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Biomedical subjects

O Ozsarlak

Publications and source records attributed to O Ozsarlak.

At least 19 recordsLinked to original sources
PubMed2005

New developments in the neuroradiological diagnosis of craniocerebral trauma.

Accurate radiographic diagnosis is a cornerstone of the clinical management and outcome prediction of the head-injured patient. New technological advances, such as multi-detector computed tomography (MDCT) scanning and diffusion-weighted magnetic resonance imaging (MRI) have influenced imaging strategy. In this article we review the impact of these developments on the neuroradiological diagnosis of acute head injury. In the acute phase, multi-detector CT has supplanted plain X-ray films of the skull as the initial imaging study of choice. MRI, including fluid-attenuated inversion recovery, gradient echo T2* and diffusion-weighted sequences, is useful in determining the severity of acute brain tissue injury and may help to predict outcome. The role of MRI in showing diffuse axonal injuries is emphasized. We review the different patterns of primary and secondary extra-axial and intra-axial traumatic brain lesions and integrate new insights. Assessment of intracranial hypertension and cerebral herniation are of major clinical importance in patient management. We discuss the issue of pediatric brain trauma and stress the importance of MRI in non-accidental injury. In summary, new developments in imaging technology have advanced our understanding of the pathophysiology of brain trauma and contribute to improving the survival of patients with craniocerebral injuries.

Brain Injuries↗
PubMed2004

Does the location of a vascular loop in the cerebellopontine angle explain pulsatile and non-pulsatile tinnitus?

The purpose was to investigate patients with unexplained pulsatile and non-pulsatile tinnitus by means of MR imaging of the cerebellopontine angle (CPA) and to correlate the clinical subtype of tinnitus with the location of a blood vessel (in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve). Clinical presentation of tinnitus and perceptive hearing loss were correlated. In 47 patients with unexplained tinnitus, an MR examination of the CPA was performed. Virtual endoscopy reconstructions were obtained using a 3D axial thin-section high-resolution heavily T2-weighted gradient echo constructive interference in steady state (CISS) data-set. High-resolution T2-weighted CISS images showed a significantly higher number of vascular loops in the internal auditory canal in patients with arterial pulsatile tinnitus compared to patients with non-pulsatile tinnitus (P<0.00001). Virtual endoscopy images were used to investigate vascular contacts at the cisternal part of the VIIIth cranial nerve in patients with low pitch and high pitch non-pulsatile tinnitus. A significantly different distribution of the vascular contacts (P=0.0320) was found. Furthermore, a correlation between the clinical presentation of non-pulsatile tinnitus (high pitch and low pitch) and the perceptive hearing loss was found (P=0.0235). High-resolution heavily T2-weighted CISS images and virtual endoscopy of the CPA can be used to evaluate whether a vascular contact is present in the internal auditory canal or at the cisternal part of the VIIIth cranial nerve and whether the location of the vascular contact correlates with the clinical subtype of tinnitus. Our findings suggest that there is a tonotopical structure of the cisternal part of the VIIIth cranial nerve. A correlation between the clinical presentation of tinnitus and hearing loss was found.

Adolescent↗
PubMed2004

3D time-of-flight MR angiography of the intracranial vessels: optimization of the technique with water excitation, parallel acquisition, eight-channel phased-array head coil and low-dose contrast administration.

The aim of this study is three folds: to compare the eight-channel phased-array and standard circularly polarized (CP) head coils in visualisation of the intracranial vessels, to compare the three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) techniques, and to define the effects of parallel imaging in 3D TOF MRA. Fifteen healthy volunteers underwent 3D TOF MRA of the intracranial vessels using eight-channel phased-array and CP standard head coils. The following MRA techniques were obtained on each volunteer: (1) conventional 3D TOF MRA with magnetization transfer; (2) 3D TOF MRA with water excitation for background suppression; and (3) low-dose (0.5 ml) gadolinium-enhanced 3D TOF MRA with water excitation. Results are demonstrating that water excitation is a valuable background suppression technique, especially when applied with an eight-channel phased-array head coil. For central and proximal portions of the intracranial arteries, unenhanced TOF MRA with water excitation was the best technique. Low-dose contrast enhanced TOF MRA using an eight-channel phased-array head coil is superior in the evaluation of distal branches over the standard CP head coil. Parallel imaging with an acceleration factor of two allows an important time gain without a significant decrease in vessel evaluation. Water excitation allows better background suppression, especially around the orbits and at the periphery, when compared to conventional acquisitions.

Adolescent↗
PubMed2004

Spinal tumors.

Spinal tumors are uncommon lesions but may cause significant morbidity in terms of limb dysfunction. In establishing the differential diagnosis for a spinal lesion, location is the most important feature, but the clinical presentation and the patient's age and gender are also important. Magnetic resonance (MR) imaging plays a central role in the imaging of spinal tumors, easily allowing tumors to be classified as extradural, intradural-extramedullary or intramedullary, which is very useful in tumor characterization. In the evaluation of lesions of the osseous spine both computed tomography (CT) and MR are important. We describe the most common spinal tumors in detail. In general, extradural lesions are the most common with metastasis being the most frequent. Intradural tumors are rare, and the majority is extramedullary, with meningiomas and nerve sheath tumors being the most frequent. Intramedullary tumors are uncommon spinal tumors. Astrocytomas and ependymomas comprise the majority of the intramedullary tumors. The most important tumors are documented with appropriate high quality CT or MR images and the characteristics of these tumors are also summarized in a comprehensive table. Finally we illustrate the use of the new World Health Organization (WHO) classification of neoplasms affecting the central nervous system.

Humans↗
PubMed2003

The correlation of preoperative CT, MR imaging, and clinical staging (FIGO) with histopathology findings in primary cervical carcinoma.

The aim of this study was to compare the preoperative findings of abdominal/pelvic CT and MRI with the preoperative clinical International Federation of Obstetrics and Gynecology (FIGO) staging and postoperative pathology report in patients with primary cancer of the cervix. Thirty-six patients with surgical-pathological proven primary cancer of the cervix were retrospectively studied for preoperative staging by clinical examination, CT, and MR imaging. Studied parameters for preoperative staging were the presence of tumor, tumor extension into the parametrial tissue, pelvic wall, adjacent organs, and lymph nodes. The CT was performed in 32 patients and MRI (T1- and T2-weighted images) in 29 patients. The CT and MR staging were based on the FIGO staging system. Results were compared with histological findings. The group is consisted of stage 0 (in situ):1, Ia:1, Ib:8, IIa:2, IIb:12, IIIa:4, IVa:6, and IVb:2 patients. The overall accuracy of staging for clinical examination, CT, and MRI was 47, 53, and 86%, respectively. The MRI incorrectly staged 2 patients and did not visualize only two tumors; one was an in situ (stage-0) and one stage-Ia (microscopic) disease. The MRI is more accurate than CT and they are both superior to clinical examination in evaluating the locoregional extension and preoperative staging of primary cancer of the cervix.

Adult↗
PubMed2003

Contrast enhancement in Lhermitte-Duclos disease of the cerebellum: correlation of imaging with neuropathology in two cases.

Lhermitte-Duclos disease (LDD), also known as dysplastic gangliocytoma, is a rare cerebellar lesion. It has long been regarded as avascular. We report two patients with surgically proven LDD in whom contrast enhancement was observed on MRI. Neuropathological examination revealed proliferation of veins. We suggest that peripheral enhancement of LDD probably reflects vascular proliferation of the cerebellar venous draining system, and should be considered part of the imaging features of LDD.

Adult↗
PubMed2001

Hereditary neuromuscular diseases.

This article presents the actual classification of neuromuscular diseases based on present expansion of our knowledge and understanding due to genetic developments. It summarizes the genetic and clinical presentations of each disorder together with CT findings, which we studied in a large group of patients with neuromuscular diseases. The muscular dystrophies as the largest and most common group of hereditary muscle diseases will be highlighted by giving detailed information about the role of CT and MRI in the differential diagnosis. The radiological features of neuromuscular diseases are atrophy, hypertrophy, pseudohypertrophy and fatty infiltration of muscles on a selective basis. Although the patterns and distribution of involvement are characteristic in some of the diseases, the definition of the type of disease based on CT scan only is not always possible.

Charcot-Marie-Tooth Disease↗
PubMed2000

Maxillo-facial trauma.

Injuries to the facial bones, orbits and adjacent soft tissue structures are common. Despite the increasing safety precautions in modern cars, facial injury is very often caused by motor vehicle accidents. Severe trauma to the face is a strong indication for radiological investigation. In the patient with maxillo-facial trauma, the radiological exploration of should answer two major questions: do the fractures involve areas that may alter the physiologic function of the sinuses, mouth, nasal vault or orbit?, and will the fracture result in any cosmetically detectable abnormality? The goal of the radiological work-up is to define the number and exact location of the fractures, to determine if there is any depression, elevation, or distraction of the fracture fragments, and to assess concomitant soft tissue complications. In this article, we review the role of clinical evaluation, plain X-rays, computed tomography (CT) and magnetic resonance imaging (MRI). Imaging findings are correlated with anatomic and physiopathologic considerations. We present a practical classification system of facial trauma, with emphasis on trauma of the paranasal sinuses and facial bones (nasal and tripod fractures, Le Fort fractures) and orbits (foreign bodies, soft tissue and orbital wall injuries such as blow-in and blow-out-, lateral wall- and apical fractures). A third part focuses on trauma of the mandible and the temporomandibular joints.

Diagnostic Imaging↗
PubMed1998

Transient uterine contraction mimicking adenomyosis on MRI.

Transient myometrial contraction as a physiological phenomenon may simulate pathological conditions, such as a focal or diffuse adenomyosis. Clinicians should be aware of the potential presence of this phenomenon and imaging should be repeated after a suitable interval when the nature of a bulge or a region of low intensity in the myometrium is in doubt. In this paper, we report a transient myometrial contraction that mimics an adenomyosis, but disappears in repeated series.

Adult↗
PubMed1997

The influence of MR field strength on the detection of focal liver lesions with superparamagnetic iron oxide.

The purpose of this study was to compare the value of low- vs high-field MR systems in the detection of focal liver lesions after IV administration of iron oxide particles. A prospective study was undertaken which included 20 patients with focal liver lesions on CT or US, or strong clinical suspicion of focal liver disease. Iron oxide particles were administered in an IV drip infusion over 30 min. Magnetic resonance imaging was subsequently performed on a 0.2 and a 1.5-T system. Both examinations were performed in one session. Turbo spin-echo T2-weighted sequences were used for further analysis (at 0.2 T: TR 4050 ms, TE 96 ms; 1.5 T: TR 3000 ms, TE 103 ms). After randomisation, images were analysed by two blinded readers. The evaluation included lesion counts, determination of lesion conspicuity and overall image quality (both graded on a scale 1-5). Quantitative analysis was performed on 29 lesions. Lesion-to-liver signal intensity and contrast-to-noise ratios (CNRs) were calculated. The total lesion count (cumulative counts for two observers) was 59 on the high-field system and 63 on the low-field system. Statistical analysis showed no significant difference. On both systems median value for lesion conspicuity was 3. No statistically significant difference was found. Global image quality was rated higher on the high-field system: 3 vs 2 for the low-field system (p = 0.0017). Quantitative analysis showed no significant difference for lesion-to-liver signal intensity ratios or CNRs. Although subjective image quality is significantly better on the high-field system, this does not result in better lesion detection or better lesion conspicuity. No significant difference in objective quantitative parameters was found in our series.

Adult↗
PubMed1996

Recurrent hepatic hydatid disease with secondary splenic infestation.

Hydatid disease caused by Echinococcus granulosus is a common problem throughout the world, but is rarely encountered in the Western Countries. The liver and lungs are the most frequently involved organs in hydatid disease. The cyst may become very large and rupture. Abdominal, pelvic and pleural dissemination due to spread of parasitic contents may follow. Splenic involvement in hydatid disease is uncommon, representing less than 2% of all human infestations by Echinococcus. We report a recurrent liver hydatidosis with secondary splenic infestation.

Adult↗
PubMedDate not supplied

Pattern recognition of degenerative disorders in the lumbar spine. Guidelines to MR image interpretation.

Interpreting MR images of the lumbar spine remains a formidable diagnostic challenge, especially in patients with degenerative changes. What are the pertinent findings? Which abnormalities are clinically relevant? Which changes should be viewed as normal aging? The purpose of this presentation is to present a standardized 7-step approach towards interpreting MR images of the degenerative lumbar spine.

Humans↗
PubMedDate not supplied

Cervical spine fractures and soft tissue injuries.

Spinal cord injury is the major cause of quadriplegia and disability. Plain radiographs have a low sensitivity for identifying traumatic cervical spine lesions. Therefore trauma victims with plain films negative for cervical injury but with a high clinical suspicion of injury, or positive for cervical injury should undergo CT or MR for a more definitive evaluation of the cervical spine. Besides the higher sensitivity than plain radiography in detecting fractures, CT is also able to show soft-tissue abnormalities. MR is the definitive modality in assessing cervical soft-tissue injuries, especially in the evaluation of the spinal cord, intervertebral discs, and ligaments. It also allows differentiate spinal cord hemorrhage and edema, which may have a prognostic value. The role of medical imaging in the evaluation of whiplash injuries remains to be determined.

Cervical Vertebrae↗