| Background and objectiveLiver is the biggest and the most important digestive gland in our body. It plays an important role in maintaining the life activities of human and participates in the processes of digestive, metabolism, secretion, detoxification, excretion, phagocytosis and defense, etc. In recent years, with the development of science and technology, imaging techniques and checking methods of ultrasonic medicine is developing rapidly, ultrasound has the advantages of non-invasive, real-time, efficient, cheap, which make it be widely used in clinical diagnosis and treatment, the detection rate and the accuracy of location and qualitative diagnosis of focal liver lesions have risen greatly. Focal liver lesions mainly include benign lesions, such as hepatic cyst, hepatic hemangioma, hepatic focal nodular hyperplasia (FNH), solitary necrotic nodule of liver (SNNL), and primary malignant, secondary malignant tumors. Since the biological characteristics of benign lesions are apparently different from that of malignant lesions, the effects of them on individuals are significantly different, identifying them have important implication for the choice of clinical treatment strategy and prognosis prediction.With the influence of physical properties of ultrasound waves, performance of ultrasonic diagnostic instrument, operating methods of examiners, conventional ultrasound has some difficulties in displaying equal echo lesions, lesions under the background of liver cirrhosis, lesions after several interventionl therapies, subphrenic lesions, lesions obscured by excessive gas of gastrointestinal tract, etc. Whereas computed tomography (CT) is less susceptible to these factors, it has better imaging quality. At the same time, CT has some shortcomings of poor real-time capability, high cost, radioactive damage. Image fusion successfully combining the advantages of two types of imaging techniques, namely, real-time of ultrasound and spatial resolution of CT, and that it uses magnetic localization technology to pair and fuse ultrasound images with CT images in space, which makes both of them display in the same time and in all planes come true. The technique not only expands its imaging range, but also has ability to qualitative diagnosis of lesions, and it represents a bright prospect in clinical application.In this study, to determine the feasibility and accuracy of image fusion, we use it to localize and qualitative diagnosis of focal liver lesions, and the value of clinical application of this technique are investigated.Materials and methods1. Clinical dataForty-two patients diagnosed with liver focal lesions in Qilu hospital of Shandong University from July2013to January2014were examined, including24males and18females, aging at31to73years, with mean age of (55.88±9.94) years. Among them, seven people have a prior history of colon cancer, three people have a prior history of renal cancer, one people have a prior history of lung cancer, one people have a prior history of stomach cancer, one people have a prior history of cervical cancer.2. Materials and methods2.1Experiment instruments Ultrasonic instrument is LOGIQ E9color Doppler ultrasonic diagnostic apparatus made by GE company (USA), which equipped with C5-1broadband convex array probe with frequency of3to5MHz. Image fusion system is constituted by image fusion software installed in ultrasonic diagnostic apparatus, field frequency signal generator, tracing instruments, tool connection unit, etc. SIEMENS16-layer spiral CT and Philip MAX80004layer spiral CT were chosen, contrast agent is lopromide or lohexol. 2.2Methods Images scanned by contrast-enhanced CT, which can display intrahepatic vessels and lesions clearly were chosen and imported into ultrasonic diagnostic apparatus in DICOM standard. Fusing images use point-face matching method of internal calibration. After the success of imaging fusion, the time needed for image fusion, the number and ultrasonic features of lesions are recorded, at the same time, qualitative diagnosis of lesions are made. Comparing the accuracy of qualitative diagnosis of lesions of image fusion and that of CT examination technique, through contrast diagnose to conclusion drawn from clinical feature, other imaging examination, laboratory examination, postoperative pathologic results, biopsy and follow-up.3. Statistical analysisSPSS19.0software was used for statistical analysis. Measure data were expressed as the mean and standard deviation. Two independent samples non-parameter test was applied in the intergroup comparison.Results1. The success rates of image fusion is100%in forty-two patients, the time needed for image fusion ranging from four minutes to nine minutes, with mean time of (5.90±1.20) minutes.2. There are sixty-four liver focal lesions in forty-two patents, among them twenty-six people only have one lesion, thirteen people have two lesions, four people have three lesions. The diameters of lesions vary between0.29to10.05centimeters, with average diameter of (1.92±1.97) centimeters. Conventional ultrasound can show fifty-one lesions, with the detection rate is79.69%(51/64), contrast-enhanced CT can display sixty-three lesions, with the detection rate is98.43%(63/64), while image fusion can show six-two successfully, with the detection rate is96.87%(62/64), sixty-one of them are consistent with the location of lesions in CT images, one lesion was not displayed in CT images. The differences of the rate of detection rate between conventional ultrasound and image fusion was statistically significant (P<0.05). The differences of the detection rate between contrast-enhanced CT and image fusion was not statistically significant (P>0.05).3. Among sixty-four lesions, thirty-eight lesions were definitely diagnosed by CT, with the rate of definite diagnosis is58.46%(38/64), which consist of seventeen hepatic hemangioma lesions, one hepatic pseudolipoma lesion, eight hepatocellular carcinoma lesions, twelve metastatic hepatic carcinoma lesions. The rest of twenty-six lesions were not diagnosed clearly. Fifty-nine lesions were definitely diagnosed by image fusion, with the rate of definite diagnosis is92.18%(59/64), including thirty-six lesions diagnosed consistent with CT, and also including nine hepatic hemangioma lesions, one SNNL lesion, five hepatocelluar carcinoma lesions, eight metastatic hepatic carcinoma lesions. The differences of the rate of definite diagnosis between contrast-enhanced CT and image fusion was statistically significant (P<0.05).4. Comparing with final clinical diagnosis, the accuracy rate of CT is59.38%(38/64), including seventeen hepatic hemangioma lesions, one hepatic pseudolipoma lesion, eight hepatocellular carcinoma lesions, eleven metastatic hepatic carcinoma lesions, whereas the accuracy rate of image fusion is89.06%(57/64), including twenty-six hepatic hemangioma lesions, one SNNL lesion, one inflammatory pseudotumor of the liver lesion, eleven hepatocellular carcinoma lesions, twenty-two metastatic hepatic carcinoma lesions. The differences of the accuracy rate of contrast-enhanced CT and image fusion was statistically significant (P<0.05).ConclusionImage fusion with features such as easy operation, safe and non-invasion has opened the new way for the detection, localization and definite diagnosis of liver focal lesions, and it represents a bright prospect in clinical application. |
PDF Full Text Request