Venous Sinus Thrombosis Disease - Essay Example

?Comparison of MRV techniques Introduction Venous sinus thrombosis disease is the presence of a blood clot in the dural venous sinuses that drains blood from the brain. Doctors use different methods in diagnosing this condition. Different techniques yield similar results, yet they are said to contrast in a number of ways. Commonly applied techniques in the diagnosis of venous sinus thrombosis disease include the MRV techniques: 3D Contrast Enhanced (CE) MRV brain, 3D Phase Contras (PC) MRV, and 2D Time of Flight (TOF) MRV. Focus of the various research done in the past compare the efficiency and effectiveness of these techniques in diagnosing venous sinus thrombosis disease. This literature review is a comparison of these techniques. As such, the concern of the paper will be a focus on the effectiveness of each technique in diagnosing this condition and the reliability of the results. While some of the previous studies did compare either two or all three techniques, this research focuses on the three techniques. Using technical programs and methods, I will rely the verdict of the three techniques in the following literature review. In providing clinical neuroradiologists who perform clinical magnetic resonance venography (MRV) of the brain with the most reliable method of imaging the brain, Campeau, N. & Patton, A. (2013, p. 3671) compares the effect of 3D-TOF, 2D-TOF and gadolinium enhanced MRV techniques, all applied in 23 patients. Accuracy of the resultant PC-MRV images in detecting vascular stenosis as well as the quality and artifacts of the images obtained was used as the determinant for the most reliable technique. According to the results, 3D PC MRV acquisition was robust and successfully obtained in all patients. However, two attempts of Bolus gadolinium MRV yielded no results in a newborn, yet 3D PC MRV provided results in the same patient. For patients who register negative results to gadolinium, 3D PC MRV is recommended. The superiority of this technique in comparison to all three methods is seen by the fact that the technique provides less saturation dropout and has an improved visualization of cortical veins. Choosing the appropriate volume orientation minimizes saturation effects. Compared to sagittal or coronal directions, artifacts are more marked in the brain with axial acquisition. Techniques in medicine are said to be reliable if they yield better results. From the study, results of 3D PC MRV technique were more reliable and more effective in diagnosing venous sinus thrombosis in the patients, making it the best technique among all other techniques available. Various clinical situations necessitate imaging of the complex intracranial venous system. These include intracranial venous thrombosis and the preoperative assessment of meningioma among other intracranial tumors which require clear depiction of the patency of adjacent dural neural venous sinuses (Jui-Hsun et al. 2010, p.31). There has been a wide use of the two-dimensional time-of-flight (2D TOF) magnetic resonance venography (MRV) as a means of visualizing the intracranial venous system. The major limitation of 2D TOF MRV is its intravascular signal loss resultant from either in-hale saturation of spins or tortuosity and turbulent flows that occurs from various points such as the posterior portion of the sagittal sinus, torcular herophili, transverse sinus, transverse-sigmoid junction, and sigmoid sinuses. In their study, Jui-Hsun et al. (2010) sought to provide a remedy to this. 3-dimensional gadolinium-enhanced elliptic centric-ordered (3D GEC) MRV was found as the most effective technique. This technique is flow-insensitive, and avoids common flow related artifacts seen on 2D TOF MRV. To prove this, the researchers sought to compare real-time three-dimensional gadolinium-enhanced elliptic centric-ordered Mr Venography and two-dimensional time-of-flight Mr Venography of the intracranial venous system. In their study, 53 patients were subjected to 2D and 3D MRV tests and their venous structures evaluated by 2 neuroradiologists. In their results, the superiority of the 3D MRV over 2D MRV technique was evident. The technique, as they found out, provided more details on the intracranial venous system, leading to better diagnosis of venous condition. Further research indicates that the diagnosis of dural sinus thrombosis is often difficult due to a number of reasons. Such factors as its variability and nonspecific clinical presentation as well as the overlapping signal intensities, coupled with venous flow on conventional MR images and MR venograms makes the process of diagnosing such condition hectic. To access the normal and abnormal dural sinuses as well as the extent of reliability of all the methods, the researchers compared  3D contrast-enhanced magnetization-prepared rapid gradient-echo (MP-RAGE) sequences with 2D time-of-flight (TOF) MR venography, digital subtraction angiography (DSA), and conventional spin-echo (SE) MR imaging (Liang, et al. 2001). The study involved a clinical study of 35 patients, of whom 18 were suspected to suffer from sinus thrombosis. Both the MR and DSA techniques were used in the study. SNR flow increases with the increasing contrast in concentration. However, it does not affect the angle between the tube and the scan slab. Results from the study indicated that there was no particular relationship whatsoever between the tube and the scan slab. There was a clear view of both dural sinus thrombosis and the normal anatomy of the dural sinuses in with 3D contrast-enhanced MP-RAGE compared to 2D-TOF MR venography. Three-dimensional contrast-enhanced MP-RAGE shows increased levels of diagnostic confidence on ROC curves in the diagnosis of thrombosis. While most of the studies depict 3D- dimensional contrast-enhanced depicts better results than the 2D-dimensional contrast-enhanced technique, others reveal the two to be at per with each other in reference to their results. The quality of visualizing the thalamostriate and Galen veins as well as superior sagittal, rectal, and transervese sinuses reveals the reliability of the results obtained from any of the methods used. As such, a comparison between the visualization of cerebral veins and dural sinuses at contrast material-enhanced three-dimensional (3D) fast low-angle shot (FLASH) magnetic resonance (MR) angiography, time-of-flight (TOF) MR angiography, and phase-contrast MR angiography study conducted by Kirchohof, et al (2002) revealed that both techniques had similar results. Conclusion Different studies conducted in the past have sought to determine the most effective of all the three methods used in diagnosing venous sinus thrombosis disease. Doctors and medical experts face the problem of deciding on the best out of the three methods of diagnosing the venous sinus thrombosis disease, that is 3D Contrast Enhanced (CE) MRV brain, 3D Phase Contras (PC) MRV, and 2D Time of Flight (TOF) MRV. Of all the three, research has indicates that 3D Phase Contras (PC) MRV is the most superior. With its ability to provide clear results, research reveals that this is the most reliable of all the other methods of diagnosing the disease. Although the 2D Time of Flight (TOF) MRV is a reliable technique, it cannot match the efficiency of the 3D Phase Contras (PC) MRV technique. One of the major reasons as suggested by the previous research reviewed in this essay that makes the 3D Phase Contras (PC) MRV as the imaging of the imaging quality as provided by each results. As such, this technique is more reliable than all the other techniques. Read More