Assessment of craniocerebral asymmetries in children by computed tomography

Computed tomographic (CT) scans of 32 children (mean age 2.8±2.5 years) with a wide range of craniocerebral asymmetry (CCA) were analyzed. Hemiparesis and epilepsy were the main clinical presentations. Two-thirds of the patients had brain infarcts. The degree of cerebral and ventricular asymmetry was evaluated by ratios obtained by linear measurements. The patients were divided into two groups according to the index of maximal asymmetry. The incidence of hemiparesis and the width of the cerebral ventricles did not differ in the two groups. This may be due to the fact that most of our patients suffered from perinatal insult to the brain, allowing time for remodeling and palstic changes to occur. The use of measurable structural parameters in craniocerebral asymmetry offers a basis for comparable radiological assessment.     

Growth of multiple hydatid cysts evaluated by computed tomography

A case of multiple hydatid cysts, of embolic origin from a cyst of the left atrium, is discussed. The patient was first admitted to hospital with an intracerebral haemorrhage and was treated conservatively. There was not any cystic or mass lesion other than intracerebral haemorrhage on his computed tomography (CT) scans. In the follow-up period, the CT scans after 14 months showed multiple hydatid cysts, with the largest about 6 cm in diameter, which suggested a growth rate of 5 cm per year.     

Cerebral atrophy in motor neuron disease evaluated by computed tomography

Thirty-two (64%) of 50 patients with motor neuron disease showed various patterns of cerebral atrophy (cortical, ventricular or both) at CT examination. The incidence of cerebral atrophy, particularly cortical atrophy, in motor neuron disease was greater than in a matched control group.     

Quantitative assessment of cerebral blood volume by single-photon emission computed tomography.

We implemented a technique for measuring regional cerebral blood volume using single-photon emission computed tomography and in vivo technetium-99m-labeled red blood cells and then evaluated it in nine normal human volunteers (controls) and seven patients with bilateral occlusion or severe stenosis of the internal carotid artery. We also measured regional cerebral blood flow using single-photon emission computed tomography and intravenous xenon-133 in the same subjects. We studied regional cerebral blood flow, regional cerebral blood volume, and their ratio before and after the intravenous injection of 1 g acetazolamide. Mean +/- SD baseline regional cerebral blood volume was higher in the patients than in the controls (4.1 +/- 0.6 versus 3.2 +/- 0.3 ml/100 g, p less than 0.01), and mean +/- SD baseline regional cerebral blood flow was lower in the patients than in the controls (40.5 +/- 11 versus 55.6 +/- 11 ml/100 g/min, p less than 0.05). Acetazolamide induced similar mean +/- SD increases in regional cerebral blood volume in both the controls and the patients (0.3 +/- 0.1 and 0.3 +/- 0.2 ml/100 g), while the mean +/- SD regional cerebral blood flow reactivity was significantly less in the patients than in the controls (12.6 +/- 7.6 versus 24.5 +/- 9.6 ml/100 g/min, p less than 0.05). Our study shows that single-photon emission computed tomography can provide quantitative estimates of both regional cerebral blood volume and regional cerebral blood flow in humans.     

Prediction of delayed cerebral ischaemia after subarachnoid haemorrhage by computed tomography.

Computed tomography was performed in 100 patients within 4 days of aneurysmal subarachnoid haemorrhage. The CT appearances have been divided into five grades by the thickness and extent of the subarachnoid blood. Delayed cerebral ischaemia occurred in 62.5% of patients with most blood on CT, in 33.3% of those in the next grade and in none of the other grades with less amounts of blood. The outcome from delayed ischaemia was worse in those with most CT blood.     

Detection of cerebral artery fenestrations by computed tomography angiography

Background and purposeCerebral artery fenestrations (CAF) are rare congenital variations usually diagnosed by digital subtraction angiography (DSA). The aim of this study was to examine the frequency of occurrence of fenestrations in cerebral arteries and their coexistence with cerebral aneurysms in computed tomography angiography (CTA).Material and methodsAll reports of cerebral CTA (1140) performed in one institution from March 2005 to December 2007 were analysed. We found 40 patients with single fenestrations of the intracranial arteries. All 40 examinations were retrospectively reviewed for location of vascular malformations and presence of aneurysms or subarachnoid haemorrhage (SAH). Medical histories of those patients were then analysed for evidence of SAH and referral reasons for CTA.ResultsForty fenestrated arteries were found in CTA: 18 basilar arteries (45%), 16 anterior cerebral arteries (40%), 4 anterior communicating arteries (10%) and one middle cerebral artery (2.5%). Only one vertebral artery fenestration was found due to the technique of the examination. Six patients (15%) with fenestrated arteries had a total of 8 aneurysms, although only one aneurysm was ipsilateral to the fenestration. In 8 cases of SAH, two were with no evidence of vascular malformation. The coexistence of CAF and aneurysms in CTA amounted to 15% (6/40), but the incidence of ipsilateral aneurysm was only 2.5% (1/40) and it affected the anterior cerebral artery.ConclusionsBasilar artery fenestration is the most frequent observed fenestration in CTA, followed by anterior cerebral artery and anterior communicating artery fenestrations. Coexistence of fenestration and aneurysm is uncommon in CTA examination.     

Hemodynamics of hypertensive putaminal hemorrhage evaluated by Xenon-enhanced computed tomography and acetazolamide test

Cerebral blood flow (CBF) is usually decreased in patients with hypertensive putaminal hemorrhage (HPH). However, there are few reports concerning cerebrovascular reserve capacity (CRC) in these cases. This study evaluated cerebral hemodynamics in patients with HPH by measuring CBF and CRC. CBF and CRC were measured by stable xenon enhanced computed tomography (Xe-CT) in 11 patients with HPH (HPH group) and 11 patients with essential hypertension without intracerebral hematoma (non-HPH group). CBFs of the hemisphere and thalamus in the HPH group were lower than those in the non-HPH group. And the CBF of the hemisphere was increased transiently after the surgical evacuation of the hematoma. Thereafter, it fell gradually. The CRCs were also lower in acute stage of the HPH group. The CRC recovered during the chronic stage. Hemodynamics in patients with HPH can be modulated by surgical removal of hematoma. However, some adjunct therapies are necessary to prevent delayed neuronal inactivity. Stable Xe-CT with acetazolamide test is useful to evaluate hemodynamics in the HPH patients.     

Prospective evaluation of cerebral angiography and computed tomography in cerebral haematoma.

One hundred and two consecutive patients with cerebral haematoma were prospectively allocated to one of two groups according to their CT on admission. Group 1 patients were thought to have a high probability of an underlying structural lesion and underwent cerebral angiography acutely. If normal, this was repeated at three months. Group 2 patients were thought not to have such a lesion and underwent angiography at three months. Patients older than the mean age of the study population, and hypertensive patients were much less likely to harbour an aneurysm or arteriovenous malformation than younger or normotensive patients (p < 0.01; sensitivity 87.9%, specificity 88.6%). An aneurysm or arteriovenous malformation was the cause of haemorrhage in 12.8% of hypertensive patients, in 30.9% of patients with haematoma involving the basal ganglia, and 18.2% of those with posterior fossa haemorrhage. Features of CT in isolation give a sensitivity of 77.2% and a specificity of 84.2%. Follow up angiography in group 1 showed an arteriovenous malformation in one of seven patients in whom the original study was normal. These results contrast sharply with data from previous retrospective studies. The decision to investigate a patient with cerebral haematoma should be primarily based on the patient's clinical condition, rather than on the site of haemorrhage.     

Subtle computed tomography abnormalities in cerebral deep sinus thrombosis.

A patient with cerebral deep sinus thrombosis, which was not diagnosed on the first examination, is reported. A 46-year-old woman presented with headache and vomiting. Neurological examination and a brain computed tomography (CT) scan showed no obvious abnormal findings. The patient suffered disturbed consciousness on the day after the examination, and was admitted to our emergency centre. A CT scan and magnetic resonance imaging revealed an ischaemic lesion in the left basal ganglia, suggesting deep sinus occlusion. Anticoagulant therapy was administered. One day after admission, a CT scan showed a haematoma and severe brain swelling in the same region. Cerebral angiography demonstrated a straight sinus occlusion. Intracranial pressure was not controlled with hypothermia, and the patient died 25 days after admission. Review of the initial CT scan revealed subtle, early findings of deep venous thrombosis that were missed on first examination.     

Electroconvulsive therapy and cerebral computed tomography. A prospective study

Cerebral computed tomography (CT) was performed before and after right-sided electroconvulsive therapy (ECT) in 40 patients aged 26-87 years with major affective disorders. Nine patients with a concomitant definite or possible non-acute organic brain disorder were included. Several patients had long seizure durations, maximum 6.5 min, caused by hyperventilation-induced hypocapnia. Twenty-nine patients received at least 16 treatments (maximum 46). No CT changes occurred following ECT. A questionable dilatation of the left temporal horn in a 69-year-old hypertensive man who recovered completely without side effects after 3 ECT sessions was probably unrelated to the ECT. Provided sufficient oxygenation, even relatively long ECT series and seizures lasting several minutes do not cause any brain damage visible on CT.     

Measurements of acute cerebral infarction: lesion size by computed tomography

As part of a prospective therapy study of 65 patients with acute, nonhemorrhagic, cerebral infarction, computed tomographic scans of the head were obtained at admission, 7-10 days, and 3 months. The scans were analyzed for the presence, site, size, and volume measurement of the infarction. At 7-10 days, the mean infarction volume as measured by computed tomography was 55 cm3 or about 4 x 4 x 3.5 cm (range = 0-507 cm3). At 3 months, the mean infarction volume decreased by 25% to 41 cm3. For the 26 scans showing infarction at the time of admission, the mean lesion volume was 33 cm3 at admission, 51 cm3 at 7-10 days, and 49 cm3 at 3 months. With lesion size at 7-10 days expressed as percentage of total brain volume, the mean infarction size was only 5%. Of the 49 patients with lesions revealed by computed tomography at 7-10 days, 20 had an infarction of 1% or less of total brain volume, while only six had an infarction of 20% or more of total brain volume. The lesion volumes as measured by the 7-10-day computed tomography correlated with the neurologic examination scores on admission (Spearman's rank-order correlation = 0.78) and with the scores at 1 week (Spearman's rank-order correlation = 0.79).     

Acute cerebral demyelination: clinical and pathological correlation with computed tomography.

A 30-year-old woman died eleven weeks after the onset of an acute illness during which she developed quadriplegia, dysphasia, incontinence, confusion, emotional lability and gaze palsies. The CT scan demonstrated large white matter low attenuation lesions with no mass effect and minimal contrast enhancement. At necropsy the lesions were shown to be those of massive cerebral demyelination.     

Evaluation of infratentorial atrophy by computed tomography.

Eight parameters of cranial computed tomograms were examined from 121 controls, 33 patients suffering from paleocerebellar atrophy and 53 with widespread cerebellar atrophy. With the aid of step-by-step linear discriminant analysis the most important parameters were found and their normal and limiting values were calculated. With the help of correlation analysis the correlation between normal values and the age of the controls was investigated.     

Measurement of regional cerebral blood flow using ultrafast computed tomography. Theoretical aspects

Theoretical and practical limitations have prevented the measurement of regional cerebral blood flow using dynamic x-ray computed tomography. Development of the ultrafast computed tomography scanner has made it possible to overcome the practical limitations and measure changes in contrast concentration in the brain with excellent time and spatial resolution. By applying modifications of indicator dilution theory, we have derived a method to use these changes in contrast concentration determined using ultrafast computed tomography to measure the fractional vascular volume, mean transit time of blood, and blood flow within specific regions of the brain in a relatively simple and practical manner. This method could theoretically be used in the evaluation of physiological and pathophysiological alterations in cerebral blood flow.     

Cerebral blood flow and cerebral hematocrit in patients with cerebral ischemia measured by single-photon emission computed tomography

Abstract– Single-photon emission computed tomography (SPECT) was used for the measurement of regional cerebral blood flow (CBF), cerebral blood volume (CBV) and cerebral hematocrit (Hct). CBF was measured using N-isopropyl-p-I-123-Iodoamphetamine. CBV was measured by both RBC tracer (Tc-99m RBC) and plasma tracer (Tc-99m human serum albumin) and cerebral hematocrit (Hct) was calculated. In normals, the cerebral-to-large vessel Hct ratio was 75.9%. Isovolemic hemodilution in patients with high Hct tended to increase the cerebral-to-large vessel Hct ratio. Low CBF, high CBV and slow cerebral blood mean transit time (MTT by dynamic CT scanning) was seen during the acute stage of completed infarction and during the symptom-free interval of TIA. Cerebral Hct was increased in the ischemic region of poor prognosis.     

Prognostic significance of cerebral computed tomography results in supratentorial infarction

In 69 patients with supratentorial cerebral infarction findings at computed tomography (CT) were related to clinical state on admission and course of recovery. In patients with initial disability of slight to moderate degree CT did not provide prognostically useful information; in patients with severe symptoms at onset location of lesion to the internal capsule or the right parietal lobe and the presence of a mass effect, as single factors or in combination, were ominous CT indicators in terms of functional recovery.