Cerebral Venous Thrombosis: Imaging and Spectrum of Etiologies

Transcription

1 Cerebral Venous Thrombosis: Imaging and Spectrum of Etiologies Poster No.: C-0787 Congress: ECR 2013 Type: Educational Exhibit Authors: B. Alami, S. Bellakhdar, M. Jaffal, O. Addou, M. Maaroufi, M. Boubou, I. Kamaoui, N. Sqalli, S. Tizniti; Fes/MA Keywords: Diagnostic procedure, MR, CT, Neuroradiology brain, Embolism / Thrombosis DOI: /ecr2013/C-0787 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 51

2 Learning objectives To be aware of the main etiologies of cerebral veinous thrombosis. To become familiar with imaging techniques and findings of cerebral veinous thrombosis. To learn about diagnostic pitfalls of cerebral veinous thrombosis. Background In this retrospective study we analyzed the clinical and the neuroimaging findings of patients with cerebral venous thrombosis collected at our hospital from January 2009 to December The diagnosis of cerebral venous thrombosis was made by MR and CT parenchymal images or with various venographic techniques: unenhanced time-of-#ight MR venography, and contrast material- enhanced MR venography and CT venography. I. Pathophysiology:(Fig. 1) Venous thrombosis is related to three factors commonly known as "Virchow's triad" including: Hypercoagulability Hemodynamic changes (stasis, turbulence) Endothelial injury/dysfunction The mechanism for venous infarction is obstruction of venous drainage with increasing venous pressure in the affected region of brain.. Cerebral venous infarction is initiated by thrombus propagation into draining cortical veins, causing significant extravasation of fluid into brain (vasogenic edema) and producing focal cerebral edema and hemorrhage. The lesion volume is probably influenced by the development of collateral veins. II. Anatomy of cerebral venous and dural sinus:(fig. 2) Major dural sinuses: * Superior sagittal sinus, transverse, straight and sigmoid sinuses. Page 2 of 51

3 Cortical veins: * Vein of Labbe, which drains the temporal lobe. * Vein of Trolard, which is the largest cortical vein that drains into the superior sagittal sinus. Deep veins: * Internal cerebral and thalamostriate veins. Cavernous sinus III. Radioanatomy of cerebral venous and dural sinus(fig. 3=> 8) Images for this section: Fig. 1: diagram of "Virchow's triad" Page 3 of 51

4 Fig. 2: Anatomy of cerebral venous and dural sinus Page 4 of 51

5 Fig. 3: CT of cerebral venous and dural sinus Page 5 of 51

6 Fig. 4: MRI OF dural sinus: T1WI Page 6 of 51

7 Fig. 5: MRI OF dural sinus: T2WI Page 7 of 51

8 Fig. 6: MRI of of cerebral venous and dural sinus:t1 C+ Page 8 of 51

9 Fig. 7: MRI of cerebral venous and dural sinus: T2* Page 9 of 51

10 Fig. 8: MRI of cerebral venous and dural sinus: 2DTOF Page 10 of 51

11 Imaging findings OR Procedure details 46 patients (33 women) with a mean age of 38,7 years were analyzed. In our study The most frequent clinical pattern was headache (70%) followed by seizures (15 %) and focal neurologic deficits (12%).(Fig. 9) The most frequent site of venous occlusion was superior sagittal sinus followed by lateral sinus. Clinical Manifestations Cerebral venous thrombosis has a wide spectrum of clinical manifestations and modes of onset that may mimic many other neurological disorders and lead to frequent misdiagnoses or delay in diagnosis. 1. Headache: The most common symptom of CVT. May occur in a context of isolated intracranial hypertension. May also be the only symptom and occurs in the absence of intracranial hypertension, subarachnoid hemorrhage or meningitis. 2. Isolated focal neurological deficits: The diagnosis is sometimes easy because of the pre-existence of unusual headache or a predisposing condition known to be at high risk of CVT, such as puerperium. 3. Diffuse encephalopathies with seizures: In patients with parenchymal lesions, the clinical picture is more severe and may include at various degrees: coma, motor deficits or aphasia, seizures (focal or generalized seizures, including status epilepticus). 4. Other clinical presentations: attacks of migraine with aura, isolated psychiatric disturbances, pulsatile tinnitus, Page 11 of 51

12 isolated or multiple cranial nerve involvement, subarachnoid hemorrhage. Diagnosis of CVT I) Neuroimaging of the thrombosed vessel and parenchymal abnormalities 1) CT FINDINGS a) UNENHANCED CT : (Fig. 10) Hyperdense dural sinus or cortical vein ("cord sign") Venous infarct in 50% * Cortical/subcortical petechial hemorrhages, edema * Thrombosis of internal cerebral veins, vein of Galen: thalami/basal ganglia hypodense b) CONTRAST-ENHANCED CT : (Fig. 11;12) "Empty delta" sign in 25-30% of cases * Enhancing dura surrounds non enhancing thrombus "Shaggy," irregular veins (collateral channels) c) CT-VENOGRAPHY early stage : non-enhancement of the thrombosed vein later stage : non-enhancement of the thrombus with surrounding enhancement : empty delta sign. Unlike MR, CT-venography virtually has no pitfalls.. we advocate seconds delay after the start of contrast injection. We use at least 70 cc of contrast 2) MRI FINDINGS a) T1WI : (Fig. 13) Acute thrombus (0-5 days): isointense. Subacute thrombus (6-15 days): becomes hyperintense. Page 12 of 51

13 Chronic thrombosis with incomplete recanalization of the sinus (>15 dayold): isointense b) T2WI: (Fig. 13) Clot initially hypointense. * Caution: If thrombus is hypointense, can mimic normal sinus "flow void" on T2WI Subacute thrombus appears hyperintense. Chronically occluded, fibrotic sinus eventually appears isointense or hyperintense. c) FLAIR: (Fig. 14) Thrombus: hyperintense. Venous infarcts: hyperintense. d) T2* GRE: (Fig. 15) 90% have hypointense clot in occluded vessel on the first MRI-scan Additional value for the diagnosis of CVT, particularly: in isolated cortical venous thrombosis at the very early stage when T1 and T2- sequences are not sensitive enough. Petechial and/or parenchymal hemorrhages: hypointense e) DWI(Fig. 16;20) 40% have hyperintense clot in occluded vessel. DWI findings in parenchyma variable, heterogeneous: vasogenic edema (with increased ADC values presumably related to venous congestion), cytotoxic edema (with decreased ADC values related to cellular energy disruption), Hemorrhage may occur with both types of edema, Various patterns may coexist in the same region. In contrast with arterial ischemic states, many parenchymal abnormalities secondary to venous occlusion are reversible. f) T1 C+(Fig. 17) Peripheral enhancement around acute clot. Chronic sinus thrombosis can enhance due to organizing fibrous tissue. Page 13 of 51

14 Contrast enhancement of the sinus on MR images does not definitively indicate patency, and venography usually is necessary for a definitive diagnosis. Parenchymal enhancement, may be seen in areas of cytotoxic or vasogenic edema and in the presence of either irreversible or reversible brain abnormalities. Increased tentorial enhancement, adjacent leptomeningeal enhancement, prominent cortical venous enhancement also may be visible. g) MRV The MR-techniques that are used for the diagnosis of cerebral venous thrombosis are: Time-of-flight (TOF), phase-contrast angiography (PCA) and contrast-enhanced MRvenography (3D Gd+) (Fig. 18) TOF angiography is based on the phenomenon of flow-related enhancement of spins entering into an imaging slice.as a result of being unsaturated, these spins give more signal that surrounding saturated spins. * Absence of flow in occluded sinus on 2D TOF MRV(Fig. 19) * "Frayed" or "shaggy" appearance of venous sinus * Abnormal collateral channels * Tl hyperintense (subacute) clot can masquerade as flow on MRV, evaluate standard sequences and source images to exclude artifacts PCA uses the principle that spins in blood that is moving in the same direction as a magnetic field gradient develop a phase shift that is proportional to the velocity of the spins. * PCA not limited by Tl hyperintense thrombus Contrast-enhanced MR-venography uses the T1-shortening of Gadolinium. better demonstrates thrombus, small vein detail, and collaterals, much faster than 2D TOF (Fig. 20). II) other investigations 1. Lumbar Puncture: There are no pathognomonic features Page 14 of 51

15 Abnormalities are found in up to 84% of cases and include raised CSF pressure, increased protein content, the presence of red blood cells and pleocytosis. 2. Screening with D-dimer test: Negative D-dimer has high negative predictive value. Normal value does not go against CVT. 3. Etiological investigation: investigation for: prothrombotic states, coagulopathies, vasculitis, other biochemical parameters like serum homocystiene are indicated. Etiology of CVT The causal factors in our study were: Infectious (n=11), gyneco obstetric (n=9), systemic (n=14), local (n=2) and unknown(n=10). (Fig. 21) 1. Infectious causes :(Fig. 22=>26) Intracranial infectious process: abscess, subdural empyema, meningitis. Parameningeal infections (ear, sinus, mouth, face, and neck). Sepsis and systemic infection. 2. Gyneco obstetric causes: (Fig. 27;28) In young women, CVT occurs more frequently during the puerperium than during pregnancy. The use of oral contraceptives is associated with an increased risk of CVT++ +. The great majority of younger nonpregnant women with CVT are oral contraceptive users. The risk of CVT with oral contraceptive use in women is greater among those with a hereditary prothrombotic factor. 3. Systemic causes: (Fig. 29=>35) Page 15 of 51

16 a) Genetic prothrombotic disorders: The hereditary resistance to activated protein C caused by the mutation in factor V Leiden is the most common. Less common are deficiencies in protein C, protein S, and ATIII. b) Acquired hypercoagulable disorders: Disseminated intravascular coagulation, heparin-induced thrombocytopenia, plasminogen deficiency, epsilon aminocaproic acid treatment, sickle cell disease, polycythemia vera, paroxysmal nocturnal hemoglobinuria, thrombocythemia, antiphospholipid antibody syndrome, nephrotic syndrome, dehydration (Changes in blood flow/viscosity). thyrotoxicosis, hypercoagulability associated with malignancy, anemia due to iron deficiency. c) Inflammatory disorders: Cerebral venous thrombosis may be the first manifestation of an inflammatory systemic disease such as: Behçet disease, lupus erythematosus, sarcoidosis, ulcerative colitis, crohn disease, Wegener granulomatosis. 4. Local causes: (Fig. 36) Head trauma with skull fractures extending to a dural venous sinus or jugular bulb. Intracranial surgeries 5. Idiopathic causes: (Fig. 37; 38) The proportion of cases of unknown etiology remains high, between 20% and 35%. Page 16 of 51

17 In these cases, even after an extensive initial evaluation is performed, repeated investigations are advisable. Potential Pitfalls in Image Interpretation 1. Sinus Hypoplasia: (Fig. 39) Hypoplasia and atresia of the transverse sinuses occur frequently. 2. Arachnoid Granulations: (Fig. 40) Arachnoid granulations are normal structures that protrude into the dural sinus lumen or lateral lacunae. Arachnoid granulations typically have signal intensity and attenuation similar to those of cerebrospinal fluid and appear as focal rounded filling defects with a characteristic anatomic distribution: usually identified in the lateral part of the transverse sinus, near the entrance sites of the Labbé vein. When they are prominent, they may simulate sinus thrombosis. Images for this section: Page 17 of 51

18 Fig. 8: MRI of cerebral venous and dural sinus: 2DTOF Page 18 of 51

19 Fig. 9: clinical patterns in our study Page 19 of 51

20 Fig. 10: Neuroimaging of the thrombosed vessel and parenchymal abnormalities CT findings Page 20 of 51

21 Fig. 11: Neuroimaging of the thrombosed vessel and parenchymal abnormalities CT findings Page 21 of 51

22 Fig. 12: Neuroimaging of the thrombosed vessel and parenchymal abnormalities CT findings Page 22 of 51

23 Fig. 13: Neuroimaging of the thrombosed vessel and parenchymal abnormalities T1 and T2WI findings Page 23 of 51

24 Fig. 14: Neuroimaging of the thrombosed vessel and parenchymal abnormalities FLAIR WI findings Page 24 of 51

25 Fig. 15: Neuroimaging of the thrombosed vessel and parenchymal abnormalities T2*WI findings Page 25 of 51

26 Fig. 16: Neuroimaging of the thrombosed vessel and parenchymal abnormalities DWI findings Page 26 of 51

27 Fig. 17: Neuroimaging of the thrombosed vessel and parenchymal abnormalities T1 C + findings Page 27 of 51

28 Fig. 18: MR Venography findings Page 28 of 51

29 Fig. 19: 2DTOF findings Page 29 of 51

30 Fig. 20: 3D GD+ findings Page 30 of 51

31 Fig. 21: Table 1: The causal factors of CVT in our study Page 31 of 51

32 Fig. 22: Infectious cause of CVT: Otomastoiditis Page 32 of 51

33 Fig. 23: Infectious cause of CVT: Otomastoiditis Page 33 of 51

34 Fig. 24: Infectious cause of CVT:Tuberculous meningitis Page 34 of 51

35 Fig. 25: Infectious cause of CVT:Lymphocytic meningitis Page 35 of 51

36 Fig. 26: Infectious cause of CVT:sphenoiditis Page 36 of 51

37 Fig. 27: Extensive cerebral veinous thrombosis during the postpartum period Page 37 of 51

38 Fig. 28: CVT in a user of oral contraceptives Page 38 of 51

39 Fig. 29: CVT in in a patient with Behçet disease Page 39 of 51

40 Fig. 30: CVT in a woman with breast cancer Page 40 of 51

41 Fig. 31: CVT in a woman with breast cancer and bone metastasis Page 41 of 51

42 Fig. 32: CVT in a boy with acute lymphoblastic leukemia Page 42 of 51

43 Fig. 33: CVT in a woman with celiac disease + nephrotic syndrome Page 43 of 51

44 Fig. 34: CVT in a boy with dehydration Page 44 of 51

45 Fig. 35: CVT in a man with meningioma Page 45 of 51

46 Fig. 36: CVT in a patient with head truma Page 46 of 51

47 Fig. 37: CVT with unknown etiology Page 47 of 51

48 Fig. 38: Extensive CVT in a boy with unknown etiology Page 48 of 51

49 Fig. 39: sinus hypoplasia Page 49 of 51

50 Fig. 40: Arachnoid Granulations Page 50 of 51

51 Conclusion Cerebral venous thrombosis is a relatively uncommon but serious neurologic disorder. Since the possible causal factors and clinical manifestations of thrombosis are many and varie. Imaging plays a primary role in diagnosis. References 1. StamJ.Cerebral venous and sinus thrombosis: incidence and causes in ischemic stroke. Adv Neurol2003; 92: James L. Leach et al.imaging of Cerebral Venous Thrombosis: Current Techniques, Spectrum of Findings, and Diagnostic Pitfalls. October 2006RadioGraphics,26, S19-S Colin S. Poon et al.radiologic Diagnosis of Cerebral Venous Thrombosis: Pictorial Review. AJR 2007; 189:S64-S Gustavo Saposnik et al. Diagnosis and Management of Cerebral Venous Thrombosis: A Statement for Healthcare Professionals From the American Heart Association/ American Stroke Association. Stroke April 1, : Barbara Simons et al. Cerebral venous thrombosis. (neuroradiology index). 6. Mark E et al. Parenchymal Abnormalities Associated with Cerebral Venous Sinus Thrombosis: Assessment with Diffusion-Weighted MR Imaging. AJNR 25: , November/December Provenzale JM et al.dural sinus thrombosis: findings on CT and MR imaging and diagnostic pitfalls. AJR 1998; 170: Personal Information Page 51 of 51