Benefits of perfusion MR imaging relative to diffusion MR imaging in the diagnosis and treatment of hyperacute stroke.

BACKGROUND AND PURPOSE: The development of thrombolytic agents for use with compromised cerebral blood flow has made it critical to quickly identify those patients to best treat. We hypothesized that combined diffusion and perfusion MR imaging adds vital diagnostic value for patients for whom the greatest potential benefits exist and far exceeds the diagnostic value of diffusion MR imaging alone. METHODS: The cases of patients with neurologic symptoms of acute ischemic stroke who underwent ultra-fast emergent MR imaging within 6 hours were reviewed. In all cases, automatic processing yielded isotropic diffusion images and perfusion time-to-peak maps. Images with large vessel distribution ischemia and with mismatched perfusion abnormalities were correlated with patient records. All follow-up images were reviewed and compared with outcomes resulting from hyperacute therapies. RESULTS: For 16 (26%) of 62 patients, hypoperfusion was the best MR imaging evidence of disease distribution, and for 15 of the 16, hypoperfusion (not abnormal diffusion) comprised the only imaging evidence for disease involving large vessels. For seven patients, diffusion imaging findings were entirely normal, and for nine, diffusion imaging delineated abnormal signal in either small vessel distributions or in a notably smaller cortical branch in one case. In all cases, perfusion maps were predictive of eventual lesions, as confirmed by angiography, CT, or subsequent MR imaging. CONCLUSION: If only diffusion MR imaging is used in assessing patients with hyperacute stroke, nearly one quarter of the cases may be incorrectly categorized with respect to the distribution of ischemic at-risk tissue. Addition of perfusion information further enables better categorizing of vascular distribution to allow the best selection among therapeutic options and to improve patient outcomes.

Functional evaluation of arteriovenous malformations.

Detailed knowledge of the angioarchitecture of arteriovenous malformations (AVMs) is necessary in determining the optimal timing and method of treatment of these challenging lesions. Many techniques are available for studying the functionality of surrounding cortical structures of AVMs. These include the use of positron emission tomography, functional magnetic resonance imaging, magnetoencephalography, and direct provocative testing of cortical function. The use of these methods to determine flow dynamics and tissue perfusion is also reviewed. These techniques are discussed in the present study, and their judicious utilization will enhance the safety of AVM therapy.

Delayed progressive restenosis of the supraclinoid internal carotid artery treated with percutaneous transluminal angioplasty in a patient with aneurysmal subarachnoid hemorrhage.

Typically occurring between 3 days and 3 weeks post-hemorrhage, cerebral vasospasm in the acute stage after aneurysmal subarachnoid hemorrhage is a major contributor to the morbidity and mortality associated with patient outcomes, despite advances in aneurysm treatment and vasospasm management. Though incompletely understood, cerebral vasospasm is well described in the immediate post-hemorrhage patient. Less detailed descriptions exist of delayed or progressive restenosis after aneurysmal subarachnoid hemorrhage and resultant vasospasm. We report a case of delayed progressive supraclinoid internal carotid artery restenosis treated with angioplasty 10 weeks after initial hemorrhage.

Intracranial complications of frontal sinusitis in children: Pott's puffy tumor revisited.

The objective of the present study is to describe the diagnosis and treatment of intracranial complications of frontal sinusitis (Pott's puffy tumor) in a series of pediatric patients at our institution. A rare entity, Pott's puffy tumor has been reported in only 21 pediatric cases in the literature of the antibiotic era. The hospital records and radiographic files at Rainbow Babies and Childrens Hospital, Cleveland, Ohio, USA, over the previous 16 years were retrospectively reviewed in a search for patients with the diagnosis of Pott's puffy tumor, defined as scalp swelling and associated intracranial infection. There were 6 male patients and 1 female patient. Ages ranged from 11 to 18 years (median 14.5 years). Intracranial infections consisted of epidural abscess in 5 patients, subdural empyema in 4 and brain abscess in 1. Intraoperative cultures grew anaerobic organisms in 1 patient, microaerophilic streptococcus in 5 patients, Klebsiella species in 1 patient and Streptococcus pneumoniae in another. All patients presented with frontal scalp swelling, and other common symptoms included headache, fever, nasal drainage and frontal sinus tenderness. Five patients were treated with antibiotics prior to their presentation. Four patients presented with neurologic decompensation characterized by varying degrees of hemiparesis, obtundation, pupillary dilatation or aphasia. All patients underwent craniotomy and evacuation of the intracranial infection. Even severely impaired patients demonstrated full neurologic recovery. Despite the widespread use of antibiotics, neurosurgical complications of sinusitis continue to occur. A high degree of suspicion, along with prompt neurosurgical intervention and the use of appropriate antibiotics, can result in favorable outcomes in even the sickest patients.

Delayed rupture of traumatic intracranial pseudoaneurysm in a child following gunshot wound to the head.

BACKGROUND AND OBJECTIVES: Traumatic intracranial aneurysms (TICAs) are highly unstable lesions that may rupture within minutes after formation or remain quiescent for several weeks and manifest with delayed hemorrhage and neurologic deterioration. Mortality following a rupture may be 30% to 40%. Among all cerebral aneurysms, the incidence of TICAs is less than 1%; 20% to 30% of TICAs occur in children. METHODS AND MATERIALS: A child with a low-caliber craniocerebral gunshot wound deteriorated neurologically 12 days after the initial injury and emergency evacuation of an intracranial hematoma. A new massive left frontal hematoma was discovered, caused by the rupture of an unsuspected left pericallosal artery pseudoaneurysm. The new hematoma was evacuated, and the aneurysm was trapped using microsurgical techniques. RESULTS AND/OR CONCLUSIONS: A high index of suspicion should be maintained for delayed pseudoaneurysm genesis and rupture. A cerebral arteriogram should be obtained when significant subarachnoid hemorrhage or intraparenchymal hematomas are present, when missiles traverse major arteries, or when the pterional or cranioorbitofacial regions are violated. Treatment should be prompt.