急性尿路梗阻继发肺部CT表现的动物实验研究

目的:建立动物尿路梗阻模型,了解尿路梗阻后实验动物肺部影像学表现及病理改变,为临床判断尿路梗阻后肺改变提供资料。方法:以新西兰大白兔为实验动物分别制作单侧(单侧组)和双侧(双侧组)输尿管完全梗阻模型,术后第2天始行胸部高分辨CT扫描及血肌酐(Cr)、尿素氮(BUN)和心钠素(ANP)检查,实验中及实验后取肺组织进行病检。结果:单侧组血Cr、BUN、ANP的值与术前比较无统计学意义(P>0.05),胸部高分辨CT扫描表现及病检结果均正常;双侧组动物自术后4 d各项指标均出现异常。结论:单侧尿路梗阻不引起血Cr、BUN、ANP改变及肺高分辨CT和病理异常表现;双侧尿路梗阻后肺部CT表现、病理表现及血Cr、BUN、ANP值出现明显异常。     

Multidetector CT of bowel obstruction: value of post-processing

The value of imaging in patients with suspicion of bowel obstruction is dependent on the ability to answer questions relevant to the clinical management of patients. Is there mechanical obstruction? Is it a small bowel obstruction (SBO) or a large bowel obstruction (LBO)? What is the transition point? What is the cause of the obstruction? What is the severity of the obstruction? The results of studies published more than 10 years ago using axial and single-slice helical CT gave rise to findings based on axial slices that enables CT to answer these different questions. With the recent advent of multislice CT, large numbers of thin sections can be generated with short image intervals, which is well suited to postprocessing. Postprocessing techniques include standard reformatting methods such as sagittal, coronal and oblique reformatting, curved reformatting, maximum and minimum-intensity projection, variable thickness viewing, and volume and surface rendering. This pictorial review illustrates the added value of postprocessing for answering different questions concerning patients with suspicion of bowel obstruction.     

磁共振尿路造影在临床泌尿道梗阻中的诊断价值

目的：评估磁共振尿路造影在临床泌尿道梗阻中的诊断价值。方法：回顾性对61例例泌尿系统梗阻患者的的MRU检查所见与手术和病理结果对照分析。结果：61例泌尿系梗阻患者，输尿管癌7例，输尿管结石8例，下腔静脉后输尿管1例，输尿管良性狭窄11例，先天性输尿管狭窄27例，膀胱癌侵及输尿管4例，泌尿系改道手术后再次发生良性梗阻患者3例，所有病例MRU均确定梗阻水平并且清晰显示梗阻端形态和特征。结论：NMR是一种安全、可靠、无创的检查方法，尤对IVU不显影或仅显示扩张的肾盏、肾孟影的重度肾积水病例或对比剂过敏的患者更有诊断价值。     

MDCT在肾盂癌和肾癌鉴别诊断中的价值

目的探讨多层螺旋CT(MDCT)三期增强扫描在肾盂癌和肾癌鉴别诊断中的价值,以期提高术前诊断的准确性。方法回顾性分析经病理证实的11例[男9例,女2例;平均年龄(70.2±11.7)岁]肾盂癌及26例[男21例,女5例;平均年龄(67.3±11.7)岁]肾癌,所有病人术前均行64层螺旋CT平扫及三期增强扫描。分析病人的CT表现,测量并计算病人各期肿瘤/皮质CT比值及肿瘤-皮质CT差值,并采用独立样本t检验比较2组间各期CT参数值的差异。结果肾盂癌病人动脉期及实质期的肿瘤/皮质CT比值均低于肾癌病人(均P0.05),2组病人平扫及排泄期的肿瘤/皮质CT比值差异均无统计学意义(均P0.05)。肾盂癌病人实质期的肿瘤-皮质CT差值低于肾癌病人(P0.05),而2组病人平扫、动脉期及排泄期的肿瘤-皮质CT差值差异无统计学意义(均P0.05)。结论肾盂癌及肾癌的三期增强扫描CT参数存在明显差异。肿瘤/皮质CT比值对两者具有更好的鉴别诊断能力。     

99Tcm-二亚乙基三胺五乙酸肾动态显像对兔单侧急性上尿道梗阻的应用研究

目的 应用99Tcm-二亚乙基三胺五乙酸(99Tcm-DTPA)肾动态显像观察兔单侧急性上尿道梗阻不同时期肾功能的变化以及与梗阻解除后恢复状况的比较.方法 健康家兔24只,手术制作左侧输尿管完全梗阻模型,术前及术后1周均行基础99Tcm-DTPA肾动态显像.选择梗阻后1周、3周、5～7周和8周以上不同时间点解除梗阻,并行99Tcm-DTPA利尿肾动态显像(利尿显像).结果 兔左侧输尿管形成梗阻后1周和3周,利尿显像可见左肾显影,但左肾肾小球滤过率(GFR)、摄取率降低,达峰时间延长,与术前比较有显著性差异(t=2.916,t=7.034,P<0.01).梗阻5～7周后,左侧肾脏仅见皮质显影,左肾GFR、摄取率明显降低,达峰时间明显延长,与术前比较有显著性差异(t=6.722,t=7.470,t=3.678,P<0.01),梗阻后8周以上,未见明显肾皮质影像,无法进行图像分析.利尿显像示梗阻1～3周后解除梗阻4周观察到左肾GFR为31.23±14.4(f=2.627,P<0.05),摄取率为4.09±2.10(t=2.795,P<0.05),与解除梗阻前相比功能基本恢复;达峰时间与解除梗阻前无显著差异(t=1.435,P>0.05).梗阻5～7周后解除梗阻4周时左肾GFR、摄取率部分恢复,与解除梗阻前相比无显著差异.梗阻8周以上再解除梗阻,肾功能无法恢复.结论 急性单侧上尿道完全梗阻后肾功能降低迅速,以早期最为显著,早期梗阻解除后肾功能恢复明显.晚期梗阻,即使解除梗阻肾功能也不易恢复.99Tcm-DTPA肾动态显像方法是评价肾功能恢复的有效手段.     

Dose reduction in multidetector CT of the urinary tract. Studies in a phantom model

A novel ureter phantom was developed for investigations of image quality and dose in CT urography. The ureter phantom consisted of a water box (14 cm×32 cm×42 cm) with five parallel plastic tubes (diameter 2.7 mm) filled with different concentrations of contrast media (1.88–30 mg iodine/ml). CT density of the tubes and noise of the surrounding water were determined using two multidetector scanners (Philips MX8000 with four rows, Siemens Sensation 16 with 16 rows) with varying tube current–time product (15–100 mAs per slice), voltage (90 kV, 100 kV, 120 kV), pitch (0.875–1.75), and slice thickness (1 mm, 2 mm, 3.2 mm). Contrast-to-noise ratio as a parameter of image quality was correlated with dose (CTDI) and was compared with image evaluation by two radiologists. The CT densities of different concentrations of contrast media and contrast-to-noise ratio were significantly higher when low voltages (90 kV versus 120 kV, 100 kV versus 120 kV) were applied. Smaller slice thickness (1 mm versus 2 mm) did not change CT density but decreased contrast-to-noise ratio due to increased noise. Contrast phantom studies showed favourable effects of low tube voltage on image quality in the low dose range. This may facilitate substantial dose reduction in CT urography.     

输尿管镜治疗急性上尿路梗阻性肾功能衰竭临床研究

目的探讨输尿管镜治疗急性上尿路梗阻性肾功能衰竭的安全性及有效性。方法回顾性分析2009年4月至2016年3月解放军281医院收治的急性上尿路梗阻性肾功能衰竭的45例患者的临床资料。本组患者均采用输尿管镜进行治疗,观察治疗效果。结果 44例患者顺利完成手术,1例因输尿管穿孔转为开放手术。所有患者术后肾功恢复正常或接近正常。结论输尿管镜技术治疗急性上尿路梗阻性肾功能衰竭操作简单、创伤小,具有很强的实用性及可操作性,治疗效果满意。     

The low attenuation area on dual-energy perfusion CT: correlation with the pulmonary function tests and quantitative CT measurements

Purpose

To retrospectively investigate the distribution of the low attenuation area (LAA) on dual energy perfusion CT (DEpCT) in comparison with the results of pulmonary function tests (PFTs) and quantitative CT measurements.

Materials and methods

Twenty-eight patients (15 male and 13 female; mean age: 62.21 years) underwent DEpCT and PFTs within a 1-month interval. The ranges of the LAA on DEpCT were classified into six groups with attenuation values of 0–3, 0–5, 0–8, 0–10, 0–13 and 0–15 HU and the ratios of LAA in each group were compared with the percentage of forced expiratory volume in the 1st second (%FEV_1.0), FEV_1.0/forced vital capacity (FEV_1.0/FVC) and the relative area of the lung with attenuation coefficients lower than −950 HU (RA₋₉₅₀).

Results

The LAAs on the DEpCT images were significantly correlated with the RA₋₉₅₀, %FEV_1.0 and FEV_1.0/FVC, and the regression analysis showed that the best values of LAA on DEpCT were 0–10 HU with RA₋₉₅₀ (r = 0.63), 0–8 HU with %FEV_1.0 (r = −0.52) and 0–8 HU with FEV_1.0/FVC (r = −0.61) per patient.

Conclusion

The iodine disturbance on DEpCT had a moderate correlation with the results of the PFTs and RA₋₉₅₀, but further examination would be needed for evaluation of iodine distribution.     

急性梗阻性自发性尿外渗的CT诊断(附3例报道)

目的：探讨梗阻性自发性尿外渗的CT表现以及在临床诊断中的重要意义。方法：搜集3例急腹症患者,经临床初步诊断泌尿系梗阻或伴有肠梗阻,并行CT检查。结果：3例患者均显示患侧肾脏体积明显增大,皮质较对侧肿胀,除了肾盂、肾盏或输尿管扩张外,伴有肾周间隙、输尿管周围不规则液体密度影,增强扫描可见对比剂渗入腹腔内。结论：CT检查对急性梗阻性自发性尿外渗诊断和鉴别具有重要意义。     

Role of MR renography in the evaluation of acute upper urinary tract obstruction

Purpose

To present the role of MR renography in diagnosis of upper urinary tract obstruction (UTO) with evaluation of diagnostic criteria for acute obstruction.

Material and methods

Thirty consecutive patients with obstructive anuria were included in our study. For identification of the cause of obstruction, all patients were subjected to plain abdominal X-ray (KUB), gray scale ultrasonography, non-contrast CT for the abdomen and pelvis (NCCT). There were five patients with bilateral obstruction and 25 with obstructed solitary functioning kidney, so the study included 35 units. All patients were subjected to radioisotope diuretic renography and magnetic resonance renography (MRR) before relief of obstruction and 3 days after drainage. Of the 30 patients included, 20 were men and 10 women.

Results

Among our patients the mean serum creatinine at time of presentation was 7 ± 4.5 mg/dl (range 2.4–12) and GFR ranged from 33 to 48 ml/min (mean ± SD; 38 ± 4.2). All the renal units have hydronephrosis. The mean pre drainage SI values 133 ± 22 (range 120–180). The mean time to peak (TP) for each unit was 171.6 ± 78 s and at isotope renography it was 320 ± 66 s. There was good corticomedullary differentiation (CMD) in 31 units and the remaining 4 showed loss of CMD differentiation. The CMD crossing time was 163.6 ± 70.4 s. Post kidney drainage the parenchymal SI was increased in 30 units, in 3 units there was drop and no change in 2 (r = 0.29). There is relative reduction in the time to peak, it becomes 67 ± 79 s after drainage (r = 0.76).

Conclusion

MR renography is a clinically valuable technique that provides diagnostic criteria to diagnose the acute urinary obstruction and allows follow up of renal function.     

CT尿路造影对非结石性尿路梗阻疾病的诊断作用

目的评价CT尿路造影(CTU)对非结石性尿路梗阻疾病的诊断作用。方法40例非结石性尿路梗阻病例给予实质期、分泌期增强螺旋扫描。分泌期数据经第2次重建后在工作站以三维方式获得CTU影像。结果40例中，24例良性梗阻呈轻度或重度积水。18例先天畸形CTU呈现各自特征；4例输尿管炎表现为鸟嘴样狭窄，2例前列腺增生可见膀胱后壁压迹。16例肿瘤患者梗阻端呈截断或锥状狭窄伴局部软组织影，12例尿路中度积水，4例重度积水。其中4例呈双侧积水。对6例一侧无分泌功能者，可采用最小强度投影等予以显示，并与对侧最大强度投影像等整合。结论CTU对非结石性尿路梗阻疾病的诊断具有良好的效果。     

急性胰腺炎CTSI评分与肝／脾CT 值比的相关性分析

目的：探讨急性胰腺炎（acute pancreatitis ,AP）的CTSI评分与肝/脾CT值比（ liver to spleen CT attenuation value ratio ,L/S ）的相关性。方法对87例AP患者进行腹部CT扫描,测量肝脏、脾脏CT值并计算L/S。根据CTSI分级标准由两名放射科医师盲法阅片将A P分为轻度、中度、重度组。分析A P评分分级与L/S之间的关系。结果87例A P患者L/S降低发生率为55％;轻、中、重度A P患者L/S降低发生率分别为23％、53％、88％;轻度、中度、重度A P患者L/S平均值分别为1．07±0．13、0．95±0．20、0．69±0．26。AP的CTSI评分与L/S呈负相关（r ＝-0．451,P ＝0.00）。结论肝/脾CT值比可以反映AP的严重程度,随着AP严重程度的增加,肝损伤的发生率也在增加。     

多层螺旋CT后处理技术在肠梗阻诊断中的价值

目的:评价多层螺旋CT在肠梗阻诊断的临床意义。方法:对34例临床怀疑为肠梗阻的病例进行多层螺旋CT扫描检查,22例扫描前60min分次口服等渗甘露醇溶液1000～1500ml,余12例因腹张、呕吐频繁等原因未服甘露醇溶液。均行平扫+三期增强扫描。成像方法包括薄层横断面、多方位重建成像(MPR)、容积再现法(VR)和最大密度投影(MIP)血管成像。结果:在34例临床怀疑肠梗阻病例中,经MSCT检查明确为肠梗阻者27例,其中低位小肠梗阻14例,较高位小肠梗阻2例,11例为不同部位的结肠梗阻。其中炎性病变9例、粘连8例、肠道原发肿瘤7例、肿瘤术后复发或转移2例、腹股沟斜疝1例。结论:多层螺旋CT对判断肠梗阻的部位、程度及原因、有无闭袢性肠梗阻及肠缺血、肠绞窄有重要临床意义。     

急性尿路梗阻及尿路梗阻性肾周围炎的影像学研究

目的：分析急性尿路梗阻的原因及由尿路梗阻引起的肾周围炎的 CT、MR 影像表现,评价 CT、MR 对尿路梗阻及尿路梗阻性肾周围炎的诊断价值。方法分析72例急性尿路梗阻的原因及尿路梗阻性肾周围炎 CT、MR 表现,着重探讨 CT、MR 在输尿管结石及肾周围炎诊断中各自的优势。结果70例(72个部位)输尿管结石患者中,CT 诊断结石准确率为100%,MR 诊断结石准确率为59.7%;72例肾周围炎患者中,MR 对肾周软组织内积液的显示明显优于 CT。结论CT、MR 在尿路梗阻及尿路梗阻性肾周围炎诊断中各有优势,CT 对输尿管结石的诊断有明显的优势,MR 对肾周围炎诊断有明显优势。     

CT urography: a comparison of strategies for upper urinary tract opacification

A consensus is yet to be reached regarding the best strategy for ensuring maximum ureteric delineation during CT urography (CTU). In this study we have compared various CTU protocols to try to establish the best method for ureteric delineation. Saline infusion in the supine position, saline infusion in the prone position, furosemide administration (10 mg, iv) and buscopan administration (20 mg iv) with saline infusion in the prone position were tried in four groups, each having 15 patients who were undergoing CTU. The pelvicalyceal system and ureter were divided into six segments, to each of which an opacification score was assigned (0, unopacified segment; 1, less than 50% opacified segment; 2, 50–99% of the segment opacified; or 3, completely opacified segment) and the results compared. Furosemide administration resulted in complete opacification of 93% of the ureters (28 of 30). In the distal (below the sciatic notch) ureter, the mean score with furosemide was 2.9, while that with saline, supine and prone positioning was 1.87 and 1.83, respectively, and this difference was highly significant (P = 0.0002 and P = 0.0001). It was also significantly higher than the buscopan group (score 2.3, P = 0.002). Also in the lower (the iliac crest to the sciatic notch) and upper (above the iliac crest) ureter, furosemide had significantly higher scores than saline infusion in either position. Saline infusion in the supine and prone positions had very similar scores in all segments that were less than the buscopan group, but this difference was not statistically significant. During CT urography, furosemide administration in low doses is the most effective and convenient technique for ureteric opacification.     

CT尿路造影对上尿路梗阻性疾病的诊断价值

目的 探讨CT尿路造影（CTU） 在上尿路梗阻性疾病中的应用价值.方法 66例临床可疑有上尿路梗阻性疾病患者,分别在常规平扫、动脉期及静脉期扫描后行分泌期扫描,在图像工作站对获得图像进行最大密度投影（MIP）、多平面重建（MPR）及容积再现（VR）等三维后处理,获得泌尿系立体图像.由2名主治医师以上专家进行影像诊断,并追踪病理及治疗结果.结果 所有病例都成功重建出双肾、输尿管及膀胱三维图像,图像能清晰显示泌尿系统整体和局部细微结构.结论 CTU通过MPR、MIP、VR技术多角度清晰显示上尿路梗阻的病变及其形态,可提高诊断水平,更好地满足临床需要,在上尿路梗阻病变诊断方面有独特优势.     

Opacification of the urinary tract in portal venous spiral CT without delayed scans

In portal venous spiral CT there is no visible renal contrast excretion within the usual period of scanning. To opacify collecting systems additional delayed scanning is required. We administered an extra pre-dose of contrast medium before the main portal venous bolus in order to opacify the urinary tract and studied its effects on liver attenuation. In 32 patients examined first by non-contrast spiral CT 20 ml of a non-ionic IV CM were injected. Five minutes later, orientating cuts in the liver and along the urinary tract were obtained. Immediately thereafter, a 120-ml bolus was administered at 3 ml/s for portal venous phase helical CT (60-s delay craniocaudad). The quality of renal excretion was graded visually (excellent, fair, poor, none). Hepatic attenuation measurements were performed at comparable regions of interest. In all patients 20 ml CM opacified the renal pelvis after 5 min. Depiction of the ureters was excellent in 14, fair in 11 and poor or none in 7 cases. There was little effect on mean hepatic attenuation by the 20-ml pre-bolus after 5 min: mean enhancement 2.3 HU (range –0.6 to 7.8 HU). Mean hepatic enhancement after the 120-ml portal venous bolus ranged between 23.6 and 74.1 HU (mean 51.5 HU). When opacification of the urinary tract is necessary, pre-administration of a 20-ml bolus 5 min before portal venous scanning may save an extra delayed spiral. The effects on hepatic enhancement are negligible. Received: 29 October 1998; Revision received: 6 January 1999; Accepted: 1 February 1999     

Unenhanced helical CT: the “unbeatable” emergency examination for acute flank pain

Unenhanced helical CT has made the excretory urogram virtually obsolete in the evaluation of patients presenting to the emergency department with acute flank pain. A case is presented demonstrating yet another advantage of unenhanced helical CT: that of unmasking the clever malingerer who feigns renal colic in order to obtain controlled drugs.     

Impact of micturating cystourethrography and DMSA renal scintigraphy on the investigation scheme in children with urinary tract infection

Objective  The relationships among urinary tract infection (UTI), vesicoureteral reflux (VUR), and permanent renal damage in children are not fully understood. The aim of this study was to evaluate the incidence of renal scarring in children with a history of UTI and to determine the change in the probability of permanent renal damage owing to the presence of VUR documented on micturating cystourethrography (MCU). Methods  We analyzed 201 children (400 renal units, two children with solitary kidney). Seventy-four boys and 127 girls (aged 7 months to 7 years, median 2.5 years) with culture verified UTI were referred for technetium-labeled dimercaptosuccinic (DMSA) renal scintigraphy 4-6 months after acute UTI. MCU was also performed mostly 1 month prior to DMSA. Statistical analysis was performed using χ² test or Fisher’s exact test. Likelihood ratio (LR) positive and negative, diagnostic odds ratio (DOR), and post-test probability of (no) disease were calculated for VUR on MCU versus scarring on DMSA. Results  Vesicoureteral reflux was found in 158 (39.5%) kidneys, and evaluated as grades I, II, III, IV, and V in 3, 70, 43, 25, and 17 refluxing renal units (RRU), respectively. Permanent renal damage according to DMSA was seen in 15.2% (61/400) kidneys. Scarring was shown in 29.7% (47/158) of kidneys with VUR and in 5.8% (14/242) kidneys without VUR (P < 0.0001). LR positive was 2.353 (95% CI 1.889, 2.865), LR negative 0.341 (95% CI 0.209, 0.523), and DOR 6.895 (95% CI 3.533, 14.093). Rate of scarring significantly increased with VUR of grades III, IV, and V. There was no significant difference in the incidence of scarring in kidneys without VUR and RRU with low-grade (I and II) VUR (P = 0.306). The presence of VUR on MCU increased the chance of renal damage on DMSA by about 15%, whereas negative MCU increased the chance of no-renal involvement by 9%. Conclusions  Micturating cystourethrography should not be used as a first-line test to rule out the permanent renal damage owing to UTI. The priority of imaging strategy should be focused on early identification of renal lesions to prevent further deterioration.     

Multidetector helical CT in the evaluation of acute small bowel obstruction: comparison of non-enhanced (no oral, rectal or IV contrast) and IV enhanced CT

Purpose

To compare accuracy of non-enhanced CT (NECT) (no oral or IV contrast) and enhanced CT (ECT) (IV enhanced only) to diagnose small bowel obstruction and evaluate reviewer's experience impact.

Materials and methods

Ninety-nine adult patients underwent 105 NECT and ECT (6 patients had 2 examinations) on a four-detector CT. An abdominal radiologist, an abdominal imaging fellow, a second-year radiology resident retrospectively reviewed NECTs and ECTs separately and independently blinded to outcome. Discrepancy of diameter of proximal and distal small bowel ± a transition was considered indication of mechanical bowel obstruction. Reference standard was surgery in 26 and chart review in 79.

Results

Mechanical obstruction was present in 56% (59/105). The average sensitivity, specificity, negative and positive predictive and accuracy values for NECT were 88.1% (CI: 80-96%), 77% (CI: 65-89%), 83.0% (CI: 72-95%), 83% (CI: 74-92%), and 83% (CI: 76-90%) with no significant difference between three reviewers. The corresponding numbers for ECT were 87.6% (CI: 79-96%), 75% (CI: 63-88%), 82.6.0% (CI: 71-94%), 82.1% (CI: 73-92%), and 82% (CI: 75-90%) (p > 0.5). Area under curve (AUC) of ROC curves of three reviewers did not show significant statistical difference (p > 0.5).

Conclusions

NECT and ECT have comparable accuracy to diagnose mechanical small bowel obstruction and can be interpreted by reviewers with different levels of expertise.