To study the dynamic changes of CT perfusion parameters during the first 12 h in the embolic cerebral ischemia models. Local cerebral ischemia model were established in 7 New Zealand white rabbits. All CT scans were performed with a GE Lightspeed 16 multislice CT. Following the baseline scan, further CT perfusion scans were performed at the same locations 20 min, 1-6 h and 8, 10 and 12 h after the embolus delivery. Maps of all parameters were obtained by CT perfusion software at each time point. The brains, taken 12 h after the scan, were sliced corresponding to the positions of the CT slices and stained by 2,3,5-triphenyltetrazolium chloride (TTC). On the basis of the TTC results, the ischemic sides were divided into 3 regions: core, penumbra and the relatively normal region. The changes of all parameters were then divided into 3 stages. In the first two hours (the first stage), the CBV dropped more remarkably in the core than in the penumbra but rose slightly in the relatively normal region while the CBF decreased and MTT, TTP extended in all regions to varying degrees. In the 2nd-5th h (the second stage), all the parameters fluctuated slightly around a certain level. In the 5th-12th h (the third stage), the CBV and CBF dropped, and MTT and TTP were prolonged or shortened slightly in the core and penumbra though much notably in the former while the CBV, CBF rose and MTT, TTP were shortened remarkably in the relatively normal region. We experimentally demonstrated that the location and extent of cerebral ischemia could be accurately assessed by CT perfusion imaging. The pathophysiology of the ischemia could be reflected by the CT perfusion to varying degrees.
Blood Flow Velocity ; Brain Ischemia/physiopathology ; Brain Ischemia/*radiography ; Cerebrovascular Circulation ; Stroke/physiopathology ; Tomography, X-Ray Computed

To evaluate the efficacy of magnetic resonance imaging in brainstem stroke, we studied 21 cases of clinically definite brainstem ischemic stroke with brain magnetic resonance imaging (MRI) and conventional computed tomography (CT). MRI demonstrated brainstem lesions in 79% of the cases (16.5 out of 21), while CT revealed 33% (7 out of 21) when cases with suspicious lesions counted as 0.5. Although MRI was done a few days later than CT in most cases, MRI was superior to CT in detecting the number and the size of ischemic lesions, with clear delineation of anatomy and visualization of the status of the blood flow in the vertebral-basilar artery. Disappearance of the flow signal void in the basilar artery can be an important clue in diagnosing occlusion or thrombus of the basilar artery. By delineating the extent and the location of the infarction, MRI findings allowed an interpretation of whether the ischemic vessel is a small basilar branch or a large vessel vertebral or basilar artery.
Adult ; Aged ; Brain Ischemia/complications/*diagnosis/radiography ; Brain Stem/blood supply/*pathology/radiography ; Cerebral Infarction/etiology/pathology ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Tomography, X-Ray Computed

Intra-carotid urokinase (UK) infusion in 20 patients with acute internal carotid artery (ICA) territorial ischemic stroke achieved immediate recanalization in 45% and the clinical outcome in patients with recanalization was superior to that of patients without recanalization. The procedure was most effective in patients with smaller arterial occlusions: 7 of 10 patients with MCA branch occlusions (M2 to M4) achieved recanalization compared to only 2 of 10 with distal ICA or M1 occlusions, which should be an important issue for the critical evaluation of the efficacy of thrombolytic therapy (TT). Hemorrhagic transformation was observed in 9 patients on CT scan; petechial hemorrhage in 5 and intraparenchymal hematoma formation in 4. Among 4 patients with hematoma formation, clinical deterioration was seen in 3 cases and the angiography at the immediate end of the UK infusion showed recanalization in only one patient. The average dose of UK in patients with parenchymal hematoma formation was higher than that of patients without hemorrhagic transformation (123.3 x 10(4) units vs 101 x 10(4) units). The administration of a large dose of UK, probably more than 100 x 10(4) units, and the absence of immediate recanalization seemed to increase the risk of parenchymal hematoma formation. Despite the effort of investigators, the in-hospital time delay for the TT was significant which was mainly related to the time consuming preparation for angiography especially during night. A more effective system for the earlier intervention of acute ischemic stroke needs to be developed.
Adult ; Aged ; Angiography ; Brain Ischemia/*drug therapy/radiography ; Carotid Artery Thrombosis/*drug therapy/radiography ; Female ; Human ; Male ; Middle Age ; Support, Non-U.S. Gov't ; Thrombolytic Therapy/*methods ; Tomography, X-Ray Computed ; Urinary Plasminogen Activator/*administration & dosage

OBJECTIVECerebral infarction (CI) is one of severe diseases of central nervous system in neonates, and some infants with CI could have poor prognosis in the long term. This study aimed to analyze the clinical data and prognosis of all neonatal cases with cerebral infarction in recent years and to help future clinical work.

METHODTotally 58 neonatal cases with CI admitted to NICU of the hospital from January 1999 to December 2010 were included in this study. We analyzed all clinical data and prognosis by retrospective analysis.

RESULTSFifty-two term babies and six preterm babies were included. There were altogether 51 cases with asphyxia and 7 with hemorrhagic cerebral infarction. Perinatal hypoxia-ischemia was the most common high-risk factor and it accounted for 46.6%. Seizure was the most frequent initial symptom and the most common clinical manifestation (accounted for 77.6%), and it was followed by intermittent cyanosis, apnea and lethargy. Cerebral CT scan and magnetic resonance imaging were major methods to help to make the diagnosis and they also had close relation with prognosis. Diffusion weighted imaging was very helpful to diagnose infarction in early stage. Left middle cerebral artery was the most common artery to be involved. Supportive therapy and symptomatic treatment were the main methods in the acute stage of neonatal cerebral infarction. Those babies with poor prognosis mostly had large infarction involving cerebral hemisphere, thalamus and basal ganglia.

CONCLUSIONSNeonatal cerebral infarction was a severe brain injury affecting long tern nervous system prognosis. Perinatal hypoxia was the most common high-risk factor and seizure was the most frequent initial symptom. Diffusion weighted imaging was valuable to diagnose infarction in early stage. Most of infants with poor prognosis had large infarction involving hemisphere, thalamus and basal ganglia. Early diagnosis with brain imaging would be helpful for rehabilitation therapy and improving prognosis.

Brain ; diagnostic imaging ; pathology ; Cerebral Infarction ; diagnosis ; etiology ; pathology ; therapy ; Cerebral Palsy ; etiology ; Humans ; Hypoxia-Ischemia, Brain ; complications ; Incidence ; Infant ; Infant, Newborn ; Magnetic Resonance Imaging ; Male ; Prognosis ; Radiography ; Retrospective Studies ; Risk Factors ; Seizures ; etiology ; Ultrasonography, Doppler, Color

Midgut volvulus secondary to intestinal malrotation usually presents within the first month of life. Diagnostic delay may result in midgut infarction and mortality. In this retrospective study, we review seventeen cases of midgut volvulus to assess the importance of early recognition for midgut volvulus in pediatric patients of any age.. These patients were diagnosed as having a midgut volvulus by operation at Ewha Womans University Hospital. Eleven patients (64.7 %) were less than 1 month of age, and fifteen were boys (88.2 %). The mean gestational age was 38.3 weeks and the birth weight was 3.1 kg. Eight patients (47.1 %) had one or more combined anomalies such as heart malformation, brain ischemia, Down's syndrome or duodenal atresia. Vomiting was the most common symptom. Only thirteen patients underwent preoperative diagnostic procedures; 13 abdominal sonography demonstrated the whirlpool sign in 8 patients, upper gastrointestinal tract roentgenography showed a cork-screw pattern in 7 patients, and barium enema or small bowel series demonstrated positive findings in 7 patients. A Ladd's procedure was was formed on all patients.. There was no mortality or severe morbidity such as short bowel syndrome. Midgut volvulus should be included in the differential diagnosis in any infant or child who presents with the symptoms of acute abdomen, especially with vomiting.
Abdomen, Acute ; Barium ; Birth Weight ; Brain Ischemia ; Child* ; Diagnosis, Differential ; Down Syndrome ; Enema ; Female ; Gestational Age ; Heart ; Humans ; Infant ; Infarction ; Intestinal Volvulus* ; Mortality ; Radiography ; Retrospective Studies ; Short Bowel Syndrome ; Upper Gastrointestinal Tract ; Vomiting

To assess the regional cerebral blood flow (rCBF) in ischemic stroke, we analyzed the findings of single photon emission computed tomography (SPECT) using technetium-99m hexamethyl propyleneamine oxime (Tc-99m HMPAO). The SPECT images revealed abnormal areas of decreased perfusion in 29 out of 31 subjects (93.5%), which represented a higher detection rate than those for CT and MR (89.5%, respectively). Also, the areas of decreased perfusion were frequently larger than the lesions on CT and MR. Areas of decreased perfusion remote from the CT/MR lesions were found in 10 patients, including 8 with crossed cerebellar diaschisis (CCD). Thus, studies of rCBF by Tc-99m HMPAO SPECT can be useful in the assessment of ischemic stroke.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Brain Ischemia/*physiopathology/radiography/radionuclide imaging ; Cerebrovascular Circulation/*physiology ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Regional Blood Flow ; Tomography, Emission-Computed, Single-Photon ; Tomography, X-Ray Computed

Image fusion is fast catching attention as Wagner pointed out in his 2006 version of the recent progress and development presented at the annual meeting of Society of Nuclear Medicine. Prototypical fusion of bone scan and radiograph was already attempted at in 1961 when Fleming et al. published an article on strontium-85 bone scan. They simply superimposed dot scan on radiograph enabling simultaneous assessment of altered bone metabolism and local bone anatomy. Indeed the parallel reading of images of bone scan and radiography, CT, MRI or ultrasonography has been practiced in nuclear medicine long since. It is fortunate that recent development of computer science and technology along with the availability of refined CT and SPECT machines has permitted us to open a new avenue to digitally produce precise fusion image so that they can readily be read, exchanged and disseminated using internet. Ten years ago fusion was performed using Bresstrahlung SPECT/CT and it is now achievable by PET/CT and SPECT/CT software and SPECT/CT hardware. The merit of image fusion is its feasibility of reliable assessment of morphological and metabolic change. It is now applicable not only to stationary organs such as brain and skeleton but also to moving organs such as the heart, lung and stomach. Recently, we could create useful fusion image of cardiac SPECT and 64-channel CT angiograph. The former provided myocardial metabolic profile and the latter vascular narrowing in two patients with coronary artery stenosis and myocardial ischemia. Arterial stenosis was severe in Case 1 and mild in Case 2.
Angiography* ; Brain ; Constriction, Pathologic ; Coronary Stenosis* ; Coronary Vessels* ; Heart ; Humans ; Internet ; Lung ; Magnetic Resonance Imaging ; Metabolism ; Metabolome ; Microcomputers* ; Myocardial Ischemia ; Nuclear Medicine ; Positron-Emission Tomography and Computed Tomography ; Radiography ; Skeleton ; Stomach ; Tomography, Emission-Computed, Single-Photon* ; Ultrasonography

This study aimed to investigate inflammatory edema after cerebral ischemia through 7.0T MRI and proton magnetic resonance spectroscopy (MRS). All SD rats were randomly divided into sham operated group and middle cerebral artery occlusion (MCAO)-1 day, -3 day and -7 day groups. MRI scan of the brain was performed on a 7.0 Tesla MRI scanner. The volume of positive signals in the ischemic side was detected by using a T2 weighted spinecho multislice sequence; the changes in the height of water-peak were measured with point resolved spectroscopy (PRESS) sequences; cortical edema was detected by using wet-dry weight method; the degrees of nerve injury were evaluated by Bederson neurological score system; double-labeling immunofluorescence technique was used to explore the molecular mechanisms of post-ischemia cerebral edema. The results showed that high T2WI signals were observed in MCAO-1 day, -3 day and -7 day groups, and the water-peak height and water-peak area of MCAO groups were higher than those of sham operated group (P<0.05). Neurological score results were consistent with the degree of brain edema, and a large number of microglia accumulated in the ischemic cortex. Our results suggested that non-invasive MRI technology with the advantage of high spatial resolution and tissue resolution can comprehensively and dynamically observe inflammatory edema after cerebral ischemia from a three-dimensional space, and contribute to evaluation and treatments in clinic.
Animals ; Brain ; diagnostic imaging ; pathology ; Brain Edema ; diagnostic imaging ; etiology ; Brain Ischemia ; complications ; CD11b Antigen ; metabolism ; Immunohistochemistry ; Infarction, Middle Cerebral Artery ; complications ; Inflammation ; diagnostic imaging ; etiology ; Magnetic Resonance Imaging ; methods ; Magnetic Resonance Spectroscopy ; Male ; Microglia ; metabolism ; Microscopy, Confocal ; Microscopy, Fluorescence ; Radiography ; Rats ; Rats, Sprague-Dawley ; Reproducibility of Results ; Time Factors

OBJECTIVE: Hyperdense lesions can frequently be observed on the CT obtained immediately after intra-arterial (IA) thrombolysis, and it is sometimes difficult to differentiate contrast extravasation from the hemorrhagic lesions. The purposes of this study are to classify the hyperdense lesions according to their morphologic features and to track the outcome of those lesions. MATERIALS AND METHODS: Among the 94 patients who suffered with anterior circulation ischemic stroke and who were treated with IA thrombolysis, 31 patients revealed hyperdense lesions on the CT obtained immediately after the procedure. The lesions were categorized into four types according to their volume, shape, location and density: cortical high density (HD), soft HD, metallic HD and diffuse HD. The follow-up images were obtained 3-5 days later in order to visualize the morphologic changes and hemorrhagic transformation of the lesions. RESULTS: Among the 31 patients with HD lesions, 18 (58%) showed hemorrhagic transformation of their lesion, and six of them were significant. All the cortical HD lesions (n = 4) revealed spontaneous resolution. Seven of the soft HD lesions (n = 13) showed spontaneous resolution, while the rest of the group showed hemorrhagic transformation. Among them the hemorrhage was significant in only two patients (2/6) who did not achieve successful recanalization. All the metallic HD lesions (n = 10) resulted in hemorrhagic transformation; among them, three cases (30%) with a maximum CT value more than 150 HU (Hounsfield unit) subsequently showed significant hemorrhagic transformation on the follow-up CT. There were four diffuse HD lesions, and two of them showed hemorrhagic transformation. CONCLUSION: The parenchymal hyperdense lesions observed on the CT obtained immediately after IA thrombolysis in ischemic stroke patients exhibited varying features and they were not always hemorrhagic. Most of the soft HD lesions were benign, and although all of the metallic HD lesions were hemorrhagic, some of them were ultimately found to be benign.
Treatment Outcome ; *Tomography, X-Ray Computed ; Thrombolytic Therapy/*methods ; Statistics, Nonparametric ; Retrospective Studies ; Middle Aged ; Male ; Magnetic Resonance Imaging ; Infusions, Intra-Arterial ; Humans ; Fibrinolytic Agents/therapeutic use ; Female ; Cerebrovascular Accident/*drug therapy/pathology/*radiography ; Brain Ischemia/*drug therapy/pathology/*radiography ; Aged ; Acute Disease

The regional cerebral blood flow of four patients with delayed carbon monoxide sequelae and four age matched controls was measured, using a xenon inhalation CT scan (GE 9800). Variable patterns of decreased cerebral blood perfusion according to the clinical state of the patient were noted among the patients. Follow up studies, 2 months later, indicated that there was a correlation between the fluctuation of symptoms and the changes in regional cerebral blood flow. It is suggested that the impairment of cerebral perfusion may play a critical role in delayed carbon monoxide sequelae.
Administration, Inhalation ; Aged ; Brain/*blood supply ; Brain Ischemia/chemically induced/physiopathology/*radiography ; Carbon Monoxide Poisoning/*complications ; Case Report ; Female ; Human ; Male ; Middle Age ; Regional Blood Flow/drug effects ; Support, Non-U.S. Gov't ; Time Factors ; Tomography, X-Ray Computed ; Xenon/administration and dosage/diagnostic use