Neuro-imaging in intracerebral hemorrhage: updates and knowledge gaps.

Intracerebral hemorrhage (ICH) is characterized by hematoma development within the brain's parenchyma, contributing significantly to the burden of stroke. While non-contrast head computed tomography (CT) remains the gold standard for initial diagnosis, this review underscores the pivotal role of magnetic resonance imaging (MRI) in ICH management. Beyond diagnosis, MRI offers invaluable insights into ICH etiology, prognosis, and treatment. Utilizing echo-planar gradient-echo or susceptibility-weighted sequences, MRI demonstrates exceptional sensitivity and specificity in identifying ICH, aiding in differentiation of primary and secondary causes. Moreover, MRI facilitates assessment of hemorrhage age, recognition of secondary lesions, and evaluation of perihematomal edema progression, thus guiding tailored therapeutic strategies. This comprehensive review discusses the multifaceted utility of MRI in ICH management, highlighting its indispensable role in enhancing diagnostic accuracy as well as aiding in prognostication. As MRI continues to evolve as a cornerstone of ICH assessment, future research should explore its nuanced applications in personalized care paradigms.

Neuroimaging mimics of anoxic brain injury: A review.

Diffuse cortical diffusion changes on magnetic resonance imaging (MRI) are characteristically ascribed to global cerebral anoxia, typically after cardiac arrest. Far from being pathognomonic, however, this neuroimaging finding is relatively nonspecific, and can manifest in a myriad of disease states including hypoxia, metabolic derangements, infections, seizure, toxic exposures, and neuroinflammation. While these various conditions can all produce a neuroimaging pattern of widespread cortical diffusion restriction, many of these underlying causes do have subtly unique imaging features that are appreciable on MRI and can be of clinical and diagnostic utility. Specific populations of neurons are variably sensitive to certain types of injury, whether due to differences in perfusion, receptor type density, or the unique tropisms of infectious organisms. In this narrative review, we discuss a number of distinct etiologies of diffuse cortical diffusion restriction on MRI, the unique pathophysiologies responsible for tissue injury, and the resulting neuroimaging characteristics that can be of assistance in differentiating them. As widespread cortical injury from any cause often presents with altered mental status or coma, the differential diagnosis can be enhanced with rapid acquisition of MRI when clinical history or detailed physical examination is limited. In such settings, the distinct imaging features discussed in this article are of interest to both the clinician and the radiologist.

MRI findings in spinal subdural and epidural hematomas.

BACKGROUND: Spinal hematomas are rare entities that can be the cause of an acute spinal cord compression syndrome. Therefore, an early diagnosis is of great importance. PATIENTS AND METHODS: From 2001 to 2005 seven patients with intense back pain and/or acute progressive neurological deficit were studied via 1.5 T MRI (in axial and sagittal T1- and T2-weighted sequences). Follow-up MRI was obtained in six patients. RESULTS: Four patients showed the MRI features of a hyperacute spinal hematoma (two spinal subdural hematoma [SSH] and two spinal epidural hematoma [SEH]), isointense to the spinal cord on T1- and hyperintense on T2-weighted sequences. One patient had an early subacute SEH manifest as heterogeneous signal intensity with areas of high signal intensity on T1- and T2-weighted images. Another patient had a late subacute SSH with high signal intensity on T1- and T2-weighted sequences. The final patient had a SEH in the late chronic phase being hypointense on T1- and T2-weighted sequences. DISCUSSION: MRI is valuable in diagnosing the presence, location and extent of spinal hematomas. Hyperacute spinal hematoma and the differentiation between SSH and SEH are particular diagnostic challenges. In addition, MRI is an important tool in the follow-up in patients with conservative treatment.

The emerging role of multidetector row CT angiography in the diagnosis of cervical arterial dissection: preliminary study.

INTRODUCTION: Cervical artery dissection is an important cause of ischemic stroke, particularly in young patients. The diagnosis can be made with invasive catheter angiography or non-invasive imaging, either with MRI in conjunction with MR angiography (MRA) or CT angiography (CTA). Both modalities have been shown to have a high specificity and sensitivity. New developments such as multi-slice CTA (MSCTA) are emerging as an alternative methods for imaging the cervical and intracranial arteries. However, the contribution of modern MSCTA to carotid artery dissection has not been reported. METHODS: We present a retrospective series of seven patients in whom both MSCTA and cervical axial T1 MRI and MRA were performed in the acute to subacute setting of internal carotid artery dissection. RESULTS: Carotid artery dissection was identified in all seven patients by MSCTA. The combination of MRI and MRA identified dissection in five of the seven patients. Additionally, a pseudoaneurysm was identified by MSCTA that was missed by MRI and MRA. CONCLUSION: Our findings confirm that MSCTA is a complementary technique in comparison to cervical axial T1 MRI and cervical MRA for diagnosing carotid artery dissection, and at times may provide additional information that can impact patient management.

Dynamic susceptibility contrast-enhanced perfusion and conventional MR imaging findings for adult patients with cerebral primitive neuroectodermal tumors.

BACKGROUND AND PURPOSE: Preoperative differentiation of primitive neuroectodermal tumors (PNETs) from other tumors is important for presurgical staging, intraoperative management, and postoperative treatment. Dynamic, susceptibility-weighted, contrast-enhanced MR imaging can provide in vivo assessment of the microvasculature in intracranial mass lesions. The purpose of this study was to determine the perfusion characteristics of adult cerebral PNETs and to compare those values with low and high grade gliomas. METHODS: Conventional MR images of 12 adult patients with pathologically proved cerebral PNETs were analyzed and provided a preoperative diagnosis. Relative cerebral blood volume (rCBV) measurements and estimates of the vascular permeability transfer constant, K(trans), derived by a pharmacokinetic modeling algorithm, were also obtained. These results were compared with rCBV and K(trans) values obtained in a group of low grade gliomas (n = 30) and a group of high grade gliomas (n = 55) by using a Student t test. RESULTS: On conventional MR images, PNETs were generally well-defined contrast-enhancing masses with solid and cystic components, little or no surrounding edema, and occasional regions of susceptibility. The rCBV of cerebral PNETs was 4.76 +/- 1.99 SD, and the K(trans) was 0.0033 +/- 0.0035. A comparative group of patients with low grade gliomas (n = 30) had significantly lower rCBV (P <.0005) and lower K(trans) (P <.05). Comparison with a group of high grade gliomas showed no statistical significance in the rCBV and K(trans) (P =.53 and.19, respectively). CONCLUSION: Dynamic, susceptibility-weighted, contrast-enhanced MR imaging shows areas of increased cerebral blood volume and vascular permeability in PNETs. These results may be helpful in the diagnosis and preoperative differentiation between PNETs and other intracranial mass lesions (such as low grade gliomas), which have decreased perfusion but may sometimes have a similar conventional MR imaging appearance.