Perfusion Imaging With 64-Slice CT In Solitary Pulmonary Spherical Lesions

This study was divided into two parts: Part One, to evaluate the stability and reliability of postprocessing techniques in 64-slice CT pulmonary perfusion; Part Two, to study the hemodynamic changes of the solitary pulmonary spherical Lesions and the peri-lesions via the measurement of CT perfusion parameters and to possess the diagnostic values of these parameters.Part One: The stability of the postprocessing technology of pulmonary perfusion imaging with 64-slice CT scannerObjective To evaluate the stability and reliability of perfusion parameters got via postprocessing techniques in 64-slice CT pulmonary perfusion.Materials and methods Ten patients (7 males and 3 females) with solitary pulmonary spherical lesions were performed with the body perfusion technique of 64-slice CT scanner. The scanning scope included 2.88cm through the maximum slice of lesions; injection rate was set at 6.0 mL/s via high pressure syringe; scanning was started 2s later after injection and lasted 30s. All raw data were postprocessed via Syngo workstation by two independent observers, trained to use the technology proficiently, to get the perfusion images and the parameters (BF, BV, PS, and MTT). A month later, using the same technology, an observer of the two postprocessed the raw data again. Inter- and intraobserver agreement was assessed using the Reliability Analysis and the Bland-Altman test.Results⑴The mean difference for interobserver agreement (95% limits of agreement) was BF 2.10 (-3.7 to 7.9), BV -0.75 (-2.33 to 0.83), PS 0.62 (-3.67 to 4.91), MTT -1.00 (-1.8 to 2.8). The intraclass correlation coefficient (95% confidence of interval) was 0.87(0.74 to 0.92), 0.85(0.71 to 0.94), 0.90(0.81 to 0.98), 0.93(0.76 to 0.98) for BF, BV, PS and MTT respectively.⑵The mean difference for intraobserver agreement (95% limits of agreement) was BF -0.71(-1.8 to 0.38), BV 0.06 (-0.337 to 0.457), PS -0.71 (-1.89 to 1.2), MTT -0.70 (-2.5 to 1.1). The intraclass correlation coefficient (95% confidence of interval) was 0.93(0.88 to 0.98), 0.88(0.75 to 0.93), 0.97(0.94 to 0.99), 0.96(0.86 to 0.99) for BF, BV, PS and MTT respectively.Conclusion There is great stability for CT perfusion parameters measured via postprocessing techniques in 64-slice CT pulmonary perfusion, all parameters (BF, BV, PS, and MTT) can be used for quantitative analysis.Part Two:Value of CT perfusion parameters of lesions and peri-lesions in diagnosing the solitary pulmonary spherical lesions.Objective To study the value of CT perfusion parameters of lesions and peri-lesions in diagnosing the solitary pulmonary spherical lesions.Materials and Methods Fifty-seven cases of the solitary pulmonary spherical lesions divided into three groups (37 with malignant masses, 11 with benign masses, and 9 with inflammatory masses), underwent CTPI. Among them, 22 cases (14 with malignant masses, 8 with benign masses) located at the region with pulmonary artery or right ventricle were underwent CTPI of peri-lesion. The scanning scope included 2.88cm through the maximum slice of lesions; injection rate was set at 6.0 mL/s via high pressure syringe; scanning was started 2s delay after injection and lasted 30s. All raw data were postprocessed via Syngo workstation to produce CTPI maps and parameters. Immunohistostaining was achieved with pieces, near the lesions within 1.0cm to and opposite the hi1um of lung, got after surgical resection in patients received peri-lesion CTPI to count MVD.Results⑴The differences of BF, BV, PS between malignant and benign group were statistically significant(P <0.01), when BF≥55, BV≥6 and PS≥23 were set as the threshold, the sensitivity was 97.3%, specificity was 94.6%. The differences of BF, BV between inflammatory and benign group were statistically significant(P <0.01), when BF≥55 and BV≥6 were set as the threshold, the sensitivity was 90.9%, specificity was 89.9%; The difference of PS was not significant(P>0.05). The differences of BF, BV between inflammatory and malignant group were not statistically significant(P>0.05), The difference of PS was statistically significant(P <0.01), when PS≥23 were set as the threshold, the sensitivity was 93.6%, specificity was 90.2%. The differences of MTT among three groups were not significant(P>0.05).⑵The differences of CTPI parameters were not statistically significant between peri-lesions and the same region of opposite lung of benign group or malignant group. The differences of peri-lesions CTPI parameters were not statistically significant between benign and malignant group.⑶T he differences of MVD were not statistically significant between peri-lesions and the same lung of benign group or malignant group(P>0.05). The differences of relative MVD in peri-lesions were not statistically significant between benign and malignant group(P>0.05).Conclusion⑴Parameters of 64-slice CTPI may objectively reflect the hemodynamic changes of the pulmonary spherical lesions and peri-lesions. There were different diagnostic efficacies of BF, BV and PS. Diagnostic efficacy would be higher if they were associated.⑵There were not definite help of CTPI parameters of peri-lesions in diagnosing the pulmonary spherical lesions.