| [Objective]To explore the value of DSCT dual-energy technique in the clinical diagnosis of gouty arthritis.[Material and Methods]1. The animal experiments:The New Zealand rabbit was injected sodium urate to the limbs joints and back subcutaneous to induce acute gouty arthritis. The pig was fed high-protein and high-purine foods for about1year to lead chronic gouty arthritis. Then we use DSCT dual-energy scanning to observe if there are with or without green markers to form in the injection areas of the rabbit and in the trotters tendon areas. Then we take the tendon to analysis by Ion Chromatography if the green markers seen by DSCT were uric acid salt crystals.2. The clinical research:154patients were selected from2009to2011in the First Affiliated Hospital of Kunming Medical University who were scanned by DSCT dual energy technique. There were112males and42females. The scanned site included the bilateral foot, hand, knee, elbow and sternoclavicular joint. They were divided into three groups based on clinical data and laboratory tests. Group A:clinical diagnosis of gouty arthritis49cases, in it,43cases had a high uric acid,6cases in the normal range. Group B:clinical suspected gouty arthritis but not yet confirmed11cases,5cases had a high blood uric acid. Group C (control group):94cases, which were10cases of both hands,44cases of both feet.25cases of both knees.15cases of both elbow, were selected by trauma. bone tumors and ligament repair postoperative treatment. None of them had hyperuricemia, gout family history and gout suspicious signs. All the patients were scanned by DSCT dual energy technique. The output images were sent to Gout software, which could display the crystal of uric acid salt on target positions through color marked MPR and VRT images to diagnosed gouty arthritis.[Results]1. The animal experiment:injection with uric acid sodium to animals to produce gouty arthritis can not be detected by the the DSCT dual Gout software. By high purine and high protein concentrate feeding the pig to induce chronic gouty arthritis can be detected by DSCT dual-energy the Gout software.2. The clinical research:(1)47cases of urate crystals were detected in49cases(A group). Control group of94cases,4cases urate crystals were detected.(2)75cases urate crystals were detected Group in80cases of feet in A and B group, which in metatarsophalangeal joint, ankle, tarsus, toe next to the calcaneus. The majority of patients with first metatarsophalangeal joint were detected urate crystals.60cases of urate crystals were detected in66cases of knees, which around the knee ligaments and joint cavity.24cases of urate crystals were detected in28cases of hands, which in the interphalangeal joints, metacarpophalangeal joints, wrist joints.2cases of elbow had no positive detection.2cases in sternoclavicular joint had positive detection, which around the sternoclavicular joint.(3)43cases were detected uric acid salt crystals in43high blood uric acid patients.4cases were detected urate crystals in6normal serum uric acid patients. By the chi-square test,χ=14.943. P=0.013<0.05, the difference was statistically significant.(4)In the clinically suspected but not yet confirmed cases,3cases were diagnosed as gouty arthritis by laboratory tests and clinical treatment effect at last.(5)In the control group,4cases of94patients were detected urate crystals, which were all of acute trauma fracture patients.(6)In group A,35cases of49patients were found tophi by clinical examination, which were detected47cases of urate crystals by DSCT. In the35cases of tophi, urate crystals were detected in all of them. In the14cases of non-tophi patients, DSCT detected12cases of urate crystals. Based on paired chi-square test, P=0.000<0.05, there was significant difference.(7)Based on clinical diagnosis/screening test, the sensitivity of the DSCT detection of gouty arthritis is about 95.9%. specificity is about95.7%. false negative rate is about4.1%. false positive rate is about4.3%, negative predictive value is about97.8%, positive predictive value is about92.2%.(8)In A, B and C group (154people), the average CTDIvol (mGy) is9.893±1.938. The average DTP (mGyxcm) is244.91±57.985. The average ED (mSv) is2.957±0.436.[Conclusion]1. The sensitivity of the DSCT detection of gouty arthritis is about95.9%. specificity is about95.7%, false negative rate is about4.1%, false positive rate is about4.3%, negative predictive value is about97.8%, positive predictive value is about92.2%.2. DSCT dual-energy technique has a high detection rate of urate crystals. It can detect more parts of urate crystals than clinical findings. It can also detect urate crystals where the biopsy can not reach, false negative in some pathological examinations and sub-clinical gouty arthritis.3. DSCT can provide more information for differentiating clinical atypical gouty arthritis.4. For the rare site of gouty arthritis, DSCT may be the only preoperative method to help diagnose.5. Patients with high blood uric acid may likely have gout arthritis than those who has a normal blood uric acid.6.Only one-time scanning can DSCT analyze the bone, soft tissue, the vascular around the tophi and urate crystals. It is fast. simple, noninvasive. high sensitivity and specificity and can recommended as a one-stop images of gouty arthritis. |
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