Cenk Eraslan

Comparison between dynamic susceptibility contrast magnetic resonance imaging and arterial spin labeling techniques in distinguishing malignant from benign brain tumors.

OBJECTIVES The purpose of this study was to preliminarily compare unenhanced arterial spin-labeled (ASL) imaging, dynamic susceptibility contrast-enhanced cerebral blood volume (DSCE-CBV) magnetic resonance imaging (MRI) for evaluation of tumor perfusion in patients with brain tumors. MATERIALS AND METHODS A total of 27 patients with brain tumors were examined in 1,5T MRI. Single phase and multiphase ASL, DSCE-CBV examinations were assessed by both qualitative and quantitative analysis for the detection of malignancy. Imaging results were correlated with a histopathology or follow-up. RESULTS Based on 31 studies in 27 patients with brain tumors, the visual inspection sensitivities for ASL and dynamic DSC perfusion imaging were 88% and 94%, respectively, with 100% specificity for both. On qualitative evaluation, sensitivities for ASL and DSC perfusion imaging perfusions were 88% and 94%, respectively, with 100% specificity for both. The highest sensitivity values for quantitative ASL imaging were obtained using a normalized cut-off ratio of 1.65, resulting in sensitivity of 94% for ASL imaging and cut-off ratio of 1.95 and sensitivity 94% for DSCE-CBV imaging. CONCLUSION The present study revealed similar sensitivity and specificity for both multhiphase ASL and DSC MRI. Thus, we suggest that ASL perfusion can be used in daily clinical practice.

Mild encephalitis/encephalopathy with reversible splenial lesion (MERS) associated with Streptococcus pneumoniae Bacteraemia

Summary Mild encephalopathy with a reversible splenial lesion (MERS) is a clinico-radiological syndrome that can be related to infectious and non-infectious conditions. Patients present with mild neurological symptoms, and magnetic resonance imaging typically demonstrate a reversible lesion with transiently reduced diffusion in the splenium of the corpus callosum. Here, we describe MERS in a 10-year-old boy who presented with fever and consciousness and who completely recovered within a few days. Streptococcus pneumoniae was the causative agent. Although viruses (especially influenza A and B) are the most common pathogen of MERS, for proper management, bacteria should be considered, as they may also lead to this condition.

Building 3D anatomical model of coiling of the internal carotid artery derived from CT angiographic data

The purpose of this study is to recreate live patient arterial anomalies using new recent application of three-dimensional (3D) printed anatomical models. Another purpose of building such models is to evaluate the effectiveness of angiographic data. With the help of the DICOM files from computed tomographic angiography (CT-A), we were able to build a printed model of variant course of the internal carotid artery (ICA). Images of coiling of the ICA taken by CT-A, were then converted into 3D images using Google SketchUp free software, and the images were saved in stereolithography format. Imaging helped us conduct the examination in details with reference to geometrical features of ICA, degree of curve, its extension, location and presence of loop. Challenging vascular anatomy was exposed with models of adverse curve of carotid anatomy, including highly angulated necks, conical necks, short necks, tortuous carotid arteries, and narrowed carotid lumens. It assisted us to comprehend spatial anatomy configuration of life-like models. 3D model can be very effective in cases when anatomical difficulties are detected through the CT-A, and therefore, a tactile approach is demanded preoperatively. 3D life-like models serve as an essential office-based tool in vascular surgery as they assist surgeons in preoperative planning, develop intraoperative guidance, teach both the patients and the surgical trainees, and simulate to show patient-specific procedures in medical field.

The expanding phenotypic spectrum of ARFGEF2 gene mutation: Cardiomyopathy and movement disorder

Mutations in ADP-ribosylation factor guanine nucleotide-exchange factor 2 (ARFGEF2) gene was recently recognized to cause bilateral periventricular nodular heterotopia, putaminal hyperintensity and movement disorder. A ten year-old girl with severe developmental and growth delay, feeding problems and involuntary movements is presented. Bilateral periventricular nodular heterotopia and putaminal hyperintensity were detected in cranial magnetic resonance imaging. Her echocardiographic examination revealed left ventricular non-compaction cardiomyopathy. Sequence analysis of ARFGEF2 gene demonstrated a homozygous c.5126G>A, p.Trp1709(∗) mutation. The mutation is the first nonsense mutation described in ARFGEF2 gene and the case is the second reported case of ARFGEF2 gene mutation with cardiomyopathy. The presented case supports the view that the presence of cardiomyopathy in ARFGEF2 gene mutations is more than a coincidence and thus expands the phenotypic spectrum of ARFGEF2 gene mutations. Mutations in the ARFGEF2 gene must be considered in the presence of bilateral periventricular nodular heterotopia and putaminal hyperintensity in children presenting with movement disorder, severe developmental delay and microcephaly. In case of ARFGEF2 gene mutation, screening for cardiomyopathy may be indicated.

Development of Life-Size Patient-Specific 3D-Printed Dural Venous Models for Preoperative Planning

BACKGROUND Despite significant improvement in clinical care, operative strategies, and technology, neurosurgery is still risky, and optimal preoperative planning and anatomical assessment are necessary to minimize the risks of serious complications. Our purpose was to document the dural venous sinuses (DVS) and their variations identified during routine 3-dimensional (3D) venography created through 3D models for the teaching of complex cerebral anatomy. METHODS 3D models of the DVS networks were printed. Compared with the controls, cases with cortical venous thrombosis have altered venous anatomy, which has not been previously compared. RESULTS Geometrical changes between the neighboring DVS could be easily manipulated and explored from different angles. Modeling helped to conduct the examination in detail with reference to geometrical features of DVS, degree of asymmetry, its extension, location, and presence of hypoplasia/atresia channels. Challenging DVS anatomy was exposed with models of adverse anatomical variations of the DVS network, including highly angulated, asymmetrical view, narrowed lumens, and hypoplasia and atresia structures. It assisted us in comprehending spatial anatomy configuration of life-like models. CONCLUSIONS Patient-specific models of DVS geometry could provide an improved understanding of the complex brain anatomy and better navigation in difficult areas and allow surgeons to anticipate anatomical issues that might arise during the operation. Such models offer opportunities to accelerate the development of expertise with respect to new and novel procedures as well as new surgical approaches and innovations, thus allowing novice neurosurgeons to gain valuable experience in surgical techniques without exposing patients to risk of harm.

Creating vascular models by postprocessing computed tomography angiography images: a guide for anatomical education

BackgroundA new application of teaching anatomy includes the use of computed tomography angiography (CTA) images to create clinically relevant three-dimensional (3D) printed models. The purpose of this article is to review recent innovations on the process and the application of 3D printed models as a tool for using under and post-graduate medical education.MethodsImages of aortic arch pattern received by CTA were converted into 3D images using the Google SketchUp free software and were saved in stereolithography format. Using a 3D printer (Makerbot), a model mode polylactic acid material was printed.ResultsA two-vessel left aortic arch was identified consisting of the brachiocephalic trunk and left subclavian artery. The life-like 3D models were rotated 360° in all axes in hand.ConclusionsThe early adopters in education and clinical practices have embraced the medical imaging-guided 3D printed anatomical models for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between the anatomical structures. Printed vascular models are used to assist in preoperative planning, develop intraoperative guidance tools, and to teach patients surgical trainees in surgical practice.

Clinical and video head impulse test in the diagnosis of posterior circulation stroke presenting as acute vestibular syndrome in the emergency department

INTRODUCTION Head impulse test (HIT) is the critical bedside examination which differentiates vestibular neuritis (VN) from posterior circulation stroke (PCS) in acute vestibular syndrome (AVS). Video-oculography based HIT (vHIT) may have aadditional strength in making the differentiation. METHODS Patients admitted to the emergency department of a tertiary-care medical center with AVS were studied. An emergency specialist and a neurologist performed HIT. vHIT was conducted by an neuro-otology research fellow. RESULTS Forty patients 26 male, 14 female with a mean age of 49 years were included in the analyses. Final diagnoses were VN in 24 and PCS in 16 patients.In the VN group, clinical HIT was assessed as abnormal in 19(80%) cases by the emergency specialist and in 20(83%) by the neurologist. In all PCS patients, HIT was recorded as normal both by the emergency specialist and the neurologist (100%).On vHIT, patients with VN had significantly low gain values for both the ipsilesional and contralesional sides when compared with the healthy controls, with significantly lower figures for the ipsilesional side (p < 0.001). All patients in this group had normal DWI-MRI.PCS patients had bilaterally low gain (p < 0.05) on vHIT. However, gain asymmetry was not significant. Subgroup analyses according to presence of brainstem involvement revealed bilateral low gain (p < 0.05) in patients with brainstem infarction (anterior inferior cerebellar artery-posterior inferior cerebellar artery stroke, AICA-PICA stroke) whereas patients with pure cerebellar infarction (posterior inferior cerebellar artery-superior cerebellar artery stroke, PICA-SCA stroke) had gain values similar to healthy controls.With a gain cut-off ≤0.75 and gain asymmetry cut-off ≥17%, as determined by ROC analysis, 100% of PCS patients and 80% of VN patients were correctly diagnosed. CONCLUSIONS Clinical HIT, either performed by an emergency specialist or neurologist is equivalent to vHIT gain and gain asymmetry analysis as conducted by neuro-otologist in the diagnosis of PCS, albeit mislabeling about 20% of VN patients. vHIT does not appear to yield additional diagnostic information. These findings indicate the strength of clinical HIT. Pure gain-based vHIT analysis seems limited and needs to be incorporated with saccade analysis.

Necrotizing Liver Granuloma/Abscess and Constrictive Aspergillosis Pericarditis with Central Nervous System Involvement: Different Remarkable Phenotypes in Different Chronic Granulomatous Disease Genotypes

Chronic granulomatous disease (CGD) is a primary immune deficiency causing predisposition to infections with specific microorganisms, Aspergillus species and Staphylococcus aureus being the most common ones. A 16-year-old boy with a mutation in CYBB gene coding gp91phox protein (X-linked disease) developed a liver abscess due to Staphylococcus aureus. In addition to medical therapy, surgical treatment was necessary for the management of the disease. A 30-month-old girl with an autosomal recessive form of chronic granulomatous disease (CYBA gene mutation affecting p22phox protein) had invasive aspergillosis causing pericarditis, pulmonary abscess, and central nervous system involvement. The devastating course of disease regardless of the mutation emphasizes the importance of early diagnosis and intervention of hematopoietic stem cell transplantation as soon as possible in children with CGD.

Non-alkolik nedenlere bağlı gelişen Wernicke ensefalopatisinde manyetik rezonans görüntüleme bulguları

Amac: Wernicke ensefalopatisi (WE) tiamin (vitamin B1) eksikligine bagli olarak gelisen noropsikiyatrik bir hastaliktir. Siklikla kronik alkolizme bagli olarak gorulmekle birlikte tiamin alim veya emilim eksikligine neden olan her turlu durumda ortaya cikabilir. Bu calismanin amaci tedavi edilmedigi takdirde olume kadar giden ciddi sonuclar dogurabilen bu hastaligin tani ve izleminde manyetik rezonans goruntulemenin (MRG) onemini vurgulamaktir. Gerec ve Yontem: Calismamiza kurumumuzda hospitalize edilen ve non-alkolik nedenlerle WE tanisi alan 10 hasta dahil edildi. Hastalarin MRG tetkiklerinde tutulum yerlerinin lokalizasyonuna gore tipik ve atipik bulgularin varligi degerlendirildi. Ayrica eslik eden difuzyon kisitliligi varligi arastirildi. Bulgular: Kraniyal MRG’de tipik tutulum alanlari 10 hastada bilateral talamus mediali, 8 hastada bilateral mamiller cisim, 7 hastada periakuaduktal alan/tektal plak olarak tespit edildi. Atipik tutulum alanlari ise 5 hastada forniks, 4 hastada serebral korteks, 2 hastada putamen, 1 hastada ise serebellum tutulumu seklinde idi. 8 hastada bu bulgulara difuzyon kisitliligi eslik etmekteydi. Sonuc: Sunulan calismanin sonuclarina gore, n on-alkolik WE tanili olgularda MRG’de, alkolik WE tanili olgularla benzer bulgular gozlenmektedir. Bu hastalarin tani ve tedavilerinin gecikmemesi amaciyla MR goruntulemenin kullaniminin onemli rol oynadigi sonucuna varilmistir.

Creation of 3-Dimensional Life Size: Patient-Specific C1 Fracture Models for Screw Fixation

BACKGROUND Transarticular screw fixation has fatal complications such as vertebral artery (VA), carotid artery, and spinal cord injuries. The landmarks for deciding the entry point for C1 lateral mass screws were clarified by using life-size 3-dimensional (3D) patient-specific spine models. METHODS This study included a total of 10 patients with C1 fractures. Dual-energy computed tomography (CT) scan data from C1 pre- and postscrewing were modified into 3D patient-specific life-size cervical spine models. The detailed information, such as bony and vascular elements, of 13 separate parameters of C1 was used as an intraoperative reference. RESULTS 3D patient-specific models were created preoperatively with the fracture and postoperatively with the screwed vertebrae. After CT scans of the models were measured, the life-size patient-specific models were proven to be individualized. 3D models assisted in determining the fracture locations, pedicle sizes, and positions of the VA. The range of the measurements for ideal point of entry reveals the need for patient-specific intervention was required. CONCLUSIONS 3D models were used in surgical planning maximizing the possibility of ideal screw position and providing individualized information concerning cervical spinal anatomy. The individualized 3D printing screw insertion template was user-friendly, of moderate cost, and it enabled a radiation-free cervical screw insertion.