Combined CT Angiography Research Articles

P-007 Initial experience with a combined multi-detector row CT and a biplane angiography suite with a single interactive table for the evaluation and treatment of vascular disease involving the head and neck

Introduction and purposeThe purpose of this study is to present our initial experience with the usefulness of a combined multi-detector row CT and biplane angiographic system with a single interactive...

Incremental Value of Adenosine-induced Stress Myocardial Perfusion Imaging with Dual-Source CT at Cardiac CT Angiography

First, to assess the feasibility of a protocol involving stress-induced perfusion evaluated at computed tomography (CT) combined with cardiac CT angiography in a single examination and second, to assess the incremental value of perfusion imaging over cardiac CT angiography in a dual-source technique for the detection of obstructive coronary artery disease (CAD) in a high-risk population. Institutional review board approval and informed patient consent were obtained before patient enrollment in the study. The study was HIPAA compliant. Thirty-five patients at high risk for CAD were prospectively enrolled for evaluation of the feasibility of CT perfusion imaging. All patients underwent retrospectively electrocardiographically gated (helical) adenosine stress CT perfusion imaging followed by prospectively electrocardiographically gated (axial) rest myocardial CT perfusion imaging. Analysis was performed in three steps: (a)Coronary arterial stenoses were scored for severity and reader confidence at cardiac CT angiography, (b)myocardial perfusion defects were identified and scored for severity and reversibility at CT perfusion imaging, and (c)coronary stenosis severity was reclassified according to perfusion findings at combined cardiac CT angiography and CT perfusion imaging. The sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of cardiac CT angiography before and after CT perfusion analysis were calculated. With use of a reference standard of greater than 50% stenosis at invasive angiography, all parameters of diagnostic accuracy increased after CT perfusion analysis: Sensitivity increased from 83% to 91%; specificity, from 71% to 91%; PPV, from 66% to 86%; and NPV, from 87% to 93%. The area under the receiver operating characteristic curve increased significantly, from 0.77 to 0.90 (P < .005). A combination protocol involving adenosine perfusion CT imaging and cardiac CT angiography in a dual-source technique is feasible, and CT perfusion adds incremental value to cardiac CT angiography in the detection of significant CAD.

Usefulness of Y-shaped sheaths in CT angiography for examination of liver tumors

To conduct a single-stage, combined computed tomography (CT) arterial portography (CTAP) and CT arteriography (CTA) imaging operation, we used Y-shaped sheaths with 2 valves, which allowed the insertion of 2 catheters simultaneously. Of 1254 patients who underwent abdominal angiography for transarterial embolization and/or intraarterial chemotherapy in our department from May 2002 to November 2009, 664 patients in whom Y-shaped sheaths with 2 valves were used underwent CT angiography using a combination of CTA and CTAP. The Seldinger method was used to insert a 10 cm Y-shaped short sheath with 2 valves into the femoral artery. Under radiographic guidance, a 3.2 French (Fr) catheter was placed in the celiac artery or proper hepatic artery, and a second 3.2 Fr catheter was then placed distal to the inferior pancreaticoduodenal artery of the superior mesenteric artery. CTAP was then performed followed by CTA 10 min later. Photographs were taken during the early and late phases of the procedure. Insertion of 3.2 Fr catheters was not possible in 6 of 664 (0.9%) patients with strong curvature of the femoral artery and 4 of 664 (0.6%) patients with strong curvature of the abdominal aorta. In addition, performing CTAP and CTA as a single-stage combined intervention was not possible in 14 of 664 (2.1%) patients whose right hepatic artery originated from the superior mesenteric artery and in 8 of 664 (1.2%) patients whose left hepatic artery branched from the left gastric artery. There were no sheath-related complications such as those related to arterial dissection or hemostasis. Although transfers to and from the CT room were necessary for anatomically variant patients, CT angiography using the Y-shaped sheath for combined CTAP and CTA was considered useful.

Dynamische CT-Angiographie und CT-Perfusion mit einem 320-Zeilen-CT. Protokoll und aktuelle klinische Anwendungen

The aim of this study is to report the authors' initial clinical experience of a 320-detector row computed tomography (CT) scanner in cerebrovascular disorders. Volumetric CT using the full 160-mm width of the 320 detector rows enables full brain coverage in a single rotation that allows for combined time-resolved whole-brain perfusion and four-dimensional CT angiography (CTA). The protocol for the combined dynamic CTA and CT perfusion (CTP) is presented, and its potential applications in stroke, stenoocclusive disease, arteriovenous malformations and dural shunts are reviewed based on clinical examples. The combined CTA/CTP data can provide visualization of dynamic flow and perfusion as well as motion of an entire volume at very short time intervals which is of importance in a variety of pathologies with altered cerebral hemodynamics. The broad coverage enabled by 320 detector rows offers z-axis coverage allowing for whole-brain perfusion and subtracted dynamic angiography of the entire intracranial circulation.

Prospective ECG-gated 320 row detector computed tomography: implications for CT angiography and perfusion imaging

Cardiac multidetector computed tomography has evolved from early four detector systems that first demonstrated the feasibility of non-invasive angiography to today’s wide-area detector computed tomography systems, such as 320-row detector computed tomography. As detector arrays have widened, there have been great improvements in image quality that have improved test accuracy. In addition, wider detector arrays have allowed for the application of prospective ECG-gating for CT angiography, although the current 64-row detector systems have some limitations. 320-row detector computed tomography with full cardiac coverage allows for cardiac imaging in a single heart beat. This technology has realized some of the great advantages provided by full cardiac coverage in regards to image quality (elimination of step artifacts and variation in contrast enhancement), patient safety (reductions in overall radiation and contrast dose), and the prospects for combined CT angiography and myocardial perfusion imaging are very promising. We will review the technical aspects of 320-row detector computed tomography and their implications for coronary angiography and perfusion imaging.

15.25: Lowering radiation dose of combined PET-CT and CT angiography in the biomorphologic assessment of coronary artery disease: First experience with prospectively gated CT angiography

15.25: Lowering radiation dose of combined PET-CT and CT angiography in the biomorphologic assessment of coronary artery disease: First experience with prospectively gated CT angiography

CT coronary angiography: Quantitative assessment of myocardial perfusion using test bolus data–initial experience

The aim of this study is to quantify myocardial perfusion during coronary CT angiography using data from a modified timing test-bolus acquisition. Institutional review board approval and informed consent were obtained. Nineteen patients with suspected coronary artery disease underwent combined coronary CT angiography and cardiac (82)Rubidium-PET perfusion. Prior to the CT angiogram a retrospectively ECG-gated dynamic test bolus was obtained following 25 mls of IV contrast medium injected at 5 ml/s. Images were acquired every 1.5 s for 30 s using 4 x 1.25-mm slices at 120 kV, 35 mAs. Regions of interest were drawn to delineate the myocardium and aorta on the resulting transaxial images. Time density curves were created and perfusion calculated using two simple approaches: maximum-slope method and peak method. In patients with normal PET myocardial perfusion, the mean (SD) resting myocardial perfusion estimated by CT using the maximum-slope method was 0.89 (+/-0.27) ml/min/g and 0.93 (+/-0.21) ml/min/g at end-systole and end-diastole, respectively, and 0.69 (+/-0.11) ml/min/g and 0.79 (+/-0.19) at end-systole and end-diastole, respectively, for the peak method. Thus quantification of myocardial perfusion from a routine coronary CT angiography test bolus is possible. CT-derived myocardial perfusion values are consistent with published values derived from other techniques.

Abstract 1637: Radiation Dose Measurements on Subjects Undergoing Combined CT Perfusion and CT Angiography Imaging with a Prototype 256-row MDCT Scanner

Introduction: The purpose of this study was to directly measure the radiation dose on subjects undergoing combined CT Perfusion (CTP) and CT Angiography (CTA) imaging on a 256-row MDCT scanner. Methods: Fifteen patients underwent combined CTP and CTA imaging on a prototype 256 row MDCT scanner (Toshiba, Nasu, Japan). The prototype 256-row MDCT scanner consists of 256 rows of 0.5 mm size detectors with the capability to scan 12.8 cm length in the axial plane per CT gantry rotation in 0.5 secs. The protocol included a scout scan and test bolus scan followed by adenosine stress CTP (120 kVp, 200 mA, gantry rotation speed of 0.5 secs for 3 rotations, 128x1.0 mm) and rest CTA (120 kVp, 350 mA, gantry rotation speed of 0.5 secs for 3 rotations, 256x0.5 mm) in an axial scan mode. Direct dose measurements were performed using a custom vest worn by the patient fitted with 15–25 thermoluminiscent dosimeters (TLDs) (Landauer, IL) placed in AP and lateral locations. An anthropomorphic phantom was also scanned with the same protocol with TLDs positioned on the surface and inside the phantom at various organ locations. Effective doses were estimated based on the maximum surface dose according to previously validated methodology. Results: The effective dose from TLD measurements ranged from 22 to 32 mSv for the entire protocol. This is based on direct dose measured on subjects and not based on dose derived from phantom measurements as done routinely. Conclusions: The doses reported in this study are comparable to similarly measured doses from 64-slice MDCT coronary angiography alone. This prototype scanner uses 3 gantry rotations and a 1.5 second exposure time in it current configuration. Since, 256-row MDCT can cover the entire heart in a single rotation, it eliminates the need for tissue overlap from low pitch values. Efforts are currently underway to develop a prospective ECG-gated protocol that can limit radiation exposure to a single rotation for both stress and rest CTA scans. With a single rotation, the effective dose can be reduced to nearly one-third of the dose measured with this prototype, or approximately 7–11 mSv for a combined CTP and CTA imaging.

Benefit of CT venography for the diagnosis of thromboembolic disease

The aim of this study was to determine the benefit of lower extremity CT venography (CTV) with pulmonary CT angiography (CTA) for diagnosing thromboembolic (TE) disease. Reports of all CTAs and CTVs over a 3-year interval (Group I) and CTAs, CTVs, and lower extremity Doppler ultrasounds (US) over a 1 1/2-year subset (Group II) were reviewed. Patient population was inpatients and emergency department patients who were assessed for pulmonary embolism (PE) and deep venous thrombosis (DVT) at a tertiary care hospital. Reported results for CTA or CTV were categorized as positive (CTA(P), CTV(P)), negative (CTA(N), CTV(N)), or indeterminate for PE or DVT. When CTV and US results were discrepant, medical records were reviewed for clinical management. Additional benefit of CTV was assessed by chi-square analysis. In Group I, 737 (81.1%) of 909 CTAs from combined CTA/CTV studies were negative. The diagnosis rate of TE disease increased from 13.0% to 17.3% with the addition of CTV(P)s (P=.01). Of the 119 cases in Group II undergoing combined CTA, CTV, and US, CTV and US were both positive in eight and both negative in 88. Of the seven discordant CTVs and USs with clinical follow-up, five CTVs were positive while USs were negative, three of which were treated clinically for TE disease, while two were considered falsely positive. As CTA also proved positive in one of the three, CTV therefore affected management in two of these five cases and increased the rate of thromboembolism diagnosis from 21.0% to 22.6%; however, this was not significant (P>.05). Two CTV(N)s were managed as false negatives. The combined use of CTA and CTV significantly increases the rate of TE disease over CTA alone. In cases in which ultrasound is performed, however, there is no significant advantage to performing combined CTA/CTV studies.

Tools of the Trade for CTA: MDCT Scanners and Contrast Medium Injection Protocols

The introduction of multi-detector row computed tomography (MDCT) scanners in 1998 ushered in new advances in CT angiography (CTA). The subsequent expansion of MDCT scanner capabilities, coupled with advances in understanding of contrast medium (CM) dynamics, has further improved the clinical availability and consistency of CTA. We will review recent advances in CT scanner technology and discuss early CM dynamics. Specifically, we describe an approach tailored to the available scanner technology and to patient size aimed at providing consistently robust CTA studies across all vascular territories. A rational method to design combined CTA scan/injection protocols to facilitate this goal will be described. Our current experience with a simplified protocol for CTA with 64-MDCT will also be explained.

The clinical significance of CT angiography in the diagnosis of arterioportal shunts associated with hepatocellular carcinoma

目的 探讨CT血管成像(CTA)对肝细胞癌(HCC)合并肝动脉-门静脉分流(APS)的诊断价值.方法 127例HCC患者分别接受肝脏多层螺旋CT动态增强扫描和DSA检查,间隔时间3～15 d.所有患者进行CTA检查,并以DSA为标准,对照分析CT动态增强扫描基础上进行CTA成像对APS的诊断价值.结果 DSA证实52例(40.94%)HCC患者合并APS,中央型33例,周围型19例.CT横断面与横断面基础上结合CTA诊断APS的敏感度均为94.23%(49/52),特异度分别为84.00%(63/75)和97.33%(73/75),正确率分别为88.19%(112/127)和96.06%(122/127),阳性预测值分别为80.33%(49/61)和96.08%(49/51),阴性预测值分别为95.45%(63/66)和96.05%(73/76).CTA排除了横断面CT对4例中央型APS和6例周围型APS的假阳性诊断.与DSA比较,多层螺旋CT对APS的分型符合率达88.46%(46/52),其中,中央型90.91%(30/33),周围型84.21%(16/19).CTA还直观地显示23例重度分流中央型APS的供血动脉,其中19例为肝固有动脉分支,4例为胃十二指肠动脉分支.结论 在多层螺旋CT动态增强扫描基础上进行CTA成像,能有效提高APS诊断的特异度和正确率。

Utility of CT during Arteriography in Superselective Transarterial Chemoembolization for Invasive Bladder Cancer

Background & Aims : To assess the effectiveness of CT during arteriography (CTA) in superselective transarterial chemoembolization (TACE) for invasive bladder cancer, and to report preliminary results of superselective TACE. Methods : Angiography was performed in 20 patients with invasive bladder cancer, using a combined CT-Angiography system. Of the 20 tumors, 19 were T3, one was T2. The vesical arteries were selected using a 3F microcatheter, and perfusion was confirmed using CTA. TACE was performed after administrating 40 to 100 mg of cisplatin, with and without gelatin sponge particles. The effects of TACE were assessed by surgery or a combination of cystoscopy and CT in 15 cases. Results : The vesical arteries were successfully selected in 18 of 20 patients. In 16 small tumors, the tumor stain was clearly depicted on CTA. In two large tumors, the vascular supply was identified as involving multiple arteries. One case showed complete remission, six showed partial remission, and eight showed no change. Complications included mild local pain around the perineum during TACE, and transient nausea in some patients. Conclusion : CTA may be useful in superselective TACE for invasive bladder cancer, and may contribute to effective treatment of bladder tumors.

Combined CT pulmonary angiography and venography for diagnosis of pulmonary embolism and deep vein thrombosis: radiation dose.

A major concern about combined pulmonary CT angiography (PCTA) and CT venography (CTV) refers to the additional radiation exposure to the patient. The purpose of this paper is to analyze the organ dose, the effective dose, and the gonadal dose of combined PCTA and CTV. Effective dose and gonadal dose in PCTA and CTV were calculated. Also measured was the organ doses with thermoluminescence dosimeters in six patients who underwent combined PCTA/CTV. The risk from the effective dose and gonadal dose in combined PCTA/CTV is low. Nevertheless, additional CTV increases the gonadal dose by a significant factor and use of this procedure should be limited in younger patients.

Use of a Combined CT-Angiography System for Demonstration of Correlative Anatomy during Embolotherapy for Hepatocellular Carcinoma

Use of a Combined CT-Angiography System for Demonstration of Correlative Anatomy during Embolotherapy for Hepatocellular Carcinoma

Radiologic damage control: evaluation of a combined CT and angiography suite with a pivoting table.

To evaluate retrospectively the integrated diagnostic and therapeutic management of severely polytraumatized patients using a combined computed tomography (CT) and angiography suite with a single pivoting table. Eleven patients, aged 16-74 years (median 30 years), were managed with spiral CT and angiography without patient transfer. Four patients were unstable, seven had received blood transfusions (2-18 units) and six were intubated. In 10 patients in whom active bleeding was demonstrated (splenic 5, hepatic 2, renal 2, left inferior epigastric artery 1), hemostatic embolization was obtained. Total procedure time did not exceed 80 min. Immediate hemostasis was achieved in all patients. Recurrent bleeding from the liver required additional embolization in one patient. Median length of stay in the intensive care unit was 4 days and median hospital stay was 27 days. All patients survived without significant sequelae. The use of a combined CT-angiography suite enables rapid diagnostic investigation and hemostatic embolization in actively bleeding trauma patients.