TY - JOUR
T1 - Decay constant of Doppler flow waveform as a possible indicator of ovarian malignancy
AU - Tepper, Ron
AU - Keselbrener, Laurence
AU - Manor, Moshe
AU - Eyal, Shulamit
AU - Beyth, Yoram
AU - Zimmeri, Yair
AU - Akselrod, Solange
N1 - Funding Information:
Acknowledgements--The authors thank Sally Esakov for technical assistance, and the Abramson Research Fund of the Tel Aviv University for their support.
PY - 1997
Y1 - 1997
N2 - The objectives of this study were to analyze the decay constant (τ) of the Doppler flow waveform in ovarian tumors; to determine if differences in this constant can discriminate between malignant and benign ovarian tumors; and to compare the decay constant to the known resistive index (RI), in order to determine its potential prognostic application. Patients with ovarian masses (46) were evaluated in a retrospective study; 13 had malignant tumors, 7 showed tumors with low malignant potential (LMP), 11 had benign masses, 4 had secondary ovarian metastases and 11 had functional ovarian masses. Doppler flow waves measured in the ovary before operation were analyzed from archival videotapes. The RI was calculated preoperatively, and the decay constant of the flow waveform was analyzed retrospectively. We approximated the decaying portion of the flow waveform from the systolic peak to the diastolic level to an exponential curve. Then, the decay constant associated with the flow signal was compared for different types of ovarian pathology. Ovaries with malignancies showed significantly higher mean values for the decay constant (89.7; 95% confidence interval 60.0-119.3) than those with benign tumors (41.8; 25.7-57.9) (p < 0.007), where τ is provided in pixels (in this study each pixel equals approximately 11.4 ms). The mean RI value for malignant tumors was 0.44 ± 0.12 whereas, in benign tumors, it was 0.622 ± 0.11. For the benign tumors, both τ and RI did not differ significantly from the measured indices in LMP tumors, metastases and functional ovarian findings. In addition, when the cutoff value of τ was set at 48, 92.3% of all malignancies were identifiable using only τ. This preliminary study indicates that the decay constant of the Doppler flow waveform is able to discriminate between malignant and benign masses and may, thus, provide substantial assistance as an additional parameter in the diagnosis of malignant ovarian tumors in postmenopausal patients.
AB - The objectives of this study were to analyze the decay constant (τ) of the Doppler flow waveform in ovarian tumors; to determine if differences in this constant can discriminate between malignant and benign ovarian tumors; and to compare the decay constant to the known resistive index (RI), in order to determine its potential prognostic application. Patients with ovarian masses (46) were evaluated in a retrospective study; 13 had malignant tumors, 7 showed tumors with low malignant potential (LMP), 11 had benign masses, 4 had secondary ovarian metastases and 11 had functional ovarian masses. Doppler flow waves measured in the ovary before operation were analyzed from archival videotapes. The RI was calculated preoperatively, and the decay constant of the flow waveform was analyzed retrospectively. We approximated the decaying portion of the flow waveform from the systolic peak to the diastolic level to an exponential curve. Then, the decay constant associated with the flow signal was compared for different types of ovarian pathology. Ovaries with malignancies showed significantly higher mean values for the decay constant (89.7; 95% confidence interval 60.0-119.3) than those with benign tumors (41.8; 25.7-57.9) (p < 0.007), where τ is provided in pixels (in this study each pixel equals approximately 11.4 ms). The mean RI value for malignant tumors was 0.44 ± 0.12 whereas, in benign tumors, it was 0.622 ± 0.11. For the benign tumors, both τ and RI did not differ significantly from the measured indices in LMP tumors, metastases and functional ovarian findings. In addition, when the cutoff value of τ was set at 48, 92.3% of all malignancies were identifiable using only τ. This preliminary study indicates that the decay constant of the Doppler flow waveform is able to discriminate between malignant and benign masses and may, thus, provide substantial assistance as an additional parameter in the diagnosis of malignant ovarian tumors in postmenopausal patients.
KW - Decay constant
KW - Doppler flow waveform
KW - Ovarian neoplasm
UR - http://www.scopus.com/inward/record.url?scp=0030806543&partnerID=8YFLogxK
U2 - 10.1016/S0301-5629(97)00125-7
DO - 10.1016/S0301-5629(97)00125-7
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AN - SCOPUS:0030806543
SN - 0301-5629
VL - 23
SP - 1171
EP - 1177
JO - Ultrasound in Medicine and Biology
JF - Ultrasound in Medicine and Biology
IS - 8
ER -