Classification Of Stenosis Research Articles

Pathologico-Anatomic Categories of Choledochal End-Piece Stenosis Due to Chronic Pancreatitis and Clinical Significance

Background: Chronic pancreatitis caused by common bile duct segment stenosis is a common complication. It often results in near side bile duct expansion, bile drain disorder, appearing serious obstructive jaundice, biliary cirrhosis, lifethreatening. However, chronic pancreatitis causes not bravery manager narrow some light, some heavy, and the clinical manifestation is different too. We think there may be different kinds of pathological anatomy. As a result, we carried out the research of this subject. Objective: To investigate the anatomicopathological classification of terminal stenosis of the common bile duct (CBD) caused by chronic pancreatitis (CP) and the treatment. Method: A retrospective analysis was made for the management of sympatomatic stenosis of the terminal end of CBD 47 CP cases. Autopsy was performed in 25 bodies to verify our classification. Result: By analyzing operation and postoperative follow-ups to 47 patients with obvious choledochal dilatations (diameter ≥ 15 mm) due to chronic pancreatitis, the authors have found that there exist three pathologico-anatomic categories of choledochal end-piece stenosis due to chronic pancreatitis. The stenosis of type I is the external-pressing annular stricture (59.6%); type II is front wall of choledochus being compressed one (31.9%); and type III is the pseudocystic oppression one (8.5%). Conclusion: The treatment of CP patients complicated with terminal stenosis of CBD need individual consideration. Clinical Significance: Type I should be treated with biliary-enterostomy owing to more serious stricture (only No.3 the Bake’s dilstors and smaller ones can be passed through its stenotic segment). Type II Could be managed with T-tube drainage because of its slighter stricture (Bake’s dilators bigger than No.6 and No.12 French urinary catheter can get through the Choledochal terminal). If there aren’t biliary and pancreatic complicated diseases, non-operative treatment can be carried out. Type III can undergo with the T-tube replacement between biliary tract and pseudocyst if pseudocystic decompression doesn’t lead to obvious stenosis (type IIIo and IIIb). If type III combines type I, the internal drainage should be performed in both ectatic bile duct and cyst.

Diagnosis of Heart Valve Disorders through Trapezoidal Features and Hybrid Classifier

Numerous studies are being conducted in recent years focusing on phonocardiographic (PCG) signals due to their capability to characterize heart sounds. These characteristics can be exploited in developing computer-aided auscultation system as a complementary tool for clinicians in diagnosis of cardiovascular disorders. This study proposes a new type of features to distinguish five categories of heart sounds, including normal, mitral stenosis, mitral regurgitation,aortic stenosis, and aortic regurgitation. PCG signals were collected from online resources and training CDs. Wavelet packet transform was utilized for heart sound analysis as opposed to discrete wavelet transform that has been extensively used in the previous studies. Then, trapezoidal function was calculated for deriving feature vectors. A hybrid classifier was designed composing of three types of classifiers, multilayer perceptron (MLP) artificial neural network, k-nearest neighbor (KNN), and support vector machine (SVM), to classify feature vectors.The promising results demonstrate the effectiveness of the proposed trapezoidal features and hybrid classifier for heart sound classification.

Peripheral Arterial Occlusive Disease: 3.0-T versus 1.5-T MR Angiography Compared with Digital Subtraction Angiography

To prospectively evaluate the diagnostic accuracy of 3-T versus 1.5-T contrast material-enhanced (CE) magnetic resonance (MR) angiography with high spatial resolution in patients who have peripheral arterial occlusive disease, with conventional digital subtraction angiography (DSA) serving as the reference standard. Institutional review board approval and written informed consent were obtained. DSA and standardized single-injection, three-station, moving-table CE MR angiography, with similar acquisition protocols and contrast agent doses at 3 T and 1.5 T, were consecutively performed in 19 patients (13 men and six women; mean age ± standard deviation, 67 years ± 9). Stenosis was scored visually in 500 arterial segments (97.5% of all available) in consensus by two radiologists in a blinded manner (the radiologists were unaware of the field strength and prior DSA and MR angiographic results and used randomized analysis order). Contrast-to-noise ratio was determined in the vascular tree of both legs. Statistical significance in stenosis scoring was evaluated by using generalized estimating equations. Contrast-to-noise differences were evaluated with paired t tests. Agreement between MR angiography and DSA was evaluated by using Fleiss-Cohen κ statistics. Both 3-T and 1.5-T CE MR angiography showed similar excellent agreement with DSA regarding stenosis classification (κ = 0.96 and 0.93, respectively). All sensitivity and specificity values exceeded 90%. Mean contrast-to-noise ratio was 3.0-4.2 times higher at 3 T than at 1.5 T. Standardized single-injection, three-station, moving-table 3-T CE MR angiography is reliable for classification of stenosis in patients suspected of having peripheral arterial occlusive disease, and diagnostic performance was similar to that seen with 1.5-T MR angiography. There was a significantly increased contrast-to-noise ratio for identical contrast agent dose at 3-T MR angiography.

Carotid Doppler Velocity Measurements and Anatomic Stenosis

Duplex ultrasound with Doppler velocimetry is widely used to evaluate the presence and severity of internal carotid artery stenosis; however, a variety of velocity criteria are currently being applied to classify stenosis severity. The purpose of this study is to compare published Doppler velocity measurements to the severity of internal carotid artery stenosis as assessed by x-ray angiography in order to clarify the relationship between these 2 widely used approaches to assess carotid artery disease. Scatter diagrams or "scattergrams" of correlations between Doppler velocity measurements and stenosis severity as assessed by x-ray contrast angiography were obtained from published articles for native and stented internal carotid arteries. The scattergrams were graphically digitized, combined, and segmented into categories bounded by 50% and 70% diameter reduction. These data were combined and divided into 3 sets representing different velocity parameters: (1) peak systolic velocity, (2) end-diastolic velocity, and (3) the internal carotid artery to common carotid artery peak systolic velocity ratio. The horizontal axis of each scattergram was transformed to form a cumulative distribution function, and thresholds were established for the stenosis categories to assess data variability. Nineteen publications with 22 data sets were identified and included in this analysis. Wide variability was apparent between all 3 velocity parameters and angiographic percent stenosis. The optimal peak systolic velocity thresholds for stenosis in stented carotid arteries were higher than those for native carotid arteries. Within each category of stenosis, the variability of all 3 velocity parameters was significantly lower in stented arteries than in native arteries. Although Doppler velocity criteria have been successfully used to classify the severity of stenosis in both native and stented carotid arteries, the relationship to angiographic stenosis contains significant variability. This analysis of published studies suggests that further refinements in Doppler velocity criteria will not lead to improved correlation with carotid stenosis as demonstrated by angiography.

Subaortastenose bij de newfoundland: erfelijkheid, pathofysiologie, diagnose, prognose en fokadvies

Subaortastenose is een progressieve ontwikkelingsstoornis gekenmerkt door een obstructie van de linker ventriculaire uitstroomtractus net onder de aortaklep. Een dominant overervingstype met variabele penetrantie wordt algemeen als oorzaak beschouwd. Bij muizen is homozygotie voor het allel Egfrwa2 in combinatie met een mutatie in het Ptpn11-gen geassocieerd met gevoeligheid voor een aandoening gelijkend op subaortastenose bij de newfoundland. De diagnose gebeurt op basis van de anamnese, auscultatie, elektrocardiografie, thoraxradiografie, echocardiografie en hartkatheterisatie. Bij auscultatie wordt een (holo)systolisch, vaak schurend, crescendo-decrescendo bijgeruis gehoord met een maximale intensiteit ter hoogte van de linkerhartbasis. Echocardiografisch worden de stenose en de veranderingen van de linker ventriculaire uitstroomtractus nagegaan, alsook de snelheid van de bloedstroom en de drukgradiënt gemeten over de aortaklep, de verhouding van de oppervlakte van de linker ventriculaire uitstroomtractus en de oppervlakte van de aorta en de oppervlakte ter hoogte van de stenose. De prognose is variabel. Fokadvies is niet eenvoudig en wordt gegeven op basis van echocardiografische screening op de leeftijd van achttien maanden.

Carotid Magnetization-Prepared Rapid Acquisition With Gradient-Echo Signal Is Associated With Acute Territorial Cerebral Ischemic Events Detected by Diffusion-Weighted MRI

Background— Carotid intraplaque hemorrhage has been associated with symptomatic stroke and can be accurately detected with magnetization-prepared rapid acquisition with gradient-echo (MPRAGE). Currently, there are no studies analyzing carotid MPRAGE signal and territorial ischemic events defined by diffusion restriction in the acute setting. Our aim was to determine the association of carotid MPRAGE signal with acute territorial ischemic events using carotid MPRAGE and brain diffusion tensor imaging. Methods and Results— After the addition of the MPRAGE sequence to the neck MR angiographic protocol, 159 patients with suspected acute stroke were evaluated with both brain diffusion tensor imaging and carotid MPRAGE sequences over 2 years, providing 318 carotid artery and paired brain images for analysis. Forty-eight arteries were excluded due to extracarotid sources of brain ischemia and 4 were excluded due to carotid occlusion. Two hundred sixty-six arteries were eligible for data analysis. Carotid MPRAGE-positive signal was associated with an acute cerebral territorial ischemic event with a relative risk of 6.4 ( P <0.001). The relative risk of a diffusion tensor imaging-positive territorial ischemic event with carotid MPRAGE-positive signal was increased in mild, moderate, and severe stenosis categories (10.3, P <0.001; 2.9, P =0.01; and 2.2, P =0.01, respectively). Conclusions— In the workup of acute stroke, carotid MPRAGE-positive signal was associated with an increased risk of territorial cerebral ischemic events as detected objectively by brain diffusion tensor imaging. The relative risk of stroke was increased in all carotid stenosis categories but was most elevated in the mild stenosis category.

Response to Letter Regarding Article, “Low-Flow, Low-Gradient Severe Aortic Stenosis Despite Normal Ejection Fraction Is Associated With Severe Left Ventricular Dysfunction as Assessed by Speckle-Tracking Echocardiography: A Multicenter Study”

Response: We read the comments of Dr Ozkan and would like to answer his questions and remarks. Concerning left ventricular midwall fractional shortening, it is known for a long time that it is impaired in severe aortic stenosis (AS). Midwall fractional shortening has been shown to be particularly reduced in low-flow, low-gradient AS, as shown by Hachicha et al1 and confirmed in our study.2 In both studies, midwall fractional shortening was particularly low in the group of low-flow AS, although the difference was not significant in our study ( P =0.07), probably related to the small sample size in each subgroup. Dr Ozkan underlines that values of basal strain as low as −13.9% have been reported in normal individuals,3,4 meaning that the low basal strain observed in patients with AS in our study does not systematically represent left ventricular dysfunction. However, a …

Toward automatic detection of vessel stenoses in cerebral 3D DSA volumes

Vessel diseases are a very common reason for permanent organ damage, disability and death. This fact necessitates further research for extracting meaningful and reliable medical information from the 3D DSA volumes. Murray's law states that at each branch point of a lumen-based system, the sum of the minor branch diameters each raised to the power x$, ? > is equal to the main branch diameter raised to the power x. The principle of minimum work and other factors like the vessel type, impose typical values for the junction exponent x. Therefore, deviations from these typical values may signal pathological cases. In this paper, we state the necessary and the sufficient conditions for the existence and the uniqueness of the solution for x. The second contribution is a scale- and orientation- independent set of features for stenosis classification. A support vector machine classifier was trained in the space of these features. Only one branch was misclassified in a cross validation on 23 branches. The two contributions fit into a pipeline for the automatic detection of the cerebral vessel stenoses.

Reconstrução cirúrgica da estenose cicatricial de vias biliares pós-colecistectomia

To evaluate a series of cases of cicatricial stenosis of the biliary tract after cholecystectomy undergoing surgical reconstruction. We conducted a retrospective study with 27 patients who underwent surgical reconstruction of the biliary tree for cicatricial stenosis. We analyzed the type of cholecystectomy that resulted in injury, age, gender, signs and symptoms, time of diagnosis, early or late, presence of previous surgery in an attempt to reconstruct the biliary tree, classification of stenosis and type of operation used for treatment of the injury. Twenty-six injuries occurred during a laparotomy and one during laparoscopy. Sixteen (59%) lesions were diagnosed intraoperatively or within the first postoperative day, seven (26%) havinh been submitted to reoperation at the local hospital, with poor results; nine patients in this group (33%) had no reoperation. Eleven patients (41%) had the classic form of cicatricial stenosis, without apparent intraoperative accidents and late development of biliary obstruction. All patients underwent Roux-en-Y hepatic-jejunal anastomosis; in two cases the right and left hepatic ducts were implanted separately in the excluded jejunal loop. Twenty-six patients (96.3%) had no early complications; one patient had biliary fistula and died. One patient presented with stenosis recurrence, secondary cirrhosis and is awaiting liver transplantation. Most injuries were diagnosed during cholecystectomy within the first postoperative days; seven patients had been reoperated in an attempt to reconstruct the biliary tract. Roux-en-Y hepaticojejunostomy proved safe and effective in draining the bile duct in the short and long term.

Grading Carotid Stenosis Using Ultrasonic Methods

The controversy as to whether Doppler ultrasonic methods should play a role in clinical decision-making in the prevention of stroke is attributable to reported disagreement between angiographic and ultrasonic results and the lack of internationally accepted ultrasound criteria for describing the degree of stenosis. Foremost among the explanations for both is the broad scatter of peak systolic velocities in the stenosis, the criterion that has so far received most attention. Grading based on a set of main and additional criteria can overcome diagnostic errors. Morphological measurements (B-mode images and color flow imaging) are the main criteria for low and moderate degrees of stenosis. Increased velocities in the stenosis indicate narrowing, but the appearance of collateral flow and decreased poststenotic flow velocity prove a high degree stenosis (≥70%), additionally allowing the estimation of the hemodynamic effect in the category of high-degree stenosis. Additional criteria refer to the effect of a stenosis on prestenotic flow (common carotid artery), the extent of poststenotic flow disturbances, and derived velocity criteria (diastolic peak velocity and the carotid ratio). This multiparametric approach is intended to increase the reliability and the standard of reporting of ultrasonic results for arteriosclerotic disease of the carotid artery.

Abstract 3013: Cerebral Perfusion Parameter Differences in Clinically Relevant Categories of Carotid Stenosis/Occlusion.

Hypothesis: To determine whether clinically relevant categories of carotid stenosis are associated with changes in cerebral blood flow. Methods: We examined a consecutive cohort of stroke patients with confirmed stroke on DWI imaging who underwent CT angiography (CTA) and perfusion CT imaging on presentation with acute symptoms. Degree of carotid stenosis was measured per NASCET criteria on CTA. Perfusion CT was analyzed to calculate relative mean transit time (rMTT), relative cerebral blood volume (rCBV) and relative cerebral blood flow (rCBF) of normal brain tissue ipsilateral to carotid disease. Measurements excluded areas of infarction to avoid confounding hemispheric perfusion changes with local changes due to distal cerebral artery occlusion(s), and subjects with MCA occlusions on any side were excluded. Results: The cohort consisted of 119 patients. Of these 8.4% had 100% ipsilateral carotid occlusion, 1.7% had near-occlusion, 5% had 70-99% stenosis, 5.9% had 50-69% stenosis, and 79% had <50% stenosis. Subjects with 100% carotid occlusion had a higher rMTT (median 1.503, IQR 0.974 to 2.44; p=0.02) when compared to the expected normal rMTT of 1.0. These patients also had a lower rCBF (median 0.708, IQR 0.553 to 1.116; p=0.048) when compared to the expected normal rCBF of 1.0. Perfusion parameters of subjects with carotid near-occlusion did not differ significantly from the expected normal values. Subjects with 70-99% stenosis had slightly higher rMTT (median 1.246, IQR 1.034 to 1.422; p=0.031) and slightly higher rCBV (median 1.088, IQR 1.046 to 1.142; p=0.031) when compared to the expected normal of 1.0. Subjects with 50-69% carotid stenosis and <50% stenosis did not have significantly different perfusion parameters when compared to expected normal values. Conclusions: This is the first reported correlation between clinically relevant categories of carotid stenosis and perfusion parameters measured by perfusion CT imaging of the brain. Subjects with 100% occlusion appeared to have hemodynamically significant changes in perfusion (increased rMTT by ∼50%, decreased rCBF by ∼30%). Patients with 70-99% stenosis had less pronounced changes in rMTT, and no change in rCBF. Interestingly, patients with carotid near-occlusion showed no significant change in perfusion parameters, suggesting that this subgroup of patients may have developed sufficient collateral circulation. Patients with 0-69% stenosis had no significant changes in perfusion parameters. These findings may have significant implications in our approach to patients with carotid occlusion/stenosis and need to be confirmed in larger patient populations.

Abstract 55: Correlation Of Carotid Intraplaque Hemorrhage With Acute Territorial Cerebral Ischemic Events Using Magnetic Resonance Imaging

Background: Carotid intraplaque hemorrhage has been associated with clinical stroke symptoms and can be detected with MPRAGE (Magnetization-Prepared Rapid Acquisition with Gradient-Echo). Currently, there are no studies correlating carotid intraplaque hemorrhage (IPH) concurrent with acute territorial ischemic events defined by brain diffusion weighted imaging (DWI). Our aim was to determine the association of carotid intraplaque hemorrhage with acute territorial ischemic events using carotid MPRAGE and brain DWI. Methods and Results: Carotid IPH was defined as at least 2-fold higher carotid MPRAGE signal intensity compared to adjacent sternocleidomastoid muscle. Using the MPRAGE sequence, IPH was identified with an accuracy of 91.2%, sensitivity of 91.3%, and specificity of 90.9% as compared to histology in 91 slides from 10 endarterectomy subjects. The Kappa values for interobserver and intraobserver agreement on MPRAGE signal were 0.806 and 0.818 respectively (very good agreement). After the addition of the MPRAGE sequence to the neck MRA protocol, 131 consecutive patients with suspected acute stroke were evaluated with both brain DWI and carotid MPRAGE sequences over the course of 1.5 years, providing 262 carotid artery and paired brain images for analysis. 34 arteries were excluded due to an extracarotid etiology of brain ischemia and 4 were excluded due to carotid occlusion. 224 arteries were eligible for data analysis. Carotid IPH was associated with acute territorial ischemic events with a relative risk of 4.1 (p<0.05). This is demonstrated by the representative image below depicting left carotid IPH as hyperintense MPRAGE signal (left) and an acute ischemic event in the left middle cerebral artery distribution with diffusion restriction on brain DWI (right). The relative risk of an ischemic event with carotid IPH was increased in mild, moderate and severe stenosis categories (5.1, 2.9, and 1.8, p<0.05). Conclusion: In the workup of acute stroke, carotid IPH increased the risk of simultaneous territorial cerebral ischemic events in all carotid stenosis categories. By using objective data from brain DWI, accurate risk assessment of vulnerable plaque components can be obtained.

3T versus 1.5T MR angiography in peripheral arterial occlusive disease: an equivalence trial in comparison with digital subtraction angiography

Summary Standardized single-injection 3-station moving-table 3T contrast-enhanced MR angiography (CE-MRA) is reliable for stenosis detection and classification in peripheral arterial occlusive disease with equivalent diagnostic performance as 1.5T CE-MRA, while contrast-to-noise ratio significantly increased at 3T for identical contrast dosage. Background Contrast-enhanced MR angiography (CE-MRA) has evolved into a reliable imaging technique for peripheral arterial occlusive disease (PAOD). Recent advances in MRI technology offer large homogeneous magnetic fields with comparable Field-of-Views at 3T and 1.5T, allowing visualization of the complete runoff vascular tree by single-injection 3-station (pelvic/thigh/calf) moving-table CE-MRA. Diagnostic performance of 3T versus 1.5T CE-MRA has not yet been described. The purpose of this study was to compare diagnostic accuracy of 3T CE-MRA in POAD in an equivalence trial with 1.5T CE-MRA, with conventional digital subtraction angiography (DSA) as the standard of reference. Methods In nineteen patients (13 men; mean age 69 years), DSA and standardized single-injection 3-station moving-table CE-MRA with equivalent acquisition protocols and contrast dosage were performed at 3T and 1.5T MRI (Philips, Best, the Netherlands). For CE-MRA, 0.2 mmol/kg body weight gadoterate meglumine was injected, with the first half of the bolus at 2 mL/s and second half at 0.6 mL/s. At 1.5T, a quadrature body coil (QBC) was used for imaging pelvic and thigh stations and a 4-element phased array coil for calf station. At 3T, a QBC was used in all three stations. DSA was performed using iomeprol injection at variable volumes and flow rates depending on the arterial segment. The arterial tree in each patient was divided into 27 segments, infrarenal aorta, common and external iliac arteries, common and superficial femoral arteries, popliteal arteries in thigh and calf station, tibiofibular trunk, proximal and distal halves of the anterior and posterior tibial arteries and peroneal arteries. Visual stenosis classification was performed in consensus by two radiologists in blinded manner using the following categories: class 1 (0%-stenosis), 2 (1-50%), 3 (51-75%), 4 (76-99%) and 5 (100%). Quantitative analysis of contrast-to-noise ratio (CNR) was performed for the external iliac artery and the superficial femoral artery. Results

Lack of Sex Disparity in Cardiovascular Testing After Coronary Computerized Tomographic Angiography

The authors assessed whether there was a sex disparity in testing of patients after coronary computerized tomographic angiography (CTA) was performed for emergency department (ED) patients with potential acute coronary syndromes (ACS). In theory, once coronary anatomy has been determined, any disparity in subsequent workup should not be the result of differences in presentation. This was a prospective cohort study of ED patients who presented with potential ACS and received coronary CTAs at a university hospital. Demographics, history, cardiac risk factors, follow-up testing, and procedures were recorded. Follow-up at 30 days was obtained by structured record review and telephone contact. Patients were stratified by sex and coronary CTA results (max stenosis: none, 1% to 24%, 25% to 49%, 50% to 69%, and ≥70%). Main outcome was the relative risk (RR) of a male receiving a stress test or catheterization within 30 days, stratified by categories of percent maximal stenosis. A total of 1,144 patients received coronary CTAs (mean ± SD age = 47.8 ± 8.7 years), 55% were female, and 64% were black or African American. Overall, 161 patients received follow-up testing within 30 days, 113 during their index visit. Men were more likely to receive further testing (RR = 1.51; 95% confidence interval [CI] = 1.14 to 1.99) compared to women. However, when stratified by percentage of stenosis, men were not more likely to receive further testing within 30 days after coronary CTA compared to women (RR = 1.14; 95% CI = 0.68 to 1.91). In multivariable modeling for risk of further testing, stenosis remained significant (adjusted relative risk [aRR] = 1.51; 95% CI = 1.19 to 1.91), while male sex, age, race, and Thrombolysis in Myocardial Infarction (TIMI) risk score were not. Male patients with potential ACS who receive a coronary CTA as a part of their ED evaluation were no more likely than female patients to receive further testing within 30 days.

Decision-making in lumbar spinal stenosis

Surgical decision-making in lumbar spinal stenosis involves assessment of clinical parameters and the severity of the radiological stenosis. We suspected that surgeons based surgical decisions more on dural sac cross-sectional area (DSCA) than on the morphology of the dural sac. We carried out a survey among members of three European spine societies. The axial T2-weighted MR images from ten patients with varying degrees of DSCA and morphological grades according to the recently described morphological classification of lumbar spinal stenosis, with DSCA values disclosed in half the assessed images, were used for evaluation. We provided a clinical scenario to accompany the images, which were shown to 142 responding physicians, mainly orthopaedic surgeons but also some neurosurgeons and others directly involved in treating patients with spinal disorders. As the primary outcome we used the number of respondents who would proceed to surgery for a given DSCA or morphological grade. Substantial agreement among the respondents was observed, with severe or extreme stenosis as defined by the morphological grade leading to surgery. This decision was not dependent on the number of years in practice, medical density or specialty. Disclosing the DSCA did not alter operative decision-making. In all, 40respondents (29%) had prior knowledge of the morphological grading system, but their responses showed no difference from those who had not. This study suggests that the participants were less influenced by DSCA than by the morphological appearance of the dural sac. Classifying lumbar spinal stenosis according to morphology rather than surface measurements appears to be consistent with current clinical practice.

Abstract 8918: Diagnostic Criteria for Ultrasound Diagnosis of Internal Carotid Artery Stenosis Vary Widely Among Accredited Vascular Laboratories. A Survey from the Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL)

Background: Carotid duplex ultrasound (DUS) is widely used for diagnosis of internal carotid artery (ICA) stenosis and therapeutic decisions are often on the basis of DUS findings. There are no universal standard DUS criteria to grade the severity of ICA stenosis. A 2003 publication from the Society for Radiologists in Ultrasound (SRU) provided consensus criteria for grading ICA stenosis, but their integration into clinical practice is unknown. Methods: Random sample of 10% of vascular laboratories accredited in extracranial carotid testing. Data were abstracted from the ICAVL database, including most recent accreditation application. A single reviewer (HLG) compared laboratory diagnostic criteria to published references. Results: 152 vascular laboratories were sampled, 57.2% of which were outpatient based. Mean annual carotid volume 1,330 + 124.1 studies (range 100-9,858). There were 17 diagnostic criteria in use among 117 labs with the remaining facilities utilizing locally developed (6 labs) or unreferenced or hybrid criteria (29 labs). Mean number of categories of ICA stenosis was 5.80 + .084 (range 3-12). Cut-points for the mildest disease stratum ranged from 0 to 0-60% with normal or 0% most commonly reported (67.1% of labs). The cut-point for most severe (non-occlusive) stenosis ranged from 70 to 91% with 80% most commonly reported (64.5% of labs). SRU consensus-based criteria were used in only 27.0% of laboratories, although there was a statistically significant increase in SRU utilization among labs accredited after versus before 2005 (50.0% vs. 18.8%, P <0.001). Despite divergent diagnostic criteria and severity cut-points, self-reported accuracy of DUS for diagnosis of ICA stenosis from correlation studies was high (mean 85.8 + 0.65%). Conclusion: Diagnostic criteria and cut-points for grading severity of ICA stenosis using DUS vary widely in accredited vascular laboratories. Despite this, diagnostic accuracy is acceptable. Uptake of SRU consensus criteria has been limited, but is more common among recently accredited facilities. Health care providers must be aware of the lab-to-lab variation in reporting of ICA stenosis while further efforts to achieve consensus reporting are considered by professional societies.

Quantitative Relationship Between the Extent and Morphology of Coronary Atherosclerotic Plaque and Downstream Myocardial Perfusion

The purpose of this study was to quantify the effects of coronary atherosclerosis morphology and extent on myocardial flow reserve (MFR). Although the relationship between coronary stenosis and myocardial perfusion is well established, little is known about the contribution of other anatomic descriptors of atherosclerosis burden to this relationship. We evaluated the relationship between atherosclerosis plaque burden, morphology, and composition and regional MFR (MFR(regional)) in 73 consecutive patients undergoing Rubidium-82 positron emission tomography and coronary computed tomography angiography for the evaluation of known or suspected coronary artery disease. Atherosclerosis was seen in 51 of 73 patients and in 107 of 209 assessable coronary arteries. On a per-vessel basis, the percentage diameter stenosis (p = 0.02) or summed stenosis score (p = 0.002), integrating stenoses in series, was the best predictor of MFR(regional). Importantly, MFR(regional) varied widely within each coronary stenosis category, even in vessels with nonobstructive plaques (n = 169), 38% of which had abnormal MFR(regional) (<2.0). Total plaque length, composition, and remodeling index were not associated with lower MFR. On a per-patient basis, the modified Duke CAD (coronary artery disease) index (p = 0.04) and the number of segments with mixed plaque (p = 0.01) were the best predictors of low MFR(global). Computed tomography angiography descriptors of atherosclerosis had only a modest effect on downstream MFR. On a per-patient basis, the extent and severity of atherosclerosis as assessed by the modified Duke CAD index and the number of coronary segments with mixed plaque were associated with decreased MFR.

Outcome in 55 dogs with pulmonic stenosis that did not undergo balloon valvuloplasty or surgery

To determine the outcome, independent predictors of cardiac death, and the Doppler-derived pressure gradient cut-off for predicting cardiac death in dogs with pulmonic stenosis, with or without tricuspid regurgitation, that do not undergo balloon valvuloplasty or valve surgery. Review of medical records of two UK referral centres between July 1997 and October 2008 for all cases of pulmonic stenosis that had no balloon valvuloplasty or valve surgery. Inclusion criteria included a diagnosis of pulmonic stenosis; spectral Doppler pulmonic velocity greater than 1·6 m/s; characteristic valve leaflet morphological abnormalities. Exclusion criteria included concurrent significant cardiac defects, including tricuspid dysplasia. Dogs with tricuspid regurgitation were included. Dogs were classified according to Doppler-derived pressure gradients into mild, moderate or severe pulmonic stenosis categories. Presence of tricuspid regurgitation and severe stenosis were independent predictors of cardiac death. A pulmonic pressure gradient of more than 60 mmHg was associated with 86% sensitivity, and 71% specificity of predicting cardiac death. There is an increased probability of cardiac death in those cases which have a pulmonary pressure gradient greater than 60 mmHg and tricuspid regurgitation, though the effect of severity of tricuspid regurgitation on outcome was not measurable because of small sample sizes. These animals might benefit from intervention.

PVSS10. Clinical Value of CTA in Patients with ≥50% ICA Stenosis by Duplex Ultrasound

Objectives: CT angiography (CTA) is frequently employed in current clinical practice to evaluate the extent of cerebrovascular disease in patients with DU 50% extracranial ICA stenosis. We studied a) the prevalence of additional clinically significant intracranial or proximal arch occlusive disease not detected by DU, and b) whether such CTA findings predict progression in DU ICA stenosis category. Methods: From 2005 to 2010, 111 consecutive patients were studied retrospectively. 81 were asymptomatic and 30 symptomatic (TIA, stroke, AF). Kappa agreement between DU stenosis category and CTA was determined. Findings on CTA considered significant were 50% intracranial ICA stenosis, proximal CCA stenosis, intracranial aneurysm, vertebral stenosis or occlusion, 50% subclavian stenosis and diffuse atherosclerosis of the aortic arch. Progression of DU ICA stenosis from 50-79% to 80-99% was determined in relation to CTA findings. Results: Patient demographics were similar between asymptomatic and symptomatic patients Table 1. DU and CTA were performed within 6 months in 95% of cases. Agreement between DU and CTA was 0.9 (Kappa). 19% (21/111) of patients had CTA findings not detected by DU, of which 17 (21%) were in asymptomatic and 4 (13%) in symptomatic patients (p 0.60, NS) Table 2. Median follow up was 3.2 years. Progression from 50-79% to 8099% was detected in 4 (19%) and in 13 (14.4%) patients with and without additional CTA findings respectively (NS). Conclusions: For patients harboring 50% carotid bifurcation ICA stenosis by DU, CTA provides minimal information of clinical use. Progression of stenosis is unrelated to the presence of remote atherosclerotic plaque burden as detected on CTA. These findings suggests that CTA is over utilized in clinical practice and that DU performed in an ICAVL accredited lab is sufficient for planning carotid intervention if necessary.

Discriminating Carotid Atherosclerotic Lesion Severity by Luminal Stenosis and Plaque Burden

To determine associations between stenosis, measures of plaque burden, and compositional features of carotid atherosclerosis, including high-risk features of intraplaque hemorrhage (IPH) and surface disruption. Institutional Review Board approval and informed consent for all participants were obtained before study initiation. Patients with either carotid stenosis >50% by duplex ultrasound or suspected coronary artery disease underwent multi-contrast carotid MRI at 3.0 T. For each artery, stenosis, percent wall volume (PWV=100%×wall volume/total vessel volume), and mean wall thickness (MWT) were measured. Presence or absence of a lipid-rich necrotic core, calcification, IPH, and surface disruption were recorded. One hundred eighty-one patients were included in the final analysis. The area under the curve (AUC) calculated from receiver-operating-characteristics analysis found the presence of IPH was similarly classified by stenosis (AUC=0.82), PWV (AUC=0.88), and MWT (AUC=0.88). Notably, IPH was present in the lowest category of each parameter. Prevalence of IPH in arteries with 0% stenosis was 4.4%. In arteries with PWV <40%, prevalence was 3.2%; in arteries with MWT <1.0 mm, prevalence was 2.3%. Strength of classification for surface disruption was similarly classified by stenosis (AUC=0.87), PWV (AUC=0.93), and MWT (AUC=0.94). Measures of plaque burden do not substantially improve disease assessment compared to stenosis. The finding of IPH in all categories of stenosis and plaque burden suggests that direct characterization of plaque composition and surface status is necessary to fully discriminate disease severity.