Diagnostic value of one-stop CT energy spectrum and perfusion for angiogenesis in colon and rectum cancer.

OBJECTIVE: Evaluation of the predictive value of one-stop energy spectrum and perfusion CT parameters for microvessel density (MVD) in colorectal cancer cancer foci. METHODS: Clinical and CT data of 82 patients with colorectal cancer confirmed by preoperative colonoscopy or surgical pathology in our hospital from September 2019 to November 2022 were collected and analyzed retrospectively. Energy spectrum CT images were measured using the Protocols general module of the GSI Viewer software of the GE AW 4.7 post-processing workstation to measure the CT values of the arterial and venous phase lesions and the neighboring normal intestinal wall in a single energy range of 40 kev∼140 kev, and the slopes of the energy spectrum curves (λ) were calculated between 40 kev-90 kev; Iodine concentration (IC), Water concentration (WC), Effective-Z (Eff-Z) and Normalized iodine concentration (NIC) were measured by placing a region of interest (ROI) on the iodine concentration map and water concentration map at the lesion and adjacent to the normal intestinal wall.Perfusion CT images were scanned continuously and dynamically using GSI Perfusion software and analyzed by applying CT Perfusion 4.0 software.Blood volume (BV), blood flow (BF), surface permeability (PS), time to peak (TTP), and mean transit time (MTT) were measured respectively in the lesion and adjacent normal colorectal wall. Based on the pathological findings, the tumors were divided into a low MVD group (MVD < 35/field of view, n = 52 cases) and a high MVD group (MVD ≥ 35/field of view, n = 30 cases) using a median of 35/field of view as the MVD grouping criterion. The collected data were statistically analyzed, the subjects' operating characteristic curve (ROC) was plotted, and the area under curve (AUC), sensitivity, specificity, and Yoden index were calculated for the predicted efficacy of each parameter of the energy spectrum and perfusion CT and the combined parameters. RESULTS: The CT values, IC, NIC, λ, Eff-Z of 40kev∼140kev single energy in the arterial and venous phase of colorectal cancer in the high MVD group were higher than those in the low MVD group, and the differences were all statistically significant (p < 0.05). The AUC of each single-energy CT value in the arterial phase from 40 kev to 120 kev for determining the high or low MVD of colorectal cancer was greater than 0.8, indicating that arterial stage has a good predictive value for high or low MVD in colorectal cancer; AUC for arterial IC, NIC and IC + NIC were all greater than 0.9, indicating that in arterial colorectal cancer, both single and combined parameters of spectral CT are highly effective in predicting the level of MVD. The AUC of 40 kev to 90 kev single-energy CT values in the intravenous phase was greater than 0.9, and its diagnostic efficacy was more representative; The AUC of IC and NIC in venous stage were greater than 0.8, which indicating that the IC and NIC energy spectrum parameters in venous stage colorectal cancer have a very good predictive value for the difference between high and low MVDs, with the greatest diagnostic efficacy in IC.The values of BV and BF in the high MVD group were higher than those in the low MVD group, and the differences were statistically significant (P < 0.05), and the AUC of BF, BV, and BV + BF were 0.991, 0.733, and 0.997, respectively, with the highest diagnostic efficacy for determining the level of MVD in colorectal cancer by BV + BF. CONCLUSION: One-stop CT energy spectrum and perfusion imaging technology can accurately reflect the MVD in living tumor tissues, which in turn reflects the tumor angiogenesis, and to a certain extent helps to determine the malignancy, invasion and metastasis of living colorectal cancer tumor tissues based on CT energy spectrum and perfusion parameters.

Automated CT Perfusion Detection of the Acute Infarct Core in Ischemic Stroke: A Systematic Review and Meta-Analysis.

INTRODUCTION: In patients with acute ischemic stroke, the location and volume of an irreversible infarct core determine prognosis and treatment. We aimed to determine if automated CT perfusion (CTP) is non-inferior to diffusion-weighted imaging (DWI) or fluid-attenuated inversion recovery (FLAIR) in predicting the acute infarct core. METHODS: In this systematic review and meta-analysis, we searched MEDLINE and EMBASE from 1960 to December 2020. Five outcome measures were examined: volumetric difference, volumetric correlation, sensitivity and specificity at the patient level, Dice coefficient, and sensitivity and specificity at the voxel level. A random-effects meta-analysis was performed for volumetric difference and correlation. RESULTS: From 3,986 studies retrieved, 48 studies met our inclusion criteria with 46 studies on anterior circulation, one study on posterior circulation, and one study on lacunar infarct strokes. In anterior circulation stroke, there were no significant mean volumetric differences between CTP and acute DWI (cerebral blood flow [CBF] 0.52 mL, 95% CI [-0.07, 1.11], I2 0.0%; relative CBF [rCBF] 3.01 mL, 95% CI [-0.46, 6.48], I2 82.6%; relative cerebral blood volume [rCBV] -12.84 mL, 95% CI [-38.56, 12.88], I2 96.2%) and between CTP and delayed DWI or FLAIR (rCBF -1.29 mL, 95% CI [-6.49, 3.92], I2 91.8%; rCBV -5.80 mL, 95% CI [-16.20, 4.60], I2 84.2%). Mean correlation between CTP and acute DWI was 0.90 (95% CI [0.80, 0.95], I2 60.0%) for rCBF and 0.84 (95% CI [0.58, 0.94], I2 93.5%) for rCBV. Mean correlation between CTP and delayed DWI or FLAIR was 0.74 (95% CI [0.57, 0.85], I2 94.6%) for rCBF and 0.90 (95% CI [0.69, 0.97], I2 93.1%) for rCBV. Sensitivity and specificity at the patient level were reported by three studies and Dice coefficient by four studies. Statistical analysis could not be performed for sensitivity and specificity at the voxel level. Limited evidence was available for posterior circulation or lacunar infarct strokes. CONCLUSION: Due to significant heterogeneity and insufficient high-quality studies reporting each outcome, there is insufficient evidence to reliably determine the accuracy of CTP prediction of the infarct core compared to DWI or FLAIR.

Changes of Arterial and Venous Cerebral Blood Flow Correlation in Moderate-to-Severe Traumatic Brain Injury: A CT Perfusion Study.

We compared differences in perfusion computed tomography (PCT)-derived arterial and venous cerebral blood flow (CBF) in moderate-to-severe traumatic brain injury (TBI) as an indication of changes in cerebral venous outflow patterns referenced to arterial inflow. Moderate-to-severe TBI patients (women 53; men 74) underwent PCT and were stratified into 3 groups: I (moderate TBI), II (diffuse severe TBI without surgery), and III (diffuse severe TBI after the surgery). Arterial and venous CBF was measured by PCT in both the middle cerebral arteries (CBFmca) and the upper sagittal sinus (CBFuss). In group I, CBFmca on the left and right sides were significantly correlated with each other (p < 0.0001) and with CBFuss (p = 0.048). In group II, CBFmca on the left and right sides were also correlated (p < 0.0000001) but not with CBFuss. Intracranial pressure reactivity (PRx) and CBFuss were correlated (p = 0.00014). In group III, CBFmca on the side of the removed hematoma was not significantly different from the opposite CBFmca (p = 0.680) and was not correlated with CBFuss. Conclusions: The increasing severity of TBI is accompanied by an impairment of the correlation between the arterial and venous CBF in the supratentorial vessels suggesting shifting in arterial and venous CBF in severe TBI associated with increased ICP reflected by PRx.

Multidisciplinary and standardized management of patients with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

BACKGROUND: The appropriate management of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH) remains uncertain. We aimed to evaluate the effect of implementing a standardized protocol for detection and management of DCI after aSAH on cerebral infarction and functional outcome. METHODS: We studied two cohorts of aSAH patients, one before (pre-implementation cohort: January 2012 to August 2014) and one after (post-implementation cohort: January 2016 to July 2018) implementation of a multidisciplinary approach, with standardized neurological and radiological assessment and risk-based medical treatment of DCI. We assessed the presence of new hypodensities on CT within 6 weeks after aSAH and categorized cerebral infarction into overall and DCI-related infarctions (hypodensities not within 48 h after IA repair and not attributable to aneurysm occlusion or intraparenchymal hematoma). Functional outcome was assessed at 3 months using the extended Glasgow outcome scale (eGOS), dichotomized into unfavorable (eGOS: 1-5) and favorable (eGOS: 6-8). We calculated odds ratios (OR) with corresponding 95% confidence intervals (CI's), and adjusted for age, WFNS grade, Fisher score, and treatment modality (aOR). RESULTS: In the post-implementation (n = 158) versus the pre-implementation (n = 143) cohort the rates for overall cerebral infarction were 29.1% vs 46.9% (aOR: 0.41 [0.24-0.69]), for DCI-related cerebral infarction 17.7% vs. 31.5% (aOR: 0.41 [0.23-0.76]), and for unfavorable functional outcome at 3 months 37.3% vs. 53.8% (aOR: 0.30 [0.17-0.54]). For patients with DCI, the rates for unfavorable functional outcomes at 3 months in the post-implementation versus the pre-implementation cohort were 42.3% vs. 77.8% (aOR: 0.1 [0.03-0.27]). CONCLUSIONS: A multidisciplinary approach with more frequent and standardized neurological assessment, standardized CT and CT perfusion monitoring, as well as tailored application of induced hypertension and invasive rescue therapy strategies, is associated with a significant reduction of cerebral infarction and unfavorable functional outcome after aneurysmal aSAH.

Application of low dose pancreas perfusion CT combined with enhancement scanning in diagnosis of pancreatic neuroendocrine tumors.

PURPOSE: To explore the diagnostic value of pancreatic perfusion CT combined with contrast-enhanced CT in one-time scanning (PCECT) in pancreatic neuroendocrine tumors (PNETs) and to evaluate the difference of perfusion parameters between different grades of PNETs. MATERIALS AND METHODS: From October 2016 to December 2018, forty consecutive patients with histopathological-proven PNETs were identified retrospectively that received PCECT for the preoperative PNETs evaluation. Two board certified radiologists who were blinded to the clinical data evaluated the images independently. The image characters of PNETs vs. tumor-free pancreatic parenchymal and different grades of PNETs were analyzed. RESULTS: One-time PCECT scanning had a detection rate of 89.1% for PNETs, which was higher than the detection accuracy of the perfusion CT only (83.6%). The perfusion parameters of PNETs including blood volume (BV), blood flow (BF), mean slope of increase (MSI), and capillary surface permeability (PS) were significantly increased than those of tumor-free pancreatic parenchyma (p < 0.05, respectively). For differential comparison between grade I (G1) and grade II (G2) tumors, the parameters of BF and impulse residue function (IRF) of tumor tissue were significantly higher in the G2 tumors (p < 0.05, for both). In this study, the total radiation dose of the whole PCECT scan was 16.241 ± 2.289 mSv. CONCLUSION: The one-time PCECT scan may improve the detection of PNETs according to morphological features and perfusion parameters with a relative small radiation dose. The perfusion parameters of BF and IRF may be used to help distinguish G1 and G2 tumors in the preoperative evaluation.

Perfusion CT detects alterations in local cerebral flow of glioma related to IDH, MGMT and TERT status.

BACKGROUND: The aim of this study was to investigate the relationship between tumor biology and values of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), time to peak (TTP), permeability surface (PS) of tumor in patients with glioma. METHODS: Forty-six patients with glioma were involved in the study. Histopathologic and molecular pathology diagnoses were obtained by tumor resection, and all patients accepted perfusion computed tomography (PCT) before operation. Regions of interests were placed manually at tumor and contralateral normal-appearing thalamus. The parameters of tumor were divided by those of contralateral normal-appearing thalamus to normalize at tumor (relative [r] CBV, rCBF, rMTT, rTTP, rPS). The relationships of the parameters, world health organization (WHO) grade, molecular pathological findings were analysed. RESULTS: The rCBV, rMTT and rPS of patients are positively related to the pathological classification (P < 0.05). The values of rCBV and rPS in IDH mutated patients were lower than those IDH wild-type. The values of rCBF in patients with MGMT methylation were lower than those MGMT unmethylation (P < 0.05). The MVD of TERT wild-type group was lower than TERT mutated group (P < 0.05). The values of rCBV were significant difference in the four molecular groups divided by the combined IDH/TERT classification (P < 0.05). The progression free survival (PFS) and overall survival (OS) were significant difference in the four molecular groups divided by the combined IDH/TERT classification (P < 0.05). CONCLUSIONS: Our study introduces and supports the changes of glioma flow perfusion may be closely related to its biological characteristics.

Utility of admission perfusion CT for the prediction of suboptimal outcome following uncomplicated minor traumatic brain injury.

PURPOSE: To compare the perfusion parameters of patients with uncomplicated mild traumatic brain injury (mTBI) with healthy controls and to assess whether admission perfusion CT parameters can be used to predict outcome at 6 months post-injury in patients with uncomplicated mTBI. METHODS: Institute ethical committee approval was obtained for this prospective cohort study and informed written consent obtained from all subjects. Patients who sustained mTBI and had no abnormalities on non-contrast CT from June 2010 to January 2012 (20 months) and 10 healthy controls were included and underwent perfusion CT at admission. Outcome was determined at 6 months follow-up using the extended Glasgow Coma Outcome Scale score. RESULTS: Forty-nine patients were included, of which 16 (32.7%) had symptoms at 6 months post-injury (suboptimal outcome). The mean cerebral blood flow and volume were lower in both the gray and white matter of all three arterial territories in the study group than in the control group (p value < 0.05). In the study group, these values were lower in those with suboptimal outcome than in those with optimal outcome (no symptoms). Cerebral blood flow showed higher area under the curve for predicting the outcome. CONCLUSION: Perfusion parameters are altered even in patients with uncomplicated mTBI. A single ROI (region of interest) evaluation of the gray matter in the posterior cerebral artery territory on admission perfusion CT could provide a quick and efficient way to predict patients who would have a suboptimal outcome at 6 months post-injury.

Advanced CT techniques for assessing hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the sixth-most common cancer in the world, and hepatic dynamic CT studies are routinely performed for its evaluation. Ongoing studies are examining advanced imaging techniques that may yield better findings than are obtained with conventional hepatic dynamic CT scanning. Dual-energy CT-, perfusion CT-, and artificial intelligence-based methods can be used for the precise characterization of liver tumors, the quantification of treatment responses, and for predicting the overall survival rate of patients. In this review, the advantages and disadvantages of conventional hepatic dynamic CT imaging are reviewed and the general principles of dual-energy- and perfusion CT, and the clinical applications and limitations of these technologies are discussed with respect to HCC. Finally, we address the utility of artificial intelligence-based methods for diagnosing HCC.

Intravenous Thrombolysis Guided by Perfusion CT with Alteplase in >4.5 Hours from Stroke Onset.

INTRODUCTION: The benefit of intravenous thrombolysis (IVT) in wake-up stroke (WUS), stroke of unknown time of onset (SUKO), or when time exceeds 4.5 h from last-seen-normal (LSN) guided by CT perfusion (CTP) or MRI has been recently suggested. However, there is limited information of IVT in those patients in real-world studies. OBJECTIVE: Our aim was to evaluate safety and efficacy of IVT selected by CTP in patients with WUS, SUKO, or stroke of time onset beyond 4.5 h. MATERIAL AND METHODS: We studied a prospective cohort of patients who underwent IVT from January 2010 to December 2017. Two groups were defined: standard of care group (SC) included patients with time onset <4.5 h and CTP group included patients with WUS, SUKO, or onset beyond >4.5 h from LSN with penumbra area in CTP. We evaluated baseline characteristics, functional outcomes according to modified Rankin Scale (mRS) at discharge and at 90 days, and intracranial hemorrhages rates. RESULTS: 657 patients were studied: 604 (92%) were treated in the SC group and 53 (8%) in the CTP group. The mean NIHSS score was 9.8 in the CTP group versus 13 in the SC group (p = 0.001). Seventeen patients in the CTP group (32.1%) received bridging therapy with mechanical thrombectomy (MT). Last time seen well-to-needle time was 538 versus 155 min (p < 0.001). The incidence of symptomatic intracranial hemorrhage was equal in both groups (3.8 vs. 3.8%, p = 1). Good functional outcome (mRS < 2) was achieved in both groups (72 vs. 60.4%, p = 0.107). CONCLUSIONS: IVT in patients with WUS, SUKO, or stroke beyond >4.5 h from LSN, with salvageable brain tissue on CTP, seems to be safe and has similar functional outcomes at 90 days to the standard therapeutic window, even when combined with MT.

Admission Perfusion CT for Classifying Early In-Hospital Mortality of Patients With Severe Traumatic Brain Injury: A Pilot Study.

OBJECTIVE. The purposes of this study were to assess the feasibility and safety of perfusion CT of patients with severe traumatic brain injury (TBI) at hospital admission and to examine whether early in-hospital mortality could be characterized with perfusion CT (PCT). The hypothesis was that PCT can be used to characterize brain death, when present, in patients with severe TBI at hospital admission. SUBJECTS AND METHODS. In this prospective cohort pilot study, PCT was performed on patients with severe TBI at first imaging workup at hospital admission. PCT images were processed at the end of the study and assessed for features of brain death. The PCT features were then compared with the clinical outcome of in-hospital mortality. RESULTS. A total of 19 patients (13 men [68.4%]; six women [31.6%]; mean age, 36.4 years; median, 27.5 years) had a mean hospital stay longer than 1 month. No complications of PCT were found. In the first 48 hours after admission, four patients (21%) died. Admission PCT changes suggesting brainstem death were sensitive (75%) and specific (100%) and had high positive (100%) and negative (93.75%) predictive value for correct classification early in-hospital mortality. CONCLUSION. Admission PCT of patients with severe TBI was feasible and safe. Admission PCT findings helped in correctly classifying early in-hospital mortality in the first 48 hours of hospital admission.

Dynamic Volume Perfusion CT of the Foot in Critical Limb Ischemia: Response to Percutaneous Revascularization.

OBJECTIVE. The purpose of this study was to assess the reproducibility and validity of quantitative perfusion parameters derived from dynamic volume perfusion CT in patients with critical limb ischemia (CLI) and to evaluate perfusion parameter changes before and after endovascular revascularization. SUBJECTS AND METHODS. Patients with CLI referred for unilateral extremity endovascular arterial recanalization were enrolled in this study. CT examinations obtained 1-3 days before the procedure and then within 1 week after the treatment were evaluated at two reading sessions. Blood flow (BF), blood volume (BV), and time to peak (TTP) were measured on color-coded maps and compared statistically. Intraobserver agreement was assessed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS. Endovascular treatment was technically successful for all 16 patients. The posttreatment BF and BV showed a statistically significant increase in both dermal and muscle areas (p < 0.05). The posttreatment TTP shortened at a statistically significant level (p < 0.05). In the 3-month clinical follow-up period, the limb salvage rate was 81% and the percentage change in BF and BV of patients with poor response to treatment had no statistically significant increase after treatment, consistent with the clinical assessment. The percentage change in BF and BV correlated well with the improvement of the clinical condition (r = 0.673-0.901). ICC values showed excellent agreement in the range of 0.95-0.98. CONCLUSION. As a reproducible method, dynamic volume perfusion CT of the foot may enable quantitative evaluation of the perfusion of soft tissues and also provide a novel approach to assessing response to endovascular recanalization in CLI.

Updates on Imaging of Liver Tumors.

PURPOSE OF REVIEW: We review advances in imaging of liver tumors, by particularly focusing on the utility of novel imaging in diagnosis and management of these lesions. RECENT FINDINGS: Contrast-enhanced CT and/or MRI are currently utilized for accurate diagnosis of liver tumors, but several ongoing studies are examining the use of other advanced techniques. Novel CT (i.e., dual-energy CT and perfusion CT), MRI (diffusion-weighted imaging, MR elastography, and T1 mapping), and image processing (texture analysis and artificial intelligence-based methods) techniques have emerged and can be used for precise characterization of liver tumors, quantification of treatment responses, and prediction of overall survival rate of patients. Recent advancements in imaging of liver tumors allowed for a precise assessment of tumor features. These evolving technologies can be utilized for applying individualized treatment based on the presence of specific imaging biomarkers.

The Treatment of a Ruptured Anterior Communicating Artery (ACoA) Aneurysm with Coiling and Flow Disruptor (WEB-Device) and Management of Symptomatic Post-Interventional Delayed Vasospasm: A Case Report.

The article reports a clinical case illustrating a favorable outcome of endovascular treatment of a patient with a ruptured wide range neck ACoA aneurysm by WEB-Device. The peculiar characteristics of the pre-procedural period and the procedure are described.

Assessment of Collateral Circulation Using Perfusion CT in Middle Cerebral Artery Thrombectomy-Treated Patients.

INTRODUCTION: The prognostic value of leptomeningeal collateral circulation in thrombectomy-treated patients remains unclear. We evaluated the construct validity of assessing leptomeningeal collateral circulation using a new regional perfusion CT source image-based approach, the Perfusion Acquisition for THrombectomy Scale (PATHS). We also compared the prognostic value of PATHS with a further 6 scales based on various techniques: CT-angiography, perfusion CT, and digital subtraction angiography. Additionally, we studied the relationship between the scores for the different scales. PATIENTS AND METHODS: We performed a retrospective study of consecutive patients with stroke and M1/terminal carotid occlusion treated with thrombectomy in our center. Leptomeningeal collateral circulation was prospectively evaluated using 7 scales: Tan and Miteff (CT Angiography); Calleja, Cao, American Society of Intervention and Therapeutic Neuroradiology/Society of Interventional Radiology, and PATHS (perfusion); and Christoforidis (Digital Subtraction Angiography). Correlations were studied using the Spearman method. RESULTS: The study population comprised 108 patients. All scales predicted the modified Rankin Scale at 3 months (P ≤ .02) and all but 1 (Christoforidis) correlated with 24-hour brain infarct volume (P ≤ .02). These correlations were higher with PATHS (rho = -0.47, P < .001 for 3-month modified Rankin Scale; rho = -0.35, P < .001 for follow-up infarct volume). The multivariate analysis showed PATHS to be an independent predictor of modified Rankin Scale at 3 months less than equal to 2. A crosscorrelation analysis revealed a better correlation between scales that used the same techniques. CONCLUSIONS: PATHS can be used to assess leptomeningeal collateral circulation. PATHS had better prognostic value than other scales; therefore, it might be considered for assessment of leptomeningeal collateral circulation in candidates for thrombectomy. The moderate correlation between scales suggests that scores are not interchangeable.

A prospective clinical trial on sorafenib treatment of hepatocellular carcinoma before liver transplantation.

BACKGROUND: Patients with hepatocellular carcinoma waiting for liver transplantation are commonly treated with locoregional treatments, such as TACE and ablation, to prevent tumor progression and dropout and to improve long-term outcome after transplantation. We wanted to prospectively assess feasibility of systemic antitumor treatment with sorafenib as neoadjuvant treatment for hepatocellular carcinoma while waiting for liver transplantation, evaluating tolerability, toxicity and posttransplant morbidity. We also wanted to evaluate perfusion CT parameters to assess tumor properties and response early after start of sorafenib treatment in patients with early hepatocellular carcinoma. METHODS: Twelve patients assigned for liver transplantation due to hepatocellular carcinoma, within the UCSF and who fulfilled other criteria, were included January 2012-August 2014. After baseline evaluation, sorafenib treatment was started. Treatment was evaluated by perfusion CT at 1, 4 and 12 weeks and thereafter every 8 weeks. Toxicity and quality of life was assessed at 1 and 4 weeks and every 4 weeks thereafter during treatment. Treatment was stopped when patients were prioritized on the transplantation waiting list or when intolerable side effects or tumor progress warranted other treatments. Posttransplant morbidity after 90 days was registered according to Clavien-Dindo. RESULTS: Baseline perfusion CT parameters in the tumors predicted the outcome according to RECIST/mRECIST at three months, but no change in CTp parameters was detected as a result of sorafenib. Sorafenib as neoadjuvant treatment was associated with intolerability and dose reductions. Therefore the prerequisites for evaluation of the sorafenib effect on both CT parameters and tumor response were impaired. CONCLUSIONS: This study failed to show changes in CTp parameters during sorafenib treatment. Despite the curative treatment intention, tolerability of neoadjuvant sorafenib treatment before liver transplantation was inadequate in this study. TRIAL REGISTRATION: EudraCT number: 2010-024306-36 (date 2011-04-07).

Seizure in code stroke: Stroke mimic and initial manifestation of stroke.

BACKGROUND: Although seizure is one of the common causes of stroke mimics and can be an initial manifestation of acute stroke, accurate diagnosis of seizure during acute stroke management is frequently difficult. The objective of this study was to analyze the frequency, characteristics and results of neuroimaging including CT perfusion in patients with seizures manifesting initially as stroke-like symptoms. METHODS: We retrospectively reviewed the medical records of patients who were treated with code stroke alarming system. We studied the frequency and characteristics of patients who were finally diagnosed with seizures and further correlated their clinical features with the results of neuroimaging including CT perfusion. RESULTS: Among the 4673 patients who were treated with code stroke alarming system, seizure was the third most frequent diagnosis (188 patients, 4.0%) among the causes of stroke mimics including 27 patients who manifested seizure as an initial manifestation of acute stroke. CT perfusion showed perfusion changes in more than 25% of them (49 of 188 patients, 26.1%). Thrombolysis was not performed in six patients who presented with seizure as an initial presentation of stroke for delayed diagnosis while one patient underwent thrombolysis for misdiagnosis of seizure. CONCLUSIONS: Seizure is a frequent final diagnosis in acute stroke management. However, careful interpretation of clinical features and results of perfusion imaging is necessary to avoid unnecessary thrombolysis in patients with seizure as a stroke mimic and thrombolysis failure due to delayed diagnosis of seizure as an initial manifestation of stroke.

CT Perfusion evaluation of gastric cancer: correlation with histologic type.

OBJECTIVES: To prospectively evaluate if the perfusion parameters of gastric cancer can provide information on histologic subtypes of gastric cancer. METHODS: We performed preoperative perfusion CT (PCT) and curative gastrectomy in 46 patients. PCT data were analysed using a dedicated software program. Perfusion parameters were obtained by two independent radiologists and were compared according to histologic type using Kruskal-Wallis, Mann-Whitney U test and receiver operating characteristic analysis. To assess inter-reader agreement, we used intraclass correlation coefficient (ICC). RESULTS: Inter-reader agreement for perfusion parameters was moderate to substantial (ICC = 0.585-0.678). Permeability surface value of poorly cohesive carcinoma (PCC) was significantly higher than other histologic types (47.3 ml/100 g/min in PCC vs 26.5 ml/100 g/min in non-PCC, P < 0.001). Mean transit time (MTT) of PCC was also significantly longer than non-PCC (13.0 s in PCC vs 10.3 s in non-PCC, P = 0.032). The area under the curve to predict PCC was 0.891 (P < 0.001) for permeability surface and 0.697 (P = 0.015) for MTT. CONCLUSION: Obtaining perfusion parameters from PCT was feasible in gastric cancer patients and can aid in the preoperative imaging diagnosis of PCC-type gastric cancer as the permeability surface and MTT value of PCC type gastric cancer were significantly higher than those of non-PCC. KEY POINTS: • Obtaining perfusion parameters from PCT was feasible in patients with gastric cancer. • Permeability surface and MTT were significantly higher in poorly cohesive carcinoma (PCC). • Permeability surface, MTT can aid in the preoperative imaging diagnosis of PCC.

Blood-Brain Barrier Permeability in Aneurysmal Subarachnoid Hemorrhage: Correlation With Clinical Outcomes.

OBJECTIVE: The current understanding of the utility of blood-brain barrier permeability (BBBP) evaluation with extended-pass perfusion CT in the clinical setting is limited. We assessed whether BBBP parameters evaluated with perfusion CT correlate with unfavorable clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH). MATERIALS AND METHODS: A retrospective cross-sectional analysis was performed of 22 patients who underwent perfusion CT on days 0-3 after SAH. Extended perfusion CT data were postprocessed into BBBP quantitative maps of kep (washout rate constant of contrast agent from the extravascular extracellular space [EES] to the intravascular space), PS (permeability surface area product), Ktrans (volume transfer constant from blood plasma to EES), and Ve (EES volume per unit tissue volume) using Olea Sphere software (version 2.0). Clinical outcomes data regarding the presence of permanent neurologic deficits and modified Rankin scores were collected at discharge. ROC curve analyses and unpaired t tests were performed. RESULTS: The 22 patients were stratified on the basis of their clinical outcomes of permanent neurologic deficit and modified Rankin scores. In patients with unfavorable clinical outcomes (i.e., patients with permanent neurologic deficit and those with modified Rankin scores of 3-6), PS and Ve were significantly increased and kep and Ktrans were significantly decreased. A multiparameter ROC curve analysis combining the four parameters yielded an AUC of 0.80 for permanent neurologic deficit and an AUC of 0.89 for modified Rankin scores of 3-6. CONCLUSION: SAH patients with unfavorable outcomes had significantly elevated PS and Ve and significantly decreased kep, indicating increased BBBP, compared with SAH patients with unfavorable outcomes. Evaluation of BBBP parameters may provide prognostication of unfavorable outcomes in patients with SAH and help guide management.

Perfusion computed tomography in patients with stroke thrombolysis.

See Saver (doi:10.1093/awx020) for a scientific commentary on this article.Stroke shortens an individual's disability-free life. We aimed to assess the relative prognostic influence of pre- and post-treatment perfusion computed tomography imaging variables (e.g. ischaemic core and penumbral volumes) compared to standard clinical predictors (such as onset-to-treatment time) on long-term stroke disability in patients undergoing thrombolysis. We used data from a prospectively collected international, multicentre, observational registry of acute ischaemic stroke patients who had perfusion computed tomography and computed tomography angiography before treatment with intravenous alteplase. Baseline perfusion computed tomography and follow-up magnetic resonance imaging were analysed to derive the baseline penumbra volume, baseline ischaemic core volume, and penumbra salvaged from infarction. The primary outcome measure was the effect of imaging and clinical variables on Disability-Adjusted Life Year. Clinical variables were age, sex, National Institutes of Health Stroke Scale score, and onset-to-treatment time. Age, sex, country, and 3-month modified Rankin Scale were extracted from the registry to calculate disability-adjusted life-year due to stroke, such that 1 year of disability-adjusted life-year equates to 1 year of healthy life lost due to stroke. There were 772 patients receiving alteplase therapy. The number of disability-adjusted life-year days lost per 1 ml of baseline ischaemic core volume was 17.5 (95% confidence interval, 13.2-21.9 days, P < 0.001). For every millilitre of penumbra salvaged, 7.2 days of disability-adjusted life-year days were saved (ß = -7.2, 95% confidence interval, -10.4 to -4.1 days, P < 0.001). Each minute of earlier onset-to-treatment time resulted in a saving of 4.4 disability-free days after stroke (1.3-7.5 days, P = 0.006). However, after adjustment for imaging variables, onset-to-treatment time was not significantly associated with savings in disability-adjusted life-year days. Pretreatment perfusion computed tomography can (independently of clinical variables) predict significant gains, or loss, of disability-free life in patients undergoing reperfusion therapy for stroke. The effect of earlier treatment on disability-free life appears explained by salvage of penumbra, particularly when the ischaemic core is not too large.

Hyperperfusion after Clipping of Aneurysm: A Rare Entity.

BACKGROUND: Cerebral vasospasm is an uncontrollable and sometimes fatal complication occurring after subarachnoid hemorrhage. However, cerebral hyperperfusion syndrome is a rare complication after subarachnoid hemorrhage. Although plain computed tomography of cerebral hyperperfusion syndrome looks similar to cerebral infarction induced by cerebral vasospasm, they should be distinguished from each other because they require completely different treatments. CASE DESCRIPTION: A 65-year-old man complained of severe headache and vomiting. A computed tomography scan of his head showed subarachnoid hemorrhage with acute hydrocephalus caused by intraventricular hematoma and aneurysm of the left middle cerebral artery. After endoscopic irrigation of the ventricular hematoma to decrease the intracranial pressure, we performed neck clipping for the ruptured aneurysm. We used a temporary clip to the proximal M1 segment twice for a total of 15 minutes. Five days after the clipping, a computed tomography scan of the patient's head showed a large low-density area in the left cerebral hemisphere. Although cerebral infarction caused by cerebral vasospasm was suspected, his perfusion computed tomography demonstrated a state of hyperperfusion corresponding to the low-density area. We started treatment to prevent vasodilation and excessive cerebral blood flow instead of treatment for cerebral vasospasm. After changing the treatment, the patient's symptoms gradually improved, and his perfusion computed tomography (8 days after surgery) showed no excessive increased blood flow. CONCLUSIONS: We present a case of cerebral hyperperfusion syndrome and its successful treatment, distinct from that of cerebral vasospasm, after ruptured aneurysm clipping. In addition, we discuss the mechanism of this rare syndrome based on previous reports.