Anatomical relationships between medullary veins and three types of deep-seated malignant brain tumors as detected by susceptibility-weighted imaging.

BACKGROUND: Deep-seated brain tumors can be difficult to differentiate. Three tumor types (primary central nervous system lymphoma [PCNSL], high-grade glioma, and metastatic brain tumors), identified by susceptibility-weighted imaging, have different relationships with small medullary veins, and these relationships can be used to enhance diagnostic accuracy. METHODS: Records of patients with pathology confirmed malignant brain tumors who received susceptibility-weighted imaging between 2009 and 2015 were reviewed. A total of 29 patients with deep-seated malignant brain tumors in the territory of small medullary veins were enrolled in this study. The sensitivity, specificity, and diagnostic accuracy of medullary vein blockage (MVB), defined as a small medullary vein terminating at the margin of the tumor, for indicating malignant brain tumors were analyzed. RESULTS: Of 11 patients with PCNSLs, 5 with high-grade gliomas, and 13 with metastases, only the latter presented MVBs. The sensitivity, specificity, and accuracy of using MVBs for diagnosing metastatic tumors were 76.9%, 100%, and 89.7%, respectively. CONCLUSION: An MVB is an accurate sign for differentiating metastatic brain tumors from two other common malignancies and thus provides a useful tool for preoperative planning.

Predicting Mortality in Patients With "Malignant" Middle Cerebral Artery Infarction Using Susceptibility-Weighted Magnetic Resonance Imaging: Preliminary Findings.

To evaluate malignant middle cerebral artery (MCA) infarction (defined as space-occupying edema in more than 50% to 75% of the MCA territory) on magnetic resonance imaging (MRI) with susceptibility-weighted imaging (SWI) sequence and assess the usefulness of SWI findings, diffusion-weighted imaging (DWI) findings, and apparent diffusion coefficient (ADC) as predictors of clinical outcome.Data from 16 patients with large MCA infarction previously admitted to our institution between December 2009 and October 2012 were retrospectively collected and analyzed. Within 7 days after stroke onset, 1 neurologist and 1 neuroradiologist estimated the area of infarction on DWI/ADC and extent of prominent vessel sign (PVS) on SWI images using the Stroke Program Early MR Score (SPEMRS). The PVS on SWI was defined as a local prominence of hypointense vessels with either increased vessel number or diameter in the target area, when compared with the number or diameter of the contralateral MCA territory vessels.Six patients died and 10 survived. Although the DWI/ADC-SPEMRS and clinical profiles were similar between the nonsurvivor and survivor groups, SWI-SPEMRS was significantly lower in the nonsurvivor group (P < 0.001).The area of deoxygenation on SWI in patients with malignant MCA infarction can predict mortality. Lower SWI-SPEMRS is a potentially better predictor of poor outcome than lower DWI-SPEMRS. A larger prospective study is needed to clarify the role of SWI as a therapeutic guide in malignant MCA.

Prominent vessel sign on susceptibility-weighted imaging in acute stroke: prediction of infarct growth and clinical outcome.

BACKGROUND AND PURPOSE: Predicting the risk of further infarct growth in stroke patients is critical to therapeutic decision making. We aimed to predict early infarct growth and clinical outcome from prominent vessel sign (PVS) identified on the first susceptibility-weighted image (SWI) after acute stroke. MATERIALS AND METHODS: Twenty-two patients with middle cerebral artery (MCA) infarction had diffusion-weighted imaging, SWI, MR angiography, and clinical evaluation using the National Institutes of Health Stroke Scale at 7-60 hours and 5-14 days after stroke onset. Late-stage clinical evaluation at 1 and 3 months used the modified Rankin Scale. The infarct area and growth were scored from 10 (none) to 0 (infarct or growth in all 10 zones) using the Alberta Stroke Program Early CT Score (ASPECTS) system. RESULTS: Infarct growth on the second MRI occurred in 13 of 15 patients with PVS on the first MRI and not in any patient without PVS (n=7; r=0.86, P<0.001). The extent of PVS was significantly correlated with infarct growth (r=0.82, P<0.001) and early-stage outcome (P=0.02). No between-group difference in late-stage clinical outcome was found. CONCLUSION: PVS on the first SWI after acute MCA territory stroke is a useful predictor of early infarct growth. Extensive PVS within the large MCA territory is related to poor early-stage outcome and could be useful for clinical assessment of stroke.

Intracranial venous hemodynamics and rupture of cerebral aneurysm.

Many uncertain and inconsistent etiologies of cerebral aneurysmal rupture including a wide spectrum of factors have been reported. Our recent observation discloses the potential new factor of cerebral aneurysm rupture with cerebral venous pressure gradient. We retrospectively reviewed 52 cases treated with coil embolization with or without cerebral aneurysmal rupture. Seventeen males and 30 females were recruited in this study. Quantitative color-coded cerebral angiography was performed during coil therapeutic procedures to measure cerebral venous circulation. Ruptured cases had shorter and symmetrical cerebral venous circulation time (P <0.05). In addition, an asymmetrical venous outflow pattern was critical for aneurysmal rupture. Non-ruptured cases tended to have slower and asymmetrical cerebral venous circulation compared with rupture cases. Symmetrical and shorter cerebral venous circulation in the dysplasia venous outlet may be a potential new factor for cerebral aneurysm rupture.

Advanced MR imaging of gliomas: an update.

Recent advances in the treatment of cerebral gliomas have increased the demands on noninvasive neuroimaging for the diagnosis, therapeutic planning, tumor monitoring, and patient outcome prediction. In the meantime, improved magnetic resonance (MR) imaging techniques have shown much potentials in evaluating the key pathological features of the gliomas, including cellularity, invasiveness, mitotic activity, angiogenesis, and necrosis, hence, further shedding light on glioma grading before treatment. In this paper, an update of advanced MR imaging techniques is reviewed, and their potential roles as biomarkers of tumor grading are discussed.

Predicting stroke evolution: comparison of susceptibility-weighted MR imaging with MR perfusion.

OBJECTIVES: To investigate the ability of susceptibility-weighted imaging (SWI) to predict stroke evolution in comparison with perfusion-weighted imaging (PWI). METHODS: In a retrospective analysis of 15 patients with non-lacunar ischaemic stroke studied no later than 24 h after symptom onset, we used the Alberta Stroke Program Early CT Score (ASPECTS) to compare lesions on initial diffusion-weighted images (DWI), SWI, PWI and follow-up studies obtained at least 5 days after symptom onset. The National Institutes of Health Stroke Scale scores at entry and stroke risk factors were documented. The clinical-DWI, SWI-DWI and PWI-DWI mismatches were calculated. RESULTS: SWI-DWI and mean transit time (MTT)-DWI mismatches were significantly associated with higher incidence of infarct growth (P = 0.007 and 0.028) and had similar ability to predict stroke evolution (P = 1.0). ASPECTS values on initial DWI, SWI and PWI were significantly correlated with those on follow-up studies (P ≤ 0.026) but not associated with infarct growth. The SWI ASPECTS values were best correlated with MTT ones (ρ = 0.8, P < 0.001). CONCLUSIONS: SWI is an alternative to PWI to assess penumbra and predict stroke evolution. Further prospective studies are needed to evaluate the role of SWI in guiding thrombolytic therapy. Key Points • SWI can provide perfusion information comparable to MTT • SWI-DWI mismatch can indicate ischaemic penumbra • SWI-DWI mismatch can be a predictor for stroke evolution.

Diagnosis and management of cerebral venous thrombosis: a statement for healthcare professionals from the American Heart Association/American Stroke Association.

BACKGROUND: The purpose of this statement is to provide an overview of cerebral venous sinus thrombosis and to provide recommendations for its diagnosis, management, and treatment. The intended audience is physicians and other healthcare providers who are responsible for the diagnosis and management of patients with cerebral venous sinus thrombosis. METHODS AND RESULTS: Members of the panel were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and represent different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 1966 and used the American Heart Association levels-of-evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee. CONCLUSIONS: Evidence-based recommendations are provided for the diagnosis, management, and prevention of recurrence of cerebral venous thrombosis. Recommendations on the evaluation and management of cerebral venous thrombosis during pregnancy and in the pediatric population are provided. Considerations for the management of clinical complications (seizures, hydrocephalus, intracranial hypertension, and neurological deterioration) are also summarized. An algorithm for diagnosis and management of patients with cerebral venous sinus thrombosis is described.

Susceptibility weighted imaging and cerebrovascular disorders.

To investigate the correlation between the SWI findings and prognosis of the cerebrovascular disorders. From July 2008 to July 2010, 299 ischemic stroke patients were found in our hospital. The gender ratio is as male and female being 157 to 142. The mean age of all patients is 65.4, mean female age is 69.1, and mean male age is 62.6. There were 86 patients who had satisfactory pre-and post-treatment of CT, MRI with SWI. 23 of these 86 patients had catheter cerebral angiography. 50 of these 86 patients had MR angiogram or CT angiogram. 13 of these 86 patients did not have angiogram. We have also collected 7 severe cardiac arrested and cessation of cerebral circulation and 2 patients with chronic venous hypertension. Among the 86 patients, 23 patients who had negative with deoxygenated vessel on SWI were with small infarction on DWI. Thirty-one patients had negative on initial CT head scan. CT finding did not accord with presence of hypointense vessel on SWI. Sixty-three patients had varied degree of abnormal hypointense vessels on SWI as deoxygenated vessels. The initial small foci on DWI may result with a larger infarction if there were with prominent hypointense vessels.

Venous hypertension and cerebral aneurysm rupture.

To investigate the correlation between the sinus asymmetry and aneurysm rupture. We retrospectively reviewed all diagnostic and therapeutic conventional angiograms of patients with cerebral aneurysms in our hospital from January 2000 to April 2008. Cases were categorized according to gender, presence or absence of aneurysm rupture, and presence or absence of symmetric dural sinuses. Exclusion criteria included patients with underlying fibromuscular dysplasia, dissecting aneurysms, pseudoaneurysms, and the presence of arteriovenous malformations or fistulas. The venous pressure was measured by MR phase contrast with standard fluid dynamics notation as Poiseuille's Law. A total of 193 cases (131 females and 62 males) were included for Chi-squared analysis, which showed significant difference (p < 0.05) between aneurysm rupture and venous asymmetry in the entire group as well as in females, but not in males. There was an association between side of rupture and side of asymmetry as well as between the size of hemorrhage. Ruptured aneurysm is more frequent at the same side of dominant dural sinus than the side of hypoplasia venous sinus. MRA phase contrast is able to show the venous pressure gradient of asymmetrical dural sinuses. With our preliminary data, we propose that dural sinus asymmetry is associated with aneurysm rupture.

Susceptibility-weighted imaging for differential diagnosis of cerebral vascular pathology: a pictorial review.

Susceptibility-weighted imaging (SWI) is a high-spatial resolution, three-dimensional, gradient-echo (GRE) magnetic resonance (MR) technique. This fully velocity-compensated pulse sequence utilizes the magnetic susceptibility differences of various tissues or substances, such as blood products, iron, and calcification. By postprocessing the magnitude images using a phase mask, it emphasizes the magnetic properties of different susceptibility effects. Generated minimal intensity projection (minIP) images can further demonstrate tortuous vasculature and the continuity of vessels or abnormalities across slices. SWI has been used to improve the diagnosis of neurological trauma, brain neoplasm, neurodegenerative disorders, and cerebrovascular disease because of its ability to demonstrate microbleeds and conspicuity of the veins and other sources with susceptibility effects. We have used SWI to identify cerebrovascular lesions which may be obscured on other MR sequences to aid in the differential diagnosis. We present a review with selected cases to demonstrate the usefulness of this new neuroimaging technique in improving the diagnosis of cerebral vascular pathology.

Mobile healthcare: the opportunities and challenges.

Mobile healthcare is an important extension of electronic healthcare. It enables the caregivers to have an ubiquitous and uninterrupted access to patients' clinical data and the latest medical knowledge; concurrently, it allows patients with chronic conditions to remain under constant observation without needing to be physically present at the clinic. The critical challenges to a full-scale implementation include establishing interoperability among electronic health records, developing better display technologies and security controls for mobile devices and developing smart algorithms to detect clinically significant events before notifying caregivers. As a consequence of mobile healthcare, new opportunities for physician-patient joint decision-making and personalized healthcare are beginning to take shape. Accompanying them are the challenges of mindset adjustment, the empowerment of patients with medical knowledge in everyday language and ensuring the confidentiality of patient data.

Cerebral sinovenous thrombosis. Neuroimaging diagnosis and clinical management.

SUMMARY: Cerebral sinovenous thrombosis (CSVT) is an uncommon disorder that affects the dural venous sinus and cerebral vein. In our study, thirty- four patients were examined. Pre and/or post contrast-enhanced CT was done in 28 patients. MRI studies were done in 24 patients. 2-D TOF MR venography (MRV) and contrast-enhanced MRV (CEMRV) were done in 19 cases. Digital subtraction angiography (DSA) was done in 18 patients. Sixteen patients received systemic intravenous heparinization, and 12 received endovascular thrombolytic treatment with urokinase combined with anticoagulant therapy. Neuroimages of CSVT can be acquired by direct visualization of the thrombus within the dural sinus or by parenchymal changes secondary to venous occlusion. As there are some pitfalls to MRI in the diagnosis of CSVT, the combination of MRI and MRV is now the gold standard in the diagnosis of CSVT. Usually, accuracy can be improved by applying 2-D TOF MRV and CE MRV. Furthermore, the source image of MRV is critical in differentiating between normal sinus variations and diseased ones. DSA is the best tool for demonstrating dynamic intracranial circulation in CSVT and mostly is used for endovascular treatment. Systemic intravenous anticoagulant therapy with heparin is accepted as a first line treatment. Except for clinical manifestations after systemic heparinization, abnormal MR findings of parenchymal change can be used to determine when to initiate thrombolytic treatment. Endovascular therapy can be finished at the antegrade flow within the dural sinus and continuous anticoagulation is sufficient to facilitate clinical improvement. Clinical suspicion and excellent neuroimaging are crucial in making the diagnosis of CSVT. Proper management with anticoagulants and/or endovascular thrombolytic therapy is mandatory in preventing propagation of the thrombosis and improving the clinical outcome.

The impact of globalisation on teleradiology practice.

Some advocates of globalisation argue that a free market with little regulation is the best approach for achieving cost-effective healthcare. Healthcare, however, is different from other business activities in that it is typically less profit-driven; instead, it often involves the goal of providing equitable care to the underprivileged. Traditionally, the government has subsidised the expenses of delivering affordable healthcare to underserved communities. Because of the many recent advances in telecommunications technology, telemedicine has gained increasing attention. Teleradiology, in particular, is by far the maturest of all telemedicine disciplines and, thus, it may serve as a pivotal indicator of whether telemedicine on a global scale is feasible or not. In this paper, a prediction of the future landscape of globalised teleradiology operations is attempted based on the extrapolation of the historical trends in teleradiology practice as well as the growing pressure on federal and local governments to reduce their regulatory power under the General Agreement on Trade in Services (GATS).

Static magnetotherapy for the treatment of insomnia.

Magnets have been used for centuries to treat a number of physical disorders. The vast majority of research, however, on static magnet therapy for insomnia has been confined to the auricular type of therapy, with publications limited to Chinese journals. Most of these studies have depended on the subjective self-assessment of participants rather than objective scientific measurements. In this study, the authors report the positive preliminary results of insomnia treatment using pillows with embedded magnets, magnetic insoles and TriPhase bracelets. The analysis is based on objective actigraphic and polysomnographic data. A theory of accelerated transition from wakefulness to sleep is proposed to explain the process of insomnia relief through low-strength static magnetic fields. Analysis by functional Magnetic Resonance Imaging (fMRI) is used to further investigate the theory.

Cerebral venous congestion as indication for thrombolytic treatment.

PURPOSE: To carry out a retrospective analysis of patients with acute dural sinus thrombosis, and the role of cerebral venous congestion in patient management. METHODS: Twenty-five patients were identified with the clinical and imaging diagnosis of acute dural sinus thrombosis. The imaging diagnosis was by magnetic resonance (MR) and/or computed tomography (CT) venography. There was a female predominance with a female to male ratio of 1.5 to 1 (16 women, 9 men). The age range was from 19 to 64 years old with an average age of 37 years. The first 10 patients, who ranged in age from 21 to 64 years old (average 37 years), received only anticoagulation therapy with heparin and warfarin for periods ranging from 5 days to 2 months. The remaining 15 patients ranged in age from 19 to 57 years old (average 38 years). They either underwent subsequent thrombectomy after a trial of anticoagulation therapy, or went straight to thrombectomy. These latter 15 patients had initial evidence of cerebral venous congestion, either clinically by severe or worsening symptoms despite anticoagulation therapy, or on initial or subsequent CT or MR imaging. In our experience, the cerebral venous congestion imaging findings included intracranial hemorrhage, a hematoma, or edema. The thrombolytic treatment technique consisted of the advancement of a 6 Fr guiding catheter to the jugular bulb or sigmoid sinus from a transfemoral approach. A microcatheter was then advanced to the proximal portion of the thrombus and then either tissue plasminogen activator (tPA) or urokinase was injected to prevent clot propagation. A balloon catheter was used to perform thrombectomy since the thrombolytic agents can be injected via the inner lumen with an inflated balloon. The inflated balloon helped to keep the venous flow from washing out the thrombolytic agent, thus facilitating the agent's effect. RESULTS: The first 10 patients received only anticoagulation therapy with heparin and warfarin for periods ranging from 5 days to 2 months. Eight of these were diagnosed with dural sinus thrombosis only, and had a stable hospital course without worsening of symptoms. These patients also did not have imaging evidence of cerebral venous congestion. The remaining 2 patients had cerebral edema on the CT scan. One had only a small amount of edema in the right cerebellum, but the other had severe edema in the bilateral basal ganglia and thalamic areas. Nine of these patients had a stable hospitalization course and experienced a symptom-free recovery, but 1 died with severe cerebral edema and hemorrhage. Seven of the remaining 15 patients were initially treated with anticoagulation therapy for periods ranging from 2 days to 2 months (average 11 days). These 7 patients were considered to have failed anticoagulation therapy since they had worsening symptoms, and 5 of these had developed hemorrhage on subsequent CT or MR imaging scans. Five of the 7 then underwent thrombectomy with the administration of tPA. Of the remaining 2, 1 underwent thrombectomy alone without the administration of tPA, and the other was given 1 million units of urokinase instead of tPA. Three of these patients had a symptom-free recovery, but 2 had residual left-sided weakness, 1 patient had a minimal gait disturbance, and another patient developed a transverse sinus arteriovenous fistula 7 months after thrombolytic therapy. The remaining 8 patients did not receive anticoagulation therapy, and went straight to treatment with thrombectomy and administration of tPA. All of these presented with worsening clinical symptoms. Six had hemorrhage on their imaging studies, 1 had new edema on a subsequent CT scan, and 1 had edema along with the dural sinus thrombosis, but experienced worsening clinical symptoms consisting of headache and atypical dystonia. Five of these 8 patients experienced a symptom-free recovery, and 3 patients had mild residual weakness. CONCLUSION: In patients with acute dural sinus thrombosis, an indication for thrombectomy or thrombolytic therapy may be the development of cerebral venous congestion which appears to include (1) worsening or severe clinical symptoms, and/or (2) CT or MR imaging findings including intracranial hemorrhage, a hematoma, or edema. It appears that anticoagulation therapy alone is not adequate in patients with acute dural sinus thrombosis when they develop cerebral venous congestion. This may be due to a lack of sufficient collateral flow. Those patients who went straight to thrombectomy because of worsening symptoms, or the imaging findings of cerebral vascular congestion, survived with either a symptom-free recovery or only mild residual neurologic deficit. The patient with evidence of cerebral venous congestion died while on anticoagulation therapy. Thus, the presence of cerebral venous congestion in patients with dural sinus thrombosis, even while on anticoagulation therapy, appears to be an indication for thrombectomy and infusion of thrombolytic agent through a balloon catheter to the site of thrombosis. Our experience suggests that this approach appears to improve the chance of survival, with either a symptom-free recovery or a recovery with only mild residual neurologic deficit.

Use of Yttrium-90 TheraSphere for the treatment of unresectable hepatocellular carcinoma.

This is a retrospective analysis of a new treatment modality, intra-arterial administration of Yttrium-90 TheraSphere, for unresectable hepatocellular carcinoma (HCC). Patients with HCC not amenable to surgical treatment who had satisfactory physiological function without comorbid disease or significant pulmonary shunting were eligible for treatment. Patients were categorized into complete, partial, or no response based on serum alpha-fetoprotein (AFP) levels and CT or MRI imaging. Fourteen patients were considered candidates for treatment. Three patients were excluded due to significant hepatopulmonary shunting. Eleven patients were treated with TheraSphere. One patient (9%) had a complete response, eight patients (78%) had a partial response, and two patients (18%) showed no response. Partial and complete responders with AFP-associated HCC demonstrated a median decrease in AFP levels of 79 per cent at 73 days. No patients developed liver toxicity nor died due to treatment. Five patients (45%) died of progressive disease at a median of 7 months post-treatment. Six patients (54%) were alive at a median of 11 months (range, 9 to 20 months). Okuda stage 2 and 3 patients showed a median survival of 11 months and 7 months, respectively. Yttrium-90 TheraSphere treatment for unresectable hepatocellular carcinoma is well tolerated and appears to extend survival.

Quantitative functional MR imaging of the visual cortex at 1.5 T as a function of luminance contrast in healthy volunteers and patients with multiple sclerosis.

BACKGROUND AND PURPOSE: In patients with multiple sclerosis (MS), a few preliminary functional MR (fMR) imaging studies of the visual cortex reveal information about magnitude differences between healthy individuals and patients with MS at only a single luminance level. We therefore investigated whether varying luminance contrast levels can help uncover subtle changes in fMR imaging characteristics of the visual cortex in healthy volunteers and patients with MS. METHODS: Blood oxygenation level-dependent fMR imaging signal changes in the primary visual cortex were examined as a function of luminance contrast at 1.5 T in 10 healthy volunteers and nine patients with MS. Ten axial sections through the calcarine fissure were obtained with an echo-planar T2*-weighted imaging sequence (4000/54/1 [TR/TE/excitation]; field of view, 220 mm; voxel size, 1.72 x 1.72 x 5 mm). The imaging series consisted of an alternating 20-second rest epoch (black screen) with a 20-second activation epoch (flickering checkerboard) repeated six times. Each imaging series used a graded increase of eight luminance contrast levels. A paired t test between rest and activation images was used to analyze significant (P <.001) contiguous voxels in the region of interest (primary visual cortex). RESULTS: A progressive increase in fMR imaging activation across all luminance contrast levels in healthy controls and patients with MS was shown. The patients with MS had a significantly lower magnitude in the number of fMR imaging activated voxels at all luminance contrast levels (P <.001). A statistically significant increase in fMR imaging activation (activation threshold) was seen at the second luminance contrast level in controls and at the seventh level in patients with MS. CONCLUSION: Quantifiable changes in blood oxygenation level-dependent signal and a progressive increase in activated voxels within the primary visual cortex with increasing luminance contrast were demonstrated at 1.5 T in controls. The patients with MS showed a significant decrease in the number of activated voxels and an increase in activation threshold compared with healthy controls.