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Venous Sinus Occlusive disease: Comparing Routine MRI to Diffusion Weighted Images
Z. Miabi
Iranian Journal of Radiology , 2005,
Abstract: Introduction & Background: Brain MR findings in cerebral venous thrombosis (CVT) are mass effect, hyperintense parenchymal abnormalities on T2 weighted images, and intraparenchymal hematoma. Unlike conventional MR images, diffusion weighted (DW) MR is sensitive to water diffusion, and thus can differentiate vasogenic from toxic edema. In this study, we sought to characterize parenchymal changes associated with CVT on DW images, and de-termine whether this technique could differentiate resolvable injuries from permanent ones. Patients & Methods: We reviewed patient charts and T2 weighted MR images of 20 patients with CVT complicated by intraparenchymal abnormality. DW and conventional MR images were evaluated for any change in the signal intensity, and the signal intensity of the normal appearing contralateral brain was used for comparison. Results: DW images disclosed 3 lesion types: lesions with a high diffusion that resolved, consistent with vasogenic edema; lesions with a low diffusion that persisted, consistent with cytotoxic edema in patients without seizure activity; and lesions with low diffu-sion that resolved in patients with seizure activity. Conclusion: The DW imaging can help to prospec-tively determine the severity of irreversible brain in-jury, and have clinical implications in patient man-agement.
Diffusion-weighted MR imaging of cystic lesions of neurocysticercosis: a preliminary study
Raffin, Luciana S.;Bacheschi, Luiz A.;Machado, Luis R.;Nóbrega, José P.S.;Coelho, Christina;Leite, Claudia C.;
Arquivos de Neuro-Psiquiatria , 2001, DOI: 10.1590/S0004-282X2001000600001
Abstract: neurocysticercosis is an endemic disease in some developing countries. it has pleomorfic clinical and imaging findings, which are variable from patient to patient. in this preliminary note, we studied the magnetic resonance (mr) diffusion-weighted images (dwi) of sixteen patients presenting with cystic lesions of this disease diagnosed by clinical and laboratorial findings. all the lesions had hypointense signal and the similar apparent diffusion coeficient (adc) values as the cerebrospinal fluid (csf).
Diffusion-weighted MR imaging of cystic lesions of neurocysticercosis: a preliminary study  [cached]
Raffin Luciana S.,Bacheschi Luiz A.,Machado Luis R.,Nóbrega José P.S.
Arquivos de Neuro-Psiquiatria , 2001,
Abstract: Neurocysticercosis is an endemic disease in some developing countries. It has pleomorfic clinical and imaging findings, which are variable from patient to patient. In this preliminary note, we studied the magnetic resonance (MR) diffusion-weighted images (DWI) of sixteen patients presenting with cystic lesions of this disease diagnosed by clinical and laboratorial findings. All the lesions had hypointense signal and the similar apparent diffusion coeficient (ADC) values as the cerebrospinal fluid (CSF).
Reliability of diffusion weighted MR imaging in differentiating degenerative and infectious end plate changes
Ozgur Oztekin, Cem Calli, Omer Kitis, Zehra Hilal Adibelli, Cemal Suat Eren, Melda Apaydin, Mehmet Zileli, Taskin Yurtseven
Radiology and Oncology , 2010, DOI: 10.2478/v10019-010-0006-z
Abstract: Background. The aim of the study was to investigate the value of diffusion weighted MR imaging in the diagnosis of Modic type 1 change, which may be confused with the acute infectious spondylodiscitis on conventional MR imaging. Patients and methods. Twenty-seven patients with erosive intervertebral osteochondrosis, Modic type 1 and 18 patients with spondylodiscitis were included in this retrospective study. All images were acquired using on 1.5 Tesla MR units. Lumbar spinal MR imaging of 45 patients were retrieved from a digital database of a radiology record system and evaluated by one experienced radiologist. Patients with Modic type 1 change had CT slices obtained from the diseased disc space and the affected vertebrae. Results. Bone marrow adjacent to the vertebral end plate in both Modic type 1 change and acute spondylodiscitis were hypointense on T1-weighted images. On T2-weighted images corresponding levels of vertebral end-plates showed hyperintense signal intensity in both group. All the patients with spondylodiscitis and Modic type 1 change were hyperintense and hypointense on diffusion-weighted MR images, respectively. Conclusions. Our findings suggest that diffusion weighted MR imaging is an useful method in differentiating Modic type 1 changes from acute spondylodiscitis, both of which may mimic each other, either on clinical or conventional MRI findings.
Comparison of MR images for age determination; T1 weighted images (T1WI) versus T2* weighted images (T2*WI)  [cached]
Yoshikazu Shimada,Daisuke Shimao,Jiro Kobayashi,Chikako Nakahori
Asian journal of Sports Medicine , 2012,
Abstract: Purpose: T1WI (T1 weighted image) was acquired in order to grade bone fusion following the studies by FIFA (Federation Internationale de Football Associations). Research using images other than T1WI has not been reported. The aim of this study is to evaluate the grade of epiphyseal fusion by T2* weighted images (T2*WI) and to investigate new findings on T2*WI as compared with T1WI.Methods: A total of 87 subjects, all junior football players between the ages of 12 and 17 years old, were examined. T1 and T2* WI were obtained using a 1.2T Open type MR system. The T1WI and T2*WI were rated twice randomly by four radiologists using the FIFA grading system.Results: The intra-rater reliability for grading was higher in T1WI (The Intraclass Correlation Coefficient (ICC)=0.949-0.985) than in T2*WI (ICC=0.917-0.943). The inter-rater reliability for grading was also higher in T1WI (ICC=0.923) than in T2*WI (ICC=0.867).Conclusions: This research showed that T1WI is a better sequence than T2*WI to evaluate bone fusion following FIFA protocol. It was speculated that the reason for this is that T1WI has higher tissue contrast resolution and enables clearer images of the epiphyseal fusion than T2*WI and the grading system by T1WI was not suitable for T2*WI.
Analysis of Cerebral Infarct Signal Intensity on Diffusion-Weighted MR Images Using Frequency Domain Techniques
American Journal of Biomedical Engineering , 2012, DOI: 10.5923/j.ajbe.20120203.06
Abstract: Early and accurate diagnosis of cerebral infarction plays a vital role in the implementation of successful treatment and thereby improving the quality of life. Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) is a highly sensitive tool for the detection of early changes in the water diffusion that characterizes various brain pathologies, largely, cerebral infarctions. Studies were performed on a set of Diffusion Weighted (DW) images of the human brain (in the axial plane) to find the relationship between the light intensity High Frequency Power (HFP) values and the time course of cerebral infarction, and to present evidence in defining the stages of cerebral infarction. Analysis of the results show that the difference in the light intensity HFP values on the DW images for the subjects with cerebral infarction compared to their contralateral normal hemisphere, were highly significant (p < 0.01) in the areas of the brain, where there was a high incidence of infarction. The relative increase in the light intensity HFP values (RHFP) for the subjects with cerebral infarction were in the range of (153.06 – 1780.43) times compared to their corresponding HFP values on the contralateral normal hemisphere. The observed RHFP values increased progressively with time and were at the peak for the examinations between 1 to 4 days and thereafter reduced to reach the minimum after 15 days. There was a negative correlation (r = - 0.74) observed between the RHFP values and the time stage of cerebral infarction. The evolution of the RHFP values observed subsequent to infarction is suggestive that they can be supportive in understanding the developmental stages of infarction and can be helpful in predicting the stage of infarction. The quantitative changes in the light intensity HFP values can be assessed to derive information about the early changes taking place in the brain tissue. Further their adoption in clinical diagnosis and treatment of cerebral infarction could be helpful and informative. In conclusion, the proposed method could positively assist the neuro-surgeons for speedy diagnosis and execution of treatment to protect the subjects from additional damage to their brain tissue. In summary, the present study provides evidence that the light intensity HFP values on the DW images in the region of cerebral infarction can be used to markedly distinguish the infarct subjects quantitatively from the normal subjects. The relative increase in the light intensity HFP values on the DW images for the subjects with cerebral infarction were in the range of (153.06 – 1780.43) times compared to their corresponding HFP values on the contralateral normal hemisphere. The quantitative changes in the values of the light intensity HFP parameter on the DW images can be assessed and positively employed to provide useful information about the early changes taking place in the brain tissue and can be helpful in determining the stage of cerebral infarction. Therefore the adop
Quantitative Analysis of Diffusion Weighted MR Images of Brain Tumor Using Signal Intensity Gradient Technique  [PDF]
S. S. Shanbhag,G. R. Udupi,K. M. Patil,K. Ranganath
Journal of Medical Engineering , 2014, DOI: 10.1155/2014/619081
Abstract: The purpose of this study was to evaluate the role of diffusion weighted-magnetic resonance imaging (DW-MRI) in the examination and classification of brain tumors, namely, glioma and meningioma. Our hypothesis was that as signal intensity variations on diffusion weighted (DW) images depend on histology and cellularity of the tumor, analysing the signal intensity characteristics on DW images may allow differentiating between the tumor types. Towards this end the signal intensity variations on DW images of the entire tumor volume data of 20 subjects with glioma and 12 subjects with meningioma were investigated and quantified using signal intensity gradient (SIG) parameter. The relative increase in the SIG values (RSIG) for the subjects with glioma and meningioma was in the range of 10.08–28.36 times and 5.60–9.86 times, respectively, compared to their corresponding SIG values on the contralateral hemisphere. The RSIG values were significantly different between the subjects with glioma and meningioma , with no overlap between RSIG values across the two tumors. The results indicate that the quantitative changes in the RSIG values could be applied in the differential diagnosis of glioma and meningioma, and their adoption in clinical diagnosis and treatment could be helpful and informative. 1. Introduction Neurological disorders pose a great challenge to healthcare in developing countries, as limited resources and manpower are not enough to tackle the increasing burden [1]. Although brain tumor is not a frequent neurological disorder, still it contributes significantly to morbidity and is no longer rare in clinical practice [2, 3]. Brain tumors can present challenging medical problems, and effective medical management would result in decreased morbidity and mortality and improved quality of life. Brain tumors are generally classified as either primary (originating from within the brain cavity) or secondary (originating elsewhere in the body, and then spread to the brain). The most common types of primary brain tumors are gliomas and meningiomas, constituting, respectively, 60% and 20% of all intracranial tumors (tumors within the brain) in adults [4]. Treatment varies from one tumor type to the other and often involves a combination of surgery, radiotherapy, and chemotherapy. Meningiomas are almost always benign tumors and have good prognosis after surgery, whereas gliomas being malignant tumors comprise multidisciplinary approach and have relatively poorer prognosis. Hence it is very essential to differentiate between the two tumor types especially when
A case of progressive multifocal leukoencephalopathy (PML): diffusion-weighted MR imaging findings  [PDF]
Oguz B,Karli-Oguz K,Akpinar E,Cila A
Neuroanatomy , 2003,
Abstract: Progressive multifocal leukoencephalopathy (PML) is a progressive subacute demyelinating disease caused by neurotropic papova virus, usually in immunocompromised patients. As the number of cases of AIDS increases so close the incidence of PML, the ability to diagnose PML noninvasively is of increasingly importance. A case of PML is presented with conventional magnetic resonance and diffusion-weighted images (DWI) performed at two consecutive months. Conventional MR imagings were performed on a 0.5 T and DWI was performed on 3 T scanner at follow-up.
Differential MRI Diagnosis Between Brain Abscess and Necrotic or Cystic Brain Tumors Using Diffusion Weighted Images
Zinat Miabi
Iranian Journal of Radiology , 2009,
Abstract: "nIntroduction: Differentiating brain abscesses from cystic or necrotic tumors by CT or MR imaging can be difficult. Difficulties in the diagnosis of intracranial abscess are mainly due to the combination of often unspecified clinical findings and similarities in the morphologic appearance of some intracranial mass lesions, such as cystic gliomas, metastases, and brain abscesses. Diffusion-weighted imaging provides a way to evaluate the diffusion properties of water molecules in tissue and has been used for diseases such as ischemia, tumors, epilepsy, and white matter disorders. The goal of this study was to evaluate the diagnostic utility of diffusion MRI to differentiate between brain abscesses and necrotic or cystic brain tumors. "nMaterials and Methods: MRI was performed in 17 patients (12 men and five women; age range, 19–74 years [mean, 55 years]) with necrotic lesions and MR imaging evidence of ring-shaped enhancement after the injection of contrast material .In addition to standard MR sequences diffusion weighted MRI with apparent coefficient (ADC) maps. "nResults: Eleven patients had tumors, and six had pyogenic abscesses. The tumors were glioblastomas (five patients), anaplastic astrocytoma (three patients), metastases (three patients), and primary malignancy, including lung (2) and breast (1) cancer. Surgical or stereotactic biopsies were obtained, and histologic studies were performed in all except one case (case 5). In the cases of abscess, bacteriologic analysis was also conducted. None of these lesions appeared hemorrhagic on T1-weighted images. "nConclusion: Diffusion-weighted imaging is useful for differentiating brain abscess from cystic or necrotic brain tumor, which is often difficult with conventional MR imaging. Diffusion-weighted imaging is useful as an additional imaging technique for establishing the differential diagnosis between brain abscesses and cystic or necrotic brain tumors. It requires less imaging time and is more accurate than conventional MRI. In differentiating between brain abscesses and cystic or necrotic brain tumors, diffusion-weighted imaging may improve the results compared to the use of a single technique.
Benchmarking the Quality of Diffusion-Weighted Images  [PDF]
Jan Klein,Sebastiano Barbieri,Miriam H. A. Bauer,Christopher Nimsky,Horst K. Hahn
Computer Science , 2011,
Abstract: We present a novel method that allows for measuring the quality of diffusion-weighted MR images dependent on the image resolution and the image noise. For this purpose, we introduce a new thresholding technique so that noise and the signal can automatically be estimated from a single data set. Thus, no user interaction as well as no double acquisition technique, which requires a time-consuming proper geometrical registration, is needed. As a coarser image resolution or slice thickness leads to a higher signal-to-noise ratio (SNR), our benchmark determines a resolution-independent quality measure so that images with different resolutions can be adequately compared. To evaluate our method, a set of diffusion-weighted images from different vendors is used. It is shown that the quality can efficiently be determined and that the automatically computed SNR is comparable to the SNR which is measured manually in a manually selected region of interest.
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