Veysel Akgun

Pediatric abdominal masses: diagnostic accuracy of diffusion weighted MRI.

PURPOSE To retrospectively identify apparent diffusion coefficient (ADC) values of pediatric abdominal mass lesions, to determine whether measured ADC of the lesions and signal intensity on diffusion-weighted (DW) images allow discrimination between benign and malignant mass lesions. MATERIALS AND METHODS Approval for this retrospective study was obtained from the institutional review board. Children with abdominal mass lesions, who were examined by DW magnetic resonance imaging (MRI) were included in this study. DW MR images were obtained in the axial plane by using a non breath-hold single-shot spin-echo sequence on a 1.5-T MR scanner. ADCs were calculated for each lesion. ADC values were compared with Mann-Whitney U test. Receiver operating characteristic curve analysis was performed to determine cut-off values for ADC. The results of visual assessment on b800 images and ADC map images were compared with chi-square test. RESULTS Thirty-one abdominal mass lesions (16 benign, 15 malignant) in 26 patients (15 girls, 11 boys, ranging from 2 days to 17 years with 6.9 years mean) underwent MRI. Benign lesions had significantly higher ADC values than malignant ones (P < .001). The mean ADCs of malignant lesions were 0.84 +/- 1.7x10(-3) mm2/s, while the mean ADCs of the benign ones were 2.28 +/- 1.00x10(-3) mm2/s. With respect to cutoff values of ADC: 1.11x10(-3) mm2/s, sensitivity and negative predictive values were 100%, specificity was 78.6% and positive predictive value was 83.3%. For b800 and ADC map images, there were statistically significant differences on visual assessment. All malignant lesions had variable degrees of high signal intensity whereas eight of the 16 benign ones had low signal intensities on b800 images (P < .001). On ADC map images, all malignant lesions were hypointense and most of the benign ones (n=11, 68.7%) were hyperintense (P < .001). CONCLUSION DW imaging can be used for reliable discrimination of benign and malignant pediatric abdominal mass lesions based on considerable differences in the ADC values and signal intensity changes.

Diffusion-weighted imaging in the characterization of focal liver lesions: efficacy of visual assessment.

Objectives: The objective of the study was to assess the value of visual assessment of signal intensities on b800 diffusion-weighted images and apparent diffusion coefficient (ADC) maps in differentiation of benign and malignant focal liver lesions (FLLs). Methods: Approval for this retrospective study was obtained from the institutional review board. One hundred forty-three FLLs in 65 patients (38 women, 27 men; mean age, 50.8 years) underwent magnetic resonance (MR) imaging and diffusion-weighted imaging (DWI) with a respiratory-triggered single-shot echo-planar imaging sequence. Focal liver lesions were evaluated visually according to the signal intensities on b800 and ADC map images, and ADC values were also calculated. The conventional MR imaging, follow-up imaging findings, and histopathologic data were regarded as gold standard. Normal distribution was assessed with Kolmogorov-Smirnov test. The accuracies of visual assessment and ADC values in differentiating benign and malignant FLLs were assessed with the Student t test, and threshold values were determined with receiver operating characteristic curve analysis. Results: By using a cutoff value of 1.21 × 10−3 mm2/s, ADC had a sensitivity of 100%, a specificity of 89.3%, and an accuracy of 92.3% in the discrimination of malignant FLLs. With the visual assessment of the DWIs and ADC maps, malignant lesions were differentiated from benign ones, with 100% sensitivity, 92.2% specificity, and 94.4% accuracy. Although some benign lesions were interpreted as malignant, no malignant lesion was determined as benign in visual assessment. Conclusions: Most FLLs are benign ones such as hemangiomas and cysts, which can be readily and practically characterized only by using visual assessment of DWIs without requiring time-consuming conventional and dynamic contrast-enhanced imaging sequences. Some benign lesions that are falsely interpreted as malignant can be further characterized by using conventional and contrast-enhanced MR studies.

Normal Anatomical Features and Variations of the Vertebrobasilar Circulation and Its Branches: An Analysis with 64-Detector Row CT and 3T MR Angiographies

Purpose. To determine the normal anatomical features and variations of the vertebrobasilar circulation and its branches in patients who underwent multidetector computed tomography (CT) or magnetic resonance (MR) angiographies of the brain. Methods. 135 patients (male, 83 and female, 52; mean age, 50.1 years) who underwent CT (n = 71) or MR (n = 64) angiographies of the vertebrobasilar vasculature for various reasons were analyzed retrospectively. The right and left distal vertebral arteries (VAs), posterior inferior cerebellar arteries (PICAs), anterior inferior cerebellar arteries (AICAs), superior cerebellar arteries (SCAs), posterior cerebral arteries (PCAs), and posterior communicating arteries (PCoAs) were analyzed individually. Results. In 24.4% of the cases (33/135) right PICA, in 19.3% of the cases (26/135) left PICA, in 17.8% of the cases (24/135) right AICA, and in 18.5% of the cases (25/135) left AICA were absent. In cases without PICA or AICA, there was a statistically significant, moderately or well-developed AICA or PICA on the same side, respectively (P < 0.001). The most common variation was isolated absence of right PICA and was seen in 17.8% of the cases. Conclusions. The anatomic features of the branches of the vertebrobasilar circulation may be different from well-known normal anatomy. CT and MR angiographies allow a precise and detailed evaluation of vertebrobasilar circulation.

Hiccup as a result of late lead perforation: report of two cases and review of the literature.

Pacemaker (PM) lead perforation is a rare complication with an incidence of <1%. Late lead perforation is defined as the perforation of a device lead through the myocardium more than 1 month after implantation. It is a subcategory of overall lead perforation and it has been described in several case reports. In the current paper, we present two cases with late partial lead perforation developing after the PM implantation.

MRI diagnosis of dural sinus—Cortical venous thrombosis: Immediate post-contrast 3D GRE T1-weighted imaging versus unenhanced MR venography and conventional MR sequences

OBJECTIVE Primary aim is to compare the diagnostic value of contrast-enhanced 3D GRE T1-weighted sequences with unenhanced MR venography and conventional magnetic resonance imaging (MRI), in detection of dural venous sinus (DVS) and cortical venous thrombosis; secondary aim is to determine the relationship between DVS thrombosis/site and gender, age, infarction or hemorrhage. METHODS We retrospectively reviewed conventional MR images, unenhanced MR venography and immediate post-contrast 3D GRE T1-weighted MR images in 30 patients (17 male and 13 female, 21-70 years old, mean age 40.1) with clinically suspected DVS thrombosis. MR examinations had been performed with 1.5T or 3T MR Scanners. DVSs were evaluated in 10 sub-segments, including cortical veins. Each set of MR images were examined separately, blinded to the final diagnosis. Associated findings were also noted and sensitivity, specificity and accuracy of each MRI technique were calculated. RESULTS Final diagnosis of cortical venous and/or dural sinus thrombosis was established in 24 (80%) of 30 cases and 67 (22.3%) out of 300 segments. For detection of the thrombotic segment, sensitivity, specificity, and accuracy were 83.6%, 95.3%, and 92.7% by conventional MR sequences, 89.6%, 91.8%, and 91.3% by unenhanced MR venography, and 92.5%, 100%, and 98.3% by contrast-enhanced 3D GRE T1-weighted sequence, respectively. Infarction and hemorrhage were more frequent in cases with cortical venous thrombosis, while gender and age had no significant relation with DVS thrombosis or its site. Conventional MR sequences and unenhanced MR venography were helpful due to additional information they provided in some cases with isolated cortical venous thrombosis, with hyperintense thrombus material and with associated hemorrhage or infarction. CONCLUSION Contrast-enhanced 3D GRE T1-weighted MRI is the most accurate imaging method for the detection of DVS and/or cortical venous thrombosis. Infarction and hemorrhage were more frequent in cases with cortical venous thrombosis.

Pulmonary artery embolism due to a ruptured hepatic hydatid cyst: clinical and radiologic imaging findings

Hydatid pulmonary embolism is an uncommon condition resulting from the rupture of a hydatid heart cyst or the opening of a visceral hydatid cyst into the venous circulation. We report a rare case with multiple intra-arterial pulmonary hydatid cyst emboli originating from a hepatic hydatid cyst ruptured into the hepatic segment of the inferior vena cava. We present the ultrasonography findings of hepatic hydatid cyst and multidetector computed tomography pulmonary angiography images demonstrating both multiple hydatid cyst emboli and their hepatic origin.

Bronchial arteries: normal anatomy, variation and radiologic evaluation.

We have read the recent article by Osiro et al. [5] with a great interest. They reviewed the anatomy, variation and pathophysiology of the bronchial arteries in humans, considering the recent advances in imaging techniques. But, we need to clarify a few topics not to lead misunderstandings in radiologists, anatomists and clinicians. Firstly, coronary artery–bronchial artery communications are not uncommon as mentioned by the authors. On the other hand, the authors stated the case represented by Battal et al. [1] as an aberrant bronchial artery originating from coronary artery fistula. Indeed, in this case, neither there was a fistula between coronary and bronchial arteries, nor a coronary artery originating from that fistula. In this case, in contrast to previously reported coronary–bronchial arterial fistulas, the right bronchial artery was originating as an aberrant branch from the right coronary artery with normal origin and course. Moreover, there was no other origin for right bronchial artery in contrast to fistulas. Therefore, it was determined as an aberrant right bronchial artery originating from right coronary artery instead of a fistula between coronary and bronchial arteries. Secondly, although Cauldwell et al. [3] reported that type 1 bronchial arteries (one right, two left bronchial arteries) were the most common one, subsequent conventional and multidetector computed tomography (MDCT) angiographic studies reported that type 2 and 3 bronchial arteries were more frequently encountered. In a recent and comprehensive study based on anatomy and variations of bronchial arteries in MDCT angiography performed by Battal et al. [2], the most common type of bronchial artery pattern was revealed as one on each side, followed by two bronchial arteries on the right side and one bronchial artery on the left side. The majority of the right bronchial arteries (45.4 %) were originating from aorta as an intercostobronchial trunk. The number and mean diameter of the right bronchial arteries were significantly higher than the left bronchial arteries. There were more bronchial arteries in males probably due to larger volume of tissue supplied by the bronchial arteries [2]. Third, the authors reported that the mean diameter of the normal bronchial arteries was 1.5 mm at the origin and those with larger than 2 mm were abnormal and prone to rupture. But, Battal et al. [2] reported that the diameters of the normal bronchial arteries and intercosto-bronchial trunks might be up to 3 and 5 mm, respectively. In another study performed by Morita et al. [4], the mean diameters of bronchial arteries, right bronchial arteries, left bronchial arteries, and common bronchial trunks were reported as 1.98, 2.05, 1.69, and 2.38 mm, respectively. Finally, the authors claimed that with recent advances magnetic resonance (MR) angiography could demonstrate the anatomy, course and pathology of the bronchial arteries as computed tomography (CT) angiography. Even recent MR imaging systems with high magnetic field strengths, sophisticated coils and fast sequences cannot adequately demonstrate fine calibrated bronchial arteries within highly mobile thoracic structures such as heart and lungs. We still believe that CT angiography is superior to MR angiography in demonstrating bronchial arteries.

A case of anomalous left coronary artery arising from the pulmonary artery in adulthood: multidetector computed tomography coronary angiography findings.

Anomalous left coronary artery arising from the pulmonary artery (ALCAPA) is a rare but very serious congenital coronary artery anomaly. Multidetector computed tomography (MDCT) coronary angiography has recently become the gold standard for depicting anatomical variations and anomalies of the coronary arteries because the origin and course of anomalous arteries can be demonstrated very accurately by this technique. In this report, we present a case of 22-year-old female who was admitted to our emergency department with cardiac arrest. In the course of diagnosis, MDCT coronary angiography revealed a left coronary artery arising from the pulmonary artery as well as marked dilatation of the coronary arteries.

Malformations of cortical development: 3T magnetic resonance imaging features.

Malformation of cortical development (MCD) is a term representing an inhomogeneous group of central nervous system abnormalities, referring particularly to embriyological aspect as a consequence of any of the three developmental stages, i.e., cell proliferation, cell migration and cortical organization. These include cotical dysgenesis, microcephaly, polymicrogyria, schizencephaly, lissencephaly, hemimegalencephaly, heterotopia and focal cortical dysplasia. Since magnetic resonance imaging is the modality of choice that best identifies the structural anomalies of the brain cortex, we aimed to provide a mini review of MCD by using 3T magnetic resonance scanner images.

Measures of pituitary gland and stalk: from neonate to adolescence.

Abstract Objective: The aim of this study is to provide normative data about pituitary diameters in a pediatric population. Pituitary imaging is important for the evaluation of the hypothalamo-pituitary axis defect. However, data about normal pituitary gland diameters and stalk are limited, especially in children. Structure and the measurements of pituitary gland and pituitary stalk may change due to infection, inflammation, or neoplasia. Methods: Among 14,854 cranial/pituitary gland magnetic resonance imaging scans performed from 2011 to 2013, 2755 images of Turkish children aged between 0 and 18 were acquired. After exclusions, 517 images were left. Four radiologists were educated by an experienced pediatric radiologist for the measurement and assessment of the pituitary gland and pituitary stalk. Twenty cases were measured by all radiologists for a pilot study and there was no interobserver variability. Results: There were 10–22 children in each age group. The maximum median height of the pituitary gland was 8.48±1.08 and 6.19±0.88 mm for girls and boys, respectively. Volumes were also correlated with gender similar to height. Minimum median height was 3.91±0.75 mm for girls and 3.81±0.68 mm for boys. The maximum and minimum pituitary stalk basilar artery ratios for girls were 0.73±0.12 and 0.59±0.10 mm. The ratios for boys were 0.70±0.12 and 0.56±0.11 mm. Conclusion: Our study demonstrated the pituitary gland and stalk size data of children in various age groups from newborn to adolescent. It is thought that these data can be applied in clinical practice. Future prospective follow-up studies with larger samples, which correlate the structural findings with the clinical and laboratory results are awaited.