Role of proton magnetic resonance spectroscopy in diagnosis of pilocytic astrocytoma in children

Pilocytic astrocytomas are the second overall most common pediatric brain tumor. Magnetic resonance [MR] imaging is widely used in the diagnosis and follow up of pediatric patients with pilocytic astrocytomas because of its ability to provide anatomical detail. However conventional MR imaging does not provide information about tissue biochemistry. To study the role of proton magnetic resonance spectroscopy in diagnosis of pilocytic astrocytoma in children. This study included seven pediatric patients with histopathologically proven pilocytic astrocytoma. All patients were subjected to full history taking and thorough clinical examination. Magnetic resonance [MR] imaging was performed at 1.5 Tesla MR system using a standard head coil. Imaging included conventional MRI and proton magnetic resonance spectroscopy. Proton magnetic resonance spectroscopy was done using either single or multi-voxel technique. Surgical biopsy was then performed to all patients and correlation with histopathological data was done. Out of the seven patients included in this study, six were females and one was male with mean age of 9.5 years, the tumor was located in five of them in the posterior fossa, located in right thalamo-peduncular region in one patient and located in the hypothalamic-chiasmatic region in one patient. MR spectroscopic study showed the same findings in all the lesions including high Cho/NAA and Cho/Cr ratios [3.53 +/- 1.5] and [7.21 +/- 4.2], respectively, relative low concentration of creatine with increased NAA/Cr ratio [2.32 +/- 1.1]. Lactate doublet was detected in all cases while no lipid peaks were detected. Based on the findings in this study we suggest that pilocytic astrocytoma has a specific spectroscopic metabolic profile which could be diagnostic for this type of tumor

Correltion between magnetic resonance imaging and arthroscopic findings in patients with anterior cruciate injuries

The stabilizing anterior cruciate ligament prevents anterior translation and abnormal internal rotation of the tibia during standing and walking. Its disruption lead to loss of stability and potential significant dysfunction. This work was performed to evaluate the role of MRI in diagnosis of ACL injuries. This study was carried out on 50 patients with anterior cruciate ligaments injuries. They were classified into acute and chronic tears according to the time interval between injury and time of examination. All were examined by Magnetic Resonance Imaging [MRI] and by knee arthroscopy. A variety of MR signs were encountered and were classified into primary and secondary signs. Correlation of MR findings with arthroscopic findings was done revealing sensitivity, specificity, and accuracy of MR to be 88.8%, 50%, 81.8%. Accordingly, MRI is a non invasive reliable and versatile method of ACL tears assessment with a good sensitivity

Diagnostic value of spinal ultrasound: a comparative study with magnetic resonance imaging in infants with spinal dysraphism

Spinal dysraphism refers to abnormalities with imperfect fusion of midline neural and bony structures of the spine. It is the most common congenital central nervous system abnormality, with myelomeningoceles occurring in up to 2 per 1000 live births. Aim of the work: this study aimed to assess the diagnostic value of spinal ultrasonography in pediatrics patients with spinal dysraphism. This study was carried out on 30 infants with clinically diagnosed or suspected spinal dysraphism who were referred by the Neurosurgery Department or outpatient clinic to the Radiology Department at Alexandria University Hospital over the period from May 2004 to April 2005. Ultrasonography findings were correlated with those of MRL The degree of agreement between both modalities was determined and rated as full, partial, or no consensus. Total consensus was achieved in 24 of 30 examinations. Partial consensus was achieved in six examinations with US showing main spinal anomaly but not additional details depicted by MRL There was ho significant difference between US and MRl results in diagnosing of the main spinal anomalies. So we concluded that ultrasound is a valuable tool for the diagnosis of congenital malformations in infancy especially in patients younger than six months of age

Tuberculuous spondylitis and vertebral pyogenic infection: how far can MRI differentiate?

evaluation of the vertebral osteomyelitis and tuberculous spondylitis need an accurate and specific imaging modality to guide invasive procedures for a definitive microbiological diagnosis and to spare patients with other disorders that might mimic these entities a percutaneous or open biopsy. the aim of this study is to assess the validity of Magnetic Resonance Imaging [MRI] in diagnosis and characterization of the spinal infection, either pyogenie or graulomatous, and specifically the tuberculous spondylitis. twenty patients who were clinically and radiographically suspected of having vertebral osteomyelitis, or Tuberculous spondylitis They were evaluated with MRI after performing conventional x-ray of the involved spinal region, with analysis of the imaging findings by two experienced radiologists to set the imaging diagnosis. MRI findings showed good correlation with the clinical signs and symptoms in 19 patients out of the 20 included in this study, also these imaging findings revealed high predictive ratio for the spinal infection category in 19 out of 20 patients, with excellent accuracy and specificity ratios, ten patients were proved either radiologically or micobiologically to have spinal osteomyelitis, and the other ten to have Tuberculous spondylitis. MRI is an accurate and sensitive modality in diagnosis of spinal infection, and have a high specificity rate in characterization of the type of infection, it is also capable to give excellent anatomical details regarding the extra-vertebral extension of the encountered pathological process

Magnetic resonance imaging [MRI] of occult cerebro- vascular malformations

Occult cerebral vascular malformations [OCVMs] are an important cause of intracranial hemorrhage, epilepsy, and long-term disability in adults. There are scanty published prospective, population- based studies dedicated to the detection of any type of OCVMs [cavernous malformations, venous malformations, capillary telengectasia, and arteriovenous malformations [AVM]. The aim of this study is to assess the detection rate, and characterization of the occult vascular malformations using Magnetic Resonance Imaging [MRI]. All clinically suspected cases with OCVMs during two years, using two high magnetic fields MRI machines, CT scan was performed for the half of the cases, Angiography was performed for only four patients, while biopsy was available in six patients. The study included twenty patients with MRI diagnosis of OCVMs, either signal or multiple, and sometimes mixed forms. The MRI findings were excellent in detection of the lesions. the findings were more clear on Gradient Echo [GE] images, and the MRI diagnosis match the pathology reported in five out of six patients passed through this test Twenty one cavernomas, seven venous angiomas, three capillary telengectasias, and one thrombosed AVM were diagnosed MRI is a sensitive and specific tool for the diagnosis and morphological characterization of the OCVMs, Gradient- echo sequence should be included in its protocol for searching of such lesions, however further work may be needed for more assessment of its prevalence and detection of the mixed types