Sedat Işik

Computed tomographic evaluation of surgically significant vascular variations related with the temporal bone

Variations of the vascular structures related with the temporal bone may cause important problems in diagnosis, treatment planning and surgery. High resolution computed tomography (CT) scans of 700 temporal bones of 350 patients were retrospectively examined for the incidence of dehiscent jugular bulb, high jugular bulb, diverticulum of jugular bulb, anteriorly located sigmoid sinus and dehiscent internal carotid artery. Dehiscent jugular bulb was seen in 27 (3.9%), high jugular bulb was seen in 142 (20.3%), jugular bulb diverticulum was seen in 55 cases (7.9%). The average distance between external acoustic canal and sigmoid sinus was found to be 13.3 mm and in 12.4% of the cases this distance was < 10 mm. Of 700 temporal bones, 10 (1.4%) showed dehiscent carotid canal. To aid diagnosis, treatment planning and surgery, CT scanning is currently a very reliable tool in determining these conditions. Special attention should be paid to the position of the vascular structures in the preoperative temporal bone CT scans.

Cost‐effectiveness of Computed Tomography in the Evaluation of Patients With Headache

We report a retrospective study to determine the cost‐effectiveness of cranial computed tomogrsphy in patients with headache without neurological finding. Five hundred ninety‐two neurologically normal patients were examined between 1990 and 1993 for the complaint of headache. Examination results were reevaluated from written report and image archive systems. Results were divided into three groups. In group P0, we included patients with normal cranialcomputed tomography findings. In group P1, patients showed some minor pathologies like ischemic or atrophic changes. These findings neither explained the reason for headache nor changed the clinical or therapeutic approach. The third group (P2) was to include patients with gross intracranial pathology like space‐occupying lesions or bleeding. Five hundred forty‐six of 592 patients were in the P0group (92%), and the remaining 46 patients were in the P1group (8%). No patient was found to have serious intracranial pathology detected by computed tomography. Cost of detection of a case with significant pathology was calculated. It is our opinion that computed tomography is an unrewarding technique in the evaluation of patients with chronic headache whose neurological examinations are normal.

Differential diagnosis of solid breast lesions: contribution of Doppler studies to mammography and gray scale imaging.

To assess the role of Doppler sonography when used in conjunction with mammography and gray scale sonography in differentiating solid breast lesions and to find out whether lesion size is a limiting factor for Doppler evaluation.

Benefits of tissue harmonic imaging in the evaluation of abdominal and pelvic lesions

AbstractBackground: We compared tissue harmonic imaging (THI) and conventional ultrasonography to determine whether THI improves image quality and facilitates lesion characterization. Methods: Eighty-nine various abdominal or pelvic lesions in 71 patients(34 men and 37 women; age range = 3–90 years, median age = 52 years) were evaluated with conventional ultrasonography and THI. Examinations were performed with frequencies of 2–5 MHz. All the images were stored on a hard disk and evaluated separately by three radiologists. Results: According to the interpreters, THI improved overall image quality in 67 (74%) to 76 (84%) and lesion characterization in 28 (31%) to 36 (40%) of 89 lesions when compared with conventional ultrasonography. All three observers agreed that image quality and lesion characterization were improved in 62% and 17% of the lesions, respectively. Lesion groups containing five or more lesions were compared for any difference of improvement in overall image quality and lesion characterization. For overall image quality, a significant difference was found (p < 0.05). For lesion characterization, there was no significant difference between groups (p > 0.05). Conclusion: THI improved overall image quality and lesion characterization.

Sonographic demonstration of intestinal involvement in Henoch-Schönlein syndrome

We evaluated the efficacy of intestinal sonography in the diagnosis of gastrointestinal involvement of Henoch-Schönlein syndrome (HSS). Intestinal sonography was performed in 20 children who were clinically diagnosed as HSS and sonographic findings of the intestinal system were reviewed. Out of 20 patients, 10 who suffered from abdominal pain demonstrated sonographic findings consistent with small intestinal involvement (dilatation of intestinal segments, hypomotility, and eccentric thickening of the intestinal wall). Our results reveal that sonography of the intestine may be useful in the evaluation of the involvement of HSS.

Color Doppler imaging in uveitis.

Purpose. To evaluate the vascular hemodynamic changes that can be detected with color Doppler imaging (CDI) in diagnosis, differential diagnosis and prognosis of uveitis with different etiologies including Behçets disease. Methods. Four groups consisting of healthy volunteers, uveitis patients with different etiologies and Behçets disease patients with and without ocular involvement were examined by CDI. Central retinal artery (CRA), posterior ciliary artery (PCA), ophthalmic artery (OA) and central retinal vein (CRV) flow velocities and vascular resistances were measured prospectively by a radiologist blinded to the presence and etiology of uveitis. Results. The peak systolic and end-diastolic velocities in CRA and PCA in Behçets disease with ocular involvement were significantly lower than all other groups (p<0.001). Peak systolic and end-diastolic velocities in CRA were lower than the control group in Behçets disease patients without ocular involvement (p<0.001) but there were no differences in PCA and OA flow velocity (p>0.05). In the uveitis group, CRA and CRV flow velocities were significantly lower than in the control group (p<0.001). Conclusions. According to our results, uveitis in Behçets disease is associated with significant reductions of CRA and PCA flow velocities when compared with other types of uveitis and. healthy subjects. In cases without ocular involvement, CRA flow velocities were lower than the control group, but there were no real differences in the PCA and OA values. This suggests that vasculitic involvement of PCA is more specific to Behçets disease and occurs later in the course of the disease. The results also suggest that it may be possible to detect and follow hemodynamic changes in Behçets disease with CDI before clinical findings of ocular involvement become evident.

TL-201 scintigraphy, mammography and ultrasonography in the evaluation of palpable and nonpalpable breast lesions: a correlative study☆

PURPOSE To determine the feasibility of Tl-201 as a tumor localizing agent in palpable and nonpalpable breast lesions, in comparison with mammography and ultrasonography (US), and to evaluate the contribution of these modalities to each other in obviating biopsy. MATERIALS AND METHODS Seventy-two palpable and nonpalpable breast lesions were prospectively classified as benign, indeterminate, or malignant according to the sonographic and mammographic criteria and were further analyzed with Tl-201 scanning. These classifications were compared with biopsy results. The sensitivity, specificity, accuracy, false positive and false negative rates (FPR, FNR), negative and positive predictive values (npv, ppv) were calculated for each individual modality and combination of modalities to evaluate the contribution of these three techniques to each other. RESULTS Of 72 lesions 52 were histologically malignant and 20 were benign. Overall, mammography was the most sensitive (92%) and Tl-201 was the most specific (75%) of the three modalities. Mammography + Tl combination was the most specific (90%) and accurate (97%) of dual combinations. In mammographically or sonographically indeterminate cases, Tl-201 was much more specific (75% versus 37% for mammography and US) and more accurate (82% versus 36% for mammography and 54% for US) than the other two modalities, and mammography + Tl combination was significantly superior to other dual combinations (87% specific and 91% accurate). Use of Tl-201 scanning as an adjunct to mammography + US combination increased the specificity, ppv, and accuracy rates overall, particularly in mammographically or sonographically indeterminate cases. CONCLUSIONS In mammographically and sonographically indeterminate breast lesions thallium scanning may be offered as a third step of investigation to obviate biopsy.

Clinical significance of acute traumatic intracranial pneumocephalus

Among 1142 patients with head injuries hospitalized in the Neurosurgery Department of Gazi University Medical School during the period between 1979 and 1992, 583 had initial CT scans. A retrospective analysis of these initial CT images revealed intracranial air on admission in only 21 cases. These were classified as acute traumatic intracranial pneumocephalus: a potentially serious complication of head injury.CT scans were re-evaluated so as to reveal whether air was situated in the epidural, subdural, or subarachnoid spaces or intracerebrally; whether associated space-occupying lesions were present; and whether the air bubbles were single or multiple. Clinical data such as the presence of persistant rhinorrhea and/or otorrhea, tension pneumocephalus, severity and type of trauma, and outcome were also assessed to determine the significance of this rare finding.

Transverse Cerebellar Diameter and Transverse Cerebellar Diameter/Abdominal Circumference Index for Assessing Fetal Growth

In a prospective study of 330 pregnant women, measurements of the transverse cerebellar diameter (TCD), abdominal circumference (AC), biparietal diameter (BPD), head circumference (HC) and TCD/AC ratio and HC/AC ratio were obtained using conventional ultrasonography between 16th and 41st weeks of gestation. Measurement of BPD yielded a strong correlation with gestational age (r = 0.9880 and R2 = 0.9761) by cubic regression analysis. The measurement of TCD also had a very close relation with gestational age (r = 0.9767 and R2 = 0.9539). The ratio between TCD and AC was calculated and found to be 0.1436 +/- 0.0106 (SD) which remained fairly constant throughout pregnancy, while the BPD/AC ratio declined. The 5th and 95th percentiles for this ratio were 0.1279 and 0.1603. Ten of eleven fetuses with TCD/AC ratios exceeding 2 SD (0.1648) were found to have asymmetrical intrauterine growth retardation upon neonatal examination. It is demonstrated that both BPD and TCD measurements are reliable techniques that correlate well with gestational age, and the TCD/AC ratio is valuable in identifying babies with asymmetrical intrauterine growth retardation.

Quantitative and qualitative comparison of standard-dose and low-dose pediatric head computed tomography: a retrospective study assessing the effect of adaptive statistical iterative reconstruction.

Objectives Our aim was to assess the effect of adaptive statistical iterative reconstruction (ASIR) on pediatric head computed tomography (CT) examinations. Methods We retrospectively reviewed 305 pediatric head CT examinations. The study population consisted of standard dose (STD, n = 152) examinations reconstructed with filtered back projection and low dose (LD, n = 153) examinations reconstructed with 30% (LD30) and 0% (LD0) ASIR. We compared groups by means of radiation dose, noise measures, and visual grading. Student t test, 1-way analysis of variance test, and Mann-Whitney U test were used for statistical analysis. Results The dose in the LD30 group was significantly lower (29%) than that in the STD group (P < 0.001). The noise in the white matter (P < 0.001), SNR (P < 0.001), and subjective image noise (P = 0.044) was significantly better in the STD group than those in the LD30 group. There was no significant difference between LD30 and STD groups in the sharpness (P = 0.141), diagnostic acceptability (P = 0.079), and artifacts (P = 0.750) and contrast-to-noise ratio (P = 0.718). Conclusions In conclusion, we found that a blend of 30% ASIR in a 16-slice multidetector CT produces diagnostically acceptable pediatric head CT examinations with a 29% less dose.