Ihsan Yuce

Alveolar Echinococcosis: Spectrum of Findings at Cross-sectional Imaging

Alveolar echinococcosis is a rare parasitic disease caused by the fox tapeworm Echinococcus multilocularis, which is endemic in many parts of the world. Without timely diagnosis and therapy, the prognosis is dismal, with death the eventual outcome in most cases. Diagnosis is usually based on findings at radiologic imaging and in serologic analyses. Because echinococcal lesions can occur almost anywhere in the body, familiarity with the spectrum of cross-sectional imaging appearances is advantageous. Echinococcal lesions may produce widely varied imaging appearances depending on the parasites growth stage, the tissues or organs affected, and the presence of associated complications. Although the liver is the initial site of mass infestation by E multilocularis, the parasite may disseminate from there to other organs and tissues, such as the lung, heart, brain, bones, and ligaments. In severe infestations, the walls of the bile ducts and blood vessels may be invaded. Disseminated parasitic lesions in unusual locations with atypical imaging appearances may make it difficult to narrow the differential diagnosis. Ultrasonography, computed tomography (CT), magnetic resonance (MR) imaging with standard and diffusion-weighted sequences, and MR cholangiopancreatography all provide useful information and play complementary roles in detecting and characterizing echinococcal lesions. Cross-sectional imaging is crucial for differentiating echinococcosis from malignant processes: CT is most useful for depicting the peripheral calcifications surrounding established echinococcal cysts, and MR imaging is most helpful for identifying echinococcosis of the central nervous system.

Comparison of peritoneal tumor imaging using conventional MR imaging and diffusion-weighted MR imaging with different b values

PURPOSE The aim of this study was to evaluate the utility of DW MRI with two different b values in identifying peritoneal tumors in oncology patients. MATERIALS AND METHODS Nineteen patients with known malignancy underwent abdominal and pelvic MRI before surgery. MRI included free-breathing DWI with b values of 400 and 800 s/mm2, T1-weighted fat-suppressed spoiled gradient-echo, T2-weighted fat-saturated turbo spin-echo, and 5-min delayed gadolinium-enhanced imaging. Two observers reviewed images for peritoneal tumors at ten anatomic sites within consensus. The results of laparatomy and histopathological evaluation were compared with MRI results. Sensitivity, specificity, and accuracy of identifying peritoneal metastases were calculated for conventional MRI, combined DWI with a b value of 400 s/mm2 and conventional MRI, and combined DWI with a b value of 800 s/mm2 and conventional MRI by consensus of two observers. RESULTS One-hundred and twenty-five peritoneal metastasis sites were confirmed by surgical and histopathological findings. Conventional MRI alone identified 72 peritoneal metastases (sensitivity, 0.58; specificity, 0.87; accuracy, 0.67). Combined DWI with a b value of 400 s/mm2 and conventional MRI revealed 106 peritoneal metastases (sensitivity, 0.85; specificity, 0.88; accuracy, 0.85). Finally, combined DWI with a b value of 800 s/mm2 and conventional MRI revealed 103 peritoneal metastases (sensitivity, 0.83; specificity, 0.94; accuracy, 0.86). CONCLUSION DWI with a high b value provides complementary information that can improve the detection of peritoneal tumors when combined with conventional MRI. We recommend combined MRI and DWI with a high b value for increasing the sensitivity and accuracy of the preoperative detection of peritoneal tumors.

Follow-up of coronary artery bypass graft patency: diagnostic efficiency of high-pitch dual-source 256-slice MDCT findings.

Objectives Our aim was to evaluate the diagnostic accuracy of 256-slice, high-pitch mode multidetector computed tomography (MDCT) for coronary artery bypass graft (CABG) patency. Methods Eighty-eight patients underwent 256-slice MDCT angiography to evaluate their graft patency after CABG surgery using a prospectively synchronized electrocardiogram in the high-pitch spiral acquisition mode. Effective radiation doses were calculated. We investigated the diagnostic accuracy of high-pitch, low-dose, prospective, electrocardiogram-triggering, dual-source MDCT for CABG patency compared with catheter coronary angiography imaging findings. Results A total of 215 grafts and 645 vessel segments were analyzed. All graft segments had diagnostic image quality. The proximal and middle graft segments had significantly (P < 0.05) better mean image quality scores (1.18 ± 0.4) than the distal segments (1.31 ± 0.5). Using catheter coronary angiography as the reference standard, high-pitch MDCT had the following sensitivity, specificity, positive predictive value, and negative predictive value of per-segment analysis for detecting graft patency: 97.1%, 99.6%, 94.4%, and 99.8%, respectively. Conclusions In conclusion, MDCT can be used noninvasively with a lower radiation dose for the assessment of restenosis in CABG patients.

Ultrasound-guided shoulder MR arthrography: comparison of rotator interval and posterior approach

PURPOSE The purpose of this study was to prospectively evaluate the two different ultrasound-guided injection techniques for magnetic resonance (MR) arthrography of the shoulder. METHODS AND MATERIALS This study included 100 patients [50 rotator interval group (n=50) vs. 50 posterior approach group (n=50)]. All procedures were performed by the same radiologist. The two injection techniques were compared. The discomfort during and after arthrography was evaluated. Extraarticular contrast media extravasation was graded according to the MRI findings. The number of injection attempts, effect of contrast media extravasation rate on diagnostic quality and procedure times were recorded. RESULTS There were no significant difference between the posterior and rotator interval puncture groups with regard to pain (P=.915), procedure times (P=.401) or attempt scores (P=.182). There were significantly more contrast media extravasations with rotator interval approach than posterior approach (P<.05). CONCLUSION Both techniques were successful and well tolerated by patients. Posterior injection technique provided a more effective route with decreased extravasation rate and easier approach compared to the rotator interval approach.

Vici syndrome in siblings born to consanguineous parents

Vici syndrome (OMIM 242840) is a rare syndrome and since its initial description by Vici et al. [1988], only 29 cases have been reported. We describe two brothers from healthy consanguineous Turkish parents with psychomotor delay, congenital bilateral cataracts, high palate, long philtrum, micrognathia, fair hair, and skin. They both had general hypotonia and elevated muscle enzymes. Magnetic resonance imaging (MRI) of the brain confirmed agenesis of corpus callosum in both patients. Secundum type atrial septal defect (in Patient 1) and mild mitral, tricuspid, and pulmonary insufficiency (in Patient 2) were detected by echocardiographic examination. Immunological studies were normal, as were chromosome karyotype analyses (46, XY). Both children had bilateral cutaneous syndactyly between second and third toes and also bilateral sensorineural hearing loss. Patient 1 had poor feeding and regurgitation necessitating a feeding tube; mild laryngomalacia was subsequently detected by bronchoscopy. Mutation analysis in patient 2 showed a homozygous p.R2483* (c.7447C > T) mutation in EPG5 gene. We report a summary of the clinical findings in our patients and 29 cases from the literature.

Efficacy of ivabradin to reduce heart rate prior to coronary CT angiography: comparison with beta-blocker

PURPOSE The objective of our study was to assess the effect of ivabradine on image quality of ECG-gated multidetector computed tomography (MDCT) coronary angiography. MATERIALS AND METHODS Computed tomography coronary angiography (CTCA) was performed on two groups. In Group 1 (n=54), an intravenous beta-blocker was administered to patients with a heart rate >70 beats per minute (bpm) just before CTCA. In Group 2 (n=56), oral ivabradine 5 mg was administered twice a day for three days prior to CTCA examination to patients with a heart rate >70 bpm and contraindication to beta-blockers. Images acquired on two different MDCT scanners were scored in terms of image quality of the coronary artery segments using a 5-point grading scale (Grade 1, unreadable; Grade 5, excellent). RESULTS The mean heart rates during CTCA were 64 ± 6.7 bpm for Group 1 and 59 ± 4.1 bpm for Group 2 (P < 0.05). Mean heart rate reduction was 9 ± 5% and 14 ± 8% for Groups 1 and 2, respectively (P < 0.001). A total of 880 segments were evaluated in 110 patients. When the best reconstruction interval was used, 89.8% and 95.5% of all the coronary segments showed acceptable image quality in Groups 1 and 2, respectively. Acceptable image quality of the middle right coronary artery was obtained in 78.3% of Group 1 and 92.4% of Group 2. These ratios for the other segments were 88.4% for Group 1 and 95.2% for Group 2. CONCLUSION Reduction of heart rates with ivabradine premedication improves the image quality of CTCA. It should be considered as an alternative drug, particularly in patients with contraindications to beta-blockers.

Obturator Hernia, a Rare Cause of Small Bowel Obstruction: Case Report

Obturator hernia is a rare hernia in the world, diagnosed late since it has no specific symptoms and findings and generally occur in thin and old women with comorbidity.For this reason obturator hernia has high morbidity and mortality rates. In this study, we present an obturator hernia case that Howship-Romberg sign is positive and has typical appearance in computerized tomography. Laparotomy was performed on 89 years old female patient with body mass index 18.08 kg/m(2) by low middle line incision. Following the segmentectomy to the strangulated small bowel loop, obturator canal is repaired by retroperitoneal application. No complication occurred in the postoperative period. Obturator hernia should be taken into consideration in old and thin female patients with intestinal obstruction. Computerized tomography should be performed for early diagnosis of the obturator hernia.

Evaluation of Lower-Limb Arteries with Multidetector Computed Tomography Angiography Prior to Free Flap Surgery: A Radioanatomic Study

In this study, we aimed to evaluate the vascular structures of the lower limb with multidetector computed tomography (CT) angiography and to reveal the importance of this method in preoperative planning of microsurgical transplantation. In 24 patients, lower-limb arteries were bilaterally evaluated with 16-detector spiral CT scanner in terms of patency, stenosis, or occlusion; maximal and minimal external diameters through their traces; and variations as well as length of the peroneal artery. The peroneal artery was absent unilaterally in two patients (4.3%). The mean maximal and minimal diameters were as 2.77 and 1.63, 2.92 and 1.75, and 2.72 and 1.50 mm for anterior and posterior tibial and peroneal arteries, respectively. The ranges of lengths of peroneal arteries were 50 to 117 mm. This valuable tool can provide detailed information about vascular and the remaining anatomic structures by means of its high-resolution characteristics before planning free flap surgery.

Age and gender related prevalence of intracranial calcifications in CT imaging; data from 12,000 healthy subjects

PURPOSE Location and extent of intracranial calcifications have been detected accurately with the use of CT technology and since, many clinical or pathological entities have been linked to these calcifications. Our purpose is to provide data regarding the prevalence of calcifications in various locations in brain. MATERIAL AND METHODS We retrospectively examined 11,941 subjects who underwent non-contrast enhanced brain CT examination. We determined the prevalence of choroid plexus, pineal gland, habenula, dura mater, basal ganglia and vascular calcifications. RESULTS Of 11,941 subjects, 70.2% had choroid plexus calcifications. Calcifications were most frequently seen in pineal gland and 71.6% of the study population had pineal calcifications. Habeluna and dural calcifications were present in 19.2% and 12.5% of the population respectively. Basal ganglia calcifications and vascular calcifications only constituted 1.3% and 3.5% of the study population respectively. Male dominance was present in all calcification types except basal ganglia calcifications. CONCLUSIONS Showing associations and dissociations from the literature, our study provides a baseline data regarding the prevalence of various types of intracranial calcifications.

Contrast-Enhanced and Time-of-Flight MR Angiographic Assessment of Endovascular Coiled Intracranial Aneurysms at 1.5 T.

This study evaluated contrast-enhanced magnetic resonance angiography (CE-MRA) and three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) through comparisons with digital subtraction angiography (DSA) for the follow-up of intracranial aneurysms treated with detachable coils. Sixty-seven patients with 79 aneurysms underwent 3D-TOF-MRA, CE-MRA, and catheter angiography one year after coiling. Two independent observers classified recanalization status on images as neck or body remnant or no recanalization. For 3D-TOF-MRA and CE-MRA, the intermodality agreement, interobserver agreement, and correlation with angiography were assessed. Sixty-seven patients with 79 coiled aneurysms agreed to participate in the study. Three aneurysms could not be detected on 3D-TOF-MRA, so they were excluded from this study. Interobserver agreement was very good for 3D-TOF-MRA and CE-MRA (kappa (κ): 0.87, 0.94, respectively). Correlation of TOF-MRA with angiography was good (κ: 0.76). Correlation of CE-MRA with angiography was excellent (κ: 0.91). The sensitivity and specificity of TOF-MRA were 92% and 98%, respectively. The sensitivity and specificity of CE-MRA were 96% and 98%, respectively. After selective embolization of intracranial aneurysms, CE-MRA is useful and comparable to DSA in the assessment of aneurysmal recanalization. Agreement with the gold standard is stronger with CE-MRA than with 3D-TOF-MRA.