Spinal Arterial Blood Supply Does Not Arise from the Bronchial Arteries: A Detailed Analysis of Angiographic Studies Performed for Hemoptysis

PurposeTo determine the angiographic prevalence of spinal arteries originating directly from the bronchial arteries in the setting of embolization for hemoptysis.Materials and MethodsOver a 14-year interval, 205 patients underwent angiography for hemoptysis. Twenty-five patients were excluded because their bronchial arteries were not visualized. The remaining 180 patients underwent a total of 254 angiographic procedures (range, 1–8 per patient). Images were reviewed jointly by 2 interventional radiologists with formal fellowship training in both peripheral and neurological interventional radiology. All catheterized arteries were evaluated for arterial contribution to the spinal cord. For patients with multiple studies, each unique artery was reported only once. Embolization was performed during at least 1 procedure in 158 patients (88%). Electronic record review was used to assess neurological sequelae after the procedure.ResultsOne or 2 bronchial arteries originating from the aorta were identified in 57 patients (32%) on the right and in 75 patients (42%) on the left. Conjoined bronchial arteries were found in 76 patients (42%). Spinal arterial supply was absent in all. A total of 102 patients (57%) had at least 1 right and 11 patients (6%) at least 1 left intercostobronchial artery. Spinal arterial supply from the intercostal portion of an intercostobronchial artery was found in 6 patients (5 right, 1 left). Medical record review revealed no postprocedure symptoms referable to spinal cord injury in any patient.ConclusionsSpinal arterial supply does not originate directly from the bronchial artery but can originate from the intercostal portion of an intercostobronchial artery.     

Antiphospholipid antibodies: findings at arteriography.

PURPOSEThe purpose of this study was to determine the frequency and types of abnormalities at arteriography in patients with antiphospholipid antibodies (APA) and ischemic cerebrovascular events.METHODSTwenty-three patients with APA and ischemic cerebrovascular events who underwent arteriography were identified. Patients over the age of 65 years were excluded. No patients met diagnostic criteria for systemic lupus erythematosus. All angiograms were reviewed by two neuroradiologists.RESULTSSeventeen patients (74%) between the ages of 28 and 64 years (average age, 40 years) had abnormal angiograms. Sixteen patients had arterial abnormalities and one had dural sinus thrombosis. Ten had solely intracranial abnormalities (nine arterial and one venous), six had solely extracranial arterial abnormalities, and one had both intracranial and extracranial arterial abnormalities. Intracranial arterial abnormalities included stem or branch occlusions of the cerebral or basilar arteries, which were generally solitary (six patients), and findings suggestive of vasculitis (four patients). Four patients had stenoses of the origins of two or more great vessels. Two patients had extracranial internal carotid artery stenoses or occlusions that were not typical of atheromatous disease, considered to be embolic in one patient. In another patient, a stenosis of the origin of the internal carotid artery was present that appeared typical of atheromatous disease. Infarctions were seen on CT or MR studies in 13 of 17 patients with abnormal angiograms.CONCLUSIONIn our group of patients, typical atheromatous lesions at the common carotid artery bifurcation were rare. Some lesions that are infrequent in the general stroke population (eg, vasculitis-like findings and stenoses at the origin of great vessels) were common. Patients with APA and cerebrovascular events appear to differ from the general stroke population with regard to types of arterial abnormalities seen at arteriography.     

CT-based total vessel plaque analyses improves prediction of hemodynamic significance lesions as assessed by fractional flow reserve in patients with stable angina pectoris

BackgroundCoronary stenosis and plaque evaluation by coronary computed tomography angiography (CTA) may contribute to identify hemodynamically relevant lesions. We evaluated the most stenotic lesion including plaques proximal to it versus a total vessel analyses combined with stenosis for ischemia.MethodsPatients scheduled for clinically indicated invasive coronary angiography (ICA) for suspected coronary artery disease underwent coronary CTA and ICA including fractional flow reserve (FFR) as part of the NXT trial (clinicaltrials.gov NCT01757678). Stenoses were visually graded ≤50%, 51–70%, and >70% on coronary CTA. Semi-automated plaque analyses were performed using a proximal to the FFR pressure sensor location (including the most severe lesion to the coronary ostium) versus a total vessel (vessel diameter ≥2 mm) approach. Coronary stenosis and plaque parameters were evaluated for discrimination of ischemia by logistic regressions and combined models analyzed using receiver operating characteristics (ROC) with invasive FFR≤ 0.80 as reference standard.ResultsIn 254 patients, mean (±SD) age 64 (±10) years, 64% male, a coronary CTA stenosis >50% was present in 239 (49%) vessels. Invasive FFR was ≤0.80 in 100 (21%) vessels. Coronary stenosis severity and low-density non-calcified plaque (LD-NCP) volume were independent predictors of ischemia in the “proximal” and “total-vessel” analyses. Stenosis severity + total vessel LD-NCP assessment performed better than stenosis severity + proximal LD-NCP evaluation (Area under curve [AUC] (95%CI): 0.83 (0.78–0.87) vs 0.81 (0.76–0.86), p-value = 0.009), whereas stenosis severity + proximal LD-NCP performed better than stenosis alone (AUC (95%CI): 0.81 (0.76–0.86) vs 0.78 (0.73–0.83), p-value = 0.019).ConclusionAdding total vessel high-risk plaque volume to stenosis severity improves discrimination of ischemia in coronary CTA performed in patients with stable angina pectoris.     

Diagnostic performance of fusion of myocardial perfusion imaging (MPI) and computed tomography coronary angiography

Background  We evaluated the incremental diagnostic value of fusion images of coronary computed tomography angiography (CTA) and myocardial perfusion imaging (MPI) over MPI alone or MPI and CTA side-by-side to identify obstructive coronary artery disease (CAD > 50% stenosis) using invasive coronary angiography (ICA) as the gold standard. Methods  50 subjects (36 men; 56 ± 11 years old) underwent rest-stress MPI and CTA within 12-26 days of each other. CTAs were performed with multi-detector CT-scanners (31 on 64-slice; and 19 on 16-slice). 37 patients underwent ICA while 13 subjects did not because of low (<5%) pre-test likelihood (LLK) of disease. Three blinded readers scored the images in sequential sessions using (1) MPI alone (2) MPI and CTA side-by-side, (3) fused CTA/MPI images. Results  One or more critical stenoses during ICA were found in 28 patients and non-critical stenoses were found in 9 patients. MPI, side-by-side MPI-CTA, and fused CTA/MPI showed the same normalcy rate (NR:13/13) in LLK subjects. The fusion technique performed better than MPI and MPI and CTA side-by-side for the presence of CAD in any vessel (overall area under the curve (AUC) for fused images: 0.89; P = .005 vs MPI, P = .04 vs side-by-side MPI-CTA) and for localization of CAD to the left anterior descending coronary artery (AUC: 0.82, P < .001 vs MPI; P = .007 vs side-by-side MPI-CTA). There was a non-significant trend for better detection of multi-vessel disease with fusion. Conclusions  Using ICA as the gold standard, fusion imaging provided incremental diagnostic information compared to MPI alone or side-by-side MPI-CTA for the diagnosis of obstructive CAD and for localization of CAD to the left anterior descending coronary artery.     

Carotid angle in young stroke

PurposeTo investigate whether the carotid bifurcation angle as assessed by computed tomographic angiography (CTA) is associated with anterior circulation ischemic stroke (ACIS) in young patients.Material and methodsThirty patients (mean age 41.5 ± 6 years) with known acute ACIS (group 1) were compared to 30 control patients (mean age/ 41.2 ± 6 years) (group 2) with similar demographic variables in this retrospective study. Geometrical characteristics of bilateral carotid bifurcation were obtained by CTA. The ICA bifurcation (ICAB) angle, the carotid central bifurcation (CCB), and the carotid bifurcation wall (CBW) angle among the ICA, CCA, and ECA were measured. Carotid artery angle measurements were compared between group 1 and group 2. The comparison of pathological (ACIS) and non-pathological (non-ACIS) carotid sides in group 1 was performed as well.ResultsAll the measured angles (AMA) of group 1 were higher than group 2 (p˂0.05). In patients with left-sided ACIS, AMA on the left side were higher than the right side (p˂0.05), this was more prominent in males (p˂0.05). All angles measured were found to be higher in ipsilateral ACIS (p˂0.05). The left CCB angle values had a significant effect on ischemic stroke (p˂0.05). Male patients had more left-sided ACIS (p˂0.05). Plaque development in ICA was found statistically significant in group 1 compared to group 2 (p˂0.05).ConclusionCarotid artery geometry may play an important role in the development of ischemic events in young patients, especially in men and, also in patients with left-sided stroke. The left CCB angle had a significant effect on ACIS.     

Collateral Assessment by CT Angiography as a Predictor of Outcome in Symptomatic Cervical Internal Carotid Artery Occlusion

BACKGROUND AND PURPOSE:Cervical internal carotid artery occlusion can present with varied clinical manifestations such as transient ischemic attack, stroke, and chronic ocular ischemia, or can be asymptomatic. The outcome in these patients is considerably influenced by cerebral hemodynamic compensatory adaptation of the intracranial collateral pathways. Our aim was to study whether collateral circulation as assessed by CT angiography can predict 3-month outcome and initial stroke severity in patients with symptomatic cervical ICA occlusion.MATERIALS AND METHODS:This was a retrospective study of 65 patients with symptomatic cervical ICA occlusion from January 2011 to December 2013. The collateral vessels (anterior and posterior communicating arteries, ophthalmic artery, and leptomeningeal arteries) were assessed by CTA. The outcome at 3 months was defined as poor if the modified Rankin Scale score was ≥3.RESULTS:The mean age of subjects was 57 ± 11.6 years (range, 32–80 years), and 92% were men. Thirty-three (50.8%) patients had poor outcome. Absence of the ipsilateral ophthalmic artery, poor leptomeningeal collaterals, and <2 collaterals were predictors of stroke severity at onset and poor 3-month outcome in univariate analysis. In the multiple logistic regression analysis, inadequate flow through the secondary collaterals (ipsilateral ophthalmic artery or leptomeningeal collaterals; OR, 4.5; 95% CI, 1.4–14.9; P = .01) and higher NIHSS score at stroke onset (OR, 19.2; 95% CI, 2.2–166.2; P = .007) independently predicted poor outcome at 3 months.CONCLUSIONS:Assessment of collateral circulation with CTA can be a useful predictor of 3-month outcome in patients with symptomatic cervical ICA occlusion.

Cervical ICA occlusion can present with varied clinical manifestations such as transient ischemic attack, stroke, and chronic ocular ischemia, or can be asymptomatic. The outcome in these patients is influenced by cerebral hemodynamic compensatory adaptation, with the intracranial collateral pathways playing an important role in maintaining adequate perfusion to the ischemic zone.¹In large-artery occlusion, the primary collaterals (anterior and posterior communicating arteries) act as the immediate flow diverters and the secondary collaterals (leptomeningeal and ophthalmic arteries [OAs]) further enhance the cerebral perfusion.² The role of collaterals as predictors of stroke severity, response to thrombolysis, and outcome in patients with acute stroke and large-vessel occlusion has been investigated in multiple studies.^3–5 Good leptomeningeal collateral circulation and the presence of ≥2 collaterals were found to be associated with good outcome in patients with cervical large-vessel occlusion.^6,7Most of the earlier studies on collaterals have focused on the prognostic implications of primary collateral circulation and cerebrovascular autoregulation in patients with stroke. Only a very few of them have explored the clinical significance of secondary collaterals, especially the ophthalmic artery, in ICA occlusion. The earlier studies were also limited by the nonuniformity of study protocols, especially the imaging technique with a combination of either MRA, DSA, CTA, or transcranial Doppler for assessing the cerebral collaterals. We analyzed both primary and secondary collaterals by using CTA, which is a noninvasive technique currently recommended for the evaluation of vascular anatomy in stroke. The main objective of our study was to determine whether collateral circulation as assessed by CTA helps in predicting the 3-month outcome and initial stroke severity in patients with symptomatic cervical ICA occlusion.     

Coronary CTA enhanced with CTA based FFR analysis provides higher diagnostic value than invasive coronary angiography in patients with intermediate coronary stenosis

BackgroundCTA based FFR, a software based application, enhances diagnostic value of coronary computed tomography angiography (CTA) examination. However it remains unknown whether it improves accuracy over the gold standard of invasive coronary angiography (ICA) in predicting functionally significant coronary stenosis. The aim of our study was to compare diagnostic accuracies of coronary CTA, CTA based FFR, and ICA, with invasive FFR as the reference standard in patients with intermediate stenosis on CTA.Methods96 intermediate stenoses (50–90%) from 90 subjects, with intermediate pre-test probability of CAD, who underwent coronary CTA were analyzed. Each patient had subsequent ICA with FFR. CTA based FFR (cFFR v2.1, Siemens) analysis was performed on-site. The stenoses with invasive FFR≤0.8 were considered hemodynamically significant.Results41/96 stenoses were hemodynamically significant (FFR≤0.8). While the area under ROC curves (AUC) for identification of significant stenosis evaluated on QCA (0.653), visual ICA (0.652), qCTA (0.690) and visual CTA (0.660) did not significantly differ, the AUC for CTA based FFR (0.835) was significantly higher (p = 0.004, p = 0.004, p = 0.010, p = 0.007, respectively). The accuracies of CTA based FFR, qCTA and QCA were 76%, 63% and 58% respectively.ConclusionOur results suggest that diagnostic potential of routine coronary CTA, augmented with CTA based FFR analysis, is superior to ICA in patients with intermediate stenosis.     

Mid-cervical flame-shaped pseudo-occlusion: diagnostic performance of mid-cervical flame-shaped extracranial internal carotid artery sign on computed tomographic angiography in hyperacute ischemic stroke

Purpose

Flame-shaped pseudo-occlusion of the extracranial internal carotid artery (ICA) is a flow-related phenomenon that creates computed tomographic angiography (CTA) and digital subtraction angiography (DSA) findings that mimic tandem intracranial-extracranial ICA occlusion or dissection. We aim to determine the diagnostic performance of mid-cervical flame-shaped extracranial ICA sign on CTA in hyperacute ischemic stroke patients.

Methods

We retrospectively included consecutive anterior circulation ischemic stroke patients presenting within 6 h of symptom onset who underwent 4D brain CTA and arterial-phase neck CTA using a 320-detector CT scanner during August 2012 to July 2015. Two blinded readers independently reviewed arterial-phase neck CTA and characterized the extracranial ICA configurations into mid-cervical flame-shaped, proximal blunt/beak-shaped, and tubular-shaped groups. 4D whole brain CTA was used as a reference standard for intracranial ICA occlusion detection. Diagnostic performance of the mid-cervical flame-shaped extracranial ICA sign and interobserver reliability were calculated.

Results

Of the 81 cases, 11 had isolated intracranial ICA occlusion, and 6 had true extracranial ICA occlusion. Mid-cervical flame-shaped extracranial ICA sign was found in 45.5% (5/11) of isolated intracranial ICA occlusions but none in the true extracranial ICA occlusion group. The sensitivity, specificity, PPV, NPV, and accuracy of the mid-cervical flame-shaped extracranial ICA sign for the detection of isolated intracranial ICA occlusion were 45.5, 100, 100, 92.1, and 92.6%, respectively. Interobserver reliability was 0.90.

Conclusion

The mid-cervical flame-shaped extracranial ICA sign may suggest the presence of isolated intracranial ICA occlusion and allow reliable exclusion of tandem extracranial-intracranial ICA occlusion in hyperacute ischemic stroke setting.

     

Reduced caliber of the internal carotid artery: a normal finding with ipsilateral absence or hypoplasia of the A1 segment.

PURPOSETo determine whether a relationship exists between normal variations in anatomy of the circle of Willis and the size of the internal carotid arteries (ICA).METHODSMR angiograms and axial MR images of the brains of 104 patients were reviewed. Included were 10 patients with unilateral absence of the A1 segment of the anterior cerebral artery, 10 with hypoplasia of one A1 segment, 28 with asymmetric A1 segments, nine with isolated unilateral fetal origin of the posterior cerebral artery, and 47 with balanced circulation.RESULTSThe mean ICA diameter measurement for the total population was 4.62 +/- 0.68 mm. In patients with absent A1, the mean ipsilateral and contralateral ICA diameters were 3.63 +/- 0.41 mm and 5.25 +/- 0.52 mm, respectively. The mean percentages of the difference between the diameters of the right and left ICA (31% in the group with absent A1 and 21% in the group with hypoplastic A1) varied significantly from the differences in the ICA diameters among the rest of the population. The diameter differences produced by other common variations (unilateral small A1 segment or fetal origin of the posterior cerebral artery) did not differ significantly from those of the 47 patients with balanced intracranial circulation.CONCLUSIONSThere is an association of unilaterally absent or hypoplastic A1 segments of the anterior cerebral artery with ipsilateral decrease in ICA caliber, and this can be seen on MR angiograms.     

CT-Angiographie der Koronarien mit prospektivem EKG-Triggering

Background

The purpose of this study was to evaluate the diagnostic performance of coronary CT angiography (coronary CTA) using prospective ECG triggering (PT) for the detection of significant coronary artery stenosis compared to invasive coronary angiography (ICA).

Methods

A total of 20 patients underwent coronary CTA with PT using a 128-slice CT scanner (Definition? AS+, Siemens) and ICA. All coronary CTA studies were evaluated for significant coronary artery stenoses (≥50% luminal narrowing) by 2 observers in consensus using the AHA-15-segment model. Findings in CTA were compared to those in ICA.

Results

Coronary CTA using PT had 88% sensitivity in comparison to 100% with ICA, 95% to 88% specificity, 80% to 92% positive predictive value and 97% to 100% negative predictive value for diagnosing significant coronary artery stenosis on per segment per patient analysis, respectively. Mean effective radiation dose-equivalent of CTA was 2.6±1 mSv.

Conclusion

Coronary CTA using PT enables non-invasive diagnosis of significant coronary artery stenosis with high diagnostic accuracy in comparison to ICA and is associated with comparably low radiation exposure.     

Prognostic value of myocardial perfusion imaging after first-line coronary computed tomography angiography: A multi-center cohort study

PurposeFurther diagnostic testing may be required after a coronary computed tomography angiography (CTA) showing suspected coronary stenosis. Whether myocardial perfusion imaging (MPI) provides further prognostic information post-CTA remains debated. We evaluated the prognosis for patients completing CTA stratified for post-CTA diagnostic work-up using real-world data.MethodsWe identified all patients in our uptake area with angina symptoms undergoing first-time CTA over a 10-year period. Follow-up time was a median of 3.7 years [1.9–5.8]. The primary endpoint was a composite of myocardial infarction or death. The secondary endpoint was late revascularization.ResultsDuring the study period 53,351 patients underwent CTA. Of these, 24% were referred for further down-stream testing, 3,547 (7%) to MPI and 9,135 (17%) to invasive coronary angiography (ICA). The primary and secondary endpoints occurred in 2,026 (3.8%) and 954 (1.8%) patients. Patient-characteristic-adjusted hazard ratios for the primary and secondary endpoint using patients with a normal CTA as reference were 1.37 (1.21–1.55) and 2.50 (1.93–3.23) for patient treated medically, 1.68 (1.39–2.03) and 6.13 (4.58–8.21) for patients referred to MPI and 1.94 (1.69–2.23) and 9.18 (7.16–11.78) for patients referred for ICA, respectively. Adjusted analysis with stratification for disease severity at CTA showed similar hazard ratios for patients treated medically after CTA and patients referred for MPI and treated medically after the MPI.ConclusionIn patients completing coronary CTA, second-line MPI testing seems to identify patients at low risk of future events. MPI seems to have the potential to act as gatekeeper for ICA after coronary CTA.     

Submillisievert CT angiography for carotid arteries using wide array CT scanner and latest iterative reconstruction algorithm in comparison with previous generations technologies: Feasibility and diagnostic accuracy

ObjectivesTo assess evaluability and diagnostic accuracy of a low dose CT angiography (CTA) protocol for carotid arteries using latest Iterative Reconstruction (IR) algorithm in comparison with standard 100 kVp protocol using previous generation CT and IR.Materials and methods105 patients, referred for CTA of the carotid arteries were prospectively enrolled in our study and underwent CTA with 80 kVp and latest IR algorithm (group 1). Data were retrospectively compared with 100 consecutive patients with similar examination indications that had previously undergone CTA of carotid arteries with a standard 100 kVp protocol and a first generation IR algorithm (group 2). Image quality was evaluated with a 4-point Likert-scale. For each exam CT number, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) at level of common carotid artery (CCA), internal carotid artery (ICA) and at level of Circle of Willis and Effective Dose (ED) were evaluated. 62 Group 1 patients underwent a clinically indicated DSA and results were compared with CTA.ResultsNo exams reported as not diagnostic. The overall mean CT number value of all arterial segments was above 450 HU in both groups. Significant lower noise, and higher SNR and CNR values were found in group 1 in comparison with group 2 despite the use of 80 kVp. In 62-group 1 patients studied by DSA, CTA showed in a segment-based analysis a sensitivity, negative predictive value and accuracy of 100%, 100% and 99% respectively. Mean ED in group 1 was 0.54 ± 0.1 mSv with a dose reduction up to 86%.ConclusionsCTA for carotid arteries using latest IR algorithm allows to perform exams with submillisievert radiation exposure maintaining good image quality, overall evaluability and diagnostic accuracy.     

Predictive Value of Preprocedural Computed Tomography Angiography for the Technical Success of Transarterial Embolization of Type II Endoleaks Arising from the Lumbar Arteries

PurposeTo evaluate the ability of preprocedural computed tomography angiography (CTA) to predict the technical success of embolization of type II endoleak arising from a lumbar artery after endovascular aortic repair (EVAR).Materials and MethodsAll patients at a single academic institution who underwent angiography with possible embolization for a post-EVAR lumbar-supplied type II endoleak from 2009 to 2018 were retrospectively reviewed. Patients who did not undergo CTA before the procedure were excluded. CTAs were reviewed for the ability to trace the entire course of a feeding vessel from the internal iliac artery (IIA) to the lumbar artery at the site of the endoleak. Procedural imaging was reviewed for technical success, defined as the catheterization and embolization of the aneurysm sac through a lumbar artery.ResultsFifty-seven angiograms with a type II endoleak and suspected feeding lumbar artery were identified. On CTA acquired before the procedure, the arterial path supplying this lumbar artery could be traced from the IIA to the aneurysm sac in 18 (32%) patients. Embolization was technically successful in 16 of these 18 (89%) procedures compared with 10 of 39 (26%) procedures in which the supplying artery could not be traced using CTA (P < .001).ConclusionsA potential catheter path from the IIA through the iliolumbar and lumbar arteries to the aneurysm sac can be traced on preprocedural CTA in the minority of lumbar-supplied type II endoleaks. The ability to trace these inflow vessels may predict technical success during embolization. The low rate of technical success when the feeding vessel could not be traced using CTA suggests that these patients should be considered for percutaneous or transcaval sac puncture.     

Transcranial Doppler ultrasound in the evaluation of collateral blood flow in patients with internal carotid artery occlusion: correlation with cerebral angiography.

PURPOSETo determine the accuracy of transcranial Doppler (TCD) ultrasound for evaluation of collateral supply through the circle of Willis in patients with internal carotid artery (ICA) occlusion.METHODSThe evaluation of the collateral pathways through the circle of Willis with TCD ultrasound and with cerebral angiography was compared in 40 patients (30 men, 10 women; mean age, 55 +/- 9 years) in a total of 44 ICA occlusions of which 43 had a suitable ipsilateral temporal bone window for TCD examination.RESULTSBy TCD, a patent anterior communicating artery is indicated by a reversal blood flow in the A1-segment of the anterior cerebral artery or by a prompt fall of blood velocity in the middle cerebral artery after compression of the nonoccluded contralateral carotid artery. In 42 of 43 instances of ICA occlusion, TCD and angiography agreed in the evaluation of a present or absent anterior communicating artery collateral supply. TCD''s sensitivity was 95%, its specificity 100%. A collateral supply through the basilar artery was assumed with TCD when there was: (a) a basilar artery blood velocity of more than 70 cm/s; (b) a marked increase of basilar artery blood velocity after compression of the nonoccluded carotid artery; (c) an evident side-to-side asymmetry of the blood velocity of the posterior cerebral arteries with high blood velocity ipsilateral to the ICA occlusion. For evaluating the collateralization via the basilar artery, TCD and angiography agreed in 37 of 40 ICA occlusions. TCD''s sensitivity was 87%, its specificity 95%.CONCLUSIONSTCD is a reliable tool for the evaluation of the collateral supply in patients with ICA occlusions.     

Frequency and significance of a small distal ICA in carotid artery stenosis.

PURPOSEAccurate calculation of the percentage of stenosis is crucial for identifying candidates for endarterectomy. Our goal was to quantify the reduction in diameter of the distal internal carotid artery (ICA) as a function of proximal ICA stenosis and to discuss the implications of distal ICA narrowing on the calculation of percentage of stenosis using the criteria of the North American Symptomatic Carotid Endarterectomy Trial (NASCET).METHODSWe retrospectively reviewed the carotid angiograms of 81 patients referred for evaluation of carotid stenosis. The caliber of the ICA stenosis and the diameters of the normal distal ICA, the common carotid artery, and the internal maxillary artery were remeasured with precision calipers. The percentage of stenosis derived from the NASCET criteria were compared with vessel diameter and with the difference in size of the ipsilateral and contralateral distal ICAs. We then recalculated the percentage of stenosis by substituting the presumed normal contralateral distal ICA diameter for the ipsilateral distal ICA diameter.RESULTSIn carotid arteries without significant stenosis (<70%), the distal ICA diameter measured 5.94+/-1.10 mm, but in vessels with severe stenosis (>70%), the distal ICA diameter measured 4.69+/-1.23 mm. After recalculation, four of 26 vessels were upgraded in classification from moderate (40% to 69%) to severe (>70%) stenosis.CONCLUSIONThe diameter of the distal ICA begins to decrease when the proximal stenosis is 60% or greater. If the ICA distal to a stenosis is smaller than the contralateral ICA, recalculating the percentage of stenosis by substituting measurements of the contralateral distal ICA diameter may be warranted.     

Rationale and design of the ViCTORY (Validation of an Intracycle CT Motion CORrection Algorithm for Diagnostic AccuracY) trial

BackgroundCoronary CT angiography (CTA) has emerged as an effective noninvasive method for direct visualization of the coronary arteries, with high diagnostic performance compared with invasive coronary angiography (ICA). However, coronary CTA is prone to artifacts, including coronary motion, which may reduce its diagnostic performance. Intracycle motion compensation algorithms (MCAs) from a combination of software and hardware techniques now allow for correction of coronary motion, but the diagnostic performance of MCAs compared with traditional coronary CTA reconstruction methods remains unexplored.MethodsViCTORY (Validation of an Intracycle CT Motion CORrection Algorithm for Diagnostic AccuracY) is a prospective international multicenter trial of 218 patients which is designed to evaluate the performance of MCAs for the diagnosis of anatomically obstructive coronary artery disease (CAD) compared with an ICA reference standard, on a per-patient, per-vessel, and per-segment basis. Patients enrolled into ViCTORY will undergo investigational coronary CTA and clinically indicated ICA and will not receive heart rate-lowering medications before coronary CTA. Coronary CTA images will be reconstructed by conventional standard methods as well as by MCAs. Blinded core laboratory interpretation will be performed for coronary CTA and ICA in an intent-to-diagnose fashion.ResultsThe primary end point of ViCTORY is the per-patient diagnostic accuracy of MCAs for the diagnosis of anatomically obstructive CAD compared with ICA. Secondary end points will include other per-patient, per-vessel, and per-segment diagnostic performance characteristics, including accuracy, sensitivity, specificity, positive predictive value, and negative predictive value. Other key secondary end points will include diagnostic interpretability, image quality, the upper heart rate threshold of utility of MCAs, and the additive value of MCAs to traditionally reconstructed coronary CTA.ConclusionViCTORY will determine whether MCAs improve the diagnosis of obstructive CAD in patients undergoing coronary CTA who are not receiving heart rate-lowering medications.     

MR angiography of spinal vascular malformations.

PURPOSETo determine the potential and limitations of MR angiography in the evaluation of spinal vascular malformations.METHODSEleven consecutive patients with spinal vascular malformations proved with spinal selective arteriography underwent two-dimensional phase-contrast MR angiography.RESULTSAbnormal vessels within the spinal canal were identified with MR angiography in 10 patients. In 1 patient with a dural arteriovenous fistula no definite vascular abnormality was seen with MR angiography. Correlation of MR angiography with spinal selective arteriography showed that the former allowed identification of the arterial feeder in 3 patients with intramedullary arteriovenous malformations and 2 with perimedullary arteriovenous fistula, whereas the source of intradural draining vein was seen in only 2 of 6 patients with dural arteriovenous fistula.CONCLUSIONMR angiography is a promising complementary tool to MR imaging for detection and characterization of spinal vascular malformations.     

Redistribution of cerebropetal blood flow in patients with carotid artery stenosis measured non-invasively with fast cine phase contrast MR angiography

The purpose was to evaluate the blood flow redistribution in the neck vessels of patients with internal carotid artery (ICA) stenosis. Eighty-six patients with ICA stenosis underwent contrast-enhanced magnetic resonance angiography (CEMRA) and fast 2D phase contrast (2D-PC) sequence to measure the mean blood flow (MBF) of ICA, basilar artery (BA) and middle cerebral artery (MCA). CEMRA revealed 53 severe stenoses, 45 moderate stenoses and 3 occluded vessels. Patients with a unilateral severe ICA stenosis had a significantly reduced MBF of the ICA compared to the control group; the MBF reduction of the severely stenosed ICA was less conspicuous if associated with a controlateral severe stenosis. The MBF of the BA increased significantly in the presence of the bilateral severe ICA stenosis and in the ICA occlusion. The MBF of the MCA was unchanged in the presence of various degrees of ICA stenosis. Measurement of MBF with fast PC MRA permits cerebropethal blood flow assessment and gives additional information in grading ICA stenosis. The reduced MBF of a severe ICA stenosis has to be considered with caution since it depends also on the status of the controlateral ICA and may be considered a confident parameter only in case of unilateral carotid stenosis.     

Basilar artery fenestration detected with CT angiography

Objectives

To analyse the characteristics of basilar artery (BA) fenestrations and their coexistence with aneurysms and other anomalies in a massive cases by computed tomographic angiography (CTA).

Methods

A total of 5,657 sequential cerebral CTA images performed from January 2006 to February 2012 were reviewed. CTA images were obtained from the raw datasets by using volume rendering and maximal intensity projection reconstruction.

Results

One hundred and thirty-two (2.33 %) BA fenestrations were detected with CTA, and most common at the proximal segment (n?=?124). BA fenestration-associated aneurysms were found in 34 cases and 7 located at the posterior circulation, and the frequency of posterior circulation aneurysms was significantly different in patients with and without BA fenestrations (P?=?0.025). Other associated anomalies included arteriovenous malformation (n?=?7) and moyamoya disease (n?=?6). BA fenestrations were classified into Type I (74 cases), Type II (15 cases), Type III (41 cases) and Type IV (2 cases). A significant difference was observed between Types II + III associated with convex-lens-like and slit-like fenestrations (P?=?0.008).

Conclusions

BA fenestrations were found in 2.33 % with CTA. They were significantly more often associated with posterior circulation aneurysms than those without BA fenestration. The anterior inferior cerebral artery (AICA) tends to originate more often from convex-lens-like fenestration than slit-like.

Key Points

? Basilar artery fenestrations were found in 2.33?% of patients undergoing CT angiography. ? Fenestrations were seen more often in the lower third with slit-like configurations. ? No obvious relationship exists between basilar artery fenestration and aneurysm formation. ? Basilar artery fenestrations perhaps predispose a patient to posterior circulation aneurysm formation. ? The AICA tends to originate more often from convex-lens-like than slit-like fenestrations.     

Hybrid CT angiography and quantitative 15O-water PET for assessment of coronary artery disease: comparison with quantitative coronary angiography

Purpose

CT angiography (CTA) can rule out significant stenoses with a very high reliability, whereas its ability to confirm significant stenoses is suboptimal. In contrast, measurements of myocardial blood flow (MBF) provide information on the haemodynamic consequences of stenoses. Therefore, a combination of the two might improve diagnostic accuracy. We conducted a head-to-head comparison of CTA, measurement of MBF by ¹⁵O-water PET, and hybrid PET/CTA for the detection of significant coronary artery stenoses.

Methods

The study group comprised 44 outpatients scheduled for invasive coronary angiography (ICA) with an intermediate pretest likelihood of coronary artery disease. The patients underwent 64-slice CTA and baseline and hyperaemic PET before ICA with quantitative coronary angiography analysis.

Results

On a per-patient basis, the negative predictive values (NPV; 95 % confidence intervals in parentheses) were 88 % (64 – 97 %) for CTA, 90 % (71 – 97%) for PET and 92 % (74 – 98%) for PET/CTA, and the positive predictive values (PPV) were 71 % (53 – 85%) for CTA, 87 % (68 – 95%) for PET and 100 % (84 – 100%) for PET/CTA. Similarly, on a per-vessel basis the NPVs (which were generally high) were 97 % (94 – 100%) for CTA, 95 % (90 – 99%) for PET and 97 % (95 – 100%) for PET/CTA, and the PPVs (which were lower, but higher with PET/CTA) were 53 % (39 – 66%) for CTA, 53 % (40 – 66%) for PET and 85 % (73 – 97%) for PET/CTA. In six patients, CTA analysis was hampered by the presence of severe calcifications. However, with the addition of the PET data, all six patients were correctly categorized.

Conclusion

Cardiac quantitative hybrid PET/CTA imaging has better diagnostic accuracy than CTA alone and PET alone. CTA has a suboptimal PPV, suggesting that hybrid PET/CTA imaging should be used to assess the significance of coronary stenoses diagnosed by CTA.