Specificity Of CT Angiography Research Articles

A comparison of computed tomography angiography and digital subtraction angiography for the diagnosis of penetrating cerebrovascular injury: a prospective multicenter study.

In this research, the authors sought to characterize the incidence and extent of cerebrovascular lesions after penetrating brain injury in a civilian population and to compare the diagnostic value of head computed tomography angiography (CTA) and digital subtraction angiography (DSA) in their diagnosis. This was a prospective multicenter cohort study of patients with penetrating brain injury due to any mechanism presenting at two academic medical centers over a 3-year period (May 2020 to May 2023). All patients underwent both CTA and DSA. The sensitivity and specificity of CTA was calculated, with DSA considered the gold standard. The number of DSA studies needed to identify a lesion requiring treatment that had not been identified on CTA was also calculated. A total of 73 patients were included in the study, 33 of whom had at least 1 penetrating cerebrovascular injury, for an incidence of 45.2%. The injuries included 13 pseudoaneurysms, 11 major arterial occlusions, 9 dural venous sinus occlusions, 8 dural arteriovenous fistulas, and 6 carotid cavernous fistulas. The sensitivity of CTA was 36.4%, and the specificity was 85.0%. Overall, 5.6 DSA studies were needed to identify a lesion requiring treatment that had not been identified with CTA. Cerebrovascular injury is common after penetrating brain injury, and CTA alone is insufficient to diagnosis these injuries. Patients with penetrating brain injuries should routinely undergo DSA.

Diagnostic accuracy of large and medium vessel occlusions in acute stroke imaging by neurology residents and stroke fellows: A comparison of CT angiography alone and CT angiography with CT perfusion.

Neurology senior residents and stroke fellows are first to clinically assess and interpret imaging studies of patients presenting to the emergency department with acute stroke. The aim of this study was to compare the diagnostic accuracy of brain CT angiography (CTA) with and without CT perfusion (CTP) between neurology senior residents and stroke fellows. In this neuroimaging study, nine practitioners (four senior neurology residents (SNRs) and five stroke fellows (SFs)) clinically assessed and interpreted the imaging data of 50 cases (15 normal images, 21 large vessel occlusions (LVOs) and 14 medium vessel occlusions (MeVOs) in two sessions, 1 week apart in comparison to final diagnosis of experienced neuroradiologist and experienced stroke neurologist consensus. Interrater agreement of CTA alone and CTA with CTP was quantified using kappa statistics, sensitivity, specificity and overall accuracy. Overall, arterial occlusions were correctly identified in 221/315 (70.1%) with CTA alone and in 266/315 (84.4%) with CTA and CTP (p < 0.001). The sensitivity of overall arterial occlusions detection with CTA alone was 94.2% (95% CI: 90.8%-96.6%) while with addition of CTP was 98% (95% CI: 95.6%-99.3%), The specificity of CTA alone was 74.7% (95% CI: 67.2%-81.3%) which increased with CTP to 84.4% (95% CI: 77.7%-89.8%). The likelihood of correct identification with CTA alone was 156/189 (82.54%) for LVOs and 65/126 (51.59%) for MeVOs. This increased to 169/189 (89.42%; p = 0.054) for LVOs and 97/126 (76.98%; p < 0.001) for MeVOs when the CTA images with CTP were viewed. There was good overall interrater agreement between readers when using CTA alone (k 0.71, 95% CI, 0.62-0.80) and almost perfect (k 0.85, 95% CI, 0.76-0.94) when CTP was added to the image for interpretation. CTA and CTP had a significantly lower median interquartile range (IQR) interpretation time than CTA alone (114 [IQR, 103-120] s vs 156 [IQR, 133-160] s, p < 0.001). In cerebral arterial occlusions, the rate of LVO and MeVOs detections increases when adding CTP to CTA. The accuracy and time for diagnosing arterial occlusion can be significantly improved if CTP is added to CTA. As MeVOs are commonly missed by front-line neurology senior residents or stroke fellows, cases with significant deficits and no apparent arterial occlusions need to be reviewed with neuroradiological expertise.

Computed tomographic angiography may be used for assessing the dilatation of the anterior choroidal and posterior communicating arteries in patients with moyamoya syndrome.

To evaluate the feasibility of CT angiography (CTA) for assessing anterior choroidal artery (AChA) and posterior communicating artery (PComA) dilatation in patients with moyamoya syndrome (MMS). Eighty-eight MMS patients who underwent digital subtraction angiography (DSA) and CTA within 1 month were enrolled. The AChA was graded using both DSA and CTA. Given the features of dual blood supply, DSA was firstly used for grading of the PComA. Then, the calibers of PComA, P1 or P2 segment of the posterior cerebral artery (PCA), were recorded from CTA. Taking DSA as a reference standard, the optimal cutoff values of the PComA/P1 or PComA/P2 were calculated to determine the dilatation of PComA. Both the AChA and PComA were classified as extreme dilatation (ED, grade 2) or non-extreme dilatation (NED, grade 0 or 1). The AChA was evaluated in 149 affected hemispheres of 88 patients while the PComA was evaluated in 70 affected hemispheres of 49 patients. The sensitivity and specificity of CTA in diagnosing AChA-ED were 92% and 93.5% respectively. Both the PComA/P1 (p < 0.001) and PComA/P2 (p = 0.4) ratios were increased in the PComA-ED group with the former yielding a better detecting performance than the latter (AUC = 0.92 vs 0.85, p = 0.046). When using 0.71 as a cutoff value, the sensitivity and specificity of the PComA/P1 ratio for diagnosis of PComA-ED cases were 91.3% and 83.3% respectively. CTA could be used for the AChA classification in MMS patients, while a PComA/P1 ratio greater than 0.71 indicates the existence of PComA-ED. • CTA showed a high sensitivity, specificity, and accuracy in diagnosing AChA-ED in patients with MMS. • PComA/P1 ratio greater than 0.71 on CTA signified an extremely dilated PComA. • CTA could be used to assess the dilatation of AChA and PComA in MMS patients, especially for routine postoperative follow-up.

Overestimation of carotid stenosis on CTA – Real world experience

BackgroundSymptomatic carotid stenosis is responsible for 10% of all strokes. Currently, CT angiography (CTA) is the main diagnostic tool for carotid stenosis. It is frequently the only diagnostic test preceding recommendations for carotid angioplasty and stenting (CAS) or carotid endarterectomy (CEA). However, the specificity of CTA, especially in patients with 50–70% stenosis, was previously reported to be relatively low. Most studies testing the diagnostic accuracy of CTA were published more than a decade ago. Therefore, we aimed to test the diagnostic accuracy of CTA, performed with current available technology, compared with digital subtraction angiography (DSA) in patients with carotid stenosis. This study aims to characterize patients who were candidates for CAS/CEA based on CTA, but may not require it based on DSA. MethodsConsecutive candidates for carotid interventions (CAS or CEA) following CTA were identified from prospectively maintained stroke center registries at two large academic centers. As part of our institutional practice all patients had a routine pre-procedural diagnostic DSA. In each patient, degree of carotid stenosis was compared between CTA and DSA. Patients with concordant degree of stenosis on DSA and CTA (true positive group) were compared to patients with a discordant degree of stenosis with less than 50% on DSA (false positive group). ResultsOut of 90 patients with significant stenosis on CTA, only 70 (78%) were found to have a significant stenosis on DSA. Severe plaque calcification was significantly more common in the false-positive group. In those patients whose CTA reported stenosis of ≥90%, we found a strong agreement between CTA and DSA (positive predictive value [PPV] – 0.9) for a significant stenosis (≥50%). Conversely, the correlation between CTA and DSA in patients with CTA reported 50–70% stenosis was poor (PPV – 0.29) (p < 0.001). ConclusionsOur results suggest that despite ongoing radiological progress, the specificity of CTA in accurately assessing carotid stenosis remains relatively low in patients with both moderate stenosis and heavily calcified plaques. Consequently, patients could possibly be referred for unnecessary CEA surgery and may become exposed to associated potential complications.

A simple, refined approach to diagnosing renovascular hypertension in children: A 10-year study.

Despite advances in non-invasive vascular imaging, detection of renal artery stenosis via catheter angiography is the criterion standard for the diagnosis of renovascular hypertension (RVH). However, because of lack of evidence, the utility of various blood tests and imaging modalities remains unclear. We retrospectively analyzed the utility of blood tests (plasma renin activity [PRA], aldosterone, and renal vein renin[RVR] values) and imaging studies (computed tomography angiography [CTA], kidney ultrasonography[US]) by comparing them with catheter angiography. Ten pediatric patients with RVH at two institutions from January 2008 to December 2017 were recruited. The sensitivities for diagnosing RVH via imaging and blood tests (kidney [US], PRA, and aldosterone) were derived by examining patient records. Furthermore, the sensitivity and specificity of CT angiography were calculated by considering both the affected and non-affected renal arteries of the patients. A high sensitivity for diagnosing RVH via kidney US(89%) and PRA (80%) was observed. The sensitivity and specificity of CTA were 100%, each. RVR sampling did not aid in the diagnosis of RVH; only two of six patients with unilateral RVH showed significant laterality of RVR boundary ratios. Renal scintigraphy facilitated detection of a non-functional kidney (split renal function <5%). RVH in children could be diagnosed utilizing non-invasive blood and imaging tests, without catheter angiography. We recommend kidney length measurement along with measurement of PRA level, as a simple and highly useful screening test, followed by CTA as a diagnostic test.

Imaging features and pathological comparison of carotid web

Objective To analyze the ultrasound examination and computed tomography angiography (CTA) features of carotid web(CAW), and compare with the pathology after carotid endarterectomy, and then compare diagnostic efficacies of the two methods. Methods From June 2018 to July 2019, 159 patients underwent carotid endarterectomy(CEA) in Beijing Tian Tan Hospital were collected, ultrasound examination and CTA were performed preoperatively. The presence or absence of CAW and whether there were thrombosis or atherosclerotic plaques associated with it were identified. The location length, thickness, direction in the lumen, echo characteristics of CAW, and complicated with or without thrombosis or atherosclerotic plaques were recorded. The postoperative specimens were observed, and the pathological analysis was performed. Results Among the 159 cases of CEA, 22 cases were confirmed to have CAW structure by pathology, and HE staining showed extensive intimal fibrohyperplasia and mucoid degeneration, among which 18 cases had plaque formation at the bottom of the carotid web, and 4 cases associated with thrombosis. There were 17 cases of CAW structure diagnosed by ultrasound, 5 cases were misdiagnosed or missed, the sensitivity and specificity of ultrasound in the diagnosis of CAW were 77% (17/22) and 98% (135/137), and the accuracy was 75%. Eleven cases of CAW were diagnosed by preoperative CTA, and 11 cases were misdiagnosed and missed diagnosis, the sensitivity and specificity of CTA in the diagnosis of CAW were 50%(11/22) and 97%(134/137), and the accuracy was 47%. Conclusions The sensitivity of ultrasound in the diagnosis of CAW is higher than that of CTA, which can better display the structure of CAW and whether it is associated with plaque or thrombosis. Key words: Ultrasonography; Carotid artery web; Atherosclerosis plaque; Thrombosis; Computed tomographic angiography

Incremental diagnostic quality gain of CTA over V/Q scan in the assessment of pulmonary embolism by means of a Wells score Bayesian model: results from the ACDC collaboration.

Our objective was to evaluate the diagnostic value of computed tomography angiography (CTA) and ventilation perfusion (V/Q) scan in the assessment of pulmonary embolism (PE) by means of a Bayesian statistical model. Wells criteria defined pretest probability. Sensitivity and specificity of CTA and V/Q scan for PE were derived from pooled meta-analysis data. Likelihood ratios calculated for CTA and V/Q were inserted in the nomogram. Absolute (ADG) and relative diagnostic gains (RDG) were analyzed comparing post- and pretest probability. Comparative gain difference was calculated for CTA ADG over V/Q scan integrating ANOVA p value set at 0.05. The sensitivity for CT was 86.0% (95% CI: 80.2%, 92.1%) and specificity of 93.7% (95% CI: 91.1%, 96.3%). The V/Q scan yielded a sensitivity of 96% (95% CI: 95%, 97%) and a specificity of 97% (95% CI: 96%, 98%). Bayes nomogram results for CTA were low risk and yielded a posttest probability of 71.1%, an ADG of 56.1%, and an RDG of 374%, moderate-risk posttest probability was 85.1%, an ADG of 56.1%, and an RDG of 193.4%, and high-risk posttest probability was 95.2%, an ADG of 36.2%, and an RDG of 61.35%. The comparative gain difference for low-risk population was 46.1%; in moderate-risk 41.6%; and in high-risk a 22.1% superiority. ANOVA analysis for LR+ and LR- showed no significant difference (p=0.8745, p=0.9841 respectively). This Bayesian model demonstrated a superiority of CTA when compared to V/Q scan for the diagnosis of pulmonary embolism. Low-risk patients are recognized to have a superior overall comparative gain favoring CTA.

The role of computed tomography angiography in the detection of aerodigestive tract injury following penetrating neck injury

BackgroundThe purpose of this study was to audit our experience with computed tomography angiography (CTA) for the detection of aerodigestive tract injury (ADTI) following penetrating neck injury (PNI) and to assess the significance of deep surgical emphysema on CTA. MethodsA prospectively maintained trauma registry at the Pietermaritzburg Metropolitan Trauma Service, Pietermaritzburg, South Africa was retrospectively interrogated. The data of all patients with PNI investigated with CTA over a 4-y period were reviewed. All findings of deep surgical emphysema were correlated to an aggregate standard of reference for ADTI as demonstrated by results from clinical examination, surgical neck exploration, endoscopy or contrasted swallow to determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of this finding. ResultsA total of 383 patients underwent a CTA for PNI. A total of 94 vascular injuries were identified on 78 positive CTA studies. The sensitivity and specificity of CTA in detecting a vascular injury were 94.4% and 96.7%. Of the 383 patients investigated a total of 38 patients were diagnosed with digestive tract injury (DTI), and all of these patients were found to have deep surgical emphysema on CTA, except for one patient with a clinically insignificant oral cavity injury. Another 126 patients also had deep surgical emphysema on CTA but no DTI. The sensitivity, specificity, PPV, and NPV of deep surgical emphysema for the diagnosis of confirmed DTI in PNI were therefore 97.4%, 63.5%, 22.7%, and 99.5%, respectively. The sensitivity and NPV were, however, 100% when clinically insignificant injuries were excluded. Including patients with confirmed airway injuries and excluding all patients with pneumothoraces yielded a sensitivity, specificity, PPV, and NPV of 94.1%, 71.9%, 30.0%, and 98.9%, respectively, for the identification of ADTI. When excluding surgically irrelevant injuries, the sensitivity and NPV were again both 100%. ConclusionsCTA for PNI has a high sensitivity and specificity for demonstrating vascular injury. The absence of deep surgical emphysema in the deep cervical fascial planes virtually excludes surgically significant ADTI. The presence of deep surgical emphysema is nonspecific but warrants further investigation.

Effect of heart rate on the diagnostic accuracy of 256-slice computed tomography angiography in the detection of coronary artery stenosis: ROC curve analysis.

The aim of the present study was to investigate the effect of heart rate (HR) on the diagnostic accuracy of 256-slice computed tomography angiography (CTA) in the detection of coronary artery stenosis. Coronary imaging was performed using a Philips 256-slice spiral CT, and receiver operating characteristic (ROC) curve analysis was conducted to evaluate the diagnostic value of 256-slice CTA in coronary artery stenosis. The HR of the research subjects in the study was within a certain range (39-107 bpm). One hundred patients suspected of coronary heart disease underwent 256-slice CTA examination. The cases were divided into three groups: Low HR (HR <75 bpm), moderate HR (75≤ HR <90 bpm) and high HR (HR ≥90 bpm). For the three groups, two observers independently assessed the image quality for all coronary segments on a four-point ordinal scale. An image quality of grades 1-3 was considered diagnostic, while grade 4 was non-diagnostic. A total of 97.76% of the images were diagnostic in the low-HR group, 96.86% in the moderate-HR group and 95.80% in the high-HR group. According to the ROC curve analysis, the specificity of CTA in diagnosing coronary artery stenosis was 98.40, 96.00 and 97.60% in the low-, moderate- and high-HR groups, respectively. In conclusion, 256-slice coronary CTA can be used to clearly show the main segments of the coronary artery and to effectively diagnose coronary artery stenosis. Within the range of HRs investigated, HR was found to have no significant effect on the diagnostic accuracy of 256-slice coronary CTA for coronary artery stenosis.

A retrospective study of computed tomography angiography versus digital subtraction angiography in penetrating neck trauma at Groote Schuur Hospital, South Africa

Background: Penetrating neck trauma is commonly encountered in South African trauma units, and is associated with high mortality and morbidity rates. The imaging protocol for stable patients with penetrating neck trauma remains controversial. There is only sparse data validating the use of computed tomography angiography (CTA) in the evaluation of penetrating neck trauma in South Africa.Objectives: To assess the sensitivity and specificity of CTA versus digital subtraction angiography (DSA) in detecting arterial injury and secondarily evaluate the ability of CT to assess non-arterial injury.Method: Using hospital and radiology databases, 23 patients were identified who had undergone both CTA and DSA for penetrating neck trauma. The data was retrospectively anonymised and randomised. A radiologist experienced in the interpretation of both trauma CTA and DSA re-reported all the imaging and the findings were compared and analysed.Results: Twenty-four arterial injuries were detected. The sensitivity of CTA for detecting arterial injury was 78% and the specificity 83%. The ability of CTA to delineate wound track and detect non-arterial visceral injury was also confirmed.Conclusion: CTA is an attractive initial diagnostic investigation that, along with clinical evaluation, effectively guides further investigation and intervention. It is important for the radiologist to understand the limitations of CTA and have a low threshold for DSA in equivocal cases.

Computed tomography angiography or magnetic resonance angiography for detection of intracranial vascular malformations in patients with intracerebral haemorrhage.

Intracranial vascular malformations (brain or pial/dural arteriovenous malformations/fistulae, and aneurysms) are the leading cause of intracerebral haemorrhage (ICH) in young adults. Early identification of the intracranial vascular malformation may improve outcome if treatment can prevent ICH recurrence. Catheter intra-arterial digital subtraction angiography (IADSA) is considered the reference standard for the detection an intracranial vascular malformation as the cause of ICH. Computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are less invasive than IADSA and may be as accurate for identifying some causes of ICH. To evaluate the diagnostic test accuracy of CTA and MRA versus IADSA for the detection of intracranial vascular malformations as a cause of ICH. We searched MEDLINE (1948 to August 2013), EMBASE (1980 to August 2013), MEDION (August 2013), the Database of Abstracts of Reviews of Effects (DARE; August 2013), the Health Technology Assessment Database (HTA; August 2013), ClinicalTrials.gov (August 2013), and WHO ICTRP (International Clinical Trials Register Portfolio; August 2013). We also performed a cited reference search for forward tracking of relevant articles on Google Scholar (http://scholar.google.com/), screened bibliographies, and contacted authors to identify additional studies. We selected studies reporting data that could be used to construct contingency tables that compared CTA or MRA, or both, with IADSA in the same patients for the detection of intracranial vascular malformations following ICH. Two authors (CBJ and RA-SS) independently extracted data on study characteristics and measures of test accuracy. Two authors (CBJ and PMW) independently extracted data on test characteristics. We obtained data restricted to the subgroup undergoing IADSA in studies using multiple reference standards. We combined data using the bivariate model. We generated forest plots of the sensitivity and specificity of CTA and MRA and created a summary receiver operating characteristic plot. Eleven studies (n = 927 participants) met our inclusion criteria. Eight studies compared CTA with IADSA (n = 526) and three studies compared MRA with IADSA (n = 401). Methodological quality varied considerably among studies, with partial verification bias in 7/11 (64%) and retrospective designs in 5/10 (50%). In studies of CTA, the pooled estimate of sensitivity was 0.95 (95% confidence interval (CI) 0.90 to 0.97) and specificity was 0.99 (95% CI 0.95 to 1.00). The results remained robust in a sensitivity analysis in which only studies evaluating adult patients (≥ 16 years of age) were included. In studies of MRA, the pooled estimate of sensitivity was 0.98 (95% CI 0.80 to 1.00) and specificity was 0.99 (95% CI 0.97 to 1.00). An indirect comparison of CTA and MRA using a bivariate model incorporating test type as one of the parameters failed to reveal a statistically significant difference in sensitivity or specificity between the two imaging modalities (P value = 0.6). CTA and MRA appear to have good sensitivity and specificity following ICH for the detection of intracranial vascular malformations, although several of the included studies had methodological shortcomings (retrospective designs and partial verification bias in particular) that may have increased apparent test accuracy.

Infundibular dilation and aneurysm at the origin of the posterior communicating artery: differential diagnosis by CT angiography.

Infundibular dilation (ID) and aneurysm at the internal carotid artery (ICA)-posterior communicating artery (PComA) junction can be difficult to distinguish but may differ in clinical significance. The aim of this study was to evaluate the utility of CT angiography (CTA) in differentially diagnosing IDs and small unruptured aneurysms at the ICA-PComA junction. This retrospective study comprised 88 patients diagnosed with 107 protrusions (70 IDs and 37 aneurysms <5 mm; 19 bilateral lesions) at the ICA-PComA junction who underwent both CTA and digital subtraction angiography (DSA). Two neuroradiologists independently reviewed CTA and DSA images according to these criteria: (a) size (maximum dimension <3 or ≥3 mm), (b) shape (triangular or round/oval/irregular), (c) aneurysmal neck (absent or present), (d) horizontal direction (posteriomedial or posteriolateral), and (e) PComA origin (apex, no PComA, or base). The intermodality (between CTA and DSA) and interobserver (between the two readers) agreement were determined for each finding. We also evaluated the sensitivity and specificity of CTA for distinguishing ID and aneurysm, using DSA as the reference standard. The mean κ values of intermodality agreement for the size, shape, aneurysmal neck, horizontal direction, and PComA origin were 0.88, 0.87, 0.84, 0.71, and 0.56, respectively. All interobserver agreements of CTA and DSA were excellent. The sensitivity, specificity, and accuracy of CTA for differentiating aneurysms from IDs were 94.6, 100, and 98.0 %, respectively. CTA may be a useful noninvasive modality for differential diagnosis of ID and aneurysm at the ICA-PComA junction.

Value of dual-source computed tomography angiography of coronary artery for preoperative evaluation of old patients scheduled for noncardiac surgery

To assess the role of computed tomography angiography (CTA) using dual-source computed tomography in the preoperative evaluation of old patients scheduled for noncardiac surgery. A retrospective review of the clinical data of patients who underwent CTA in our hospital between May 2011 and May 2013 was performed, and totally 111 old patients with risk factors of coronary artery diseases scheduled for noncardiac surgery were found to coronary CTA for preoperative evaluation. Prospectively electrocardiograph-triggered sequence scan protocol with dual-source computed tomography was performed. The imaging quality, coronary artery stenosis, the treatment before operation, and perioperative complications were assessed. For 1 779 coronary artery segments in 111 patients, the number of evaluable segments was 1 676 (97.4%). The mean effective dose of CTA was (2.7 ± 0.9) mSv. Among them, 71 patients with coronary artery stenosis <50% underwent surgery without cardiac complication and 17 patients with coronary artery stenosis ≥ 70% underwent conventional coronary angiography and coronary angioplasty or bypass surgery. The sensitivity and specificity of CTA in detecting ≥ 50% stenosis were 95% and 96%, and the sensitivity and specificity of CTA in detecting ≥ 70% stenosis were 97% and 98%. For 19 patients with coronary artery stenosis between 50% and 70%, the levels of myocardial enzyme were transiently higher for two patients, and no other cardiac complication occurred. Coronary artery CTA is reliable in artery stenosis evaluation and can be used as cardiac risk stratification for old patients scheduled for noncardiac surgery.

Computed tomography angiography in the diagnosis of brain death: a systematic review and meta-analysis.

Physiological instability and confounding factors may interfere with the clinical diagnosis of brain death. Computed tomography angiography (CTA) has been suggested as a potential ancillary test for confirmation of brain death, but its diagnostic accuracy remains unclear. We searched MEDLINE, EMBASE, and CENTRAL for studies comparing CTA with other accepted methods of diagnosing brain death (clinical or radiographic). Summary estimates of diagnostic accuracy were computed using random effects models. Subgroup analyses and meta-regression were performed to assess associations between CTA sensitivity and study or patient characteristics. Twelve studies, involving 541 patients, were included. If the CTA criterion for brain death was complete lack of opacification of intracranial vessels, then the pooled sensitivity was 62% (50-74%) for venous phase and 84% (75-94%) for arterial phase imaging. The sensitivity of CTA was higher when the criterion for brain death involved absence of opacification of internal cerebral veins, either alone (99%, 97-100%) or in combination with lack of flow to the distal middle cerebral artery branches (85%, 77-93%). CTA sensitivity was not influenced by different reference standards (clinical vs. radiographic) or predominant diagnostic category (stroke vs. brain trauma). Specificity of CTA could not be adequately determined from the existing data. Many patients who progress to brain death by accepted clinical or radiographic criteria have persistent opacification of proximal intracranial vessels when CTA is performed. The specificity of CTA in the diagnosis of brain death has not been adequately assessed. Routine use of CTA as an ancillary test in the diagnosis of brain death is therefore not recommended until diagnostic criteria have undergone further refinement and prospective validation. Absence of opacification of the internal cerebral veins appears to be the most promising angiographic criterion.

Computed Tomography Angiography Compared to Catheter Based Angiography in Evaluation of Cerebral Arterial Aneurysm and Arteriovenous Malformation

Both cerebral arterial aneurysm and arteriovenous malformation are cerebrovascular disease, which required immediate diagnosis and urgent treatment. Since the introduction of multislice CT scanners, CT angiography (CTA) has become a powerful tool for imaging the vascular system. The goal of this study is to compare catheter based angiography and CTA in the evaluation of cerebral arterial aneurysm and arteriovenous malformation AVM. A retrospective analysis of 50 patients for exploring the record of patient who underwent both multislice CT angiography (MSCTA) and catheter based angiography before treatment is presented during last one year in the department of Radiology, King Fahd Hospital-Jeddah, Kingdom of Saudi Arabia. The sensitivity of CTA for picking up aneurysm is 86% and the sensitivity of catheter based angiography for picking up aneurysm is 97%. The specificity of CTA for picking up aneurysm is (76%), the false positive cases are (3%) and the false negative cases are 10%. The sensitivity of both CTA and catheter based angiography for picking up arteriovenous malformation is (90%). The specificity of CTA for picking up AVM is (76%), the false positive cases are (10%) and no false negative cases in CTA are found. The sensitivity and specificity of catheter based angiography is 100% in diagnosis and detection of cerebral arterial aneurysm and AVM. The present study concluded that CTA has high sensitivity and specificity in detecting aneurysm and AVM enough to be chosen as the first step. Catheter based angiography, still a gold standard for radiology examination, is the most accurate, sensitive and specific method in diagnosis and detection of cerebral arterial aneurysm and arteriovenous malformation, which can be done as the second step. In addition, catheter based angiography is done for treatment planning, treatment with interventional procedure and for prognosis after treatment.

Diagnostic Performance of Computed Tomography Angiography in Peripheral Arterial Injury due to Trauma: A Systematic Review and Meta-analysis

To evaluate the diagnostic accuracy of computed tomography angiography (CTA) in detecting arterial lesions in patients with suspected arterial injury of the upper or lower extremity due to trauma. A systematic review and meta-analysis was carried out. Medline and Embase were searched on August 13, 2012, for studies comparing CTA with surgery, digital subtraction angiography (DSA), or follow-up, which allowed extraction of data into two-by-two tables. The methodological quality of included studies was assessed using the QUADAS tool. Summary estimates of sensitivity and specificity of CTA in identifying or excluding arterial lesions were obtained using a bivariate model. This review included 11 studies making up a total of 891 trauma patients. The included studies were of moderate methodological quality and at risk of misclassification and verification bias. Some 4.2% of all CTA studies were non-diagnostic. The summary estimates of sensitivity and specificity of CTA were 96.2% (95% CI 93.5-97.8%) and 99.2% (95% CI 96.8-99.8%), respectively. Despite methodological flaws, the excellent estimates of sensitivity and specificity indicate that CTA is an accurate modality for evaluating arterial lesions in patients with extremity trauma and can replace DSA.

Computed tomographic angiography as a useful adjunct in the diagnosis of brain death

Because of its widespread accessibly, computed tomographic angiography (CT-A) is a promising technique in the detection of intracranial circulatory arrest in brain death (BD). Several studies assessed this tool, but neither have standardized evaluation parameters been developed nor has information about specificity become available. We conducted a prospective study between January 2008 and April 2012. Thirty patients were admitted to our University Hospital (16 men and 14 women; age, 18-88 years) and underwent CT-A scanning at two occasions: immediately after the first signs of loss of brain stem reflexes and after definitive determination of brain. The results of CT-A were compared with transcranial Doppler ultrasonography and electroencephalogram. In 3 of 30 patients, we observed a termination of contrast flow at the level of the skull base and foramen magnum in arterial scanning series before the clinical determination of BD. After the clinical determination of BD, the opacification of all vascular territories in arterial phase scanning was found in one case, but venous phase scanning revealed no blood return in internal cerebral veins. In all other cases, contrast filling ceased at level of skull base or below. The specificity of CT-A in the detection of intracranial circulatory arrest was 90%, and sensitivity was 97%. CT-A is reliable and appropriate technical investigation to detect intracranial circulatory arrest in BD. The evaluation of contrast enhancement in arterial phase scanning seems to be more reliable than that in venous phase. An international consensus about a uniformly applied CT-A protocol for the evaluation of BD should be established.

Computed tomographic angiography as a useful adjunct in the diagnosis of brain death

BACKGROUND: Because of its widespread accessibly, computed tomographic angiography (CT-A) is a promising technique in the detection of intracranial circulatory arrest in brain death (BD). Several studies assessed this tool, but neither have standardized evaluation parameters been developed nor has information about specificity become available. METHODS: We conducted a prospective study between January 2008 and April 2012. Thirty patients were admitted to our University Hospital (16 men and 14 women; age, 18–88 years) and underwent CT-A scanning at two occasions: immediately after the first signs of loss of brain stem reflexes and after definitive determination of brain. The results of CT-A were compared with transcranial Doppler ultrasonography and electroencephalogram. RESULTS: In 3 of 30 patients, we observed a termination of contrast flow at the level of the skull base and foramen magnum in arterial scanning series before the clinical determination of BD. After the clinical determination of BD, the opacification of all vascular territories in arterial phase scanning was found in one case, but venous phase scanning revealed no blood return in internal cerebral veins. In all other cases, contrast filling ceased at level of skull base or below. The specificity of CT-A in the detection of intracranial circulatory arrest was 90%, and sensitivity was 97%. CONCLUSION: CT-A is reliable and appropriate technical investigation to detect intracranial circulatory arrest in BD. The evaluation of contrast enhancement in arterial phase scanning seems to be more reliable than that in venous phase. An international consensus about a uniformly applied CT-A protocol for the evaluation of BD should be established. LEVEL OF EVIDENCE: Diagnostic study, level V.

Assessment of the distal runoff in patients with long standing diabetes mellitus and lower limb ischemia: MDCTA versus DSA

ObjectiveThe purpose of our study was to evaluate the diagnostic accuracy of multidetector computed tomography angiography (MDCTA) in comparison with digital subtraction angiography (DSA) in patients with long standing diabetes mellitus and chronic lower limb ischemia. Subjects and methodsOne hundred patients with long standing DM and chronic limb ischemia underwent both CT angiography and DSA. The distal runoff of each lower limb was divided into 13 arterial segments. The status of each segment was graded as: 1, (normal or less than 10% stenosis); 2, (10–49% stenosis); 3, (50–99% stenosis); 4, occlusion. The effect of calcification on the diagnostic accuracy of CT angiography was evaluated. CTA findings were compared with DSA findings for each arterial segment. The sensitivity and specificity of CT angiography were determined using DSA as the gold standard. ResultsA total of 100 patients were included (mean age, 58years; 70% men). The sensitivity and specificity of CT angiography were significantly affected by the degree of vessel wall calcification, and increase the need for additional imaging. ConclusionVessel wall calcifications decrease the diagnostic accuracy of CT angiography in patients with long standing DM and peripheral arterial disease.

Accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding: systematic review and meta-analysis

To assess the diagnostic accuracy of computed tomography (CT) angiography in the evaluation of patients with an episode of acute gastrointestinal haemorrhage. Systematic review and meta-analysis to estimate pooled accuracy indices. A bivariate random effects model was adjusted to obtain a summary receiver-operating characteristic (sROC) curve and the corresponding area under the curve (AUC). Twenty-two studies were included and provided data on 672 patients (range of age 5-74) with a mean age of 65 years. The overall sensitivity of CT angiography for detecting active acute GI haemorrhage was 85.2 % (95 % CI 75.5 % to 91.5 %). The overall specificity of CT angiography was 92.1 % (95 % CI 76.7 % to 97.7 %). The likelihood ratios for positive and negative test results were 10.8 (95 % CI 3.4 to 34.4) and 0.16 (95 % CI 0.1 to 0.27) respectively, with an AUC of 0.935 (95 % CI 0.693 to 0.989). The sources of heterogeneity explored had no significant impact on diagnostic performance. CT shows high diagnostic accuracy and is an excellent diagnostic tool for detection and localising of intestinal bleeding sites. It is highly available, provides fast detection and localisation of the bleeding site, and is minimally invasive. • CT angiography is increasingly used for investigating severe gastrointestinal bleeding. • This systematic review and meta-analysis updates previous ones. • In patients with massive gastrointestinal bleeding, CT angiography/MDCT detects bleeding accurately. • CT angiography is useful in locating the bleeding site and determining appropriate treatment.