Validation of a New Method for 2D Fusion Imaging Registration in a System Prepared Only for 3D

2020 ◽  
Vol 27 (3) ◽  
pp. 468-472
Author(s):  
Andreas Edsfeldt ◽  
Björn Sonesson ◽  
Helena Rosén ◽  
Marcelo H. Petri ◽  
Kiattisak Hongku ◽  
...  

Purpose: To validate a new 2D-3D registration method of fusion imaging during aortic repair in a system prepared only for 3D-3D registration and to compare radiation doses and accuracy. Materials and Methods: The study involved 189 patients, including 94 patients (median age 70 years; 85 men) who underwent abdominal endovascular aneurysm repair (EVAR) with 2D-3D fusion on an Artis zee imaging system and 95 EVAR patients (median age 70 years; 81 men) from a prior study who had 3D-3D registration done using cone beam computed tomography (CBCT). For the 2D-3D registration, an offline CBCT of the empty operating table was imported into the intraoperative dataset and superimposed on the preoperative computed tomography angiogram (CTA). Then 2 intraoperative single-frame 2D images of the skeleton were aligned with the patient’s skeleton on the preoperative CTA to complete the registration process. A digital subtraction angiogram was done to correct any misalignment of the aortic CTA volume. Values are given as the median [interquartile range (IQR) Q1, Q3]. Results: The 2D-3D registration had an accuracy of 4.0 mm (IQR 3.0, 5.0) after bone matching compared with the final correction with DSA (78% within 5 mm). By applying the 2D-3D protocol the radiation exposure (dose area product) from the registration of the fusion image was significantly reduced compared with the 3D-3D registration [1.12 Gy∙cm2 (IQR 0.41, 2.14) vs 43.4 Gy∙cm2 (IQR 37.1, 49.0), respectively; p<0.001). Conclusion: The new 2D-3D registration protocol based on 2 single-frame images avoids an intraoperative CBCT and can be used for fusion imaging registration in a system originally designed for 3D-3D only. This 2D-3D registration protocol is accurate and leads to a significant reduction in radiation exposure.

2012 ◽  
Vol 78 (10) ◽  
pp. 1029-1032 ◽  
Author(s):  
Michael Butler ◽  
Madhukar S. Patel ◽  
Samuel E. Wilson

Endovascular aneurysm repair (EVAR) is now the preferred procedure for abdominal aortic aneurysm repair. As a result of the need for fluoroscopy during EVAR, radiation exposure is a potential hazard. We studied the quantity of radiation delivered during EVAR to identify risks for excessive exposure. Fluoroscopy time, contrast volume used, and procedural details were recorded prospectively during EVARs. Using data collected from similar EVARs, an equation was derived to calculate approximate dose-area product (DAP) from fluoroscopy time. DAP values were then compared between procedures in which a relevant postdeployment procedure (PDP) was necessary intraoperatively with those without. Clinical data on 17 patients were collected. The mean age of patients was 68 (±9) years. Fluoroscopy times and approximate DAP values were found to be significantly higher in the seven patients with a PDP compared with the 10 patients without an intraoperative PDP (31.2 [±9.6] vs 22.7 [±6.0] minutes, P = 0.033 and 537 [±165] vs 390 [±103] Gy-cm2, P = 0.033, respectively). The average amount of contrast volume used was not significantly different between groups. Radiation emitted during EVARs with PDPs was significantly greater relative to those without PDPs. Device design and operators should thus aim to decrease PDPs and to minimize fluoroscopy time.


2017 ◽  
Vol 52 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Lars Stangenberg ◽  
Fahad Shuja ◽  
I. Martijn J. van der Bom ◽  
Martine H. G. van Alfen ◽  
Allen D. Hamdan ◽  
...  

High-definition fluoroscopic imaging is required to perform endovascular procedures safely and precisely, especially in complex cases, resulting in longer procedures and increased radiation exposure. This is of importance for training institutions as trainees, even with sound instruction in as low as reasonably achievable (ALARA) principles, tend to have high radiation exposures. Recently, there was an upgrade in the imaging system allowing for comparison of radiation exposure to patients and providers. We performed an analysis of consecutive endovascular aneurysm repair (EVAR) and superficial femoral artery (SFA) interventions in the years 2013 to 2014. We recorded body mass index (BMI) and fluoroscopy time (FT) and subsequently matched 1:1 based on BMI, FT, or both. We determined radiation dose using air kerma (AK) and also recorded individual surgeons’ badge readings. Allura Xper FD20 was upgraded to AlluraClarity with ClarityIQ. We identified a total of 77 EVARs (52 pre and 25 post) and 134 SFA interventions (99 pre and 35 post). Unmatched results for EVAR were BMI pre 26.2 versus post 25.8 (kg/m2, P = .325), FT 28.1 versus 21.2 (minutes, P = .051), and AK 1178.5 versus 581 (mGy, P < .001), respectively. After matching, there was a 53.2% reduction in AK (846.1 vs 395.9 mGy; P = .004) for EVAR. Unmatched results for SFA interventions were BMI pre 28.1 versus post 26.6 ( P = .327), FT 18.7 versus 16.2 ( P = .282), and AK 285.6 versus 106.0 ( P < .001), respectively. After matching, there was a 57.0% reduction in AK (305.0 vs 131.3, P < .001). The total deep dose equivalent from surgeons’ badge readings decreased from 39.5 to 17 mrem ( P = .029). Aortic and peripheral endovascular interventions can be performed with reduced radiation exposure to patients and providers, employing modern fixed imaging systems with advanced dose reduction technology. This is of particular importance in the light of the increasing volume and complexity of endovascular and hybrid procedures as well as the prospect of decades of radiation exposure during training and practice.


Author(s):  
S. Zhang ◽  
D. D. Lichti ◽  
J. C. Küpper ◽  
J. L. Ronsky

Abstract. High-Speed Biplanar Videoradiography (HSBV) is an X-ray based non-invasive imaging system that can be used to derive dynamic bony translations and rotations. The 2D-3D registration process matches a 3D bone model acquired from magnetic resonance imaging (MRI) or computed tomography (CT) scans with the 2D X-ray image pairs. This study focuses on the registration of MRI data as it can acquire detailed soft tissue contrast that cannot be easily discerned in CT scans. A novel 2D-3D registration method is reported in this paper that is suitable for the MRI-based bone models with high precision and high efficiency. In addition, an automatic initialization procedure with 64 starting poses is established to avoid user intervention in the registration. The method has been tested using the HSBV image sequence of a knee joint during walking. Thirty-five consecutive poses from the sequence were tested for the registration, and 50 non-consecutive poses randomly selected from the sequence were tested for the automatic initialization. The registration precision for each axis was 0.49 to 0.54 mm. For the initialization validation test, 48 over 50 frames were successfully initialized and two failed due to portions of the joint falling outside of the field-of-view of the system. The average time for each initialization is only about 6 min. The improved 2D-3D registration will allow determination of precise 3D kinematic parameters with high efficiency. These kinematic parameters can be used to calculate joint cartilage contact mechanics that provide insight into the mechanical processes and mechanisms of joint degeneration or pathology.


2010 ◽  
Author(s):  
Jian Wu

This document describes an ITK-based implementation of intensity-based 2D/3D rigid image registration for patient setup assessment in external beam radiotherapy. The registration framework was designed to simultaneously register two projection images to a 3D image volume. The projection geometry was set up to simulate the x-ray imaging system that attached to a medical linear accelerator for cancer treatment. The normalized correlation was used as the similarity measure and the Powell’s optimizer was used as the optimization method. Siddon-Jacobs fast ray-tracing algorithm was implemented to compute projection images from a 3D image volume.


2016 ◽  
Vol 23 (5) ◽  
pp. 791-799 ◽  
Author(s):  
Christof J. Schulz ◽  
Matthias Schmitt ◽  
Dittmar Böckler ◽  
Philipp Geisbüsch

Author(s):  
Susanne Anton ◽  
J. Barkhausen ◽  
M. Wiedner ◽  
E. Stahlberg ◽  
Janpeter Goltz ◽  
...  

Background: Standard endovascular aortic repair (EVAR) is frequently performed with few data regarding utilization of 2D-3D fusion imaging (FI). Purpose: To evaluate a) feasibility and safety of 2D-3D FI to guide limb deployment during EVAR and b) efficacy of this technique compared to standard use of digital subtraction angiography (DSA) for guidance. Materials and Methods: Iliac limb deployment by guidance of 2D-3D FI (FUSION group, n=22 limbs) during EVAR was compared to (STANDARD group, n=23 limbs). Retrospectively, we analyzed feasibility (success-rate) and safety (patency of hypogastric artery; type Ib/III endoleak) of FI for limb deployment (FUSION group). Total contrast (ml) and median dose area product (mGy*cm2) per group to visualize the iliac bifurcation were compared. Results: In the FUSION group, limb deployment was performed in 19/22 limbs (86.4%) and all hypogastric arteries were patent at the end of the procedure. Median volumes of contrast per bifurcation were 13.0 ml (RANGE 13–13ml) in the STANDARD and 2.2ml (RANGE 0–13ml) in the FUSION group (p=0.002); median dose area products per bifurcation were 11951mGy*cm2 and 2593.1mGy*cm2 (p=0.001), respectively. Conclusion: Fusion imaging for guidance of limb deployment during standard EVAR is safe and feasible in the majority of procedures and can significantly reduce contrast volume and radiation exposure even if compared with optimal preparation by predicting optimal C-arm positions. Therefore, FI should be used whenever possible


2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Luke J. Lamers ◽  
Brian H. Morray ◽  
Alan Nugent ◽  
Michael Speidel ◽  
Petch Suntharos ◽  
...  

Objectives. To quantify radiation exposure during pediatric cardiac catheterizations performed by multiple operators on a new imaging platform, the Artis Q.zen (Siemens Healthcare, Forchheim, Germany), and to compare these data to contemporary benchmark values. Background. The Artis Q.zen has been shown to achieve significant radiation reduction during select types of pediatric cardiac catheterizations in small single-center studies. No large multicenter study exists quantifying patient dose exposure for a broad spectrum of procedures. Methods. Retrospective collection of Air Kerma (AK) and dose area product (DAP) for all pediatric cardiac catheterizations performed on this new imaging platform at four institutions over a two-year time period. Results. A total of 1,127 pediatric cardiac catheterizations were analyzed. Compared to dose data from earlier generation Artis Zee imaging systems, this study demonstrates 70–80% dose reduction (AK and DAP) for similar patient and procedure types. Compared to contemporary benchmark data for common interventional procedures, this study demonstrates an average percent reduction in AK and DAP from the lowest dose saving per intervention of 39% for AK and 27% for DAP for transcatheter pulmonary valve implantation up to 77% reduction in AK and 70% reduction in DAP for atrial septal defect closure. Conclusion. Use of next-generation imaging platforms for pediatric cardiac catheterizations can substantially decrease patient radiation exposure. This multicenter study defines new low-dose radiation measures achievable on a novel imaging system.


2020 ◽  
Vol 3 ◽  
pp. 36-39
Author(s):  
Samson O. Paulinus ◽  
Benjamin E. Udoh ◽  
Bassey E. Archibong ◽  
Akpama E. Egong ◽  
Akwa E. Erim ◽  
...  

Objective: Physicians who often request for computed tomography (CT) scan examinations are expected to have sound knowledge of radiation exposure (risks) to patients in line with the basic radiation protection principles according to the International Commission on Radiological Protection (ICRP), the Protection of Persons Undergoing Medical Exposure or Treatment (POPUMET), and the Ionizing Radiation (Medical Exposure) Regulations (IR(ME)R). The aim is to assess the level of requesting physicians’ knowledge of ionizing radiation from CT scan examinations in two Nigerian tertiary hospitals. Materials and Methods: An 18-item-based questionnaire was distributed to 141 practicing medical doctors, excluding radiologists with work experience from 0 to >16 years in two major teaching hospitals in Nigeria with a return rate of 69%, using a voluntary sampling technique. Results: The results showed that 25% of the respondents identified CT thorax, abdomen, and pelvis examination as having the highest radiation risk, while 22% said that it was a conventional chest X-ray. Furthermore, 14% concluded that CT head had the highest risk while 9% gave their answer to be conventional abdominal X-ray. In addition, 17% inferred that magnetic resonance imaging had the highest radiation risk while 11% had no idea. Furthermore, 25.5% of the respondents have had training on ionizing radiation from CT scan examinations while 74.5% had no training. Majority (90%) of the respondents were not aware of the ICRP guidelines for requesting investigations with very little (<3%) or no knowledge (0%) on the POPUMET and the IR(ME)R respectively. Conclusion: There is low level of knowledge of ionizing radiation from CT scan examinations among requesting physicians in the study locations.


2020 ◽  
Vol 33 (6) ◽  
pp. 838-844
Author(s):  
Jan-Helge Klingler ◽  
Ulrich Hubbe ◽  
Christoph Scholz ◽  
Florian Volz ◽  
Marc Hohenhaus ◽  
...  

OBJECTIVEIntraoperative 3D imaging and navigation is increasingly used for minimally invasive spine surgery. A novel, noninvasive patient tracker that is adhered as a mask on the skin for 3D navigation necessitates a larger intraoperative 3D image set for appropriate referencing. This enlarged 3D image data set can be acquired by a state-of-the-art 3D C-arm device that is equipped with a large flat-panel detector. However, the presumably associated higher radiation exposure to the patient has essentially not yet been investigated and is therefore the objective of this study.METHODSPatients were retrospectively included if a thoracolumbar 3D scan was performed intraoperatively between 2016 and 2019 using a 3D C-arm with a large 30 × 30–cm flat-panel detector (3D scan volume 4096 cm3) or a 3D C-arm with a smaller 20 × 20–cm flat-panel detector (3D scan volume 2097 cm3), and the dose area product was available for the 3D scan. Additionally, the fluoroscopy time and the number of fluoroscopic images per 3D scan, as well as the BMI of the patients, were recorded.RESULTSThe authors compared 62 intraoperative thoracolumbar 3D scans using the 3D C-arm with a large flat-panel detector and 12 3D scans using the 3D C-arm with a small flat-panel detector. Overall, the 3D C-arm with a large flat-panel detector required more fluoroscopic images per scan (mean 389.0 ± 8.4 vs 117.0 ± 4.6, p < 0.0001), leading to a significantly higher dose area product (mean 1028.6 ± 767.9 vs 457.1 ± 118.9 cGy × cm2, p = 0.0044).CONCLUSIONSThe novel, noninvasive patient tracker mask facilitates intraoperative 3D navigation while eliminating the need for an additional skin incision with detachment of the autochthonous muscles. However, the use of this patient tracker mask requires a larger intraoperative 3D image data set for accurate registration, resulting in a 2.25 times higher radiation exposure to the patient. The use of the patient tracker mask should thus be based on an individual decision, especially taking into considering the radiation exposure and extent of instrumentation.


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