Quantitative Digital Subtraction Angiography Research Articles

Abstract No. 84 Comparison of qDSA with a time-of-arrival–based method for determining velocity in a porcine iliac artery model

Quantitative digital subtraction angiography (qDSA) is a recently developed 2D-DSA post-processing tool that can be used to calculate velocities in an artery-of-interest using multiple spatial and temporal points from an entire contrast injection. qDSA has been previously shown to correlate with 4D Flow MRI and intravascular Doppler. While time-of-arrival (TOA)-based methods are commercially and clinically available, they rely on a single spatial point at a particular time. This study aimed to compare velocities calculated using qDSA with a TOA-based method in a porcine iliac artery model. Thirty-three 2D-DSA acquisitions (30fps) were performed in 7 female domestic swine (∼54kg) with a 4 French catheter placed in the common iliac artery using 1.5-3 mL/s injection rates for 8 seconds. The vessel length divided by the difference in TOA of contrast was used to derive blood velocities in the common, external, and internal iliac arteries. Blood velocities were also calculated with qDSA using a shifted least squares method on the contrast-attenuation curves. The two methods were then compared with descriptive statistics, paired t-test, Pearson correlation, and Bland-Altman. Of 99 data points, one was excluded because TOA difference could not be detected. Mean blood velocities with the TOA-method versus qDSA were 39.7 ± 23.3 versus 45.6 ± 20.5 cm/s in the common (n = 33), 26.5 ± 12.2 versus 23.9 ± 9.5 cm/s in external (n = 32), and 27.6 ± 12.0 versus 34.5 ± 12.7 cm/s in internal iliac (n = 33) arteries. The two methods provided significantly different velocities based on the paired t-test (P< 0.05) and were moderately correlating (Pearson r = 0.42, P< 0.05). A Bland-Altman plot showed the TOA method to have a bias of -3.45 cm/s (95% LOA: -40.2 to 33.3), underestimating higher velocities ( >50 cm/s) with a higher degree of uncertainty. In a porcine iliac artery model, TOA-based blood velocities moderately correlated with those calculated using qDSA while TOA method underestimated higher velocities.

A technique for intra-procedural blood velocity quantitation using time-resolved 2D digital subtraction angiography

Background2D digital subtraction angiography (DSA) is utilized qualitatively to assess blood velocity changes that occur during arterial interventions. Quantitative angiographic metrics, such as blood velocity, could be used to standardize endpoints during angiographic interventions.PurposeTo assess the accuracy and precision of a quantitative 2D DSA (qDSA) technique and to determine its feasibility for in vivo measurements of blood velocity.Materials and methodsA quantitative DSA technique was developed to calculate intra-procedural blood velocity. In vitro validation was performed by comparing velocities from the qDSA method and an ultrasonic flow probe in a bifurcation phantom. Parameters of interest included baseline flow rate, contrast injection rate, projection angle, and magnification. In vivo qDSA analysis was completed in five different branches of the abdominal aorta in two 50 kg swine and compared to 4D Flow MRI. Linear regression, Bland-Altman, Pearson’s correlation coefficient and chi squared tests were used to assess the accuracy and precision of the technique.ResultsIn vitro validation showed strong correlation between qDSA and flow probe velocities over a range of contrast injection and baseline flow rates (slope = 1.012, 95% CI [0.989,1.035], Pearson’s r = 0.996, p < .0001). The application of projection angle and magnification corrections decreased variance to less than 5% the average baseline velocity (p = 0.999 and p = 0.956, respectively). In vivo validation showed strong correlation with a small bias between qDSA and 4D Flow MRI velocities for all five abdominopelvic arterial vessels of interest (slope = 1.01, Pearson’s r = 0.880, p = <.01, Bias = 0.117 cm/s).ConclusionThe proposed method allows for accurate and precise calculation of blood velocities, in near real-time, from time resolved 2D DSAs.

Stagnant venous outflow in ruptured arteriovenous malformations revealed by delayed quantitative digital subtraction angiography

PurposeTo investigate the reproducibility of quantitative digital subtraction angiography (QDSA) measurements and their associations with brain arteriovenous malformation (BAVM) hemorrhage. MethodsFrom 2011–2019, 37 patients with BAVMs who had undergone both diagnostic and stereotactic DSA were divided into hemorrhagic and nonhemorrhagic groups. QDSA analysis was performed on the 2 DSA exams. The inter-exam reliabilities of QDSA measurements across the diagnostic and stereotactic DSA were tested using intraclass correlation coefficients (ICCs). Demographics, BAVM characteristics, and QDSA results for the hemorrhagic and nonhemorrhagic groups were compared. ResultsFifteen of 37 (40.5 %) patients presented with hemorrhage were associated with smaller BAVM volume and the presence of intranidal aneurysm and exclusive deep venous drainage. The median interval between the diagnostic and stereotactic DSA was 49 days and did not differ between the groups. In both groups, the inter-exam QDSA measurements were more reliable for drainage veins and transnidal time (ICCs ranged from 0.38–0.93) than for feeding arteries (ICCs ranged from 0.01–0.74). Among the venous parameters, the hemorrhagic group had lower peak density, area under the curve, inflow gradient, and outflow gradient on both DSA exams and larger full width at half maximum and stasis index on the stereotactic DSA exam than the nonhemorrhagic group. ConclusionsIn BAVMs, the QDSA measurements for veins are more reliable than those for arteries. QDSA analysis reflecting stagnant venous drainage is associated with BAVM hemorrhage, but may be confounded by the acute hemodynamic change after hemorrhage.

Stagnant Venous Outflow Predicts Brain Arteriovenous Malformation Obliteration After Gamma Knife Radiosurgery Without Prior Intervention.

Gamma Knife radiosurgery (GKRS) obliterates 65% to 82% of brain arteriovenous malformations (BAVMs). To explore the impact of hemodynamics on GKRS outcomes. We retrospectively (2011-2017) included 98 patients with BAVMs who had received GKRS alone. Two evaluators, blinded to the outcomes, analyzed the pre-GKRS angiography and magnetic resonance images to obtain the morphological characteristics and quantitative digital subtraction angiography (QDSA) parameters. The venous stasis index was defined as the inflow gradient divided by the absolute value of the outflow gradient. Patients' follow-up magnetic resonance or digital subtraction angiography images were evaluated for the presence of complete obliteration (CO). Cox regression and Kaplan-Meier analyses were conducted to determine the correlations between the parameters and outcomes. Among the 98 patients, 63 (63.4%) achieved CO after GKRS at a median latency period of 31 mo. In multivariable analyses with adjustments for age and sex, increased BAVM volume (hazard ratio (HR) 0.949, P=.022) was an independent characteristic predictor, and venous stenosis (HR 2.595, P=.009), venous rerouting (HR 0.375, P=.022), and larger stasis index (HR 1.227, P=.025) were independent angiographic predictors of CO. BAVMs with a stasis index of >1.71 had a higher 36-mo probability of CO than those with a stasis index of ≤1.71 (61.1% vs 26.7%, P<.001). BAVMs with a larger stasis index, indicating more stagnant venous outflow, may predict obliteration after GKRS. QDSA analysis may help in predicting BAVM treatment outcomes and making therapeutic decisions.

Association of intracranial arteriovenous malformation embolization with more rapid rate of perfusion in the peri-nidal region on color-coded quantitative digital subtraction angiography

BackgroundHemodynamic alterations post-embolization of intracranial arteriovenous malformations (AVMs) may cause delayed edema/hemorrhage in brain parenchyma adjacent to the lesion.ObjectiveTo quantify and compare cerebral perfusion changes in the peri-AVM territory pre-...

Machine Learning Application With Quantitative Digital Subtraction Angiography for Detection of Hemorrhagic Brain Arteriovenous Malformations

Clinical features are the primary measures used for risk assessment of cerebrovascular diseases. However, clinical features, especially angioarchitecture, in digital subtraction angiography require further interpretation by specialized radiologists. This approach for risk assessment requires multivariable analysis and is, therefore, challenging when completed manually. In this study, we employed three machine learning models, namely the random forest, naïve Bayes classifier, and support vector machine, for the detection of hemorrhagic brain arteriovenous malformations using digital subtraction angiography. Quantitative measurements from digital subtraction angiography were used as features, and the chi-squared test, minimum redundancy maximum relevance, ReliefF, and two-sample $t$ tests were used for feature selection. Bayesian optimization was conducted to optimize the hyperparameters of the three models. The random forest model outperformed the other two models. As a human control, three radiologists diagnosed an independent testing data set. The random forest model had a computation time of less than a second for the whole data set for classification. Accuracy and the area under the receiver operating characteristic curve were 92.7% and 0.98 for the training data set and 85.7% and 0.97 for the independent testing data set, respectively. Compared with the mean diagnosis time of approximately half a minute per patient and the highest accuracy of 76.2% for the three radiologists, the random forest model was faster and more accurate for our data set. These results suggest that the machine learning model based on hemodynamic features from quantitative digital subtraction angiography is a promising tool for detecting hemorrhagic brain arteriovenous malformations.

Parametric Color Coding of Digital Subtraction Angiography in the Evaluation of the Type B Chronic Aortic Dissection During Tevar: A Preliminary Study

Introduction - Angiografic assessment of type B chronic aortic dissection (TBCAD) can be complex in TEVAR procedures, due to the presence of true and false lumen. Quantitative digital subtraction angiography (Q-DSA) with a parametric color-coding provides a novel approach for encoding temporal information and enabling quantitative measurements. (1,2) The potential value of the use of color in the display of these parametric images was recognized (3), particularly useful in situations in which there is a complex flow pattern. (4,5) The aim of this study was to evaluate whether the use of parametric color-coding in the post processing of DSA series is advantageous in the evaluation of TBCAD during TEVAR procedures. Methods - We enrolled 11 patients treated electively for a TBCAD. All cases were treated with TEVAR for a aneurysm disease of thoracic descending aorta (> 6 cm) with the coverture of proximal entry tear. For postprocessing of digital subtraction angiography (DSA) series, a newly implemented algorithm of parametric color-coding was used, turning sequential images of two-dimensional (2D)-DSA series into a single color-coded image (Syngo I-Flow, Siemens AG, Forchheim, Germany). In consensus reading, two experienced vascular surgeons valuated the initial, interventional, and post-interventional 2D-DSA series comparing them to the color-coded images, respectively. Whether parametric color-coding could facilitate evaluation of a true and false lumen and provide a more precise estimation of proximal entry tear as well as whether flow analysis could reveal objective changes during and after TEVAR treatment were investigated. Results - In 81.8 % of the cases, parametric color coding was observed to facilitate visualization of the aortic dissection angioarchitecture in term of true e false lumen contemporary vision. Estimation of proximal entry tear was considered to be improved in 45.4 % of the cases (fig. 1. maximum intensity peak DSA (a) and parametric color elaboration with entry tear enhanced (b)). For assessment of hemodynamic changes during and after treatment, parametric color coding was assumed to be helpful in 36.3 % of the cases, especially because revealing flow changes that were not visible on 2D-DSA series were now visible. Conclusion - Without additional cost in term of x-ray and contrast medium exposure, parametric color-coding is a real time application tool that might provide additional support in the angiographic evaluation of TBCAD during TEVAR. Visualization of complex aortic dissection architecture could be facilitated, and flow analysis might improve assessment of entry tear position, thereby increasing overall diagnostic confidence. During and after treatment, hemodynamic changes that were not visible on 2D-DSA series could now be depicted.

Color-coded Quantitative Digital Subtraction Angiography For Short-term Effectiveness Evaluation of Carotid Artery Stenting and Predictive Evaluation for Cerebral Hyper-perfusion Syndrome After Carotid Artery Stenting

Color-coded Quantitative Digital Subtraction Angiography For Short-term Effectiveness Evaluation of Carotid Artery Stenting and Predictive Evaluation for Cerebral Hyper-perfusion Syndrome After Carotid Artery Stenting

Fluoroscopic angiography quantifies delay in cerebral circulation time and requires less radiation in carotid stenosis patients: A pilot study.

Quantitative digital subtraction angiography (DSA) facilitates in-room assessment of flow changes in various cerebrovascular diseases and improves patient safety. The purpose of this study was to compare the diagnostic accuracy of quantitative fluoroscopic angiography (FA) and DSA. Twenty-two patients with >70% carotid stenosis according to NASCET criteria were prospectively included in the study. All patients received DSA and FA (ArtisZee, Siemens Healthcare, Forchheim, Germany) before and after carotid stenting in the same angiosuite. The regions of interest (ROIs) included the extracranial internal carotid artery (eICA), first segment of the middle cerebral artery (MCA1), and sigmoid sinus in the anterior-posterior view; cavernous portion of the ICA (cICA), parietal vein, and jugular vein in the lateral views. The time-to-peak (TTP) for all ROIs and cerebral circulation time (CCT) were measured from FA and DSA scans. TTP, CCT, and radiation doses from DSA were compared with those from FA. The mean age of the patients were 69 ± 9.5 years old. The average stenosis was 89.7% ± 7.8% before stenting and 31% ± 3.6% after stenting. No patient suffered from periprocedural stroke. The intermethod correlation for TTP for all ROIs except the eICA and cICA ranged from 0.46 to 0.65 before stenting and 0.57 to 0.73 after stenting, and that for CCT was 0.65 before stenting and 0.57 after stenting. The radiation doses were significantly lower for FA than for DSA regardless of views or periprocedural timing (p < 0.001). Stenosis facilitated the creation of a bolus by manual injection and therefore increased the accuracy of cerebral flow quantification in FA. Cerebral hemodynamic assessment by FA is quicker and associated with less radiation.

Stasis index from hemodynamic analysis using quantitative DSA correlates with hemorrhage of supratentorial arteriovenous malformation: a cross-sectional study.

Assessments of hemorrhage risk based on angioarchitecture have yielded inconsistent results, and quantitative hemodynamic studies have been limited to small numbers of patients. The authors examined whether cerebral hemodynamic analysis using quantitative digital subtraction angiography (QDSA) can outperform conventional DSA angioarchitecture analysis in evaluating the risk of hemorrhage associated with supratentorial arteriovenous malformations (AVMs). A cross-sectional study was performed by retrospectively reviewing adult supratentorial AVM patients who had undergone both DSA and MRI studies between 2011 and 2017. Angioarchitecture characteristics, DSA parameters, age, sex, and nidus volume were analyzed using univariate and multivariate logistic regression, and QDSA software analysis was performed on DSA images. Based on the QDSA analysis, a stasis index, defined as the inflow gradient divided by the absolute value of the outflow gradient, was determined. The receiver operating characteristic (ROC) curve was used to compare diagnostic performances of conventional DSA angioarchitecture analysis and analysis using hemodynamic parameters based on QDSA. A total of 119 supratentorial AVM patients were included. After adjustment for age at diagnosis, sex, and nidus volume, the exclusive deep venous drainage (p < 0.01), observed through conventional angioarchitecture examination using DSA, and the stasis index of the most dominant drainage vein (p = 0.02), measured with QDSA hemodynamic analysis, were independent risk factors for hemorrhage. The areas under the ROC curves for the conventional DSA method (0.75) and QDSA hemodynamics analysis (0.73) were similar. A venous stasis index greater than 2.18 discriminated the hemorrhage group with a sensitivity of 52.6% and a specificity of 81.5%. In QDSA, a higher stasis index of the most dominant drainage vein is an objective warning sign associated with supratentorial AVM rupture. Risk assessments of AVMs using QDSA and conventional DSA angioarchitecture were equivalent. Because QDSA is a complementary noninvasive approach without extra radiation or contrast media, comprehensive hemorrhagic risk assessment of cerebral AVMs should include both DSA angioarchitecture and QDSA analyses.

Inflammation and Hypervascularization in a Large Animal Model of Knee Osteoarthritis: Imaging with Pathohistologic Correlation

PurposeTo evaluate if synovial inflammation and hypervascularization are present in a dog model of knee osteoarthritis and can be detected on conventional magnetic resonance imaging (MRI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), contrast-enhanced magnetic resonance imaging (CE-MRI), and quantitative digital subtraction angiography (Q-DSA) imaging. Materials and MethodsSix dogs underwent MRI and angiography of both knees before and 12 weeks after right knee anterior cruciate ligament injury. Synovial vascularity was evaluated on CE-MRI, DCE-MRI, and Q-DSA by 2 independent observers. Synovial inflammation and vascularity were histologically scored independently. Cartilage lesions and osteophytes were analyzed macroscopically, and cartilage volumetry was analyzed by MRI. Vascularity and osteoarthritis markers on imaging were compared before and after osteoarthritis generation, and between the osteoarthritis model and the control knee, using linear mixed models accounting for within-dog correlation. ResultsIn all knees, baseline imaging showed no abnormalities. Control knees did not develop significant osteoarthritis changes, synovial inflammation, or hypervascularization. In osteoarthritis knees, mean synovial enhancement score on CE-MR imaging increased by 13.1 ± 0.59 (P < .0001); mean synovial inflammation variable increased from 47.33 ± 18.61 to 407.97 ± 18.61 on DCE-MR imaging (P < .0001); and area under the curve on Q-DSA increased by 1058.58 ± 199.08 (P = .0043). Synovial inflammation, hypervascularization, and osteophyte formations were present in all osteoarthritis knees. Histology scores showed strong correlation with CE-MR imaging findings (Spearman correlation coefficient [SCC] = 0.742; P = .0002) and Q-DSA findings (SCC = 0.763; P < .0001) and weak correlation with DCE-MR imaging (SCC = -0.345; P = .329). Moderate correlation was found between CE-MR imaging and DSA findings (SCC = 0.536; P = .0004). ConclusionsIn this early-stage knee osteoarthritis dog model, synovial inflammation and hypervascularization were found on imaging and confirmed by histology.

Assessment of small hepatocellular carcinoma: perfusion quantification and time-concentration curve evaluation using color-coded and quantitative digital subtraction angiography.

To explore the role of quantitative digital subtraction angiography (QDSA) in the diagnosis of small hepatocellular carcinoma (HCC).Between November 2015 and November 2017, all patients who underwent chemoembolization for HCC were retrospectively reviewed. Patients with tumors measuring more than 5 cm or evident post-processing imaging artifacts were excluded. Images were post-processed using the QDSA technique. Regions of interest were manually drawn on proper hepatic artery (as a reference), target HCC and peritumoral liver. Time-concentration curves and flow parameters of the peak ratio, subtracted time-to-peak (TTP), and area under the curve (AUC) ratio was obtained and analyzed.A total of 146 HCCs (mean diameter, 1.6 cm) of 71 cirrhotic patients (54 men, 17 women; mean age, 67.7 years) were enrolled. Compared with liver parenchyma, HCCs showed an increased and more rapid flow (peak ratio, AUC ratio, subtracted TTP, and wash-in slope; all P <.001). Compared with untreated HCCs, chemoembolized HCCs showed a slower flow (subtracted TTP and wash-in slope, P = .004 and .002, respectively). HCCs with a typical enhancement pattern on computed tomography (CT) or magnetic resonance imaging (MRI) had a trend toward Type III (washout pattern) time-concentration curves (P <.001). Chemoembolized HCCs had a trend toward Type II (plateau pattern) time-concentration curves (P = .005).QDSA technology can be used to quantify perfusion measurements of HCC and hepatic parenchyma and to assess perfusion changes after HCC chemoembolization.

Evaluating cerebral hemodynamics using quantitative digital subtraction angiography and flat-detector computed tomography perfusion imaging: A comparative study in patients with carotid stenosis

BackgroundThe efficacy of both quantitative digital subtraction angiography (QDSA) and flat-detector computed tomography perfusion (FD-CTP) is equivalent to that of magnetic resonance perfusion (MRP) in assessing perfusion deficits in carotid stenosis. This study evaluated the feasibility of using FD-CTP to monitor cerebral hemodynamics during carotid stenting. MethodsThirteen patients with extracranial carotid stenosis (>70%) were included. Both QDSA and two FD-CTP sessions were performed before and after carotid stenting. Cerebral circulation time (CCT) was defined as the difference between the time to peak (TTP) of the parietal vein and the cavernous internal carotid artery. For FD-CTP and MRP, regions of interest (ROIs) were placed in the middle cerebral artery territory at the basal ganglia level of both stenotic and contralateral hemispheres for measurement. The TTP ratio (rTTP) was defined as stenotic TTP divided by contralateral TTP; and ratio of cerebral blood volume (rCBV), ratio of mean transit time (rMTT), and ratio of cerebral blood flow (rCBF) were defined similarly. Both CCT and ratio perfusion parameters were compared during stenting. ResultsBefore stenting, only rCBF (r = 0.73) and rTTP (r = 0.58) demonstrated correlations between FD-CTP and MRP; CCT correlated with only rMTT in MRP (r = 0.69). After stenting, only rCBF (r = 0.56) indicated a correlation between FD-CTP and MRP. Regarding cerebral flow after stenting, CCT (4.61 ± 1.6 s) was shortened, rMTT (1.12 ± 0.04) and rTTP (r = 1.05 ± 0.03) decreased, and rCBF (0.91 ± 0.16) increased significantly. ConclusionFD-CTP provides a potentially more comprehensive hemodynamic assessment of parenchymal perfusion changes compared with QDSA during carotid stenting, but FC-CTP requires additional 18 min. FD-CTP confirmed that the normalization of cerebral hemodynamics began immediately and continued for 1–3 days.

4:21 PM Abstract No. 190 Quantitative 4D digital subtraction angiography: a novel technique for quantifying changes in hepatic arterial flow during transarterial embolization

4:21 PM Abstract No. 190 Quantitative 4D digital subtraction angiography: a novel technique for quantifying changes in hepatic arterial flow during transarterial embolization

Quantitative digital subtraction angiography to localize intercostal arteries during thoracic endovascular aortic repair

Quantitative digital subtraction angiography to localize intercostal arteries during thoracic endovascular aortic repair

Estimation of intra-arterial chemotherapy distribution to the retina in pediatric retinoblastoma patients using quantitative digital subtraction angiography.

Background and purpose The purpose of this article is to estimate the distribution of superselective intra-arterial chemotherapy (IAC) delivery to ocular target tissue using quantitative digital subtraction angiography (qDSA). Materials and methods From March 2010 to January 2016, 50 ophthalmic artery contrast DSAs obtained immediately prior to IAC infusions in 22 patients were analyzed. This study was conducted under a retrospective review IRB (no. 10-01862). Parametric color-coded DSAs (iFlow, Siemens Medical) were post-processed (MATLAB, The Mathworks Inc.) using two methods: two box regions of interest (pre-retina and globe) and four custom regions of interest (ROIs-ophthalmic artery, choroid, supraclinoid internal carotid artery (ICA), cavernous ICA). Mean interobserver reliability of custom ROI selection is presented as a 95% confidence interval of interclass correlation, and fractional chemotherapy delivery to selected ROIs as means ± standard deviation in this study. Results The estimated fraction of chemotherapy delivered to the globe with the first method was 79.5%. Percentage regional delivery using the second method was as follows: ophthalmic artery, 85.8%; choroid, 60.5%; supraclinoid ICA, 14.2%. The cavernous ICA ROI (encompassing distal catheter and potential reflux) gave a signal equivalent to 9.3% of total delivery. Conclusion Parametric color-coded qDSA can estimate the fraction of IAC delivered to the retina and other orbital structures in ocular retinoblastoma patients. This information can inform delivery location and dosing strategies on a patient-specific basis.

The potential role of quantitative digital subtraction angiography in evaluating type B chronic aortic dissection during TEVAR: preliminary results.

To evaluate the role of quantitative digital subtraction angiography (Q-DSA) with parametric color coding (PCC) in assessing patients with type B chronic thoracic aortic dissection (TBCAD) during thoracic endovascular aortic repair (TEVAR) procedures. A total of 11 patients electively treated in our Department for a TBCAD were retrospectively enrolled. All cases were treated with TEVAR for false lumen aneurysm of the thoracic descending aorta. For digital subtraction angiography (DSA) series post-processing, a newly implemented PCC algorithm was used to turn consecutive two-dimensional images into a single color-coded picture (syngo iFLOW, Siemens AG, Forchheim, Germany). In consensus reading, two clinicians experienced in vascular imaging evaluated the DSA series in blinded assessment and compared them to the color-coded images. PCC was assessed for its accuracy in identifying the true and false lumen as well as whether it could provide improved visualization in pre-deployment stent grafting and the final evaluation of treatment. PCC facilitated the visualization of the aortic dissection angioarchitecture in terms of contemporary true and false lumen vision in 81.8% of the cases. In 72.7% of the procedures, Q-DSA was estimated to improve aorta information assessment in terms of false lumen viewing, and it was possible to identify the proximal entry tear position in 45.4% of the cases. After stent graft deployment, in 72.7% of the cases (all 8 patients in which the aortic arch false lumen was visible in pre-treatment), Q-DSA confirmed the absence of early false lumen reperfusion. Our results indicate that Q-DSA could be useful in the intraprocedural evaluation of patients with aortic dissection during TEVAR procedures without additional x-ray costs and contrast exposure.

Quantitative digital subtraction angiography during type B chronic aortic dissection endovascular repair

Quantitative digital subtraction angiography during type B chronic aortic dissection endovascular repair

Peri-Therapeutic Quantitative Flow Analysis of Endovascular Revascularization for Ischemic Stroke Patients on Digital Subtraction Angiography

Digital subtraction angiography (DSA) and optical flow method (OFM) were integrated to quantitate cerebral blood flow in patients with ischemic stroke and the results were utilized to predict the outcome of treatment. A total of 34 patients with ischemic stroke who received endovascular therapy were included in this study. The post-treatment blood flow velocity was significantly higher (P median value of 33.36%) were more likely to have a higher MBD NIHSS improve score (> 4) than those with a lower blood flow gain (< median value). Quantitative digital subtraction angiography provides hemodynamic information for patients treated with endovascular revascularization, and offers a reliable follow-up evaluation for the ischemic stroke treatment.

Delayed Venous Drainage in Ruptured Arteriovenous Malformations Based on Quantitative Color-Coded Digital Subtraction Angiography

Clinically applicable hemodynamic risk factors to predict arteriovenous malformation (AVM) rupture are missing in the literature. The aim of this study was to use catheter angiography to identify hemodynamic parameters in ruptured and unruptured AVMs. Patients with frontal and temporal AVMs and Siemens syngo iFlow color-coding angiography were included in this study (n= 71). Clinical and radiologic data (age, sex, Spetzler-Martin [SM] and supplemented SM grade, and rupture status), and hemodynamic features (contrast mean transit time [MTT] of feeding arteries, draining veins, AVM nidus, and the cerebral circulation time [CCT]) were analyzed. Univariable analysis was performed to compare findings between ruptured and unruptured AVMs. In total, 35 ruptured and 36 unruptured AVMs were analyzed. Clinical characteristics and AVM grades were comparable between ruptured and unruptured AVMs. Ipsilateral CCT (5.2 vs. 4.0 seconds; P= 0.035), MTT between Tmax of the ipsilateral internal carotid artery and Tmax of sinus entry of the draining vein (3.2 vs. 2.0 seconds; P < 0.001), and MTT between Tmax at the start of venous outflow and Tmax of sinus entry (1.6 vs. 0.7 seconds; P<0.0001) were significantly longer in ruptured compared with unruptured AVMs. MTTs of nidus, between the internal carotid and feeding arteries, of the venous sinus passage as well as contralateral CCT and controlled ipsilateral CCT were comparable between both groups. Ruptured AVMs have significantly prolonged venous drainage times compared with unruptured AVMs; this suggests restricted AVM drainage and increased blood pressure within the AVM nidus. Prospective studies are needed to determine the predictive power of these measurements.