Cerebral venous infarctions presenting as enhancing space-occupying lesions: MRI findings

Perfusion MRI in Cerebral Venous and Sinus Thrombosis

BACKGROUND AND PURPOSE

Cerebral venous and sinus thrombosis (CVST) leads to perfusion abnormality in the brain. Our aim was to assess perfusion abnormalities in the center and periphery of the parenchymal lesion in CVST patients and correlate with the clinical outcome.

MATERIALS AND METHODS

Dynamic susceptibility contrast (DSC) perfusion imaging was performed in patients with CVST. Relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), and mean transit time (MTT) values were obtained in the center and periphery of the parenchymal lesion.

RESULTS

A total of 30 consecutive patients of CVST were included in the study. Parenchymal lesion was present in 21 (70%) patients. In rest 9, perfusion map was showing some abnormality although conventional MRI was normal. Mean rCBV and MTT were increasing from periphery of the lesion to the center (rCBV 69.93 ± 29.79 at periphery (PL2) to 92.49 ± 32.07 at center of the lesion and 69.19 ± 25.52 at normal appearing contralateral brain parenchyma (NABP). MTT 11.83 ± 3.76 at periphery (PL2) to 15.27 ± 5.49 at center of the lesion and 10.63 ± 3.37 at NABP). rCBV and MTT from abnormal perfusion areas from 9 patients without parenchymal abnormalities are 92.89 ± 17.76 and 15.92 ± 3.66 respectively.

CONCLUSION

There is an increasing trend of MTT and rCBV from periphery to center of the parenchymal lesion. MTT is the most consistent parameter to be abnormal in patients of CVST even in patients without parenchymal lesion. Residual neurological deficit was found in patients with increased rCBV and having large hemorrhagic infarct.

An Illustrative Case of Vein of Labbe Thrombosis Presented as a Glioma

Cerebral vein thrombosis is a unique and rare type of cerebrovascular disease. The main challenge in identifying cerebral vein thrombosis is the presence of vague signs and symptoms that can resemble a variety of other intracranial pathologies. Our goal is to present the unique case of a young patient whose MRI scan revealed an abnormally enhancing tumor-like brain lesion that was heterogeneous in intensity and whose intraoperative view and histopathological findings were consistent with the vein of Labbe thrombosis, with ipsilateral transverse and sigmoid sinus involvement.

Outflow-Restricted Developmental Venous Anomaly Masquerading as a Tumefactive Lesion on Imaging

BACKGROUND

Developmental venous anomalies (DVA) are rarely symptomatic. We report an unusual case of outflow-restricted DVA presenting with seizures.

CASE DESCRIPTION

Expansile signal changes due to a hemorrhagic venous infarction in the draining territory of collector vein of DVA simulated a neoplasm. Follow-up imaging showed regression of mass effect and asymptomatic thrombosis of another distant vein. Investigation for prothrombotic conditions returned negative.

CONCLUSIONS

Atypical imaging findings in the draining territory of DVA ought to raise the possibility of outflow restriction.

Cerebral Venous Thrombosis with Tumor-like Features: A Case Report and Review of the Literature

BACKGROUND

Cerebral venous thrombosis (CVT), a rare cerebrovascular condition, is induced by blocked cerebral venous reflux, often presenting non-specific symptoms. Magnetic resonance imaging (MRI) of the brain may improve the often elusive diagnosis of CVT. However, the sensitivity, specificity and full spectrum of such MRI findings are poorly understood.

CASE DESCRIPTION

We report the case of a 53-year-old male patient with CVT. The patient complained of a severe headache in addition to an enhanced lesion on contrasted T1-weighted MR images, which was originally considered an angiogenic tumor. However, surgery and pathology confirmed the case to be CVT. Following surgery and administration of an anticoagulation agent, the patient's symptoms alleviated, and cranial MRI and CT 1 month after surgery showed no abnormalities.

CONCLUSIONS

We conclude that such cases may occur where CVT appears tumor-like on MRI, including mass effect and abnormal contrast enhancement. Therefore, for young and middle-aged adults with episodic and progressive headaches presenting such MRI findings, the possibility of CVT should always be considered. MRI combined with magnetic resonance venography should be used as the preferred strategy for early diagnosis of CVT.

Pseudotumoral brain lesions: MRI review

Single or multiple space-occupying lesions on brain MRI, with or without contrast enhancement and/or perilesional oedema, evoke a neoplastic origin. However, a multitude of non-neoplastic disorders can simulate cerebral neoplasia. In this review, we will discuss the MRI characteristics of non-neoplastic disorders that can mimic cerebral neoplasia. Distinguishing MRI characteristics are discussed for each of these non-neoplastic disorders.

Dural Arteriovenous Fistula Mimicking a Supratentorial Tumor

BACKGROUND

The pathophysiology of dural arteriovenous fistulas (dAVF) is not fully understood. Retrograde venous flow can lead to venous congestion and disruption of the blood-brain barrier, resulting in diffuse contrast enhancement.

CASE DESCRIPTION

We present the case of a patient with a supratentorial dAVF associated with a solid, tumor-appearing, corticosubcortical contrast-enhancing lesion. Surgical occlusion of the dAVF was followed by complete regression of the contrast-enhancing lesion. Histologic analysis of the lesion showed normal brain tissue.

CONCLUSIONS

This case report highlights how venous congestion is an important differential diagnosis in contrast-enhancing lesions associated with dAVF and how it should be taken in consideration to avoid radiologic misdiagnoses and unnecessary treatment.

Thrombosis of a developmental venous anomaly in inflammatory bowel disease: case report and radiologic follow-up

Developmental venous anomalies (DVAs) are benign embryologic vascular variants, and before the advent of computed tomography and magnetic resonance imaging were supposed to be rare conditions. Usually, DVAs are asymptomatic and accidentally discovered during routine brain imaging studies, but sometimes they can be the cause of disabling neurologic symptoms. We describe the clinical and neuroradiologic follow-up of a 62-year-old man with a history of inflammatory bowel disease (IBD) presenting with new onset epilepsy and intracranial hemorrhage caused by thrombosis of a DVA who fully recovered after treatment with oral anticoagulant therapy. Patients with IBD have an increased risk of thrombosis because of inflammatory activity and the hypercoagulable state. Here we describe the first case of DVA thrombosis in a patient with IBD, and we show clinical and neuroradiologic follow-up after anticoagulant therapy.

Two cases of a dural arteriovenous fistula mimicking a brain tumor

SUMMARY

Dural arteriovenous fistula (d-AVF) is relatively rare. Some cases of atypical locations are often difficult to distinguish from other vascular disorders or tumors because those d-AVFs show various onsets, such as subcortical bleeding and venous infarctions. We encountered two cases of d-AVF with severe brain edema that took adequate time to distinguish from brain tumors. A 68-year-old man visited his local physician complaining of dizziness. He was diagnosed with a cerebral infarction due to the presence of an abnormal cerebellar signal on magnetic resonance imaging (MRI) and was treated by drip infusion. However, he did not recover and was admitted to our hospital with suspicion of a brain tumor. A 75-year-old woman with an onset of progressive dementia and gait disturbance showed severe edema of the right-front temporal lobe on MRI. Both these cases were examined by single photon emission computed tomography or positron emission tomography and were scheduled for craniotomy and biopsy based on the diagnosis of brain tumor. We performed preoperative angiography and found d-AVFs. We embolized the d-AVFs with liquid material and both patients recovered well. Brain edema from d-AVF or a tumor can be distinguished by carefully reading the MRI with findings such as the distribution of the edemas, differences on diffusion-weighted images, and contrast-enhanced images. Therefore, it is important to provide initial accurate diagnoses to prevent patient mistrust and irreversible disease conditions.

Superior sagittal sinus thrombosis secondary to hyperthyroidism

Superior sagittal sinus thrombosis (SSST) is associated with a variety of hypercoaguable states. Although coagulation disturbances are reported in hyperthyroidism, a direct link between hyperthyroidism and cerebral venous thrombosis is not established. We report a 39-year-old man who developed increased intracranial pressure, seizures, and rapid atrial fibrillation. Neuroimaging showed SSST, and laboratory studies were consistent with hyperthyroidism. No other causes of a hypercoaguable state were identified. Prompt treatment of his hyperthyroidism led to recanalization of the superior sagittal sinus and a full neurological recovery. Given the known effects of hyperthyroidism on factor VIII activity, we hypothesize that hyperthyroidism is an independent risk factor for SSST. A high index of suspicion for SSST is warranted in patients with hyperthyroidism and neurological symptoms. Furthermore, thyroid dysfunction should be excluded in patients with unexplained SSST.

Pitfalls in the diagnosis of brain tumours

Establishing the diagnosis of a brain tumour is not always a straightforward process. Many non-neoplastic neurological diseases can mimic brain neoplasms on neuroimaging or on histological examination, including multiple sclerosis, stroke, pyogenic abscess, toxoplasmosis, tuberculosis, cysticercosis, fungal infections, syphilis, sarcoidosis, Behçet disease, radiation necrosis, venous thrombosis, and others. Conversely, several types of brain neoplasms, such as glioblastomas, low-grade gliomas, CNS lymphomas, and brain metastases, can present in the absence of typical tumefactive lesions, posing significant diagnostic challenges. In this Review, we discuss the process of accurately establishing the diagnosis of brain tumours, focusing on pitfalls commonly encountered in clinical practice. We also discuss the rational use and limitations of new diagnostic techniques, such as diffusion-weighted MRI, perfusion-weighted MRI, magnetic resonance spectroscopy, single-photon emission tomography, and positron emission tomography, as well as new tools for histological examination, such as immunohistochemistry and molecular genetics analysis.

Therapeutic advances in interventional neurology

Rapid advances in the field of interventional neurology and the development of minimally invasive techniques have resulted in a great expansion of potential therapeutic applications. We discuss therapeutic interventional neurology as applied in clinical practice in one of the two possible ways: 1) embolization leading to occlusion of blood vessels; and 2) revascularization leading to reopening of blood vessels. These procedures can be applied to a broad range of cerebrovascular diseases. In the first section of this review, we will explore the evolution of these interventions to occlude aneurysms, arteriovenous malformations, neurovascular tumors, and injuries. In the second section, revascularization in acute ischemic stroke, stenosis, and dural venous thrombosis will be discussed.

Ischemic complication of a cerebral developmental venous anomaly: case report and review of the literature

We report a case of a nonhemorrhagic infarct associated with a thrombosed developmental venous anomaly (DVA), with secondary gliosis and Wallerian degeneration. The initial MRI scan showed an acute ischemic infarct in the region of the DVA, seen as a region of restricted diffusion on diffusion-weighted imaging (DWI), with later development of encephalomalacia and Wallerian degeneration on follow-up MRI. No blood products were seen. We believe that thrombosis of the collector vein of a DVA with associated infarction is a rare but possible complication that should be considered within the proper clinical setting and can be easily and confidently diagnosed by means of DWI.

Magnetic resonance imaging of cerebral venous sinus thrombosis

Cerebral venous sinus thrombosis (CVST) represents a diagnostic challenge due to the diversity of clinical presentation. The radiologist should be aware of the common neurological features. Unenhanced CT may show the first indications of venous sinus occlusion. Confirmatory diagnostic imaging should be performed with magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) or computed tomography (CT) venography. We illustrate the MRI and MRV features of the thrombosed venous sinus and venous oedema or infarction and discuss the diagnostic limitations of these techniques.

Nonrandomized comparison of local urokinase thrombolysis versus systemic heparin anticoagulation for superior sagittal sinus thrombosis

BACKGROUND AND PURPOSE

We sought to compare the safety and efficacy of direct urokinase thrombolysis with systemic heparin anticoagulation for superior sagittal sinus thrombosis (SSST).

METHODS

At University at Buffalo (NY) and University of Texas (Dallas, Houston), we reviewed 40 consecutive patients with SSST, treated with local urokinase (thrombolysis group) or systemic heparin anticoagulation (heparin group). The thrombolysis group (n=20) received local urokinase into the SSS followed by systemic heparin anticoagulation. The heparin group (n=20) received systemic heparin anticoagulation only. Neurological dysfunction was rated as follows: 0, normal; 1, mild (but able to ambulate and communicate); 2, moderate (unable to ambulate, normal mentation); and 3, severe (unable to ambulate, altered mentation).

RESULTS

Age (P=0.49), sex (P=0.20), baseline venous infarction (P=0.73), and predisposing illnesses (P=0.52) were similar between the thrombolysis and heparin groups. Pretreatment neurological function was worse in the thrombolysis group (normal, n=5; mild, n=8; moderate, n=4; severe, n=3) than in the heparin group (normal, n=8; mild, n=8; moderate, n=3; severe, n=1) (P=NS). Discharge neurological function was better in the thrombolysis group (normal, n=16; mild, n=3; moderate, n=1; severe, n=0) than in the heparin group (normal, n=9; mild, n=6; moderate, n=5; severe, n=0) (P=0.019, Mann-Whitney U test). Hemorrhagic complications were 10% (n=2) in the thrombolysis group (subdural hematoma, retroperitoneal hemorrhage) and none in the heparin group (P=0.49). Three of the heparin group patients developed complications of the underlying disease (status epilepticus, hydrocephalus, refractory papilledema). No deaths occurred. Length of hospital stay was similar between the groups (P=0.79).

CONCLUSIONS

Local thrombolysis with urokinase is fairly well tolerated and may be more effective than systemic heparin anticoagulation alone in treating SSST. A randomized, prospective study comparing these 2 treatments for SSST is warranted.