Wyniki wyszukiwania - BazTech

1

Automatic validation of the gantry tilt in a computed tomography scanner using a head polymethyl methacrylate phantom

Noviliawati Rakhma, Anam Choirul, Sutanto Heri, Dougherty Geoff, Mak’ruf Muhammad Ridha

Polish Journal of Medical Physics and Engineering

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2021

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Vol. 27, Iss. 1

57--62

EN

The purpose of this study was to develop an automatic method for validating the computed tomography gantry tilt. A head polymethyl methacrylate phantom with a diameter of 16 cm was used. Gantry tilt angles were measured both manually and automatically. Manual measurements were performed by measuring the length of the anteroposterior and lateral diameters from acquired images using electronic calipers. Automatic measurements consisted of a number of steps: phantom segmentation, determination of the center of the phantom, measurement of the anteroposterior and lateral diameters, and computation of the gantry tilt angle. The method was implemented on the gantry angles from 0° to 15°. The proposed method of measuring gantry angles produced accurate gantry tilt angles. The differences with the angles displayed on the gantry were less than 1°. The results of the automatic method were the same as those of the manual method (R2 > 0.98).

2

Test położenia gantry symulatora TK

Skrzyński Witold

Inżynier i Fizyk Medyczny

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2021

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Vol. 10, nr 4

341--344

PL

W pracy zaprezentowano sposób wykonania testu położenia gantry symulatora TK (GE Discovery RT). Wykorzystano fantom Catphan, ustawiony na stole tomografu i wypoziomowany. Zarejestrowano serię obrazów pokrywających początkową część fantomu. Obrazowanie powtórzono dla różnych nastawionych wartości położenia gantry z zakresu od -1° do +1°. Rzeczywiste położenie gantry wyznaczono w oparciu o analizę wartości HU w wybranych obszarach obrazu fantomu. Uzyskane wyniki wskazują na przydatność zaprezentowanej metody.

EN

The paper presents the method of performing the gantry tilt test for a CT simulator (GE Discovery). The Catphan phantom was used, placed on the CT simulator table and leveled. A series of images were acquired, covering the leading part of the phantom. Imaging was repeated for set gantry tilt values ranging from -1° to +1°. The actual gantry tilt was determined based on the analysis of HU values in selected areas of the phantom image. The obtained results show the usefulness of the presented method.

3

Correction of error in 3D reconstruction induced by CT gantry tilt

Tomaka A., Trzeszkowska-Rotkegel S., Tarnawski M.

Journal of Medical Informatics & Technologies

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2008

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Vol. 12

169--175

EN

The paper presents the problems connected with 3D reconstruction of CT slices of the database of orthodontic patients, using the commercial application software. Serious errors occurred for scans taken with a tilted CT gantry and inverse table movement. A compensation of the errors is proposed and the results after the compensation are verified by comparison to laser scans for a reference object, and to the measurements performed using the dedicated software of the CT station for selected cases in the database.