Elif Bulut

Targeted vessel reconstruction in non-contrast-enhanced steady-state free precession angiography

Image quality in non‐contrast‐enhanced (NCE) angiograms is often limited by scan time constraints. An effective solution is to undersample angiographic acquisitions and to recover vessel images with penalized reconstructions. However, conventional methods leverage penalty terms with uniform spatial weighting, which typically yield insufficient suppression of aliasing interference and suboptimal blood/background contrast. Here we propose a two‐stage strategy where a tractographic segmentation is employed to auto‐extract vasculature maps from undersampled data. These maps are then used to incur spatially adaptive sparsity penalties on vascular and background regions. In vivo steady‐state free precession angiograms were acquired in the hand, lower leg and foot. Compared with regular non‐adaptive compressed sensing (CS) reconstructions (CSlow), the proposed strategy improves blood/background contrast by 71.3 ± 28.9% in the hand (mean ± s.d. across acceleration factors 1–8), 30.6 ± 11.3% in the lower leg and 28.1 ± 7.0% in the foot (signed‐rank test, P < 0.05 at each acceleration). The proposed targeted reconstruction can relax trade‐offs between image contrast, resolution and scan efficiency without compromising vessel depiction. Copyright

Meningioangiomatosis of the cerebellum: radiopathologic characteristics of a case

Dear Editor, Meningioangiomatosis (MA) is a rare hamartomatous lesion involving cortex and overlying leptomeninges. It is characterized by cortical vascular proliferation with perivascular cuffs of proliferative spindle-shaped cells [9]. Most cases are sporadic, but association with NF type 2 is well known [2, 5]. MAmainly involves the cerebral cortex, whereas unusual locations such as thalamus and the brainstem have also been reported [3, 4, 10]. Omeis et al. reported a cerebellar MA in a patient with NF type 2, but the lesion was not radiologically demonstrated [7]. Here we present not only the first sporadic case of cerebellar MA but also the first radiologically documented one. A 55-year-old woman was admitted to the neurosurgery outpatient clinic with the symptom of vertigo for 2 months. She had no other known medical conditions and no family history of NF 2. Her physical and neurological examinations were unremarkable. MRI revealed a cortical inhomogeneous lesion with well-defined but irregular borders in left superior cerebellum. Peripheral rim of T1 hyper, T2 hypo-intensity, and susceptibility on T2* GE images were suggestive of calcification (Fig. 1a, c).MRI also detected small satellite cortical and subcortical cysts (Fig. 1a, b). The lesion showed peripheral irregular enhancement with no perilesional edema (Fig. 1b). Elevated diffusion with a high apparent diffusion coefficient (ADC) value (Fig. 1d), low myo-inositol in single voxel (TE: 30 ms) proton MR spectroscopy (MRS) suggested low cellularity and low astrocytic component, respectively. Multi-voxel (TE: 270 ms) MRS revealed moderately reduced N-acetyl-aspartate (NAA), NAA/creatine (Cr) ratio (1.06), choline, Cho/Cr ratio (0.56), Cho/NAA ratio (0.52). Lactate peak was also present. Perfusion MRI showed low relative cerebral blood volume (rCBV: 0.84), low relative cerebral blood flow (rCBF: 0.34), and increased relative mean transit time (rMTT: 2.3) (Fig. 1e). The patient underwent surgery with lateral supracerebellar approach. A neuronavigation system was used to detect the exact location. After a left retrosigmoid craniotomy, the lesion was explored on the superior cerebellar surface. The lesion was firm, similar to a meningioma; however it was totally intraparenchymal with no dural connection. Gross total resection using microsurgical techniques was performed. The postoperative course was uneventful with no operation-related morbidity. Histologically, the cerebellar cortex was variably replaced by fibrous tissue and hyalinized small-sized vessels coated with subtle proliferations of spindle cells (Fig. 1f). There were excessive psammoma bodies within the lesion and the surrounding parenchyma. Immunohistochemical examination revealed perivascular weak expressions of EMA (a meningothelial cell marker), vimentin (a non-specific mesenchymal cell marker) and Ki-67 labeling index of <1 %. MA can be broadly classified into cellular and vascular patterns according to the predominant component [10]. Over time, fibrocalcifying changes develop, and even osseous metaplasia can be seen in advanced cases. Highly variable radiologic appearance of MA reflects histopathological diversity. The CT imaging may show a variable amount of calcifications. According to the literature review, the signal intensity on MRI was generally iso-to hypointense on T1-weighted (W) and hypo-to hyperintense on T2W images. Also, various enhancement * Kader Karli Oguz kkarlioguz@gmail.com; karlioguz@yahoo.com

Deficiency of adenosine deaminase 2; special focus on central nervous system imaging

PURPOSE To increase the knowledge of central nervous system (CNS) imaging features in deficiency of adenosine deaminase 2 (DADA2) by examining magnetic resonance imaging (MRI) studies of a relatively large number of patients. METHODS We retrospectively examined neuroimages of 12 patients (7 male, 5 female) diagnosed with DADA2. The mean age of the patients at the time of initial brain MRI was 16.7±10.2 years. Seven patients (58.3%) fulfilled the classification criteria of polyarteritis nodosa. Brain MRI studies were assessed with respect to findings of ischemia, intracranial hemorrhages, focal parenchymal signal abnormalities, cerebral/cerebellar volume loss, and abnormal contrast enhancement. Angiographic studies of 7 patients were evaluated for the signs of vasculitis. RESULTS The most frequent finding was acute and/or chronic lacunar ischemic lesions in the brainstem and/or deep gray matter (n=9, 75%). Six patients (50%) revealed MRI findings compatible with recurrent ischemic attacks. Small nodular contrast enhancement (n=2, 16.6%), acute putaminal hemorrhage (n=1, 8.3%) and findings compatible with posterior reversible encephalopathy syndrome (n=1, 8.3%) were also detected. Slight-to-moderate diffuse cerebral and/or cerebellar volume loss (n=7, 58.3%), decreased T1 signal of the bone marrow (n=6, 50%) and optic atrophy (n=1, 8.3%) were the other findings on brain MRI. The only abnormal angiographic finding was reduced caliber of the right distal posterior cerebral artery in MRA of a patient (14.6%). CONCLUSION DADA2 should be included in the differential diagnosis of young patients presenting with ischemic and/or hemorrhagic lesions located in the brainstem and deep gray matter, especially if they have a family history or additional systemic abnormalities.

Trigeminal nerve and pathologies in magnetic resonance imaging – a pictorial review

A variety of conditions may affect the trigeminal nerve. Magnetic resonance imaging is the modality of choice when trigeminal nerve pathology is suspected, and this modality plays an essential role in detecting causes. This review illustrates some of the pathological conditions relevant to the trigeminal nerve in magnetic resonance imaging.

Poorly Differentiated Chordomas Showing Loss of INI1/SMARCB1: A Report of 2 Rare Cases With Diagnostic Implications

Poorly differentiated chordomas are rare musculoskeletal tumors. Case 1. A 42-year-old lady presented with quadriparesis of 2 months’ duration. Radiologic imaging disclosed a soft tissue mass in her left prevertebral- and paravertebral cervical region. Case 2. A 4-year-old male child presented with neck pain and restricted head movements of 1-year duration. Radiologic imaging revealed a contrast enhancing, paraspinal soft tissue mass in his cervical region. Microscopic examination in both the cases revealed a cellular malignant tumor composed of moderate to markedly pleomorphic cells with interspersed mitotic figures, along with focal myxoid change and necrosis. By immunohistochemistry, tumor cells in both cases were diffusely positive for pan cytokeratin (AE1/AE3) and brachyury, whereas these were negative for INI1/SMARCB1. Tumor cells in the second case were also positive for glypican3. The first case developed pulmonary metastasis, while the second case developed recurrence. Poorly differentiated chordomas are uncommon tumors, invariably characterized by loss of INI1. These tumors can be rarely seen in adults and need to be differentiated from their diagnostic mimics, in view of treatment implications and their relatively aggressive clinical outcomes.

Evaluation of spinal involvement in children with mucopolysaccharidosis VI: the role of MRI

OBJECTIVE To evaluate spinal MRI features of mucopolysaccharidosis (MPS) VI and to assess the correlation with clinical findings. METHODS We retrospectively evaluated spinal MRI scans and clinical findings at the time of imaging in 14 patients (8 male, 6 female) with MPS VI. Craniometric measurements were performed and the images were assessed for bony anomalies, spinal stenosis and spinal cord compression. The degree of cervical cord compression was scored and correlated with neurological examination findings at the time of imaging. Vertebral alignment, structural changes in spinal ligaments and intervertebral discs were also assessed. RESULTS All patients had cervical stenosis due to bony stenosis and thickened retrodental tissue (median: 6.05 mm, range 3.3-8 mm). Retrodental tissue thickness was found to increase with age (p = 0.042). Compressive myelopathy was detected at upper cervical level in 11 (79%) and lower thoracic level in 2 patients (14%). Significant inverse correlation was found between cervical myelopathy scores and neurological strength scores. The most common bony changes were hypo/dysplastic odontoid; cervical platyspondyly with anterior inferior beaking; thoracic posterior end plate depressions and lumbar posterior scalloping. Kyphosis due to retrolisthesis of the beaked lumbar vertebrae and acute sacrococcygeal angulations were other remarkable findings. CONCLUSION MRI is an essential component in evaluation of spinal involvement in MPS VI, and scanning of the entire spine is recommended to rule out thoracic cord compression. Advances in knowledge: This study provides a detailed description of spinal MRI findings in MPS VI and underlines the role of MRI in management of cord compression.

Neuroimaging: Techniques and General Applications

Abstract With many anatomical variations and diseases, detailed and enhanced imaging has become essential. Existing neuroimaging modalities have distinct advantages over other methods, so a comprehensive approach is necessary when investigating solutions for clinical or experimental problems. In this chapter, a brief technical description, application fields, and advantages and disadvantages of each imaging modality are discussed.

The effect of stabilization exercises on diaphragm muscle thickness and movement in women with low back pain

BACKGROUND Diaphragm is an important component of spinal stability. In presence of low back pain, there may be some alterations in this muscle like other muscles that are responsible for lumbal stabilization. OBJECTIVE This study aims to assess the effects of stabilization exercises on diaphragm muscle thickness and motion along with lumbopelvic stability. METHODS Twenty-one women with low back pain participated in the study. Stabilization exercises including motor control training were performed on treatment group (n= 11). In control group (n= 10), strentghening exercises were peformed for back muscles, abdominal muscles and hip muscles. The patients underwent a total of 30 sessions of treatment, 3 days in a week for 10 weeks. The diaphragm muscle thickness and motion was evaluated using ultrasound (US), and lumbopelvic stability was evaluated using lumbopelvic stability tests. RESULTS After the treatment, in the treatment group, increase in diaphragm thickness and improvement in lumbopelvic stability were statically significant (p< 0.05). However, there were no significant changes in diaphragm motion in both groups (p> 0.05). CONCLUSIONS As a result, stabilization exercises increase diaphragm muscle thickness and improve lumbopelvic stability in women with low back pain. Therefore, stabilization exercises should be considered as a part of the treatment program in low back pain.

An orbital perivascular epithelioid cell tumor in a 7-year-old boy: case report and review of the literature

We report the case of a 7-year-old boy who presented with a swollen right eye. Magnetic resonance imaging revealed a right intraconal orbital mass with intense contrast enhancement. Incisional biopsy led to a diagnosis of perivascular epithelioid cell tumor (PEComa). Sirolimus was initiated but discontinued at the third week of treatment because the tumor had progressed. A minor regression of the tumor was seen after six cycles of systemic chemotherapy. Previously reported cases of PEComa were benign in nature, and full remission was achieved with surgical excision. In the present case the tumor was malignant and responded only slightly to systemic chemotherapy.

Palliation of malignant gastroduodenal obstruction: fluoroscopic metallic stent placement with different approaches

PURPOSE We aimed to evaluate the safety and effectiveness of fluoroscopy-guided gastroduodenal metallic stent placement with different approaches in malignant obstruction. METHODS We retrospectively assessed 53 patients (33 men and 20 women; mean age, 58.7±15 years) who underwent stent placement between February 2004 and April 2014. All patients had unresectable tumors. The most common causes of obstruction were gastric (38%) and pancreatic cancers (36%). Uncovered self-expandable metallic stents (SEMS) were placed under fluoroscopic guidance. In addition to transoral approach in 46 patients (86.7%), transgastric and transhepatic approaches were used in six patients (11.3%) and one patient (1.8%), respectively. Gastric outlet obstruction scoring system (GOOSS) was used to evaluate oral intake before and after stenting. Patients were followed until death or the end of the study. RESULTS Technical and clinical success rates were 100% and 92%, respectively. The median stent patency was 76 days (range, 4-985 days). Mean preprocedural GOOSS score of 0.1 increased to postprocedural GOOSS score of 2.42 (P < 0.001). Afferent loop decompression was achieved in one symptomatic patient. Neither mortality nor major complications occurred due to stenting. Stent migration occurred in one patient (2%) and stent obstruction occurred in two patients (4%). Combined biliary and duodenal stenting were performed in 21 patients (40%). Post-stenting GOOSS scores were predictive of survival (P = 0.003). CONCLUSION Fluoroscopic metallic stent placement for palliation of malignant gastroduodenal obstruction is safe and effective with high technical and clinical success rates and minimal complications. High technical success rates can be achieved using different approaches.