Feasibility study of low concentration iso_osmolar contrast agent and low tube voltage for rabbit hepatic computed tomography perfusion scanning / 中华放射医学与防护杂志

Objective To investigate the feasibility of low-c oncentration iso_osmolar contrast agent together with low tube voltage and iterative reconstruction algorithm in rabbit liver computed tonography (CT) perfusion imaging.Methods A total of 15 bealthy New Zealand rabbits were scanned twice of liver CT perfusion scans each with 24 hours interval.The first scan (routine group) was acquired at 100 kV and 100 mAs with ultravist (370 mg/ml),while the second (double low group) was acquired at 80 kV and 100 mAs with iodixanol (270 mg/ml) at 24 hours after the first scan.The obtained images were reconstructed with filtered back projection (FBP) and adaptive iterative dose reduction (AIDR-3D)algorithms in the controlled and experimental groups,respectively.The perfusion parameters including hepatic artery perfusion(HAP),portal vein perfasion(PVP),hepatic perfusion index(HPI),and total liver perfusion(TLP) and image quality as image quality score,average CT value of abdomen aorta,signalto-noise ratio(SNR),carrier-to-noise ratio(CNR),and figure of merit(FOM) were compared used pair ttest or Mann-Whitney U-test between the two groups wherever appropriate.The effective radiation dose and iodine intake were also recorded and compared.Results The image quality and perfusion parameters had no significantly different between the two groups except for FOM.The effective radiation dose and iodine intake were 38.79％ and 27.03％ lower in the double low group.Conclusions Low concentration iso _osmolar contrast agent (iodixanol,270 mg/ml) together with low tube voltage (80 kV) helps to reduce radiation dose and iodine intake without compromising perfusion parameters and image quality in liver CT perfusion imaging.

Cyclosporine-Induced Posterior Reversible Leukoencephalopathy Syndrome With Reduced Cerebral Perfusion

Posterior reversible leukoencephalopathy syndrome (PRLS) is a disorder that is characterized by reversible white-matter edema affecting the posterior regions of the brain. There are rare cases in which cyclosporine has been cited as a medication responsible for PRLS, which causes hypoperfused ischemia by endothelial injury and vasoconstriction, with resultant vasogenic edema. A PRLS patient in whom the condition was induced by cyclosporine is described herein. Perfusion computed tomography revealed a clinically relevant hypoperfused area, including the zones of vasogenic edema.

The study on hemodynamics changes of the regions surrounding hematoma in pafients with hypertensive cerebral hemorrhage / 中国医师进修杂志

Objective To the expression of cytokines assay in peripheral blood and hematoma fluid of hypertensive cerebral hemorrhage,and the hemodynamic changes in brain tissue around the hematoma by using perfusion computed tomography imaging(PCTT)and immune turbidimetric analysis and analyze its influence on prognosis.Methods Fifty-six cases of hypertensive intracerebral hemorrhage patients were inspected with conventional CT and PCTT,quantitative analysis of hematoma and the contralateral corresponding area around the cerebral blood flow(CBF),cerebral blood volume(CBV),mean transit time (MTT),comparing acute and subacute phase CBF,CBV,MTT change.Peripheral blood,hematoma fluid compiement C_3 and C_4 levels were detected.Results In 56 patients with acute phase ipsilateral CBF,CBV,MTT were(19.3 4±3.1)ml/(min·100 g),(1.4 4±0.4)ml/g,(16.5 4±3.1)s,respectively,and in eontralateral were(50.3 4±3.4)ml/(min·100 g),(2.4±1.1)ml/g,(4.8±2.6)s,the corresponding index difference between the two sides were statistically significant(P<0.05).Subaeute phase ipsilateral CBF,CBV,MTY were(29.7±2.1)ml/(min·100 g),(1.9±0.6)ml/g,(8.9±2.7)s,the in contralateral were (48.2±6.3)ml/(min·100g),(2.3±0.7)ml/g,(4.7±1.6)s,the corresponding index difference between the two sides were statistically significant(P<0.05).Subacute phase CBF,CBV,MTT compared with acute phase,the difference Wag statistically significant(P<0.05).Acute and subacute phase of complement C_3 and C_4 in peripheral blood and hematoma fluid content of the differences were statistically significant(P<0.05).Acute and subaeute phase of edema ratios were 0.9 and 0.4,the difference was statistically significant (P<0.05).Conclusions The cerebral blood flow and cerebral perfusion of the brain tissue amund hematoma after the cerebral hemorrhage are decreased.PCTI Can analyze the intracerebral hemodynamic changes of the brain tissue around hematoma after the cerebral hemorrhage,which is helpful to treat hypertensive cerebral hemorrhage and estimate its prognosis.

Perfusion Computed Tomography and Trancranial Doppler in Aneurysmal Subarachnoid Hemorrhage / 대한뇌혈관외과학회지

OBJECT: This study is designed to estimate the clinical usefulness of perfusion computed tomography (perfusion CT) as an easily accessible tool to evaluate cerebral blood flow (CBF) in patients with aneurysmal subarachnoid hemorrhage. METHOD: Twenty patients with aneurysmal spontaneous subarachnoid hemorrhage who underwent either aneurysmal neck clipping or interventional coil embolization and who also had taken transcranial doppler study and perfusion CT were included as study group. And as a control group, fifteen patients without neurologic deficit were studied with the same devices. We compared the cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) from obtained perfusion CT with the results of transcranial doppler and clinical course. RESULTS: CBF parameters of perfusion CT in control group showed close accordance with those values of reported xenon CT and positron emission tomography data. In doppler study, the blood flow velocity was higher in cases with vasospasm than without it (p=0.027). There showed significant relationship between vasospasm and perfusion CT parameters, as decrease in CBF (p=0.061) and increase in MTT (p=0.013). Perfusion CT parameters were closely correlated with TCD parameters in clinical vasospasm as reverse correlation in CBF (R2=0.45) and positive in MTT (R2=0.58). CONCLUSION: The cerebral blood flow parameters of Perfusion CT showed reliable and accurate values in control group. The perfusion CT and TCD can be used as easily accessible non-invasive tools to evaluate cerebral blood flow parameters in clinical settings of patients with aneurysmal subarachnoid hemorrhage.

First-Pass Perfusion Computed Tomography and Transcranial Doppler in Hydrocephalus / 대한뇌혈관외과학회지

OBJECTIVES: The aim of this study are clinical application of perfusion computed tomography (perfusion CT) in hydrocephalus and comparison its cerebral blood flow parameters with transcranial doppler (TCD) and clinical outcome. METHOD: 25 patients with hydrocephalus took pre- and postoperative perfusion CT and TCD. 15 patients without neurologic deficit were also examined with same protocol as a control. Blood flow parameters of perfusion CT, such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were analyzed according to clinical status and postoperative outcome. So did the TCD parameters, mean flow velocity (mFv) and pulsatility index (PI) with regard to clinical outcome. RESULTS: Perfusion CT parameters of the hydrocephalus showed decrease in CBF (gray matter P=0.035, periventricular region P=0.042) and increase in MTT (gray matter P=0.039, periventricular region P=0.045) compared to control. In postoperative improvement group, there noted reversal of perfusion parameters close to those of the control. TCD parameters showed increase in mFv (P=0.047), and decrease in PI (P=0.042) in cases with improvement. CONCLUSION: Perfusion brain CT and TCD can used as clinically useful tools to predict the postoperative outcome on hydrocephalus.