Diagnosis and targeted percutaneous management of a critical subclavian artery stenosis in a patient with absent peripheral pulses with the use of cardiac computed tomography

Current clinical practice dictates that invasive management strategies frequently are adopted in patients with both ST-segment elevation and non-ST-segment elevation acute coronary syndromes. Such strategies rely on obtaining vascular access and, as such, are not always technically feasible. We report a case in which cardiac computed tomography was used to great effect in the diagnostic and (targeted) interventional management of a patient who was the recipient of a previous coronary artery bypass grafting and presented with global myocardial ischemia, in whom the lack of peripheral pulses had previously rendered an early invasive strategy hazardous.     

Myocardial bridging on coronary CTA: an innocent bystander or a culprit in myocardial infarction?

Myocardial bridging describes the clinical entity whereby a segment of coronary artery is either partially or completely covered by surrounding myocardium. It represents the most frequent congenital coronary anomaly and has an estimated prevalence of ≤13% on angiographic series. With the emergence of cardiac computed tomography and its ability to simultaneously image the coronary arteries and also the myocardium, there has been an apparent increase in the detection rates of myocardial bridges (prevalence as high as 44%). It has now become important to evaluate their clinical significance. Myocardial bridging is generally considered a benign entity with survival rates of 97% at 5 years; however, there is now emerging evidence that certain myocardial bridge characteristics may be associated with cardiovascular morbidity. The length and depth of myocardial bridges have been associated with increased atherosclerosis, whereas the degree of systolic compression has been associated with ischemia on myocardial perfusion single-photon emission tomography. On the basis of current evidence, it appears that limiting further testing for ischemia to symptomatic patients with long and/or deep myocardial brides would be appropriate.     

Double right coronary artery diagnosed by computed tomographic angiography: A case report and systematic review of the literature

Double right coronary artery (RCA) is an extremely uncommon anomaly that is mostly detected incidentally in patients undergoing coronary angiography. It can be a benign and isolated anomaly or associated with other congenital abnormalities, mostly other coronary anomalies. Although atherosclerosis and myocardial ischemia have been frequently reported in patients with double RCA, this likely reflects that the patients were evaluated for chest pain rather than the predisposition to atherosclerosis in double RCA. Paralleling the increased awareness of this entity and the availability of non-invasive and cost-effective imaging of the coronary arteries, the diagnosis of double RCA has increased recently. Here, we present a case of double RCA diagnosed by coronary computed tomographic angiography, and provide a mini-review on the demography, anatomic variants, and clinical significance of double RCA.     

Triage of patients with suspected coronary artery disease using multislice computed tomography

RATIONALE AND OBJECTIVES: Several studies have shown that multislice computed tomography (MSCT) has a high sensitivity and specificity for detecting coronary artery stenoses. The aim of the present study was to investigate whether MSCT can reliably triage patients with suspected coronary artery disease (CAD) to coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or no revascularization. MATERIALS AND METHODS: A total of 123 patients with suspected CAD who were referred for conventional coronary angiography (CATH) additionally underwent MSCT (16*0.5 mm detector collimation). Therapeutic decisions made on the basis of CATH and MSCT strictly following current guidelines for treatment of CAD were compared with decisions made by a cardiac surgeon and an interventional cardiologist. Only MSCTs with at least adequate image quality in all coronary segments were included in the analysis (94/123). RESULTS: Decisions made on the basis of MSCT and CATH according to guidelines did not differ significantly (agreement of 88%, 82 of 94, P = .319). The therapeutic decisions made by the interventional cardiologist and the cardiac surgeon based on CATH differed significantly (overall agreement of 79%, 74 of 94 cases, P < .001; cardiologist: 78% PCI and 22% CABG versus surgeon: 38% PCI and 62% CABG), whereas there was 100% agreement regarding decisions for or against invasive treatment. CONCLUSIONS: MSCT shows good agreement with CATH in triaging patients with suspected CAD to CABG, PCI, or no revascularization. The choice of revascularization procedure is significantly more strongly influenced by whether an interventional cardiologist or a cardiac surgeon makes the decision than by the diagnostic test on which the decision is based.     

An unusual case of coronary artery fistula to the pulmonary artery,diagnosed with 64-MDCT coronary angiography

This report describes a case of complex coronary–pulmonary artery fistula with one feeding vessel from the proximal part of the right coronary. The complex anatomy of the fistula was shown in detail by multidetector computed tomography using multiplanar reconstruction and 3D volume rendering techniques.Traditionally, conventional angiography has been used for the diagnosis of coronary anomalies. With more frequent use of 64-row multi-detector computed tomography (CT) in chest and cardiac imaging, the number of incidentally found coronary artery fistulas has been increasing.     

Clinical validation of SPECT attenuation correction using x-ray computed tomography—derived attenuation maps: Multicenter clinical trial with angiographic correlation

BACKGROUND: Nonuniform attenuation artifacts cause suboptimal specificity of stress single photon emission computed tomography (SPECT) myocardial perfusion images. In phantoms, normal subjects, and patients suspected of having coronary artery disease (CAD), we evaluated a new hybrid attenuation correction (AC) system that combines x-ray computed tomography (CT) with conventional stress SPECT imaging. METHODS AND RESULTS: The effect of CT-based AC was evaluated in phantoms by assessing homogeneity of normal cardiac inserts. AC improved homogeneity of normal cardiac phantoms from 11% +/- 2% to 5% +/- 1% (P < .001). Attenuation-corrected normal patient files were created from 37 normal subjects with a low likelihood (<3%) of CAD. The diagnostic performance of AC for detection of CAD was evaluated in 118 patients who had stress technetium 99m sestamibi or tetrofosmin stress SPECT imaging and coronary angiography. SPECT images with and without AC were interpreted by 4 blinded readers with different interpretative attitudes. Overall, AC improved the diagnostic performance of all readers, particularly the normalcy rate. The degree of improvement depended on interpretative attitude. Readers prone to high sensitivity or with less experience had the greatest gain in the normalcy rate, whereas a reader prone to higher specificity had improvements in sensitivity and specificity but not the normalcy rate. Importantly, improvement of one diagnostic variable was not associated with worsening of other variables. CONCLUSION: CT-based AC of SPECT images consistently improved overall diagnostic performance of readers with different interpretive attitudes and experience. CT-based AC is well suited for routine use in clinical practice.     

Comparison of coronary artery calcium screening image quality between C-150 and e-Speed electron beam scanners

RATIONALE AND OBJECTIVE: The newest generation of electron beam tomographic scanner (e-Speed) has increased spatial and temporal resolution compared with the C-150 XP scanner. The aim of this study was to evaluate coronary artery calcium screening image quality between the e-Speed and C-150 scanners (GE Imatron, San Francisco, CA). MATERIALS AND METHODS: Studies from 41 patients (14 women and 27 men) who underwent serial coronary artery calcium screening with the C-150 (first study) and the e-Speed (second study) were analyzed. Individual computed tomography (CT) slices were assessed for coronary artery motion artifacts, and CT Hounsfield units (HU) and noise values (CT HU standard deviation) at 16 discrete cardiac sites were measured and averaged. RESULTS: With the e-Speed scanner, there were significant decreases in right coronary artery motion artifacts compared with the C-150 scanner (0.3% versus 1.8%, P < .001) as well as decreased noise values (24.3 versus 32.0 HU, P < .001). CONCLUSION: Image quality is significantly improved with use of the e-Speed scanner, due to its improved temporal and spatial resolution, compared with the C-150 scanner.     

Incremental prognostic value of combined perfusion and function assessment during myocardial gated SPECT in patients aged 75 years or older

BACKGROUND: Perfusion and functional data obtained during gated single photon emission computed tomography (SPECT) have proven prognostic value in the middle-aged patient population. The aim of this study was to investigate whether perfusion and functional cardiac gated SPECT data have prognostic value in patients aged 75 years or older. METHODS AND RESULTS: We studied clinical and gated SPECT predictors of cardiac and all-cause death in 294 patients aged 75 years or older with known or suspected coronary artery disease who were referred for tetrofosmin cardiac gated SPECT imaging. Summed perfusion scores were calculated in a 17-segment model by use of commercially available software (4D-MSPECT). Left ventricular functional data were calculated by use of QGS gated SPECT software. The median age of the study population was 78 years (range, 75-91 years). There were 160 men (54%) and 134 women (46%). During a median follow-up of 25.9 months (range, 1.8-36 months), 47 patients (16%) died (27 cardiac deaths). In a multivariate Cox proportional hazards regression analysis, the summed rest score (chi2 gain = 8.0, P = .009), transient ischemic dilatation index (chi2 gain = 6.3, P = .012), and resting left ventricular ejection fraction (chi2 gain = 7.0, P = .030) were independent predictors of all-cause death. The summed rest score (chi2 gain = 8.2, P = .004) and resting end-systolic volume (chi2 gain = 13.7, P = .005) were independent predictors of cardiac death. CONCLUSIONS: This study showed that gated SPECT left ventricular functional data assessed during myocardial gated SPECT provide independent and incremental information above clinical and perfusion SPECT data for the prediction of cardiac and all-cause death in patients aged 75 years or older referred for myocardial SPECT imaging.     

A 16-slice multidetector computed tomography protocol for evaluation of the gastroepiploic artery grafts in patients after coronary artery bypass surgery

Arterial coronary bypass grafts [internal mammary arteries and gastroepiploic artery (GEA)] are in widespread use for coronary surgery. Since selective catheterisation of the GEA graft to monitor patency, is often unsuccessful, a non-invasive protocol to visualise the GEA-graft from origin to anastomosis is presented using 16-slice multidetector computed tomography (MDCT). Twenty-six male patients (mean age 58.1±6.7 years) with GEA grafts were scanned according to a protocol of an ECG-synchronised cardiac scan followed by a thoracoabdominal scan. To terminate the scan at the correct anatomical level, the lowest level of the GEA was coded based on the lumbar vertebrae level. Scores ranging from one (excellent) to four (bad) were assigned to evaluate visualisation quality of the grafts. GEA grafts were assessable in 62% of the thoracoabdominal scans and 69% of the cardiac scans. On average, the lowest part of the GEA corresponded with a level between L1 and L2, in two cases in the upper part of L3. Mean visualisation score in the thoracoabdominal scans and cardiac scans was good (respectively 1.4±0.6 and 1.4±1.0). Sixteen-slice MDCT is a promising alternative for catheterisation in evaluating patency of GEA grafts, using the presented protocol with thoracoabdominal scan including L3 for complete coverage of the GEA graft.     

Maximal thickness of the normal human pericardium assessed by electron-beam computed tomography

The purpose of this study was to determine the maximal value of normal pericardial thickness with an electron-beam computed tomography unit allowing fast scan times of 100 ms to reduce cardiac motion artifacts. Electron-beam computed tomography was performed in 260 patients with hypercholesterolemia and/or hypertension, as these pathologies have no effect on pericardial thickness. The pixel size was 0.5 mm. Measurements could be performed in front of the right ventricle, the right atrioventricular groove, the right atrium, the left ventricle, and the interventricular groove. Maximal thickness of normal pericardium was defined at the 95th percentile. Inter-observer and intra-observer reproducibility studies were assessed from additional CT scans by the Bland and Altman method [24]. The maximal thickness of the normal pericardium was 2 mm for 95 % of cases. For the reproducibility studies, there was no significant relationship between the inter-observer and intra-observer measurements, but all pericardial thickness measurements were ≤ 1.6 mm. Using electron-beam computed tomography, which assists in decreasing substantially cardiac motion artifacts, the threshold of detection of thickened pericardium is statistically established as being 2 mm for 95 % of the patients with hypercholesterolemia and/or hypertension. However, the spatial resolution available prevents a reproducible measure of the real thickness of thin pericardium. Received: 8 January 1998; Revision received: 24 September 1998; Accepted: 25 November 1998     

Stent size selection using 64-detector coronary computed tomography angiography: a comparison to invasive coronary angiography

RATIONALE AND OBJECTIVES: Compare stent size selection using coronary computed tomography angiography (CCTA) to invasive coronary angiography (ICA). CCTA is increasingly performed before cardiac catheterization; however, the utility of incorporating these data into coronary interventions is unknown. METHODS: Retrospective study of 18 consecutive patients with 24 coronary artery lesions evaluated with 64-detector CCTA followed by ICA and resulting stent placement. Two blinded interventional cardiologists independently reviewed designated arterial segments on both CCTA and ICA during different reading sessions and determined anticipated stent length and nominal diameter, maximum stenosis, the need for postdilation of either stent margin, and final proximal and distal stent diameters. RESULTS: There was strong correlation between CCTA and ICA in the anticipated stent length (r = 0.85, P < .001) and final stent diameter (proximal end r = 0.74, P < .001; distal end r = 0.63, P = .001). Anticipated stent length was longer with CCTA compared to ICA (27.0 +/- 16.0 vs. 21.8 +/- 13.3 mm; P = .006). The final stent diameters were larger with CCTA compared to ICA, both at the proximal end (3.6 +/- 0.5 vs. 3.1 +/- 0.5 mm; P < .001) and distal end (3.2 +/- 0.6 vs. 2.9 +/- 0.4 mm; P = .004). CONCLUSIONS: Using 64-detector CCTA, interventional cardiologists select longer stents with larger final stent diameters than with ICA. Further studies are needed to determine the clinical utility of incorporating CCTA, when available, in defining interventional strategy.     

Incidental Cardiac Findings on Thoracic Imaging

The cardiac structures are well seen on nongated thoracic computed tomography studies in the investigation and follow-up of cardiopulmonary disease. A wide variety of findings can be incidentally picked up on careful evaluation of the pericardium, cardiac chambers, valves, and great vessels. Some of these findings may represent benign variants, whereas others may have more profound clinical importance. Furthermore, the expansion of interventional and surgical practice has led to the development and placement of new cardiac stents, implantable pacemaker devices, and prosthetic valves with which the practicing radiologist should be familiar. We present a collection of common incidental cardiac findings that can be readily identified on thoracic computed tomography studies and briefly discuss their clinical relevance.     

MDCT Anatomic Assessment of Right Inferior Phrenic Artery Origin Related to Potential Supply to Hepatocellular Carcinoma and its Embolization

Purpose To prospectively assess the anatomic variation of the right inferior phrenic artery (RIPA) origin with multidetector computed tomography (MDCT) scans in relation to the technical and angiographic findings during transcatheter arterial embolization of hepatocellular carcinoma (HCC). Methods Two hundred patients with hepatocellular carcinomas were examined with 16-section CT during the arterial phase. The anatomy of the inferior phrenic arteries was recorded, with particular reference to their origin. All patients with subcapsular HCC located at segments VII and VIII underwent arteriography of the RIPA with subsequent embolization if neoplastic supply was detected. Results The RIPA origin was detected in all cases (sensitivity 100%), while the left inferior phrenic artery origin was detected in 187 cases (sensitivity 93.5%). RIPAs originated from the aorta (49%), celiac trunk (41%), right renal artery (5.5%), left gastric artery (4%), and proper hepatic artery (0.5%), with 13 types of combinations with the left IPA. Twenty-nine patients showed subcapsular HCCs in segments VII and VIII and all but one underwent RIPA selective angiography, followed by embolization in 7 cases. Conclusion MDCT assesses well the anatomy of RIPAs, which is fundamental for planning subsequent cannulation and embolization of extrahepatic RIPA supply to HCC.     

Diagnostic value of TL-201 lung uptake is dependent on measurement method

BACKGROUND: Increased lung uptake during exercise thallium 201 single photon emission computed tomography is related to left ventricular dysfunction and extent of coronary artery disease (CAD). We studied the influence of the lung region of interest (ROI), used to quantify Tl-201 lung uptake, on the diagnostic value of the lung-to-heart uptake ratio (LHR) in detecting CAD with Tl-201 myocardial single photon emission computed tomography. METHODS AND RESULTS: We retrospectively studied 152 consecutive patients referred to our center for stress Tl-201 scanning. Of these, 116 had proven multivessel CAD and 36 had either normal findings on coronary angiogram or a low likelihood (<5%) of CAD. Poststress quantitative analysis was performed from a 4 x 4-pixel ROI over the hottest myocardial region, an 8 x 8-pixel left lung ROI, an 8 x 8-pixel right lung ROI, and a manual ROI encompassing the whole right lung. The LHR was calculated for each lung ROI. Right LHR (R-LHR) provided the best interobserver and intraobserver reproducibility. R-LHR and total R-LHR values were significantly higher in patients with CAD. Only history of myocardial infarction significantly influenced the R-LHR measurement. CONCLUSIONS: The methodology of LHR measurement significantly influences the clinical contribution of Tl-201 lung uptake evaluation. Optimal reproducibility and diagnostic accuracy are provided by a right lung ROI.     

Assessing the value of coronary artery computed tomography as the first-line anatomical test for stable patients with indications for invasive angiography due to suspected coronary artery disease. Initial cost analysis in the CAT-CAD randomized trial

BackgroundClinical and safety outcomes of the strategy employing coronary computed tomography angiography (CCTA) as the first-choice imaging test have recently been demonstrated in the recently published CAT-CAD randomized, prospective, single-center study. Based on prospectively collected data in this patient population, we aimed to perform an initial cost analysis of this approach.Methods120 participants of the CAT-CAD trial (age:60.6 ± 7.9 years, 35% female) were included in the analysis. We analyzed medical resource use during the diagnostic and therapeutic episode of care. We prospectively estimated the cumulative cost for each strategy by multiplying the number of resources by standardized costs in accordance to medical databases and the 2015 Procedural Reimbursement Payment Guide.ResultsThe total cost of coronary artery disease (CAD) diagnosis was significantly lower in the CCTA group as compared to the direct invasive coronary angiography (ICA) group ($50,176 vs $137,032) with corresponding per-patient cost of $836 vs $2,284, respectively. Similarly, the entire diagnostic and therapeutic episode of care was significantly less expensive in the CCTA group ($227,622 vs $502,827) with corresponding per-patient cost of $4630 vs $8,380, respectively. Overall, the application of CCTA as a first-line diagnostic test in stable patients with indications to ICA resulted in a 63% reduction of CAD diagnosis costs and a 55% reduction composite of diagnosis and treatment costs during 90-days follow-up.ConclusionsApplication of CCTA as the first-line anatomic test in patients with suspected significant CAD decreased the total costs of diagnosis. This is likely attributable to reduced numbers of invasive tests and hospitalisations. Initial cost analysis of the CAT-CAD randomized trial suggests that this approach may provide significant cost savings for the entire health system.     

Erectile dysfunction as a coronary artery disease risk equivalent

Background. The conditions that predispose patients to erectile dysfunction are substantially similar to the coronary artery disease risk factors, including diabetes mellitus, hypertension, hyperlipidemia, obesity, sedentary lifestyle, depression, age, and smoking. Because of these shared risks and overlapping pathophysiologic mechanisms, we designed this pilot study to address the hypothesis that the presence of coronary artery calcium, a known indicator of increased cardiac risk, is associated with erectile dysfunction. Methods and Results. A prospective registry enrolled 9150 men who underwent multidetector computed tomography. Subjects supplied baseline data regarding demographic variables, coronary risk factors, and erectile dysfunction symptoms or lack thereof. The 2 groups then underwent computed tomography to screen for the presence or absence of coronary artery calcium. Subjects with erectile dysfunction were older, had higher triglyceride levels, had higher blood pressures, and were more likely to have measurable coronary artery calcification than men without erectile dysfunction (79% vs 58%,P<.001). Conclusion. Erectile dysfunction is significantly associated with abnormal coronary artery calcification and, like peripheral arterial disease, might warrant consideration as a coronary artery disease risk equivalent.     

The Journal of Cardiovascular Computed Tomography year in review - 2018

Since the introduction of ≥64 detector row coronary computed tomography angiography (CCTA) as a noninvasive imaging modality, various clinical trials have established its diagnostic performance and prognostic significance when compared to other anatomic and functional tests for coronary artery disease (CAD). CCTA has been increasingly utilized for a wide range of clinical scenarios, driven by both advances in technology as well as data showing improvement in outcomes. Accumulating evidence has continually refined and supported the central role of CCTA within clinical care, and this year has witnessed continued evolution of the application of CCTA within healthcare and translational research. The purpose of the present review is to summarize the year of the Journal of Cardiovascular Computed Tomography (JCCT), highlighting the evidence base supporting the appropriate application of cardiac computed tomography across numerous clinical domains.     

Clinical benefit of power-injectable port systems: a prospective observational study

Objective

To prospectively evaluate the clinical benefit of a central venous port system, which is approved for contrast media injection during contrast enhanced computed tomography.

Materials and methods

At a university teaching hospital, 98 patients (59 female, 39 male; median age 61.7 years; range 23–83) had a power-injectable central venous port catheter system implanted. All implantations were performed under ultrasonographic and fluoroscopic guidance by interventional radiologists. Procedure related immediate (up to 24 h after implantation), early (<30 days after implantation) and late complications were documented. The frequency of port system use for contrast enhanced computed tomography scans was also considered. Any port capsule migration was assessed indirectly by determining the catheter tip position. The intended follow-up period was 180 days.

Results

An overall complication rate of 0.69 for 1,000 catheter days in 78 evaluated ports was recorded (12 ports affected, 15.4%). During the observational period, 40 of 104 contrast enhanced computed tomography scans were performed utilizing the port for contrast media administration (38.5%). 30 catheter tip retractions of more than 3 cm were observed in 82 patients (36.6%). Overall, tip dislocations were statistically more frequent in the female subgroup.

Conclusion

The complication rate found in this study is comparable to those, which have been published for standard port systems. The utilization of the device for contrast media injection during contrast enhanced computed tomography scans should be increased. Finally, the port capsule has to be carefully positioned and fixed to prevent migration.     

Coronary calcium screening in asymptomatic patients as a guide to risk factor modification and stress myocardial perfusion imaging

BACKGROUND: Previous studies have demonstrated a correlation between the extent of coronary artery calcification (CAC) and atherosclerotic plaque. As a result, CAC screening could be useful in predicting cardiovascular risk in individuals in whom atherosclerosis is developing. One possible method of detecting and quantifying CAC is by x-ray computed tomography, which potentially allows one to stratify patients into groups requiring risk factor modification or follow-up testing such as myocardial perfusion single photon emission computed tomography (SPECT). METHODS AND RESULTS: This study was designed to evaluate the clinical utility of multidetector computed tomography (MDCT) in a cardiology practice setting. A retrospective analysis was performed on data from 794 asymptomatic patients who underwent CAC screening over an 8-month period. On the basis of the CAC score and physician consultation, 102 patients underwent subsequent myocardial perfusion SPECT imaging. A substudy was also conducted in 306 patients to measure the interscan variability of MDCT across different CAC score ranges. CAC was detected in 422 of 794 patients. Of these, the CAC was moderate (Agatston score = 101-400) in 14% and severe (>400) in 9%. Patients with 3 or more cardiac risk factors were most likely to exhibit moderate to severe CAC. In myocardial perfusion SPECT testing, no patient with an Agatston score lower than 100 had an abnormal study. In contrast, 41% of patients with severe CAC had an abnormal SPECT study. In the reproducibility substudy the minimal CAC group had the largest variability (86.0%) whereas the severe CAC group had the lowest variability (9.5%). CONCLUSION: CAC screening with MDCT is justified for asymptomatic patients with 3 or more cardiac risk factors. However, risk factor assessment is poor at predicting which individuals will have CAC if fewer risk factors are present. In terms of the interscan variability, MDCT is capable of following changes in CAC for patients with Agatston scores greater than 100. Finally, this study demonstrated that an Agatston score of 400 is a logical threshold to initiate follow-up myocardial perfusion SPECT testing.