Mecit Kantarci

Detection of myocardial bridging with ECG-gated MDCT and multiplanar reconstruction.

OBJECTIVE The aim of this study was to evaluate the incidence of myocardial bridging in 626 patients examined with MDCT angiography of the coronary arteries. MATERIALS AND METHODS Six hundred twenty-six patients who were referred to Florence Nightingale and Atatürk University Hospitals were involved in this study. These patients had atypical chest pain, symptoms suggestive of coronary artery disease, or no significant cardiac complaint. Patients were in sinus rhythm and were premedicated with metoprolol tartrate (5 mg/mL IV bolus) to decrease the heart rate and nitroglycerin (5 mg sublingual 1 min before the examination) to dilate the coronary arteries. MDCT was performed on two different 16-MDCT scanners. RESULTS Among the 626 patients, 22 cases (3.5%) of myocardial bridging were detected. Fifteen cases of myocardial bridging (2.4%) were located at the middle third of the left anterior descending coronary artery (LAD), five (0.8%) were at the distal third of the LAD, and two (0.3%) were at the proximal third of the LAD. In these patients, the length of tunneled artery was between 6 and 22 mm, with a mean of 17 mm, and the depth of tunneled artery was between 1.2 and 3.3 mm, with a mean of 2.5 mm. CONCLUSION We found the incidence of myocardial bridging in this patient group to be 3.5%. This result is in agreement with some of the angiographic studies in the literature. Our study showed that MDCT is a reliable and noninvasive tool for diagnosing coronary myocardial bridging. After evaluating resource axial images, it is necessary to also evaluate the sagittal multiplanar reconstruction images for myocardial bridging.

Importance of Anatomical Asymmetries of Transverse Sinuses: An MR Venographic Study

Time-of-flight (TOF) magnetic resonance venography (MRV) is often used to examine the intracranial dural sinuses, particularly in the evaluation of dural sinus thrombosis. The goal of the study was to evaluate the use of TOF MRV in assessing the normal anatomy of dural sinuses and their variations as sources of potential pitfalls in the diagnosis of venous sinus thrombosis. Cerebral TOF MRV obtained in 105 persons with normal MR studies were reviewed to determine the presence, aplasia and hypoplasia of the transverse sinuses. Twenty-one (20%) aplasias of the left sinus, 41 (39%) hypoplasia of the left sinus, 33 (31%) symmetric, 6 (6%) hypoplasia of the right sinus, and 4 (4%) aplasias of the right sinus cases were determined in the asymmetry in sizes of transverse sinuses. These results suggested that transverse sinus flow gaps or aplasias can be observed in approximately 24% of normal population on MR imaging. The rate of these gaps in normal subjects must be kept in mind because it can be a source of misdiagnosis in cases of suspected dural sinus thrombosis.

Remarkable anatomic anomalies of coronary arteries and their clinical importance: a multidetector computed tomography angiographic study.

Objective: An anomalous origin and course of the coronary arteries can be benign or life threatening. Recently, because of new advances in computed tomography technology, radiologists have begun to interpret the diseases of coronary arteries. We aimed to demonstrate some remarkable anomalies of coronary arteries, some of which were not shown by multidetector computed tomography (MDCT) coronary angiography previously, and to discuss the clinical importance of these anomalies. Materials and Methods: Seven hundred twenty-five consequent patients referred to Florence Nightingale Hospital and Atatürk University Hospital for MDCT coronary angiography were included in this study. The patients were between the ages of 33 and 78 years (mean ± SD, 59 ± 13.86 years). Four hundred ninety-seven patients (68.6%) were men, and 228 (31.4%) were women. All the examinations were evaluated by both a radiologist and a cardiologist. Results: The incidence of anomalous anatomical origin and course of the coronaries found in our study group was 5.79% (n = 42). The anomalies found in our study are absence of the right coronary artery (RCA; n = 1, 0.13%), ectopic origin of RCA from the left anterior descending (LAD) artery (n = 1, 0.13%), absence of the left main coronary artery (n = 4, 0.52%), ectopic origin of the left main coronary artery from the right sinus of Valsalva (n = 1, 0.13%), double LAD and ectopic origin of LAD from RCA (n = 1, 0.13%), ectopic origin of the left circumflex artery from the right sinus of Valsalva (n = 3, 0.39%), ectopic origin of the left circumflex artery from RCA (n = 2, 0.26%), and myocardial bridging (n = 29, 4%). Conclusions: An anomalous origin of the coronary anatomy must be present in the interpretations because of its importance for patients, cardiologists, and surgeons. As a conclusion, our study showed that MDCT, especially volume rendering and maximum intensity projection techniques, may be useful for assessment of complex variations, when the conventional angiography may not be sufficient.

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.

Diagnostic performance of diffusion-weighted MRI in the detection of nonpalpable undescended testes: comparison with conventional MRI and surgical findings.

OBJECTIVE The aim of this feasibility study was to evaluate the role of diffusion-weighted MRI in the evaluation of nonpalpable undescended testes. MATERIALS AND METHODS Thirty-six boys with undescended testes underwent preoperative abdominal and pelvic MRI to identify the location of the testes. MRI included free-breathing diffusion-weighted imaging (DWI) with b values of 50, 400, and 800 s/mm(2), a T1-weighted turbo spin-echo sequence, and a T2-weighted fat-suppressed turbo spin-echo sequence. After laparoscopic examinations, two observers independently reviewed the preoperative images. The DW images alone were reviewed first, followed by the conventional MR images alone and the conventional MR and the DW images together. The laparoscopic and MRI findings were compared. Sensitivity, specificity, and accuracy in the identification of nonpalpable undescended testes were calculated for DWI, conventional MRI, and the combination of DWI and conventional MRI. RESULTS The combination of DWI and conventional MRI was the most sensitive and most accurate technique. Observer 1 found 31 undescended testes, and observer 2, 30 testes with this technique. Sensitivity was 0.91 and 0.88 for observers 1 and 2, and accuracy was 0.92 and 0.86. With DWI alone, observer 1 located 30 testes, and observer 2, 28 testes (sensitivity, 0.88 and 0.82; accuracy, 0.86 and 0.81). Using conventional MRI alone, both observers located 29 testes (sensitivity, 0.85; accuracy, 0.86 and 0.84). The accuracy of locating testes was superior with the combination of DWI and conventional MRI for both observers (accuracy, 0.92 and 0.86). An intraabdominal atrophic testis managed by laparoscopic orchiectomy was found by neither observer with DWI or with conventional MRI. CONCLUSION Use of DWI with a high b value yields information that complements conventional MRI findings, improving identification and location of nonpalpable undescended testes. We recommend the use of conventional MRI in addition to DWI to increase the preoperative sensitivity and accuracy of identifying and locating nonpalpable testes.

Retroaortic left renal vein: multidetector computed tomography angiography findings and its clinical importance.

Purpose: To evaluate the appearance, type, frequency, and clinical importance of retroaortic left renal vein (RLRV) in patients examined with multidetector computed tomography (MDCT) angiography. Material and Methods: A total of 1856 patients who underwent CT with urological symptoms (hematuria, flank and abdominal pain, left gonadal vein varicocele) (n = 889) or with symptoms other than urological ones (n = 967) were prospectively evaluated for the presence of RLRV. CT was performed with 110 ml of iodinated contrast material through the antecubital vein at a rate of 3.5 ml/s. Late arterial and early venous phase volumetric data sets were acquired at 30 and 65 s, respectively, from the start of the intravenous injection of contrast medium. In addition to axial images, multiplanar reconstructions (MPR), maximum-intensity projection (MIP), and three-dimensional volume-rendering (3D VR) images were used to assess left renal vein anomalies. Left renal vein anomalies were classified into four types according to their appearance: I) RLRV joining the inferior vena cava (IVC) in the orthotopic position; II) RLRV joining the IVC at level L4–L5; III) circumaortic or collar left renal vein; IV) RLRV joining the left common iliac vein. Results: RLRV was detected in 68 (3.6%) of the 1856 patients, with 26, 22, 17, and three of types I, II, III, and IV, respectively. Forty-four of the 68 patients with RLRV (65%) were in the group with urological symptoms, while 24 patients (35%) were in the group without urological symptoms. Compression of the RLRV was found in 16 patients in the urological symptoms group, while compression was detected in only three patients in the other group. This difference was statistically significant (P<0.05). The most common urological symptom was hematuria. The frequency of urological symptoms was higher in groups II and IV compared to the other groups. Conclusion: MDCT angiography with axial, MPR, MIP, and 3D VR images is effective in the detection of vascular renal anomalies such as RLRV. Diagnosing RLRV and differentiating it from other pathologic conditions causing hematuria is important in order to avoid complications during retroperitoneal surgery or interventional procedures.

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.

Angulation, Length, and Morphology of the Styloid Process of the Temporal Bone Analyzed by Multidetector Computed Tomography

Purpose: To investigate the angulation, length, and structural variations of the styloid process (SP) by multidetector computed tomography (MDCT). Material and Methods: MDCT scans were performed in 283 cases (127 M and 156 F, age range 18–77 years). The length of the SP and its angulation on the transverse and sagittal planes were measured. Structural variations of the SP were observed by means of three-dimensional (3D) and multiplanar reconstruction (MPR) images. Results: The length of the bony SP on both sides varied from 0 to 62 mm (mean 26.8±10.0 mm). Angulation ranged between 55° and 90.5° (7 2.7±6.6) in the transversal plane and between 76° and 110° (93.5±6.9) in the sagittal plane. Morphologically, the SP showed a considerable amount of variation. A solitary SP was present in 168 individuals (59.4%). In 9 individuals (3.1%), the SP was duplicated (4 unilateral and 5 bilateral). Sixty-one persons (21.6%) showed an incomplete ossified SP (42 unilateral and 19 bilateral), whereas in 7 individuals (2.5%) a bony SP was absent entirely (7 unilateral). In 38 individuals (13.4%), the stylohyoid ligament was ossified (16 entirely, 22 partial). In all individuals, 3D and MPR images showed the SP in its entire length. Conclusion: MDCT with 3D CT and MPR of SP may show further detailed information related to SP. Not only the length of the SP, but also its 3D orientation, should be in focus in anatomical and clinical studies.

Diffuse pneumocephalus associated with infratentorial and supratentorial hemorrhages as a complication of spinal surgery.

A 23-year-old woman was transferred to our department with loss of consciousness 6 h after undergoing rod placement for thoracolumbar scoliosis. Both computed tomography and magnetic resonance imaging of the brain revealed diffuse pneumocephalus and infra- and supratentorial hemorrhages. The pedicular screw tracts were analyzed with computed tomography and misplacement of a screw was noticed. It was thought that inadvertent dural injury had occurred at the time of insertion. The patient was re-operated and the dural tear was repaired. To our knowledge, this is the first description of these uncommon complications in one patient after spine surgery.

The feasibility of dual-energy CT in differentiation of vertebral compression fractures

OBJECTIVE To prospectively evaluate the ability of dual-energy CT (DECT), compared with MRI, to identify vertebral compression fractures in acute trauma patients. METHODS This institutional review board-approved study included 23 consecutive patients with 32 vertebral fractures who underwent both DECT and MRI of the spine between February 2014 and September 2014. A total of 209 vertebrae were evaluated for the presence of abnormal bone marrow attenuation on DECT and signal on MRI by five experienced radiologists. The specificity, sensitivity, predictive values and intraobserver and interobserver agreements were calculated. RESULTS MRI revealed a total of 47 vertebrae (22.4% of all vertebrae) and DECT revealed 44 vertebrae (21.0% of all vertebrae) with oedema. Using MRI as the reference standard, DECT had sensitivity, specificity, positive-predictive value, negative-predictive value and accuracy of 89.3, 98.7, 95.4, 96.9 and 96.6%, respectively. With respect to establishing the presence of oedema, the interobserver agreement was almost perfect (k = 0.82), and the intraobserver agreement was substantial (k = 0.80). CONCLUSION Compared with MRI, DECT can provide an accurate demonstration of acute vertebral fractures and can be used as an alternative imaging modality for the assessment of vertebral fractures in patients with contraindications for MRI. ADVANCES IN KNOWLEDGE Distinguishing of acute and chronic vertebral compression fracture is important for treatment choices. DECT is very fast compared with MRI and is an alternative imaging modality for the assessment of vertebral fractures in patients with contraindications for MRI.