Sixty four multi-detectors CT coronary angiography: An easy and accurate method to detect graft patency post CABG

Objective

To assess the accuracy of coronary CTA in detection of coronary artery bypass graft patency, occlusion and stenosis.

Patients and methods

Twenty-four patients with past history of coronary bypass surgery were included in this study and underwent MDCT coronary angiography. Invasive coronary angiography was done within 2 weeks of MDCT coronary angiography. All grafts considered patent were then evaluated for the presence of significant stenosis. Significant stenosis was defined as reduction in diameter of more than 50%.

Results

All the MDCT scans were interpretable and a total number of 78 CABG conduits were analyzed. At MDCT angiography 4 (5.2%) grafts were classified as occluded and 74 (94.8%) grafts were patent. Significant stenosis was detected in 7 (9.4%) out of the 74 patent grafts. At invasive coronary angiography; when occlusion and significant stenosis pooled together they were 9 grafts; 4 arterial and 5 venous. All these 9 grafts were detected at MSCT (sensitivity is 100%). In 67 out of 69 grafts occlusion or significant stenosis was correctly ruled out (specificity 97.1%). The diagnostic accuracy of MDCT angiography when compared with invasive angiography was 97.4%. The negative predictive value was 100% and positive predictive value was 81.8%.

Conclusion

MDCT coronary angiography is an accurate imaging technique for the evaluation of CABG patency and in detection of graft stenosis and confirms of previous studies using 64 MDCT.     

Diagnostic value of MDCT angiography in assessment of coronary artery bypass graft

Purpose

To evaluate the diagnostic value of MDCT angiography in assessment of coronary bypass grafts. We studied 51 patients from April 2008 to October 2011. All patients gave written informed consent, and the study protocol was approved by the Institutional Review Board. 96 grafts including 35 left internal mammary artery (LIMA) grafts, 5 radial artery grafts, and 56 saphenous vein grafts (SVG) were assessed by 64-MDCT and the results were compared with conventional coronary angiography as reference standard.

Results

The diagnostic value of multi-detector computed tomography for graft occlusion was: 100% sensitivity, 100% specificity, 100% positive predictive value, and 100% negative predictive value. The diagnostic power of multi-detector computed tomography for stenosis of the graft anastomosis was: 100% sensitivity, 96% specificity, 87.5% positive predictive value, and 100% negative predictive value, and 96.4% accuracy.

Conclusion

Multi-detector computed tomography has become an alternative to coronary angiography to diagnose graft occlusion and stenosis after coronary artery bypass. In addition, multidetector CT has the added advantage over traditional angiographic evaluation of simultaneously allowing evaluation for alternate postoperative complications that may also manifest with chest pain and dyspnea, thereby mimicking recurrent angina.     

Congenital anomalies of coronary arteries: Diagnosis with 64 slice multidetector CT

Objective

Congenital coronary artery anomalies are generally incidental, uncommon and asymptomatic. Some can cause severe potentially life threatening symptoms. The common mode of studying the coronary arteries is Conventional Coronary Angiogram. ECG-gated-multidetector CT is a non invasive modality. The objective of our study was to identify rare congenital coronary artery anomalies and discuss their clinical significance.

Material and methods

A total number of 900 MDCT coronary angiograms were carried out at our institution between the period of April 2006 and October 2010. Patients with coronary artery anomaly constituted the subject of study.

Results

The incidence of anomalous anatomical origin and course of the coronary arteries in our study was 1.55%. Hemodynamical significance was seen in five patients. 3 cases of single coronary artery originating from right coronary sinus were seen. 1 case of anomalous left coronary artery arising from main pulmonary artery was seen. 4 cases of anomalous RCA arising from left aortic cusp, 6 cases of absent LMCA with separate origin of LAD and LCX were seen.

Conclusion

Multidetector row CT is a noninvasive modality in cardiac imaging. It provides superior resolution of coronary tree and its variant. No projectional vascular overlap is seen. Various postprocessing techniques outclass catheter angiography imaging. Definition of ostia and proximal course of the coronary arteries by Multidetector CT is better than catheter angiography.     

CT coronary angiography: Coronary CT-flow quantification supplements morphological stenosis analysis

Background

Our rationale was to evaluate whether a 64-slice CT scanner allows accurate measurement of computed tomographic (CT) changes in coronary artery flow profiles and whether CT flow measurements are suitable for classifying the significance and hemodynamic relevance of a stenosis and thereby supplement as a functional parameter for morphological stenosis analysis.

Methods

A total of 50 patients prospectively underwent computed tomography coronary angiography (coronary CTA) in a multidetector CT scanner (Brilliance 64, Philips) ± 1 day before or after invasive coronary angiography (ICA). Immediately thereafter, 2 radiologists reviewed the imaging data to detect any vessel segments with morphology poorly evaluable by coronary CTA. A locally constant cyclical measurement was acquired in these coronary arteries in breath-hold technique during the passage of a 50 ml bolus of contrast media. For analysis, time–density curves of the bolus passage were registered in the coronary artery and the aorta (internal reference), the up-slopes were determined and correlated with each other. The results were compared with the ICA findings.

Results

47 of 50 CT flow measurements were evaluable. A good correlation was found between the degrees of stenosis and slope ratios in aorta and coronary artery (R² = 0.92). The threshold corridor was 0.55–0.77 for distinguishing hemodynamically (≥70%) from non-hemodynamically relevant stenoses.

Conclusions

CT-based coronary artery flow measurements (CTFM) correlate well with the angiographically determined degree of stenosis and can elevate by non-invasive means the diagnostic accuracy of coronary CTA. From both a clinically diagnostic and scientific standpoint, CTFM proves a suitable method for quantifying coronary blood flow.     

Multi-detector row CT angiography in the assessment of coronary in-stent restenosis: a systematic review

Purpose

The aim of this study was to perform a systematic review of the diagnostic accuracy of multi-detector row computed tomography angiography (MDCT) for detection of coronary in-stent restenosis in patients treated with coronary stenting when compared to invasive catheter angiography.

Materials and methods

A search of PUBMED and MEDLINE databases for English literature was performed. Only studies with at least 10 patients comparing 16- or more detector rows MDCT angiography with invasive catheter angiography in the detection of coronary in-stent restenosis (more than 50% stenosis) were included for analysis. Sensitivity and specificity estimates pooled across studies were tested using a fixed effects model.

Results

15 studies met selection criteria for inclusion in the analysis. There were eight studies performed with 16-detector row CT scanners, and five studies with 64-detector row scanners and one study with a 40-detector scanner. The remaining study was performed with a mixture of 16-and 64-detector row scanners. Prevalence of in-stent restenosis following coronary stenting was 18% (95% CI: 13, 24%). Pooled estimates of the sensitivity and specificity of overall MDCT angiography for the detection of coronary in-stent restenosis was 85% (95% CI: 78, 90%) and 97% (95% CI: 95, 98%), respectively. No significant difference was found between 16- and 64-detector row scanners regarding the sensitivity and specificity of MDCT for assessment of in-stent restenosis (p > 0.05).

Conclusion

The results showed that MDCT angiography (with 16 or more detector rows) has moderate sensitivity and high specificity for the detection of coronary in-stent restenosis when compared to invasive catheter angiography. A high specificity value of MDCT may be most valuable as a non-invasive technique of excluding coronary stent restenosis or occlusion. The main factors affecting visualization are stent diameters and stent materials.     

Value of conventional chest radiography for the detection of coronary calcifications: comparison with MSCT

Purpose

To evaluate if computed tomography (CT) coronary calcium scoring is needed after detection of coronary calcifications on conventional chest radiographs.

Materials and methods

One hundred and five patients (67 men; 57.2 ± 12.8 years) with suspected coronary artery disease underwent conventional chest radiography and non-enhanced, retrospectively ECG-gated multislice spiral CT (MSCT) of the heart (4 mm × 2.5 mm, 120 kV, 133 mAs_eff.). Chest radiographs were assessed independently by two radiologists. Detection of coronary calcifications was compared between both methods. Sensitivity, specificity, negative and positive predictive values, median, 25% and 75% percentiles for the detection of coronary calcifications were calculated. Receiver operating characteristics (ROC) analyses were computed.

Results

In 90 patients, MSCT revealed coronary calcifications. The mean coronary calcium score was 526.2 (0–4784.5). On chest radiographs, coronary calcifications were correctly detected in 46 (61) patients by observer 1 (observer 2). The corresponding sensitivity was 51.1% in observer 1 and 67.8% in observer 2. Median of detected coronary calcifications was 361.9 (426.4) for observer 1 (observer 2). Corresponding 25% und 75% percentiles were 109.6 (109.6) and 798.5 (898.5). The area under the ROC curve was 0.636 for observer 1 and 0.715 for observer 2. There was no correlation between image quality and the detection of coronary calcifications on plain film radiographs.

Conclusion

As coronary calcifications of various extents are inconsistently detected on plain chest radiographs, CT calcium scoring may not be omitted even if coronary artery calcifications were detected on conventional chest radiographs.     

Assessment of coronary artery disease by post-mortem cardiac MR

Objectives

Minimally invasive or virtual autopsies are being advocated as alternative to traditional autopsy, but have limited abilities to detect coronary artery disease. It was the objective of this study to assess if the occurrence of chemical shift artifacts (CSA) along the coronary arteries on non-contrast, post-mortem cardiac MR may be used to investigate coronary artery disease.

Methods

We retrospectively compared autopsy and CT findings of 30 cases with significant (≥75%), insignificant (<75%), or absent coronary artery stenosis to post-mortem cardiac MR findings. The chi-square test was used to investigate if the occurrence of CSA depends on the presence or absence of stenosis. Sensitivity, specificity and predictive values were calculated for each finding.

Results

CSA indicates the absence of (significant) stenosis (p < 0.001). The occurrence of paired dark bands in lieu of CSA on post-mortem cardiac MR suggests (significant) coronary arteries stenosis (p < 0.001). Both findings have a high specificity but low sensitivity.

Conclusions

CSA is a marker of vessel patency. The presence of paired dark bands indicates stenosis. These criteria improve the ability of minimally invasive or virtual autopsy to detect coronary artery disease related deaths.     

Difference of coronary stenosis severity between systolic and diastolic phases in quantitative CT angiography

Background

To compare the difference of coronary diameter stenosis by quantitative analysis of CT angiography (QCT) in the systolic (QCT-S) and diastolic phase (QCT-D) of the cardiac cycle, with invasive catheter angiography (QCA) as reference standard.

Cardiac CT angiography after coronary artery surgery in children using 64-slice CT scan

Objective

The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of graft and/or coronary angioplasty stenosis in children who had undergone coronary artery surgery.

Population and methods

Fifteen consecutive children (8 male and 7 female; age 9.2 ± 6.1 years) underwent 64-slice CT because of chest pain or ECG changes mean 4.8 ± 3.7 years after surgical coronary artery surgery; 10 patients had coronary angioplasty using a patch from the saphenous vein, four had mammary artery bypass, and one had saphenous vein bypass. Six main segments of the coronary arteries and all the bypass graft considered as a single segment were analyzed and compared with invasive angiography used as the reference standard.

Results

CT correctly identified the four children with coronary angioplasty and mammary graft lesions that were confirmed by conventional angiography: one patient had a significant stenosis (>50% stenosis) at the mammary bypass graft anastomosis site; three other had non-significant stenosis (<50% stenosis) including a mild lesion of the saphenous vein patch in two patients and a mild lesion at the anastomosis site of the mammary bypass in one. All segments identified as normal by CT in the other 11 children were also found to be normal by conventional angiography.

Conclusion

In centers expert in this technique, 64-slice CT scanning is a promising, rapid, and useful diagnostic technique for evaluating both coronary angioplasty and bypass graft lesions in children who had undergone coronary artery surgery.     

Diagnostic performance of calcification-suppressed coronary CT angiography using rapid kilovolt-switching dual-energy CT

Objectives

Multi-detector-row computed tomography angiography (MDCTA) plays an important role in the assessment of patients with suspected coronary artery disease. However, MDCTA tends to overestimate stenosis in calcified coronary artery lesions. The aim of our study was to evaluate the diagnostic performance of calcification-suppressed material density (MD) images produced by using a single-detector single-source dual-energy computed tomography (ssDECT).

Methods

We enrolled 67 patients with suspected or known coronary artery disease who underwent ssDECT with rapid kilovolt-switching (80 and 140 kVp). Coronary artery stenosis was evaluated on the basis of MD images and virtual monochromatic (VM) images. The diagnostic performance of the two methods for detecting coronary artery disease was compared with that of invasive coronary angiography as a reference standard.

Results

We evaluated 239 calcified segments. In all the segments, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for detecting significant stenosis were respectively 88%, 88%, 75%, 95% and 88% for the MD images, 91%, 71%, 56%, 95% and 77% for the VM images. PPV was significantly higher on the MD images than on the VM images (P?<?0.0001).

Conclusions

Calcification-suppressed MD images improved PPV and diagnostic performance for calcified coronary artery lesions.

Key Points

? Computed tomography angiography tends to overestimate stenosis in calcified coronary artery. ? Dual-energy CT enables us to suppress calcification of coronary artery lesions. ? Calcification-suppressed material density imaging reduces false-positive diagnosis of calcified lesion.

     

Diagnostic accuracy of dual-source CT coronary angiography in patients with atrial fibrillation: Meta analysis

Rationale and objective

To synthesize the available data to underscore the diagnostic accuracy of dual-source CT (DSCT) coronary angiography in patients with atrial fibrillation (AF).

Materials and methods

We searched in the electronic databases of PubMed for all published studies that examined patients with AF using DSCT. We used an exact binomial rendition of the bivariate mixed-effects regression model to synthesize the diagnostic data.

Results

The positive and negative likelihood ratios (LRs) at the patient level were 6.0 (CI, 3.6–10.1) and 0.03(CI, 0.004–0.2), respectively. The negative predictive values higher than 90% were available for a CAD prevalence <78%. The pooled vessel- and segment-level estimates showed higher positive and negative LRs than the patient-level estimates (15.3 [CI, 9.8–23.9] and 0.1 [CI, 0.07–0.3]; 25.1 [CI, 10.8–58.5] and 0.2 [CI, 0.2–0.3], respectively). No statistically significant heterogeneity between studies and publication bias were found at the patient level estimate. A sensitivity analysis showed that no study influenced the pooled results larger than 0.02.

Conclusions

Cardiac angiography with DSCT can be applied as an imaging test for ruling out CAD in patient with AF. However, DSCT angiography may be not an effective tool for risk stratification for the high negative LR at the artery and segment levels.     

Role of 128 slice MSCT angiography in evaluation of congenital extra-cardiac intra-thoracic vascular anomalies in children

Purpose

To investigate the value and highlight the role of multi slice computed tomography (MSCT) angiography in evaluation of extra-cardiac intra thoracic vascular anomalies in children.

The Diagnostic Accuracy, Image Quality and Radiation Dose of 64-Slice Dual-Source CT in Daily Practice: a Single Institution's Experience

Objective

We wanted to evaluate the image quality, diagnostic accuracy and radiation exposure of 64-slice dual-source CT (DSCT) coronary angiography according to the heart rate in symptomatic patients during daily clinical practice.

Materials and Methods

We performed a retrospective search for the DSCT coronary angiography reports of 729 consecutive symptomatic patients. For the 131 patients who underwent invasive coronary angiography, the image quality, the diagnostic performance (sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] for detecting significant stenosis ≥ 50% diameter) and the radiation exposure were evaluated. These values were compared between the groups with differing heart rates (HR): mean HR < 65 or ≥ 65 and HR variability (HRV) < 15 or ≥ 15.

Results

Among the 729 patients, the CT reports showed no stenosis or insignificant coronary artery stenosis in 72%, significant stenosis in 26% and non-diagnostic in 2%. For the 131 patients who underwent invasive coronary angiography, 95% of the patients and 97% of the segments were evaluable, and the overall per-patient/per-segment sensitivity, the perpatient/per-segment specificity, the per-patient/per-segment PPV and the per-patient/per-segment NPV were 100%/90%, 71%/98%, 95%/88% and 100%/97%, respectively. The image quality was better in the HR < 65 group than in the HR ≥ 65 group (p = 0.001), but there was no difference in diagnostic performance between the two groups. The mean effective radiation doses were lower in the HR < 65 or HRV < 15 group (p < 0.0001): 5.5 versus 6.7 mSv for the mean HR groups and 5.3 versus 9.3 mSv for the HRV groups.

Conclusion

Dual-source CT coronary angiography is a highly accurate modality in the clinical setting. Better image quality and a significant radiation reduction are being rendered in the lower HR group.     

Coronary artery anomalies: Role of contrast enhanced MDCT coronary angiography

Objective

The purpose of this study is to evaluate the role of MDCT in the depiction of coronary artery anomalies.

Patients and methods

Sixteen patients were included in this study. Retrospectively gated coronary CT angiography was performed in 11 patients and prospectively gated CT coronary angiography was performed in 5 patients. Post-processing techniques as maximum-intensity projection, curved multiplanar reconstruction, and volume rendering were applied to assess the origin and course of the coronary vessels.

Results

Origin and course anomalies of the central coronary artery segments were seen in 11 patients (67%), anomalies of only coronary artery origin in 2 patients (13%), origin and course anomalies of the peripheral coronary segments in 2 patients (13%) and coronary arterio-venous fistula in one patient (7%). The origin and course anomalies of the central coronary artery segment were more common in the left coronary artery involving 8 patients (73%). Malignant inter-arterial course between aortic root and pulmonary artery or the right ventricle outflow tract was seen in 3 anomalous arteries.

Conclusion

MDCT coronary angiography can precisely depict the origin and course coronary artery anomalies and is recommended in young patients and before cardiac intervention or surgery to prevent possible complications.     

CT virtual intravascular endoscopy assessment of coronary artery plaques: A preliminary study

Purpose

The purpose of this study was to investigate the potential value of CT virtual intravascular endoscopy (VIE) in the visualization and assessment of coronary plaques in patients suspected of coronary artery disease.

Materials and methods

20 (13 men, 7 women, mean age 54 years) consecutive patients with suspected coronary artery disease undergoing 64-slice CT angiography were included in the study. Four main coronary artery branches were assessed with regard to the presence of coronary plaques based on 2D axial, multiplanar reformation, 3D volume rendering and VIE visualizations. The coronary plaques were characterized into calcified, noncalcified and mixed plaques. The intraluminal appearances of these coronary plaques were demonstrated with VIE images and correlated with 2D and 3D images to determine the diagnostic value of VIE for the assessment of the plaques.

Results

VIE was able to identify and demonstrate the intraluminal appearances of coronary plaques in 18 patients involving 32 coronary artery branches which were shown as an irregularly intraluminal protruding sign in extensively calcified plaques and smooth protruding appearance in noncalcified or focally calcified plaques. An irregular intraluminal appearance was also noticed in the presence of mixed plaques due to variable components with different CT attenuations contained within the plaques. VIE accurately confirmed the degree of coronary stenosis or occlusion despite the presence of heavy calcification.

Conclusion

VIE could be used as a complementary tool to conventional CT visualizations for the analysis of luminal changes and assessment of disease extent caused by the coronary plaques.     

Magnetic resonance myocardial perfusion imaging-First experience at 3.0T

Objective

MR myocardial perfusion imaging (MRMPI) is an established technique for the evaluation of the hemodynamical relevance of coronary artery disease. Perfusion imaging at 3.0 T provides certain advantages compared to 1.5 T. Aim of this study was to evaluate myocardial MR perfusion imaging at 3.0 T.

Materials and methods

Twelve patients with stable Angina pectoris and known or suspected coronary artery disease were examined at 3.0 T. Myocardial perfusion was assessed using a saturation recovery gradient echo 2D sequence (TR 1.9 ms, TE 1.0 ms, FA 12°) with 0.05 mmol Gd-DTPA per kg body weight at stress during injection of 140 μg adenosine/kg body weight/min and at rest in short axis orientation. Perfusion analysis was based on a least square fit of the signal/time curve (peak signal intensity, slope). Perfusion series were assessed by two independent observers. Reference for the presence of relevant coronary artery stenoses was invasive coronary angiography. Two experienced observers evaluated the coronary angiograms in biplane projections for the presence and grade of stenoses. Results were compared with the MR perfusion analysis.

Results

All MR examinations could be safely performed and yielded high image quality. In eight patients stress-induced hypoperfusion was detected (stenosis >70% in coronary angiography). In four patients myocardial hypoperfusion was ruled out (stenosis <70%). The myocardial perfusion reserve index was significantly reduced in hypoperfused myocardium with 1.9 ± 1.6 compared to 2.5 ± 1.6 in regularly perfused myocardium (p < 0.05). In coronary angiography, eight patients were found to suffer from coronary artery disease, whereas in four patients coronary artery disease was ruled out.

Conclusion

Our initial results show that MRMPI at 3.0 T provides reliably high-image quality and diagnostic accuracy.     

Coronary computed tomography and triple rule out CT in patients with acute chest pain and an intermediate cardiac risk profile. Part 1: Impact on patient management

Objective

To evaluate the impact of coronary CT angiography (coronary CTA) or “triple-rule-out” CT angiography (TRO-CTA) on patient management in the work-up of patients with acute chest pain and an intermediate cardiac risk profile.

Materials and methods

100 patients with acute chest pain and an intermediate cardiac risk for acute coronary syndrome (ACS) underwent coronary CTA or TRO-CTA for the evaluation of chest pain. Patients with a high and low cardiac risk profile were not included in this study. All patients with significant coronary stenosis >50% on coronary CTA underwent invasive coronary catheterization (ICC). Important other pathological findings were recorded. All patients had a 90-day follow-up period for major adverse cardiac events (MACE).

Results

Based on a negative coronary CTA 60 of 100 patients were discharged on the same day. None of the discharged patients showed MACE during the 90-day follow-up. Coronary CTA revealed a coronary stenosis >50% in 19 of 100 patients. ICC confirmed significant coronary stenosis in 17/19 patients. Among the 17 true positive patients, 9 underwent percutaneous coronary intervention with stent implantation, 7 were received intensified medical therapy, and 1 patient underwent coronary artery bypass surgery.A TRO-CTA protocol was performed in 36/100 patients due to elevated d-dimer levels. Pulmonary embolism was present in 5 patients, pleural effusion of unknown etiology in 3 patients, severe right ventricular dysfunction with pericardial effusion in 1 patient, and an incidental bronchial carcinoma was diagnosed in 1 patient.

Conclusion

Coronary CTA and TRO-CTA allow a rapid and safe discharge in the majority of patients presenting with acute chest pain and an intermediate risk for ACS while at the same time identifies those with significant coronary artery stenosis.     

Effect of saline flush on enhancement of proximal and distal segments using 320-row coronary CT angiography

Objective

To investigate the effect of saline flush on coronary CT angiography of proximal, middle, and distal coronary artery segments, using 320-row CT, and to compare two injection duration protocols as to amount of contrast in the right heart chambers.

Methods

This retrospective study was approved by the local ethics committee, and the requirement for informed consent to participate in this study was waived. The final study group included 108 patients who underwent coronary CT angiography. The first 36 patients received contrast medium without saline flush (group 1); the next 36 patients received contrast medium for 14 s and saline flush (group 2); the last 36 patients received contrast medium for 12 s and saline flush (group 3). The CT number, noise, contrast-to-noise ratio (CNR), and number of segments with a CT number greater than 325 Hounsfield units (HU) were recorded for proximal, middle, and distal segments.

Results

The CT numbers and the CNR in groups 2 and 3 were significantly higher than that in group 1 (p < 0.005); the difference between groups 2 and 3 was not significant. The proportion of segments greater than 325 HU improved with saline flush (p < 0.05), with a larger improvement in the distal segments.

Conclusions

Saline flush improves enhancement and CNR of coronary arteries, particularly of distal segments, in coronary CT angiography using 320-row CT. An average contrast medium injection of 44 mL was feasible using a saline flush.     

Multi-slice computed tomography imaging of the post transplant complications in the recipients after living donor liver transplantation

Aim

To evaluate the clinical utility of MSCT in the detection and proper management of the different post-transplant complications in the recipients after LDLT.

Patients and methods

33 patients (28 males & 5 females) who underwent LDLT were referred to the Radiology department (CT unit) for evaluation of vascular, biliary, and parenchymal complications after LDLT using MSCT.

Results

Vascular complications were found in 16 cases (48.5%) [hepatic artery thrombosis (8 cases), hepatic artery stenosis (1 case), portal vein thrombosis (3 cases), portal vein stenosis (2 cases), hepatic veins stenosis (2 cases)]. Biliary complications were found in 9 cases (27.3%) [biloma (6 cases) 18.2%, biliary stricture (3 cases) 9.1%]. Hepatic abscess was found in 2 cases (6%), acute rejection was found in 2 cases (6%), recurrent HCC was found in 3 cases (9.1%). Neoplastic lympho-proliferative disorder was found in 1 case (3%).

Conclusion

MSCT is a non-invasive and accurate examination to detect complications after LDLT, it provides synchronous evaluation of the hepatic vasculature, biliary tract, liver parenchyma and the other abdominal organs in a single examination. MSCTA is the best option for confirming the US suspicion of vascular complications, with DSA reserved if therapeutic intervention is contemplated.     

Non-enhanced MR angiography of renal artery using inflow-sensitive inversion recovery pulse sequence: A prospective comparison with enhanced CT angiography

Purpose

To prospectively evaluate the diagnostic value of non-enhanced inflow-sensitive inversion recovery (IFIR) MR angiography for the detection of renal artery stenosis (RAS), with enhanced CT angiography performed as the reference standard.

Materials and methods

Sixty consecutive patients suspected of RAS underwent both of IFIR MR and enhanced CT angiography. Subjective image quality, renal artery depiction and renal artery grading were all evaluated on artery-by-artery basis. Spearman rank correlation analysis was used to assess agreement between the two techniques. The diagnostic sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for RAS detection at IFIR MR angiography were calculated.

Results

One hundred twenty-six main renal arteries were visualized on enhanced CT and non-enhanced MR angiographic images, respectively. The Spearman rank correlation was 0.773 (P < .001) for renal artery depiction, 0.998 (P < .001) for renal arteries grading and 0.833 (P < .001) for RAS detection between the two modalities. The sensitivity, specificity, PPV and NPV of IFIR MR angiography for RAS detection demonstrated 100%, 99.0%, 92.0% and 100%, respectively.

Conclusion

Non-enhanced IFIR MR angiography had high sensitivity, specificity, PPV and NPV for RAS detection. It could be the first choice of renal artery imaging methods to avoid ionizing irradiation and renal toxicity from contrast media.