CT Artifacts of the Proximal Aortic Neck: An Important Problem in Endograft Planning

Purpose: To describe the imaging error introduced by noncircular abdominal aortic aneurysm (AAA) necks in axial and reformatted computed tomographic (CT) images and discuss the potential implications for aortic endografting. Methods: The records of 120 endograft patients with preoperative CT axial scans and subsequent 3-dimensional (3D) computerized reconstructions were reviewed. Maximum and minimum infrarenal aortic neck diameters were measured from axial CT scans and 3D reformatted slices at the same point on the vessel. Diameter measurements were made at the largest point within the 10-mm segment of vessel below the lowest renal artery. Excluded were aneurysms with proximal neck minimum diameters >30 mm, neck lengths <15 mm, or angulation >75° measured on the axial CT slice. Results: Measuring from reformatted CT slices, 86 (71.6%) cases had ≤2-mm differences between maximal and minimal neck diameters, comprising the “round neck” group A. In 34 (28.4%) cases, the neck was not round: 26 (21.7%) had diameter differences between 2 and 4 mm (group B) and 8 (6.7%) had a >4-mm difference (group C; range 4.1–8.1 mm). Although AAA diameter, neck length, and neck angle progressively increased as the difference between neck maximum and minimum diameters grew, i.e., greater eccentricity, these trends did not reach statistical significance. Mean infrarenal neck maximum diameter was significantly larger in group C (30.2 ± 3.4 mm) compared to groups A (23.0 ± 2.9 mm, p = 0.0002) and B (23.8 ± 3.6 mm, p = 0.0003). Hence, 28.4% of AAAs had a noncircular aortic neck of varying degree, and 6.7% had an eccentricity factor that may have clinical significance. Conclusions: This study confirms the importance of selecting an endoprosthesis sized 15% to 20% larger than the infrarenal aortic neck diameter. Three-dimensional reconstruction using reformatted CT slices perpendicular to the flow lumen is an important tool that offers enhanced accuracy of infrarenal aortic neck evaluation.

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The accuracy of multi-slice three-dimensional computerized tomography on the verification of the pedicle screw trajectory

Orthopedic Reviews ◽

10.4081/or.2009.e22 ◽

2009 ◽

Vol 1 (1) ◽

pp. 22

Author(s):

Suat Erol Çelik ◽

Bilal Kelten ◽

Recai Gökcan ◽

Ahmet Cevri Yıldız

Keyword(s):

Pedicle Screw ◽

Computerized Tomography ◽

Spinal Surgery ◽

Three Dimensional ◽

Pedicle Screws ◽

Ct Reconstruction ◽

Axial Ct ◽

Diagnostic Power ◽

Ct Slices

The purpose of our study was to determine the diagnostic power of three-dimensional reformatted multi-slice computerized tomography (CT) images on misplaced pedicle screws in spinal surgery. Eighty-four consecutive patients with 458 screws in situ were investigated prospectively using both axial CT slices and reformatted images after operation by two blinded investigators. All the screw misplacements were documented and the differences between the two imaging modalities were recorded. Axial CT slices were able to show only 23 of 60 misplaced pedicle screws; multi-slice CT was three times more powerful in the diagnosis of pedicle screw complications in spinal surgery (p<0.05). We concluded that multi-slice CT reconstruction should be the primary diagnostic tool after screw implantation in the human spine.

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3D-CT vascular setting protocol using computer graphics for the evaluation of maxillofacial lesions

Pesquisa Odontológica Brasileira ◽

10.1590/s1517-74912001000300009 ◽

2001 ◽

Vol 15 (3) ◽

pp. 229-236 ◽

Cited By ~ 4

Author(s):

Marcelo de Gusmão Paraiso CAVALCANTI ◽

Axel RUPRECHT ◽

Michael Walter VANNIER

Keyword(s):

Computer Graphics ◽

Three Dimensional ◽

3D Ct ◽

3D Images ◽

Quantitative Analyses ◽

Axial Ct ◽

Interactive 3D ◽

Ct Slices

In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT) reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.

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Two-Dimensional versus Three-Dimensional CT Scan for Aortic Measurement

Journal of Endovascular Therapy ◽

10.1177/152660280301000319 ◽

2003 ◽

Vol 10 (3) ◽

pp. 531-538 ◽

Cited By ~ 16

Author(s):

Ellen D. Dillavou ◽

David G. Buck ◽

Satish C. Muluk ◽

Michel S. Makaroun

Keyword(s):

Ct Scan ◽

Intraclass Correlation ◽

Three Dimensional ◽

Major Axis ◽

Minor Axis ◽

Absolute Difference ◽

3D Reconstructions ◽

Computed Tomographic ◽

Aortic Neck ◽

Lower Neck

Purpose: To examine if 3-dimensional (3D) reconstructions of computed tomographic (CT) data, by imaging perpendicular to blood flow, can improve aortic diameter measurement accuracy over axial (2D) CT. Methods: Two independent, blinded observers used electronic calipers to measure the minor axis and the line perpendicular to it on 40 2.5-mm 2D CT scans from 31 patients. A circular electronic tool was used to estimate diameters on 3D reconstructions from the same 40 scans. Measurements of the aortic neck were obtained 5 mm below the renal arteries and the widest slice of the aneurysm was used to measure sac diameter. Only the minor axis was measured at the iliac arteries immediately above the left (LI) and right (RI) iliac bifurcations. Datasets were compared with an intraclass correlation coefficient (ICC), Bland and Altman variation assessments, and absolute differences. Results: ICC between 2D and 3D scans demonstrated high correlation with 2D minor axis measurements (neck=0.9282, sac=0.8956, RI=0.8755, LI=0.7381). 3D to 2D major axis correlation was lower (neck=0.6388, sac=0.8995). Variation between 3D and 2D minor axis measurements was low (0.51-mm average variation from the mean for the minor axis and 1.30-mm variation for the major axis). Average absolute difference between 3D and 2D diameters was 1.01 mm (minor axis) versus 2.61 mm (major axis). Interobserver correlation was highest for sac measurements both in 2D minor axis (ICC=0.8990) and 3D (ICC=0.9518). Conclusions: Minor axis measurements on axial CT scan can substitute for diameters obtained from 3D reconstructions in most clinical situations.

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In Vivo CT Analysis of Physiological Fibular Motion at the Level of the Ankle Syndesmosis During Plantigrade Weightbearing

Foot & Ankle Specialist ◽

10.1177/1938640018782602 ◽

2018 ◽

Vol 12 (3) ◽

pp. 233-237 ◽

Cited By ~ 4

Author(s):

Paul Hoogervorst ◽

Zachary M. Working ◽

Ashraf N. El Naga ◽

Meir Marmor

Keyword(s):

Imaging System ◽

Statistical Significance ◽

Ct Images ◽

Computed Tomographic ◽

Anteroposterior Translation ◽

Tibiofibular Joint ◽

Ct Evaluation ◽

Ct Analysis ◽

Axial Ct

Background. It is clear that motion at the syndesmosis occurs due to ranging of the ankle joint, but the influence of weightbearing with the foot in the plantigrade position is unclear. In vivo computed tomographic (CT) evaluation of the syndesmosis has not been previously described. The purpose of this study is to quantify physiological fibular motion at the level of the ankle syndesmosis in both weightbearing and nonweightbearing conditions with the foot in the plantigrade position. Methods. CT images were obtained from 9 normal healthy subjects using a weightbearing CT imaging system. The subjects were positioned in a nonweightbearing and weightbearing state with their foot in the plantigrade position. Fibular translation and rotation were measured from the axial CT images using previously validated techniques. Results. Both the average lateral and anteroposterior translation of the fibula between weightbearing and nonweightbearing states was minimal (0.3 mm and 0.2 mm, respectively). The largest difference in translation observed in either direction was 0.9 mm. An average of 0.5° was found for rotational differences of the fibula between weightbearing and nonweightbearing. Neither of the translational and rotational parameters reached statistical significance. Conclusion. In vivo CT analysis of the distal tibiofibular joint with an intact syndesmosis did not reveal statistically significant physiological motion between weightbearing and nonweightbearing conditions with the foot in plantigrade position. Our findings suggest that weightbearing accounts for little motion at the syndesmosis and supports further investigation into the role of early protected weightbearing after syndesmosis fixation. Levels of Evidence: Level III: Case-control study

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Integration of Patient-Specific Paranasal Sinus Computed Tomographic Data into a Virtual Surgical Environment

American Journal of Rhinology and Allergy ◽

10.2500/ajra.2009.23.3335 ◽

2009 ◽

Vol 23 (4) ◽

pp. 442-447 ◽

Cited By ~ 26

Author(s):

Sachin S. Parikh ◽

Sonny Chan ◽

Sumit K. Agrawal ◽

Peter H. Hwang ◽

Curt M. Salisbury ◽

...

Keyword(s):

Haptic Feedback ◽

Three Dimensional ◽

Sinus Surgery ◽

Patient Specific ◽

Imaging Data ◽

Cross Sectional ◽

Endoscopic Techniques ◽

Computed Tomographic ◽

Preoperative Ct ◽

Ct Data

Background The advent of both high-resolution computed tomographic (CT) imaging and minimally invasive endoscopic techniques has led to revolutionary advances in sinus surgery. However, the rhinologist is left to make the conceptual jump between static cross-sectional images and the anatomy encountered intraoperatively. A three-dimensional (3D) visuo-haptic representation of the patient's anatomy may allow for enhanced preoperative planning and rehearsal, with the goal of improving outcomes, decreasing complications, and enhancing technical skills. Methods We developed a novel method of automatically constructing 3D visuo-haptic models of patients’ anatomy from preoperative CT scans for placement in a virtual surgical environment (VSE). State-of-the-art techniques were used to create a high-fidelity representation of salient bone and soft tissue anatomy and to enable manipulation of the virtual patient in a surgically meaningful manner. A modified haptic interface device drives a virtual endoscope that mimics the surgical configuration. Results The creation and manipulation of sinus anatomy from CT data appeared to provide a relevant means of exploring patient-specific anatomy. Unlike more traditional methods of interacting with multiplanar imaging data, our VSE provides the potential for a more intuitive experience that can replicate the views and access expected at surgery. The inclusion of tactile (haptic) feedback provides an additional dimension of realism. Conclusion The incorporation of patient-specific clinical CT data into a virtual surgical environment holds the potential to offer the surgeon a novel means to prepare for rhinologic procedures and offer training to residents. An automated pathway for segmentation, reconstruction, and an intuitive interface for manipulation may enable rehearsal of planned procedures.

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Faculty Opinions recommendation of Integrated electroanatomic mapping with three-dimensional computed tomographic images for real-time guided ablations.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.10002.466764 ◽

2006 ◽

Author(s):

David Callans

Keyword(s):

Real Time ◽

Three Dimensional ◽

Electroanatomic Mapping ◽

Tomographic Images ◽

Computed Tomographic

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Imaging in Propeller Flap Surgery

Seminars in Plastic Surgery ◽

10.1055/s-0040-1715159 ◽

2020 ◽

Vol 34 (03) ◽

pp. 145-151

Author(s):

Shimpei Ono ◽

Hiroyuki Ohi ◽

Rei Ogawa

Keyword(s):

Low Cost ◽

Three Dimensional ◽

Duplex Sonography ◽

Computed Tomographic Angiography ◽

Ease Of Use ◽

Computed Tomographic ◽

Imaging Tool ◽

Preoperative Mapping ◽

Flap Design ◽

Tomographic Angiography

AbstractSince propeller flaps are elevated as island flaps and most often nourished by a single perforator nearby the defect, it is challenging to change the flap design intraoperatively when a reliable perforator cannot be found where expected to exist. Thus, accurate preoperative mapping of perforators is essential in the safe planning of propeller flaps. Various methods have been reported so far: (1) handheld acoustic Doppler sonography (ADS), (2) color duplex sonography (CDS), (3) perforator computed tomographic angiography (P-CTA), and (4) magnetic resonance angiography (MRA). To facilitate the preoperative perforator assessment, P-CTA is currently considered as the gold standard imaging tool in revealing the three-dimensional anatomical details of perforators precisely. Nevertheless, ADS remains the most widely used tool due to its low cost, faster learning, and ease of use despite an undesirable number of false-positive results. CDS can provide hemodynamic characteristics of the perforator and is a valid and safer alternative particularly in patients in whom ionizing radiation and/or contrast exposure should be limited. Although MRA is less accurate in detecting smaller perforators of caliber less than 1.0 mm and the intramuscular course of perforators at the present time, MRA is expected to improve in the future due to the recent developments in technology, making it as accurate as P-CTA. Moreover, it provides the advantage of being radiation-free with fewer contrast reactions.

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Preoperative Use of CT Angiography in Infants With Coarctation of the Aorta

World Journal for Pediatric and Congenital Heart Surgery ◽

10.1177/2150135116683929 ◽

2017 ◽

Vol 8 (2) ◽

pp. 196-202 ◽

Cited By ~ 8

Author(s):

Kirsten Rose-Felker ◽

Joshua D. Robinson ◽

Carl L. Backer ◽

Cynthia K. Rigsby ◽

Osama M. Eltayeb ◽

...

Keyword(s):

Radiation Dose ◽

Surgical Approach ◽

New Technology ◽

Three Dimensional ◽

Coarctation Of The Aorta ◽

Computed Tomographic Angiography ◽

Great Vessel ◽

Z Score ◽

Computed Tomographic ◽

Tomographic Angiography

Background: Computed tomographic angiography (CTA) and echocardiography (echo) are used preoperatively in coarctation of the aorta to define arch hypoplasia and great vessel branching. We sought to determine differences in quantitative measurements, as well as surgical utility, between modalities. Methods: Infants (less than six months) with both CTA and echo prior to coarctation repair from 2004 to 2013 were included. Measurements were compared and correlated with surgical approach. Three surgeons reviewed de-identified images to predict approach and characterize utility. Computed tomographic angiography radiation dose was calculated. Results: Thirty-three patients were included. No differences existed in arch measurements between echo and CTA ( z-score: −2.59 vs −2.43; P = .47). No differences between modalities were seen for thoracotomy ( z-score: −2.48 [echo] vs −2.31 [CTA]; P = .48) or sternotomy ( z-score: −3.13 [echo] vs −3.08 [CTA]; P = .84). Computed tomographic angiography delineated great vessel branching pattern in two patients with equivocal echo findings ( P = .60). Surgeons rated CTA as far more useful than echo in understanding arch hypoplasia and great vessel branching in cases where CTA was done to resolve anatomical questions that remain after echo evaluation. Two of three surgeons were more likely to choose the surgical approach taken based on CTA (surgeon A, P = .02; surgeon B, P = .01). Radiation dose averaged 2.5 (1.6) mSv and trended down from 2.9 mSv (1.8 mSv; n = 20) to 1.6 mSv (0.5 mSv; n = 7) ( P = .06) with new technology. Conclusion: Although CTA and echo measurements of the aorta do not differ, CTA better delineates branching and surgeons strongly prefer it for three-dimensional arch anatomy. We recommend CTA for patients with anomalous arch branching patterns, diffuse or complex hypoplasia, or unusual arch morphology not fully elucidated by echo.

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