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Program Information

New Prospective 4DCT

T Pan

T Pan1*, (1) UT MD Anderson Cancer Center, Houston, TX


TH-CD-303-5 (Thursday, July 16, 2015) 10:00 AM - 12:00 PM Room: 303

Purpose: It was reported by Yamamoto et al in 2008 that 90% of the 4DCT patient studies and 30% of the lung or mediastinal tumors were with at least one artifact caused by irregular respiration in 50 patients. A prospective 4DCT based on real-time monitoring of the respiratory signal was proposed on a single-slice Philips PQ-5000 scanner to fix the problem by Keall et al in 2007. However, there has been no progress to make prospective 4D-CT available in the modern multi-slice CT scanners (MSCT). To fill this void, we have designed a new prospective and practical 4DCT without any addition of hardware or software on MSCT.

Methods: We utilize the independence property of the cine CT scans in the design of the new prospective cine 4DCT. During the cine-CT scan of each position, the scan can be stopped if an irregular respiration occurs and can be resumed when the respiration becomes regular. This process can be repeated as many times as needed. A retrospective cine CT image reconstruction is initiated after the scan to remove the incomplete steps associated with the irregular respiratory cycles. The end result is a 4DCT free of irregular respiration. We conducted an IRB protocol to recruit 10 patients to prove this concept.

Results: Two of the 10 patients exhibited an irregular respiratory cycle during 4D-CT, and their 4DCT data acquisitions were stopped due to the irregularities, and resumed when their respiration became normal. The artifacts associated with the irregular respiratory cycles were effectively removed in both patients.

Conclusion: We have designed a new prospective 4DCT scan and processing technique to remove irregular respiratory cycles and to mitigate their impact to the 4DCT imaging. The technique can be practiced in the 4DCT on the GE MSCT scanners without any addition of hardware or software.

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