Preliminary Study About The Differential Diagnosis Value Of Ultrasonography On The Benign And Malignant Peripheral Lung Lesions

ObjectiveThis study aimed at exploring the ultrasonographic features and differential diagnosis value of benign and malignant peripheral lung lesions using the two-dimensional gray-scale sonography, Color Doppler Flow Imaging and Acoustic Radiation Force Impulse in determining the nature of the lesions. The optimum sonographic characteristics and different parameter index scopes of benign and malignant lung masses were obtained, and a new simple non-invasive auxiliary examination method for the diagnosis of lung disease was also provided.Material and methods1. Cases data83hospitalized patients with peripheral lung lesions in Qilu Hospital of Shandong University from November2012to March2014were reviewed and all the patients were divided into2groups:37cases of benign masses and46cases of malignant masses. In all the cases, there were51males (aging at35-73years, with mean age of53.2±13.1years)and32females(aging at23-69years, with mean age of56.1±11.3years). All of the involved patients underwent CT examinations and were initially diagnosed as peripheral lung lesions.2. Instrument and examination methodsGE LOGIQ E9(GE Medical Systems Ultrasound and Primary Care Diagnostics, Wauwatosa, USA) Color Doppler diagnostic instrument was used to get the two-dimensional gray-scale sonography and Color Doppler Flow Imaging of the lung mass, a Cl-5convex array probe with a central frequency of1.0-5.0MHz was used in this process. Then the Siemens AcusonS2000(Siemens Medical Solutions, Mountain View, California, USA) Color Doppler ultrasound system with VTQ quantitative analysis software and4C1convex array probe with a central frequency of3.0-4.5MHz was used to get the acoustic radiation force impulse imaging, the scanning depth of the probe ranged from2.0cm to6.0cm and the sampling frame size was fixed at1.0X0.5cm2.Firstly, conventional ultrasound was used to scan the Region Of Interest, then the masses were shown on the image with the ultrasound guidance, each nodule’s size, echo, boundary and other sonographic characteristics were observed; Secondly, the color doppler imaging technology was used to detect blood flow pattern of the mass and pulse doppler was used to sample the blood flow pattern within the mass for spectral analysis to get PSV, RI and PI values. The test was randomly measured three times continuously, and the spectral waveforms kept consistent in three consecutive cardiac cycles were deemed to meet the requirements; Finally, the VTQ function was used to obtain the SWV values, then sampled at different parts of the same lesion for five times, taking the average values as the final results. All the measurements were carried out when the patients’ breath was being held.3. Statistical analysis methodThe data were analyzed using SPSS19.0software and the measurement data were presented as the mean±standard deviation. The difference of the benign group and malignant group values (maximum diameter, PSV, RI, PI, SWV) were compared with the homogeneity test of variance and then Independent-Samples T test was used, the difference was considered statistically significant when P<0.05. Comparing the SWV values between the benign group and the malignant group, the Receiver Operator Characteristic (ROC) curve was established by the two groups’data, when the sum of sensitivity and specificity tended to maximum, the corresponding parameter was the truncated value.ResultsThe average size of benign masses was4.6±1.5cm and that of malignant masses was5.7±2.3cm, there was no significant difference between the two groups (P>0.05).The PSV of the benign group and the malignant group were28.11±8.54cm/s and30.68±9.44cm/s respectively, there was no significant difference either (P>0.05).Comparing the PI, RI values of benign group with the malignant group, there was significant difference between the two groups (P<0.05) with the values of benign group being greater than the malignant group. The SWV of the benign masses and malignant masses were1.14±0.52m/s and1.94±0.64m/s, there was significant difference between the two groups (P<0.05), and the values of malignant group were greater than the benign group.According to the Receiver operating characteristic (ROC) curve, we can find out that the area under the curve was0.843and the cut-off point of SWV was1.43m/s, corresponding to the sensitivity, specificity, positive predictive value and negative predictive value were78.1%、79.4%、78.8%and78.2%, respectively.ConclusionThere were significant differences between ultrasonic characteristics, SWV, PI and RI of lung benign masses and that of malignant masses. Therefore, using various ultrasound imaging techniques to give qualitative or quantitative assessment on the nature of peripheral lung masses provided a quick, real-time diagnostic, it can assist clinicians in making an accurate diagnosis, prevent the aggravation, and enable early intervention measures. As a new diagnostic concept, ultrasound makes up for the traditional diagnostic methods and provides extensive application prospects, which has been proved to be an important ancillary diagnostic tool as well.