Hyperintense vessel sign: isolated cortical venous thrombosis after L-asparaginase therapy

Cerebral sinovenous thrombosis (CSVT) in children: what the pediatric radiologists need to know

Cerebral sinovenous thrombosis (CSVT) is a relatively uncommon and potentially life-threatening condition in childhood, occurring in various clinical settings. Nowadays, however, it is increasingly diagnosed as related to many causes, likely due to greater clinical awareness and improvement of neuroradiologic techniques. The prompt diagnosis is an important goal to significantly reduce the risk of acute complications and long-term sequelae. The purpose of this narrative overview is to provide a useful educational tool in daily clinical practice for radiologists with a broad perspective of CSVT including a discussion of more common potential pitfalls related to misinterpretation of images in children. This paper will also review the normal venous anatomy, its variants, risk factors that contribute to cause CSVT (neonates with their specific causes of CSVT are not included in this review) and the practical imaging feature of cerebral sinovenous thrombosis on MRI and CT. Finally, a brief overview of frequent and severe CSVT conditions in children with key points in imaging is shown.

Venous injury in abusive head trauma

BACKGROUND

Abusive head trauma (AHT) is an important cause of serious brain injury in infants and young children who have characteristic clinical and imaging findings that are discordant with the clinical history provided. Recent attention has focused on abnormalities of the cranial venous sinuses and cortical veins, both on MRI and at autopsy. Although many have interpreted these to be secondary to the AHT, some have recently argued that these venous abnormalities represent primary cortical sinus and venous thrombosis that leads secondarily to subdural hemorrhage and secondary brain injury. Direct trauma to the veins and sinuses has been reported at autopsy in AHT, but there has been no systematic study of venous abnormalities in cases of AHT.

OBJECTIVE

The purpose of this study was to define the incidence and characteristics of venous and sinus abnormalities in AHT.

MATERIALS AND METHODS

We included all children <36 months of age who were diagnosed with abusive head trauma between 2001 and 2012 and who had MRI and magnetic resonance (MR) venography as part of their diagnostic workup. We analyzed age, gender and clinical findings. MRI and MR venography were analyzed independently by two neuroradiologists with a focus on abnormalities involving the intracranial veins and venous sinuses.

RESULTS

A total of 45 children were included. The median age was 3 months (range 15 days to 31 months) and 28 were boys (62%). Clinical findings included retinal hemorrhage in 71% and extracranial fractures in 55%. CT or MRI demonstrated subdural hemorrhage in 41 (91%); none had subdural effusions. In 31 cases (69%) MR venography demonstrated mass effect on the venous sinuses or cortical draining veins, with either displacement or partial or complete effacement of the venous structures from an adjacent subdural hematoma or brain swelling. We also describe the lollipop sign, which represents direct trauma to the cortical bridging veins and was present in 20/45 (44%) children.

CONCLUSION

Evidence of displacement or compression of cortical veins and sinuses from subdural hemorrhage or edema on MR venography was present in the majority of children with abusive head trauma. Evidence of direct trauma to the veins (lollipop sign) was identified in nearly half of cases. It is important to understand the superimposed effects of subdural hematoma and brain swelling on the veins and sinuses to differentiate it from cortical sinus and venous thrombosis.

Isolated cortical vein thrombosis: case series

OBJECT

Isolated cortical vein thrombosis (ICVT) accounts for less than 1% of all cerebral infarctions. ICVT may cause irreversible parenchymal damage, rendering early and accurate diagnosis critical. This case series and literature review presents the clinical and radiological findings in 7 patients with ICVT, and highlights risk factors and imaging modalities that may be most beneficial in rendering an accurate and timely diagnosis.

METHODS

Patients with CT and MRI findings consistent with ICVT examined between January 2011 and June 2014 were included in this retrospective review.

RESULTS

Seven patients (5 females, 2 males), ranging in age from 11 months to 34 years, met the inclusion criteria. The most common clinical presentations were headaches (n = 4) and seizures (n = 3). The most common comorbidities noted in these patients were hypercoagulable states (n = 4) and intracranial hypotension (n = 3). Five patients had intraparenchymal involvement. CT suggested the correct diagnosis in 4 patients, and MRI confirmed the diagnosis in all 7 patients. All patients who received anticoagulation therapy (n = 5) experienced complete resolution of their symptoms.

CONCLUSIONS

The majority of these patients were adult females, consistent with published data. Seizures and headaches were the most common presenting symptoms. Hypercoagulable state and intracranial hypotension, both known risk factors for thrombosis, were the most commonly noted ICVT risk factors. Intraparenchymal involvement was prevalent in nearly all ICVT cases and presented as vasogenic edema, early intraparenchymal hemorrhage, or hemorrhagic venous infarction. Susceptibility-weighted imaging was the most sensitive imaging technique in diagnosing ICVT.

Isolated superficial sylvian vein thrombosis with long cord sign: case report and review of the literature

Isolated cortical vein thrombosis (ICVT) is extremely rare. Only single case or small series of ICVT have been reported; clinical details are still uncertain. We report a case of isolated superficial sylvian vein thrombosis with exceedingly long cord sign. A 14-year-old female with severe sudden onset headache visited our hospital. Fluid attenuated inversion recovery and echo-planar T2(*) susceptibility-weighted imaging (T2(*)SW) showed a long cord sign on the surface of the sylvian fissure. The patency of dural sinuses and deep cerebral veins were confirmed by magnetic resonance venography (MRV), and diagnosis of ICVT was made. She recovered completely without anticoagulant agents. To clarify the clinical characteristics of ICVT, we reviewed 51 ICVT cases in the literature. In many cases, T2(*)SW was the most useful examination to diagnose ICVT. In contrast with general cerebral venous thrombosis, MRV and conventional angiography were either supporting or useless. Anastomotic cortical veins were involved frequently; symptoms of gyri around the veins were common. It also suggested that ICVTs of the silent area might have been overlooked because of nonspecific symptoms, and more patients with ICVT may exist. In cases involving patients with nonspecific symptoms, the possibility of ICVT should be considered.

Isolated cortical vein thrombosis: a widely variable clinicoradiological spectrum

BACKGROUND/AIMS

The aim of this study is to highlight the variable clincoradiological spectrum of isolated cortical vein thrombosis (ICoVT), which seems to remain a challenge to clinicians.

CASES REPORTS

We reported 3 patients with this diagnosis. One presented with only an epileptic seizure, one with worsening headache, seizures, mental disorder, speech disturbance and right-sided weakness, and the other with seizures and fluctuating paralysis in her left-sided limbs. Brain images were manifested with a strand-like abnormal signal, a large hemorrhagic infarction and a continuously enlarged space-occupying massive edema, respectively.

CONCLUSIONS

Neurologic features and brain imaging of ICoVT are highly variable, which might be partly responsible for the underestimation of ICoVT. Clinical diagnosis should probably be evoked more often.

Cerebral sinovenous thrombosis in pediatric practice

Cerebral sinovenous thrombosis (CSVT) in the pediatric population is a relatively uncommon yet under-appreciated and potentially life-threatening neurological condition. Early symptoms and signs are often vague and the clinician requesting a cranial imaging study might not even suspect sinovenous thrombosis. If left undiagnosed, or if the diagnosis of CSVT is delayed, progressive neurological deterioration, coma and death can follow. The purpose of this review is to highlight pertinent development of the cerebral venous system, discuss the causal factors of cerebral sinovenous thrombosis in the pediatric population, review practical imaging strategies using cranial sonography augmented with color and pulsed Doppler, unenhanced brain CT, CT venography, cerebral MRI, and MR venography (MRV). Finally, this review will illustrate the imaging features of sinovenous thrombosis, including a discussion of the common causes of false-positive and false-negative CT and MRI studies.

Cortical vein thrombosis: the diagnostic value of different imaging modalities

INTRODUCTION

Cortical vein thrombosis (CVT) is a rare disorder, and its diagnosis is challenging. The aim of our study was to evaluate the value of different imaging modalities for the detection of CVT.

METHODS

Thirteen patients with CVT, either isolated (n = 3) or in combination with sinus thrombosis (n = 10), and 20 control patients without any venous pathologies were included in this study. The analysis was performed independently by three blinded readers who evaluated the following imaging modalities and sequences separately: non-enhanced computed tomography (NCCT); multi-detector row CT angiography (MDCTA); diffusion-weighted (DWI), T1-weighted (T1w), PD-weighted (PDw), T2*-weighted (T2*w), and fluid-attenuated inversion recovery-weighted (FLAIRw) magnetic resonance (MR) sequences; as well as venous MR angiography (vMRA). The sensitivity, specificity, positive (PPV) and negative predictive values, and interobserver agreement of the different modalities were calculated.

RESULTS

T2*w showed the highest sensitivity for the detection of CVT (97.4%), followed by T1w (70%). FLAIRw and vMRA had a sensitivity of 50% and 41.7%, respectively, whereas the sensitivity of NCCT, MDCTA, DWI, and PDw was below 30%. The specificity and PPV of all modalities was 100%, with good to perfect interobserver agreement.

CONCLUSION

T2*w was the superior MR imaging sequence for diagnosing CVT. Besides T2*w, only T1w reached a sensitivity of over 50% for CVT, followed by FLAIRw, and vMRA. On the contrary, our results suggest that NCCT but also MDCTA might not be suitable for diagnosing CVT.