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An Image Processing Based Patient-Specific Optimal Catheter Selection

Rahman, Sami ur :
An Image Processing Based Patient-Specific Optimal Catheter Selection.
Technische Universität, Darmstadt
[Ph.D. Thesis], (2012)

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Item Type: Ph.D. Thesis
Title: An Image Processing Based Patient-Specific Optimal Catheter Selection
Language: English
Abstract:

Coronary angiography is performed to investigate coronary diseases of the human heart. For better visualization of the arteries, a catheter is used to inject a contrast dye into the coronary arteries. Due to the anatomical variation of the aorta and the coronary arteries in different humans, one common catheter cannot be used for all patients. The cardiologists test different catheters for a patient and select the best one according to the patient’s anatomy. To overcome these problems, we propose a computeraided catheter selection procedure. The basic idea of this approach is to obtain MR/CT images before starting angiography. From these images, the patients’ arteries are segmented and some geometric parameters are computed from the segmented images. At the same time, geometric parameters are computed from the available catheters. A model is developed, which is based on these parameters from the patients’ image data and parameters from the catheters. This model reduces the number of catheter choices. In the next step, the reduced number of catheters are simulated and the most optimal catheter is obtained. A series of validation tests were conducted for segmentation, geometric parameters’ estimation, parameters based catheter selection and simulation model. In our experiments, we compared catheters selected in the clinic with the catheters suggested by the image processing based model. For these experiments, the ground truth data were obtained from the clinical partner. In the clinic, angiography of twenty four cases was performed. An experienced cardiologist selected catheters based on his experience and knowledge in the field. In the next step, CT/MR image data that was acquired prior to the angiography was used for the image based catheter selection model to find optimal catheters. For every patient, three most optimal catheters were suggested by the model. These three optimal catheters were ranked as first, second and third ranked catheters. Catheters suggested by the model were compared with the catheters selected by the cardiologist. It was found that in 41% cases, model based top ranked suggestions were the same as that were used in the clinic. In 25% cases, the catheters used in the clinic were the model’s second ranked catheters. In 21% cases, the catheters used in the clinic were the model’s third ranked catheters. In 13% cases the catheters used in the clinic were not in the list of suggested catheters. In further experiments, the clinicians graded catheters based on catheter’s performance and placement in the arteries. Most optimally placed catheters were assigned good grades, and less optimal catheters were assigned bad grades. It was seen that the model suggested similar catheters to the clinically good graded catheters but suggested different catheters to the clinically bad grade catheters. All these experiments showed that the method of an image processing based catheter selection is clinically applicable, and the only requirement is to have patient’s image data before starting the angiography. It was shown that this tool will be of great help for the experienced as well as the non experienced cardiologists to have a catheter suggestion before starting the angiography.

Alternative Abstract:
Alternative AbstractLanguage
Herzerkrankungen sind die häufigste Todesursache in den entwickelten Ländern. In den Entwicklungsländern ist die Häufigkeit in den letzten Jahren stark angestiegen. Krankheiten der Koronararterien können mittels Katheterangiographie diagnostiziert werden. Während dieses Prozesses wird ein kleiner Schnitt in den oberen Oberschenkel gemacht. Dann wird eine kleine Röhre, genannt Katheter, in die Oberschenkelarterie eingeführt und in Richtung der Aorta geschoben. Danach wird das Kontrastmittel durch den Katheter injiziert und dem Blut der kleinen Gefäße zugegeben. Hierdurch erscheint das Blutgefäß undurchsichtiger, so dass klare Bilder von kleinen Gefäßen akquiriert werden können. Während der Angiographie ist die Auswahl geeigneter Katheter eine anspruchsvolle Aufgabe. Es gibt anatomische Variationen der Aorta und der Koronararterien bei verschiedenen Menschen. Für die Katheter-Auswahl, testen die Kardiologen verschiedene Katheter für einen Patienten und wählen den Besten abhängig von der Anatomie des Patienten. Diese Prozedur ist zeitaufwändig und es besteht ein geringes Krebsrisiko durch die übermäßige Strahlenbelastung. Es ist hilfreich für die Kardiologen im voraus den optimalen Katheter zu kennen, bevor sie tatsächlich mit der Angiographie beginnen. In dieser Arbeit werden wir uns mit diesem Problem beschäftigen und ein bildverarbeitungsbasiertes Verfahren vorschlagen, das zur Auswahl eines patienten-spezifisch optimalen Katheters dient.German
Place of Publication: Darmstadt
Classification DDC: 000 Allgemeines, Informatik, Informationswissenschaft > 004 Informatik
600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin, Gesundheit
Divisions: 20 Department of Computer Science > Interactive Graphics Systems
Date Deposited: 16 Jan 2013 15:33
Last Modified: 17 Jan 2013 11:12
URN: urn:nbn:de:tuda-tuprints-32634
Referees: Fellner, Dr. techn Dieter W. and Voelker, Dr. med. Wolfram
Refereed: December 2012
URI: http://tuprints.ulb.tu-darmstadt.de/id/eprint/3263
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