cerebellum, temporal, parietal and occipital lobes which are supplied by a vertebrobasilar system were compared visually with the other side and asymmetry in the perfusion was searched. After cochleovestibular tests and laboratory had been completed, vertebral arteriography was performed bilaterally in all patients. Results of digital subtraction angiography (DSA) and the vestibulocochlear test were compared with images of SPECT. Data analysis was done with Yates Chi(2) and percentages of sensitivity and specificity were calculated. RESULTS There was vestibular test and cochlear test abnormalities in eight and ten of the patients with vertigo, respectively. SPECT imaging showed hypoperfusion and decreased regional blood flow in 12 of the patients. There was statistically significant differences between the study and control groups in SPECT (P<0.05). Five patients showed abnormal findings in DSA examinations. CONCLUSION It is believed that SPECT may be helpful in the detection of vascular pathology in the patients with vertigo.