Flat-panel Angiography System Research Articles

PAE planning: Radiation exposure and image quality of CT and CBCT

PurposeTo determine accurate organ doses, effective doses, and image quality of computed tomography (CT) compared with cone beam CT (CBCT) for correct identification of prostatic arteries. MethodA dual-energy CT scanner and a flat-panel angiography system were used. Dose measurements (gallbladder (g), intestine (i), bladder (b), prostate (p), testes (t), active bone marrow of pelvis (bmp) and femura (bmf)) were performed using an anthropomorphic phantom with 65 thermoluminescent dosimeters in the pelvis and abdomen region. For the calculation of the contrast-to-noise ratio (CNR) of the pelvic arteries, a patient whose weight and height were almost identical to those of the phantom was selected for each examination type. ResultsThe effective dose of CT was 2.7 mSv and that of CBCT was 21.8 mSv. Phantom organ doses were lower for CT than for CBCT in all organs except the testes (g: 1.2 mGy vs. 3.3 mGy, i: 5.8 mGy vs. 23.9 mGy, b: 6.9 mGy vs. 19.4 mGy, p: 6.4 mGy vs. 13.2 mGy, t: 4.7 mGy vs. 2.4 mGy, bmp: 5.1 mGy vs. 18.2 mGy, bmf: 3.3 mGy vs. 6.6 mGy). For human pelvic arteries, the CNR of CT was better than that of CBCT, with the exception of one prostate artery that showed stenosis on CT. Evaluation by experienced radiologists also confirmed the better detectability of prostate arteries on CT examination. ConclusionsIn our study preprocedural CT had lower organ doses and better image quality comparedd with CBCT and should be considered for the correct identification of prostatic arteries.

Radiation Exposure During Diagnostic and Therapeutic Angiography of Carotid-cavernous Fistula

PurposeThe aim of this study was to determine local diagnostic reference levels (DRLs) during endovascular diagnostics and therapy of carotid-cavernous fistulas (CCF).MethodsIn a retrospective study design, DRLs, achievable dose (AD) and mean values were assessed for all patients with CCF undergoing diagnostic angiography (I) or embolization (II). All procedures were performed with the flat-panel angiography system Allura Xper (Philips Healthcare). Interventional procedures were differentiated according to the type of CCF and the type of procedure.ResultsIn total, 86 neurointerventional procedures of 48 patients with CCF were executed between February 2010 and July 2021. The following DRLs, AD and mean values could be determined: (I) DRL 215 Gy ∙ cm2, AD 169 Gy ∙ cm2, mean 165 Gy ∙ cm2; (II) DRL 350 Gy ∙ cm2, AD 226 Gy ∙ cm2, mean 266 Gy ∙ cm2. Dose levels of embolization were significantly higher compared to diagnostic angiography (p < 0.001). No significant dose difference was observed with respect to the type of fistula or the embolization method.ConclusionThis article reports on diagnostic and therapeutic DRLs in the management of CCF that could serve as a benchmark for the national radiation protection authorities. Differentiation by fistula type or embolization method does not seem to be useful.

Treatment Evaluation of Flow-Limiting Stenoses of the Superficial Femoral and Popliteal Artery by Parametric Color-Coding Analysis of Digital Subtraction Angiography Series.

To evaluate the hemodynamic effect of percutaneous transluminal intervention (PTI) on stenosis of the superficial femoral (SFA) and popliteal arteries (PA) using time-density curves (TDCs) derived from digital subtraction angiography (DSA) series in correlation with ultrasound peak systolic velocity ratio (PSVR) and ankle brachial index (ABI). DSA series of SFA or PA of patients with symptomatic peripheral arterial occlusive disease was obtained with a flat-panel angiography system with intention-to-treat. In DSA series acquired before and after PTI, TDCs were analyzed proximal and distal of each stenosis using parametric color coding (PCC). For correlation, ABI and PSVR measurements pre- and post-PTI were recorded for all patients. In total, 25 stenoses of the SFA or PA were treated by PTI in 22 patients (17 male, 5 female, mean age 68 years). After treatment, peak-to-peak (PTP) times between TDCs proximal and distal to the treated vessel segment decreased statistically significantly (p=0.01) on average from PTP=1.9±1.7s to mean PTP=1±1s. ABI and PSVR also changed statistically significantly after treatment (pretreatment ABI=0.7±0.2, PSVR=4.2±1.9; post-ABI=0.9±0.2, PSVR=1.3±0.4, both p<0.05). Correlation parameters did not show a strong correlation between change in TDC and clinical parameters ABI and PSVR. Using PCC for analyzing contrast medium dynamics in DSA series is clinically useful for evaluating stenoses of the SFA and PA and for immediate treatment control after PTA. Case series, IV.

Combining C-arm CT with a new remote operated positioning and guidance system for guidance of minimally invasive spine interventions

ObjectiveTo report our experience using C-arm cone beam CT (C-arm CBCT) combined with the new remote operated positioning and guidance system, iSYS1, for needle guidance during spinal interventions.MethodsA C-arm CBCT...

Latest-generation catheterization systems enable invasive submillisievert coronary angiography

The radiation risk of patients undergoing invasive cardiology remains considerable and includes skin injuries and cancer. To date, submillisievert coronary angiography has not been considered feasible. In 2011, we compared results from 100 consecutive patients undergoing elective coronary angiography using the latest-generation flat-panel angiography system (FPS) with results from examinations by the same operator using 106 historic controls with a conventional image-intensifier system (IIS) that was new in 2002. The median patient exposure parameters were measured as follows: dose-area product (DAP) associated with radiographic cine acquisitions (DAP(R)) and fluoroscopy (DAP(F)) scenes, radiographic frames and runs, and cumulative exposure times for radiography and fluoroscopy. On the FPS as compared to the traditional IIS, radiographic detector entrance dose levels were reduced from 164 to 80 nGy/frame and pulse rates were lowered from 12.5/s to 7.5/s during radiography and from 25/s to 4/s during fluoroscopy. The cardiologist's performance patterns remained comparable over the years: fluoroscopy time was constant and radiography time even slightly increased. Overall patient DAP decreased from 7.0 to 2.4 Gy × cm(2); DAP(R), from 4.2 to 1.7 Gy × cm(2); and DAP(F), from 2.8 to 0.6 Gy × cm(2). Time-adjusted DAP(R)/s decreased from 436 to 130 mGy × cm(2) and DAP(F)/s, from 21.6 to 4.4 mGy × cm(2). Cumulative patient skin dose with the FPS amounted to 67 mGy, and the median (interquartile range) of effective dose was 0.5 (0.3 … 0.7) mSv. Consistent application of radiation-reducing techniques with the latest-generation flat-panel systems enables submillisievert coronary angiography in invasive cardiology.

Application of direct lymphangiography in the diagnosis of primary chyluria

To discuss the role of direct lymphangiography in the diagnosis of primary chyluria. Iodized oil was infused into lymphatic vessel of unilateral foot in 25 cases. The condition of lymphatic system imaging was dynamically observed via Innova 2100-IQ digital flat-panel angiography system. All of them underwent direct lymphangiography. The results revealed unilateral (n = 18) or bilateral (n = 7) renal reflux of contrast media. Among 22 stenotic cases, there were partial (n = 18) or whole (n = 4) cervical section of thoracic duct, no imaging in cervicothoracic section of thoracic duct (n = 1); thin imaging in cervical section and partial thoracic section (n = 2); retroperitoneal lymphangictasia & tortuous lymphatic vessels (n = 21); reflux of contrast medium to pelvic and/or contralateral sacroiliac part (n = 13). Capable of acquiring dynamic images of chyle (lymph) circulation, direct lymphangiography provides accurate estimation for the location, scope, extent of lesions of renal chylous reflux in primary chyluria so as to guide surgery. Stenotic cervical section of thoracic duct plays an important etiologic role in primary chyluria.

Radiation exposure of operator performing interventional procedures using a flat panel angiography system: evaluation with photoluminescence glass dosimeters

Using glass rod dosimeters we investigated the radiation dose to the operator performing interventional procedures in 43 patients with the aid of a monoplane flat detector-based angiography system. During the procedures we recorded the number of radiographic frames and the radiographic conditions. After treatment we recorded the fluoroscopy time and the fluoroscopic, radiographic, and total air kerma. To obtain the total operator exposure dose we took measurements at five sites: left orbital fossa, thyroid, left hand, left chest, and pubic symphysis. The mean operator exposure dose to the left hand was higher than at the other sites we measured; it was 387.0, 209.6, 174.3, and 237.1 microGy for the stentgraft, percutaneous transluminal arteriography, transarterial chemoembolization, and hepatic infusion port placement procedures. There was a positive correlation between the fluoroscopic and radiographic air kerma value and the operator exposure dose at the left orbital fossa, thyroid, and left hand. The operator exposure dose correlated with the radiographic and fluoroscopic air kerma. Exposure of the operator's left hand was higher than at the other sites studied.