Salih Hamcan

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.

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.

Dural venous sinus thrombosis following head trauma: possible causes and safe imaging techniques

Dear Editor: We read the recent article entitled “Dural sinus and internal jugular vein thrombosis complicating a blunt head injury in a pediatric patient” by Beer-Furlan et al. [1], published online in Child’s Nervous System (doi:10.1007/s00381-013-2184-7) with a great interest. Authors presented an interesting case of a pediatric patient with blunt head injury and epidural hematoma, who developed dural sinus and internal jugular vein thrombosis with fatal outcome. When we read the article, some questions raised in our mind. We would like to contribute information regarding the possible causes and safe imaging techniques of the dural venous sinus thrombosis that may develop after the head trauma [1, 2]. Firstly, the authors reported that the patient’s neurological status worsened after the surgery and emergent computed tomography (CT) was done. Non-contrast CT showed hypodensity on the right cerebral hemisphere consistent with edema and a hyperdense area at the sigmoid sinus, suggestive of dural venous sinus thrombosis. Authors referred to Fig. 1 about this information. However, images in Fig. 1 belong to preoperative CT examination, and it does not show the sigmoid sinus. Moreover, authors stated that the right transverse sinus, sigmoid sinus, and internal jugular vein thrombosis occurred after the surgery. However, we are not precisely convinced about this information by Fig. 2, because the section level of the first-part axial CT image in Fig. 2 is not exactly appropriate and the three-dimensional volume rendering part of the figure shows as if the right transverse sinus and proximal part of the sigmoid sinus are open and normally filled with contrast. In this regard, the authors could have used more appropriate CT images for better explanation and education. Secondly, the authors argued that a thrombus was formed in the dural sinus at the time of injury and had not been identified on initial imaging. As a result of multifactorial setting such as compressive effect of the epidural hematoma, craniotomy, and edema, the thrombus gradually extended until the increase of the cytotoxic edema and intracranial pressure that accelerated the process in a vicious cycle. At this point, we speculate that the superficial main venous structures such as the veins of Labbé and Throlard might have been compressed by a large temporal–parietal epidural hematoma, and the edema that was seen as a hypodense area on the CT images might have occurred at the drainage site of these veins. In addition, possible parenchymal brain injury and compressing effect of the epidural hematoma on the right cerebral parenchyma might have contributed to edema and increased intracranial pressure. Then, dural venous sinus thrombosis might have developed due to multifactorial settings mentioned by the authors [1]. Finally, the authors reported that in a trauma setting, CT venography is the first and best option, considering the availability in most institutions, the quickness on performing the study, and the higher sensitivity when compared to magnetic resonance (MR) imaging. However, CT venography has several important disadvantages for it involves substantial ionizing radiation that is more harmful in pediatric patients and it has a limited role in the evaluation of parenchymal brain injury. We believe that, especially in pediatric patients, if patient’s situation is suitable, MR imaging including MR venography can be considered the first and best option for the evaluation of the brain parenchyma and dural venous sinuses. The dural venous sinuses may precisely evaluated B. Battal (*) :V. Akgun :B. Karaman Department of Radiology, Gulhane Military Medical School, 06018 Etlik, Ankara Province, Turkey e-mail: bilbat_23@yahoo.com

Susceptibility-Weighted Imaging in the Diagnosis of Isolated Cortical Vein Thrombosis

globin serves as an intrinsic contrast agent for cerebral veins which contain deoxygenated blood. Other extravascular blood degradation products with paramagnetic properties such as methemoglobin, hemosiderin and ferritin also create a contrast in SWI. In this sequence in order to increase the visualization of the smaller veins, a phase mask obtained from the magnetic resonance (MR) phase images is multiplied with magnitude images. After the postprocessing, susceptibility-weighted images can be displayed with the minimal intensity projection algorithm [2, 3] . SWI has become a useful method to evaluate cerebral venous sinus and isolated cortical vein thromboses by depicting direct signs of thrombus and demonstrating indirect signs such as venous stasis and collateral slow flow. Cortical vein thrombosis causes an increase of the deoxyhemoglobin concentration in the involved veins. This clearly and distinctly appears as prominent hypointense signal intensity in the affected vein on SWI [4] . The comprehensive study performed by Idbaih et al. [5] showed that T2 * SW is of additional diagnostic value for clot detection in cerebral vein thrombosis in conjunction with conventional MRI and MR venography, particularly in the acute phase of thrombosis and in cortical cerebral vein thrombosis. They also stated that conventional MRI sequences and MR venography techniques are usually insuffiDear Sir, We read the recent article entitled ‘Isolated cortical vein thrombosis: a widely variable clinicoradiological spectrum’ by Xue et al. [1] , published in European Neurology , with great interest. The authors evaluated the variable clinicoradiological spectrum of isolated cortical vein thrombosis, which is a clinicoradiological diagnostic challenge. They concluded that neurological features and brain imaging findings of isolated cortical vein thrombosis are highly variable, which might be partly responsible for the underestimation of isolated cortical vein thrombosis. Moreover, the authors stated that direct signs of thrombosis on computed tomography and magnetic resonance imaging (MRI) may be subtle or missing, and even digital subtraction angiography may fail to detect them because of a variation in number, size and location of the cortical veins. At this point, we would like to make a suggestion regarding the usefulness of susceptibility-weighted imaging (SWI) which is a relatively new MRI sequence and seems to be helpful in the early and easy diagnosis of isolated cortical vein thrombosis. SWI is a new MRI technique that is based on high-spatial-resolution, three-dimensional, fully flow-compensated gradient-echo sequences using both magnitude and phase information. The cerebral venous visualization is based the paramagnetic effects of deoxyhemoglobin due to full flow compensation. The deoxyhemoReceived: August 2, 2013 Accepted: September 22, 2013 Published online: December 4, 2013

Isolated cerebellar damage caused by carbon monoxide intoxication

An unconscious 5-year-old girl with convulsions was admitted to emergency department. Her blood carboxyhaemoglobin level was 7.3%. CO intoxication was presumed and she was referred to our department for a brain MRI. In addition to conventional sequences, diffusion-weighted imaging (DWI) was also performed. Whereas there was no pathological signal change on supratentorial images, symmetrical lesions in the grey matter were observed in both cerebellar hemispheres. MRI showed hypointensities on T1weighted image (figure 1A), hyperintensities both …

Popliteal artery entrapment syndrome with thrombosed popliteal aneurysm: multidetector computed tomography angiography findings of a case.

Popliteal artery entrapment syndrome (PAES) is a rare congenital vascular pathology caused by the compression of the popliteal artery by adjacent muscle and tendinous structures. Popliteal artery aneurysm associated with this syndrome is extremely rare. A 45-year-old male suffering from pain at the right lower extremity during exercise was admitted to our hospital. Physical examination and Doppler imaging revealed a weak pulse at the posterior tibial artery and no pulse at dorsalis pedis and anterior tibial arteries. The patient was further evaluated with multidetector computed tomography angiography (MDCTA). MDCTA revealed PAES due to compression of the accessory fibers of the gastrocnemius muscle and related thrombosed popliteal aneurysm.

Is there a correlation between bronchial artery hypertrophy and coronary artery disease

We read the recent article titled ‘‘Bronchial artery hypertrophy is correlated with coronary artery disease’’ by Tresoldi et al. (1) with great interest. The authors evaluated a possible association between bronchial artery hypertrophy and coronary artery disease in patients without known pulmonary diseases undergoing coronary computed tomography angiography. They concluded that there is an association between coronary artery disease and bronchial artery hypertrophy, and bronchial artery hypertrophy could be caused by undiagnosed underlying coronary artery disease. When we read the article, some questions were raised in our minds. We need clarification from the authors on a few topics. In addition, we would like to make a contribution regarding normal anatomical features of bronchial arteries. First, the authors stated that the scanning volume was from the carina to the diaphragm in 75% (75/100) of the patients without coronary artery bypass graft (1). This information leads to two important questions:

Imaging Findings of Jugular Foramen Meningocele in a Neurofibromatosis Type 1 Patient

Neurofibromatosis type I (NF1) is a neurocutaneous disorder that involves autosomal dominant transmission. Skull defects, including sphenoid dysplasia and calvarial defects, are a rare finding in patients with NF1. Spinal meningocele and sphenoid wing dysplasia have been identified in NF1 but the occurrence of meningoceles at the skull base is extremely rare. A rare instance of jugular foramen meningocele being identified in an NF1 patient on imaging is described in this paper. To the best of our knowledge, only two such cases have been reported in the English literature.

Recurrent ischemic priapism: A rare adverse event after human chorionic gonadotropin treatment in a three years-old boy with cryptorchidism

We present the first case of human chorionic gonadotropin (hCG) induced recurrent ischemic priapism in a 3 years-old boy in the English literature. The patient underwent second right orchidopexy and hCG treatment (1500 IU twice a week for three weeks) was initiated the day after the operation. Twenty-three days after the last injection, he presented to our clinic with the complaint of painless erections. After the diagnosis of ischemic priapism, conservative management and oral diazepam therapy was initiated and the result was successful. hCG therapy may rarely cause recurrent ischemic priapism in children.

Age- and sex-related differences in pituitary height and its effect on the optic chiasm height

We read the recent article titled ‘‘Topographic variations of the optic chiasm and the pituitary stalk: a morphometric study based on midsagittal T2-weighted MR images’’ by Long et al. [1] published in Surgical and Radiologic Anatomy (doi:10.1007/s00276-014-1265-y) with great interest. The authors evaluated topographic variations of optic chiasm and pituitary stalk in situ based on midsagittal T2-weighted MR images. We would like to make a contribution regarding ageand sex-related differences in pituitary height and its effect on the optic chiasm height. Long et al. [1] reported that the height of the optic chiasm was defined and measured as the shortest distance between the inferior margin of the optic chiasm and the upper surface of the pituitary gland. The authors separated the cases into 157 (32.7 %) children (under the age of 18) and 323 (67.3 %) adults (18 years of age or above). But, we know that the height of the normal pituitary gland is bigger in newborns than in infants. It is also bigger in women than in men. The normal highest values for the height of pituitary gland in a population younger than 12 years old, adult men and adult women are 6, 8 and 9 mm, respectively. Nevertheless, the normal values for pubertal girls and peripartum women are 10 and 12 mm, respectively. The upper border of the pituitary gland may show convexity in the peripartum and pubertal period [2].The variations in the height of the pituitary gland due to various physiologic reasons might have affected the measurement of the height of the optic chiasm in different age and gender groups. We thought that if the height of the optic chiasm was measured from the level of the anterior skull base plane instead of the upper surface of the pituitary gland, the authors would obtain more accurate results without the effect of these physiologic differences. The authors evaluated cases younger than 18 years old classified into only one group as children. However, the first 18 years of life contains newborn, pre-pubertal, pubertal (10–15 years old) and post-pubertal periods (15–18 years old). Since these periods are related with the physiologic pituitary volume changes, the data obtained from the children (under age 18 years) may not be homogenous. In other words, the height of the chiasm measured based on the upper surface of the pituitary gland may show fluctuation even in exactly the same case within the first 18 years of life. A similar situation should also be considered in peripartum women.