Preliminary Studies Of CT Perfusion Imaging In Lung Cancer Classification And Evaluation Of Chemotherapy Response

Partâ… : The study of the effect of acquisition time onlung cancer perfusion imaging parametersObjective: To investigate the effect of acquisition time on lungcancer perfusion imaging, and to explore the optimal acquisition time forlung cancer perfusion imaging.Materials and Methods: Forty-five patients with histologicallyproven lung cancer were involved in this study. A conventional thoracicCT scan was obtained as a routine to locate the lung lesions. Dynamicscans were performed at the location of the lesions with 50ml nonioniccontrast administration (300 mgI/mi) at the speed of 6 ml/s. There arethree separate scan sequences for each patient with 30 seconds' scanduration respectively. The patient was asked to breathe in and out duringthe 10s interval of each scan sequence. For each scan sequence, therotation time is 0.5s, and scan interval is 0.5s,2.5s and 4.5s, respectively.Data postprocessing was performed on Siemens workstation using lungcancer analyzing software in the package of Body Perfusion. Perfusionmeasurements were calculated for each acquisition time. The perfusionvalues of three acquisition times were then compared using the paired ttest.Results: No significant differences for BV,BF,TTS,TTP valuesamong three different acquisition times. No significant difference for thevalues of PS and PBV between data acquired for 30s and 60s. Significantdifferences for value of PS and PBV were noted between data acquiredfor 90s and 30s and 90s and 60s. The value of PS decreased with theincrease of the acquired time increase, whereas, the value of PBV increased with the acquisition time.Conclusion: Acquisition time of CT perfusion imaging had asignificant influence on PS and PBV values. PS and PBV values obtainedat different acquisition times were not comparable. In The Patlakperfusion analysis, the PS value decreases with acquisition time increasesand the PBV value increases with the acquisition time. For themeasurement of BF and BV values based on slope method, 30 secondsacquisition time may be enough. However, the measurement of PS andPBV values based on Patlak method, the acquisition time of 90 secondsmay be necessary. Partâ…¡: The value of CT perfusion imaging onclassification of lung malignanciesObjective: To investigate the hemodynamic features of differentradiological and cytopathological types of lung malignancies onmultislice spiral CT perfusion imaging.Materials and Methods: Forty-five patients with histologicallyproven lung cancers were involved in this study. A conventional thoracicCT was obtained as a routine to locate the lung lesions. Fifty milliliters ofnonionic contrast(300 mgI/ml) were injected at 6 ml/s, then, followed bydynamic CT scans at the same location. There are three separate scansequences with duration of 30 seconds for each patient. The patient wasasked to breathe in and out during the 10s interval of each scan sequence.For each scan sequence, the rotation time is 0.5s, and scan interval is0.5s,2.5s and 4.5s, respectively. Data postprocessing was performed onSiemens workstation using lung cancer analyzing software in the packageof Body Perfusion. The perfusion measurements were calculated for eachdynamic scan. The perfusion values of different types of lungmalignancies were then compared using analysis of varianceResults: No significant differences between the perfusion values ofcentral lung cancers and that of the peripheral lung cancers. The time tostart perfusion of lung adenocarcinomas was later than the time ofsquamous cell carcinomas and small cell undifferentiated carcinomas.The time to peak perfusion of squamous cell carcinomas was earlier thanlung adenocarcinomas and small cell undifferentiated carcinomas. Nosignificant differences were noted on other perfusion values amongdifferent cytopathological types of lung malignancies. Conclusion: Significant differences were noted on the values oftime to start and time to peak perfusion among different cytopathologicaltypes of lung malignancies, but further investigation is necessary for theirsignificance of prediction the cytopathology of lung malignancies. Nosignificant differences were noted on other perfusion values amongdifferent types of lung malignancies. They may be of little help ondifferentiation of different cytopathological types of lung malignancies. Partâ…¢: Application of CT Perfusion Imaging in Evaluation of Lung Cancer Chemotherapy Response: Preliminary StudyObjective: To investigate the diffferences on lung malignanciesperfusion measurement before and after chemotherapy; To investigate thepredictive value of perfusion measurement on chemotherapy responses oflung malignancies.Materials and Methods: Eight patients confirmed byhistopathology were involved in this study. All eight patients underwentchemotherapy. Three-dimensional volume measurements and perfusionmeasurements were performed before and after chemotherapies. Thepostchemotherapy evaluations were performed at one week, one month,two months, and three months. Pre and postchemotherapy volumetricmeasurements and the perfusion measurements were compared.Chemotherapy response for lung malignancies was also evaluated usingthree-dimensional volume measurement and perfusion measurement.Results: Only one of eihgt patients had partial response accordingto the RECIST criteria, and its value of BF and BV were reduced afterchemotherapy. More than 30ï¼…volumetric measurements decrease inthree cases was noted after one month of chemotherapy. Five patients'volume decrease less than 30ï¼…, and their BF and BV values weresignificant lower than the other three patients'.Conclusion: Lower prechemotherapy values of BF and BV onperfusion measurement may indicate less chemotherapy responses of lungmalignancies. Further investigations on larger sample basis are necessary.