| Objectives1. To investigate the scan methods, post-processing technology and application ofrenal CT perfusion imaging with deconvolution method.2. To explore the clinical value of CT perfusion imaging in diagnosis and differentialdiagnosis of renal space-occupying lesions, by analyzing the differences of perfusionparameter values quantitatively.Materials and Methods1. SubjectsBased on the select criterion, a total of 49 patients were sorted into 2 groups.Group A:21 patients with both two sides of kidney(normal group, n=42);Group B:28patients with unilateral space-occupying lesion were divided into 2 groups:benigngroup(n=18), including 8 cases of renal angiomyolipoma, 6 cases of renal cyst, 3cases of hematoma and 1 case of renal abscess;malignant group(n=10), including 6cases of suprarenal epithelioma, 1 case of renal chromophobe cell carcinoma, 1 caseof renal pelvic carcinoma, 1 case of nephroblastoma and 1 case of collecting ductcarcinoma.The uninvolved kidneys were used as controls(control group, n=28).2. Examination methodAfter plan scan, all patients were underwent single-level enhanced serial CTscanning with 16-detector row scanner(LightSpeed; GE Healthcare).The tableposition was decided according to the routine scanning images, and renal hilum or thecentre of mass should be included in the target cross-sections.The operatingparameters were as follows, scan mode: Cine Full, slice thickness: 5mm×4, scantime:ls, interval time:2s, tube voltage:120kV, tube current:40mAs and matrix:512×512.A bolus of 40ml contrast medium was injected at the rate of 4.0ml/s, then the scanning followed with 8 seconds delay.120 images were obtained within 30times of scanning.3. Post-processing data collectionAll sequences were transferred to AW4.2(GE Healthcare), and then analyzed byPerfusion 3 software package in kidney mode.Abdominal aorta was used as feedingartery, and regions of interest(ROIs) were drawn in renal cortex and lesion.Thetime-density curve(TDC) of ROI was automatically rendered, and the perfusionparameters including blood flow(BF), blood volume(BV), mean transit time(MTT)and permeability surface area product(PS) could be obtained directly.To observe thesharp of TDC and record all values of perfusion parameters which should bemeasured 2 times to get the mean values.4.Statistical analysisSPSS 13.0 was applied in this study.All values were expressed as the mean±standard deviation(SD) respectively.2 Paired-Samples T Test was applied to analyzethe differences of BF, BV, MTT and PS between left and right kidney in normalgroup.After test of homogeneity of variances,One-way ANOVA was applied toanalyze the values as homogeneity of variances, with LSD for two-two comparison,while Welch Test was applied to others, with Dunnett T3 for two-twocomparison.(a=0.05, P＜0.05)Results1. Representations of TDCAorta TDC: The pattern of TDC was single-peaked type, including base segment,ascending segment, descending segment and fiat segment in sequence.In details,firstly the base segment was short and even, then a sharp peak constructed by theascending and descending segment appeared, with the highest amplitude, finally theflat segment kept slight even and then declined slowly in the longest period.Renal cortex TDC: The pattern of TDC was single-peaked type, including basesegment, ascending segment, descending segment and fiat segment like the aortaTDC.In details,the base segment was even and more longer than that of aortaTDC.The slope of the ascending segment and the peak amplitude was depressed, and the amplitude of the flat segment was slightly lower than that of aorta.Malignant group TDC: The pattern was also single-peaked type, including basesegment, ascending segment, descending segment and flat segment like above.Thepeak was wider than that of aorta and renal cortex, and the amplitude was slightlylower than that of cortex.Benign group TDC: The pattern was no-peaked or single-peaked type, but theamplitude was lowest to distinguish from other groups.2. Perfusion parameters analysisIn normal group, the BV of renal cortex was 24.55±5.63 mL·100g-1, the BF446.95±103.97 mL·min-1·100g-1, the MTT 4.46±1.14 s, and the PS 64.52±13.10mL·min-1·100g-1.Significant difference of the values was not found between left andright kidney.The values of BV were 6.85±9.43 mL·100g-1(benign group), 15.95±12.53mL·100g-1(malignant group) and 24.82±7.35 mL·100g-1(control group).Significantdifference was observed between benign group, malignant group and control group,F=21.561, P=0.000.The value was highest in control group and lowest in benigngroup.The values of BF were 87.71±141.09 mL·min-1·100g-1 (benign group),240.79±219.14 mL·min-1·100g-1 (malignant group) and 413.09±138.77mL·min-1·100g-1 (control group).Significant difference was observed between benigngroup, malignant group and control group, F=24.160, P=0.000.The value was highestin control group and lowest in benign group.The values of MTT were 10.52±5.79 s (benign group), 7.78±3.44 s (malignantgroup) and 5.34±2.52 s (control group). Significant difference was observed betweenbenign group, malignant group and control group, F=7.469, P=0.004.Furthermor,two-two comparisons were used.And Significant difference was observed betweenbenign group and control group, but not observed in other pairs.The values of PS were 11.24±13.49 mL·min-1·100g-1 (benign group),23.22±14.28 mL·min-1·100g-1 (malignant group) and 58.21±15.83 mL·min-1·100g-1(control group). Significant difference was observed between benign group, malignant group and control group, F=59.871, P=0.000.The value was highest incontrol group and lowest in benign group.Briefly, the BV, BF and PS values of renal space-occupying lesions were lessthan that of cortex of the uninvolved kidney in the other side. Furthermore, the BV,BF and PS values of benign lesions were less than that of malignant ones.Conclusions1. With deconvolution method, CT perfusion imaging is helpful to assess the bloodflow of renal cortex and evaluate the renal function from different level.It is animportant functional imaging technique with a promising application prospect.2. In our renal CT perfusion method, the preparing before operation and the curvingof ROI affect the result obviously, and could be applied in clinical work simply.3. CT perfusion imaging can reflect hemodynamic status quantitatively. The BV, BFand PS values of renal space-occupying lesions are less than that of the cortex in theother side, and the values of malignant ones are more than that of benign ones.Thistechnique is valuable in diagnosis and differential diagnosis of renal space-occupyinglesions.4. In diagnosis of renal space-occupying lesions, the regular CT feature is the mostessential factor, and the TDC, the perfusion parameters and the pseudo-color mapswhich could reflect hemodynamic status should also be considered.
|
PDF Full Text Request