Four dimensional CT imaging: a review of current technologies and modalities

Moorrees, Joshua; Bezak, Eva

doi:10.1007/s13246-012-0124-6

Cited by 26 publications

(15 citation statements)

References 72 publications

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“…4D CT incorporates the patient's respiratory information into a stack of 3D images such that the sequential snapshot images at different respiratory phases can be reconstructed 4, 5. With the 4D images, the tumor excursion range with respiration can be obtained and a patient‐specific internal margin can be decided for contouring the internal tumor volume 1, 6, 7.…”

Section: Introductionmentioning

confidence: 99%

“…In the treatment planning process, if a gated treatment plan is decided, the 4D images are combined with the respiratory motion data to select an appropriate gating window 10. Several respiratory monitoring systems using external surrogates are available in the market for the purposes of measuring respiratory motion for 4D CT imaging and gated treatment 5. These systems measure the respiratory motion as the surface movement of abdomen or chest wall (eg, Real‐Time Position Management [RPM],4 C‐RAD,13 GateCT14), or the pressure change in a belt wrapped around the abdomen (eg, ANZAI,15 Bellows16), etc.…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of the combined use of two different respiratory monitoring systems for 4D CT simulation and gated treatment

Liu

Lin

Fan

et al. 2018

J Applied Clin Med Phys

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PurposeTwo different respiratory monitoring systems (Varian's Real‐Time Position Management (RPM) System and Siemens’ ANZAI belt Respiratory Gating System) are compared in the context of respiratory signals and 4D CT images that are accordingly reconstructed. This study aims to evaluate the feasibility of combined use of RPM and ANZAI systems for 4DCT simulation and gated radiotherapy treatment, respectively.MethodsThe RPM infrared reflecting marker and the ANZAI belt pressure sensor were both placed on the patient's abdomen during 4DCT scans. The respiratory signal collected by the two systems was synchronized. Fifteen patients were enrolled for respiratory signal collection and analysis. The discrepancies between the RPM and ANZAI traces can be characterized by phase shift and shape distortion. To reveal the impact of the changes in respiratory signals on 4D images, two sets of 4D images based on the same patient's raw data were reconstructed using the RPM and ANZAI data for phase sorting, respectively. The volume of whole lung and the position of diaphragm apex were measured and compared for each respiratory phase.ResultsThe mean phase shift was measured as 0.2 ± 0.1 s averaged over 15 patients. The shape of the breathing trace was found to be in disagreement. For all the patients, the ANZAI trace had a steeper falloff in exhalation than RPM. The inhalation curve, however, was matched for nine patients, steeper in ANZAI for five patients and steeper in RPM for one patient. For 4D image comparison, the difference in whole‐lung volume was about −4% to +4% and the difference in diaphragm position was about −5 mm to +4 mm, compared in each individual phase and averaged over seven patients.ConclusionsCombined use of one system for 4D CT simulation and the other for gated treatment should be avoided as the resultant gating window would not fully match with each other due to the remarkable discrepancy in breathing traces acquired by the two different surrogate systems.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evaluation of the combined use of two different respiratory monitoring systems for 4D CT simulation and gated treatment

Liu

Lin

Fan

et al. 2018

J Applied Clin Med Phys

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“…These CTs can perform a subsecond scan, but there is usually no access to the devices and licenses needed to acquire a 4D CT study. The cost of commercial respiratory motion management systems for simulation can exceed $50K, (7,8) so the use of respiratory‐guided techniques is limited.…”

Section: Introductionmentioning

confidence: 99%

Moving stereotactic fiducial system to obtain a respiratory signal: proof of principle

Pinelo

Alfonso

Pérez

et al. 2016

J Applied Clin Med Phys

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The purpose of this study was to obtain a respiratory signal with the use of an add‐on device to a specific stereotactic body frame and evaluate precision and accuracy of the method, with the use of a dynamic phantom. The authors designed and constructed a simple add‐on device which, attached to a stereotactic body frame, provides information of the patient's respiratory signal in every CT axial image acquired. To assess the approach, 12 CT studies were acquired, on a phantom that simulates respiratory motion, which was placed inside the frame with the add‐on device. Images of the phantom with sinusoidal and shark‐fin motion patterns were acquired, with different amplitude in the movement of the external surrogate and the target. Cycle time was 6 s. Images were retrospectively processed to obtain a respiratory signal from the vertical movement of the “abdomen.” The obtained signal was adjusted to a sinusoidal function; the resultant amplitude and cycle time were compared with the preset function in the phantom. The cycle amplitude and time obtained with the method agreed with the preset values within 0.4 mm and 0.29 s, respectively. In the cases of sinusoidal movements the maximal discrepancy was less than 1 mm. A respiratory signal was obtained in all cine CT sequence studies with this method that consistently coincides with the preset motion of the phantom. The authors proposed a tool to obtain a respiratory signal based on information contained into the CT axial images.PACS number: 87.57qp

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“…Breath motion management methods for precision radiotherapy of HCC include active breathing control (ABC), abdominal compression and four-dimensional computed tomography (4D CT) techniques. In essence, dynamic 4D CT images could reflect the movement and deformation regularity of liver and tumors by sorting the volumetric CT images according to breath cycle which are recorded and segmented applying a respiratory position management (RPM) system [ 9 , 10 ]. Application of 4D CT in HCC radiotherapy has shown promising clinical outcomes.…”

Section: Introductionmentioning

confidence: 99%

Feasibility and potential benefits of defining the internal gross tumor volume of hepatocellular carcinoma using contrast-enhanced 4D CT images obtained by deformable registration

Gong

Wei

et al. 2014

Radiat Oncol

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ObjectiveTo study the feasibility and the potential benefits of defining the internal gross tumor volume (IGTV) of hepatocellular carcinoma (HCC) using contrast-enhanced 4D CT images obtained by combining arterial-phase (AP) contrast-enhanced (CE) 3D CT and non-contrast-enhanced (NCE) 4D CT images using deformable registration (DR).MethodsTen HCC patients who had received radiotherapy beforehand were selected for this study. The following CT simulation images were acquired sequentially: NCE 4D CT in free breathing, NCE 3D CT and APCE 3D CT in end-expiration breath holding. All 4D CT images were sorted into ten phases according to breath cycle (CT00 ~ CT90). Gross tumor volumes (GTVs) were contoured on all CT images and the IGTV-1 was obtained by merging the GTVs in each phase of 4D CT images. The GTV on the APCE 3D CT image was deformably registered to each 4D CT phase image according to liver shape using RayStationTM 3.99.0.7 version treatment planning system. The IGTV-DR was obtained by merging the GTVs after DR on the 4D CT images. Volume differences among the GTVs and between the IGTV-1 and the IGTV-DR were compared.ResultsThe edge of most lesions could be definitively identified using APCE 3D CT images compared to NCE 4D and 3D CT images. The GTV volume on APCE 3D CT images increased by an average of 34.79% (P < 0.05). There was no significant difference among the GTV volumes obtained using NCE 4D and 3D CT images (P > 0.05). The GTV volumes after DR on 4D CT different phase images increased by an average of 36.29% (P < 0.05), as was observed using the APCE 3D CT image (P > 0.05). Lastly, the volume of IGTV-DR increased by an average of 19.91% compared to that of IGTV-1 (P < 0.05).ConclusionNCE 4D CT imaging alone has the potential risk of missing a partial volume of the HCC. The combination of APCE 3D CT and NCE 4D CT images using the DR technique improved the accuracy of the definition of the IGTV in HCC.

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Four dimensional CT imaging: a review of current technologies and modalities

Cited by 26 publications

References 72 publications

Evaluation of the combined use of two different respiratory monitoring systems for 4D CT simulation and gated treatment

Evaluation of the combined use of two different respiratory monitoring systems for 4D CT simulation and gated treatment

Moving stereotactic fiducial system to obtain a respiratory signal: proof of principle

Feasibility and potential benefits of defining the internal gross tumor volume of hepatocellular carcinoma using contrast-enhanced 4D CT images obtained by deformable registration

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