螺旋CT扫描预测上尿路结石成分的体内研究

目的:研究螺旋CT对体内上尿路结石化学成分的预测价值。方法:2005年12月～2007年9月对157例上尿路结石患者在治疗前行螺旋CT平扫,测结石CT值。定量分析各种治疗方法所获取结石的化学成分。经统计学分析,找出不同成分结石的CT值范围。结果:一水草酸钙、尿酸、羟基磷灰石三种纯结石的软组织窗平均CT值分别为(851.50±188.74)HU、(446.92±47.20)HU和(835.53±110.58)HU。尿酸结石与一水草酸钙结石、尿酸结石与羟基磷灰石之间CT值的差异均有统计学意义。13例纯尿酸结石与144例尿酸含量小于70%的其他结石的CT值差异有统计学意义。以结石的软组织窗平均CT值500 HU为标准鉴别纯尿酸结石,其灵敏度为92.31%,特异度为96.53%,阳性预测值为70.59%,阴性预测值为99.29%。结论:结石的CT值可作为鉴别尿酸结石的一种方法,CT值小于500 HU的结石多考虑为尿酸结石。     

非增强螺旋CT平扫对上尿路结石成分预测的体内研究

目的 探讨非增强螺旋CT对体内上尿路结石化学成分的预测价值.方法 回顾性分析156例有结石标本的上尿路结石患者临床资料.所有患者在治疗前采用GE High speed CT/i螺旋CT机行非增强结石扫描,扫描参数为120 kV,320 mA,螺距0.6:1,扫描层厚为5 mm.在CT软组织窗测量结石平均CT值.将获取的结石样本采用红外光谱自动分析系统进行化学成分定性分析.经统计学分析,找出各种成分结石的相应CT值范围.结果 非增强螺旋CT扫描156例结石的软组织窗CT值范围为128～ 1663亨氏单位(hounsfield unit,HU).共发现纯结石57例,其中纯一水草酸钙结石28例,纯尿酸结石19例,纯羟基磷灰石10例,混合结石99例.一水草酸钙、尿酸、羟基磷灰石三种纯结石的软组织窗平均CT值分别为(915.4±142.9) HU、(469.7±55.1) HU、(868.4±168.8)HU.尿酸结石与一水草酸钙结石、尿酸结石与羟基磷灰石之间的CT值差异有统计学意义(P＜0.05).19例纯尿酸结石和137例其他成分结石的软组织窗平均CT值之间差异有统计学意义(P＜0.05).以结石的软组织窗平均CT值＜ 550 HU为标准诊断纯尿酸结石,其灵敏度为92.8％,特异度为98.1％,阳性预测值为88.5％,阴性预测值为99％,诊断符合率为98.1％.结论 非增强螺旋CT平扫用于判断上尿路结石成分效果满意.根据软组织窗CT值不同,可将体内尿酸结石与其他成分结石区分.软组织窗平均CT值＜550 HU可作为纯尿酸结石的诊断标准.     

Prediction of calcium level in melamine-related urinary calculi with helical CT: diagnostic performance evaluation and clinical significance

The aim of the study was to investigate the relationship between CT-attenuation and stone calcium level in melamine-related urinary calculi (MRUC). A total of 25 MRUC with known composition and calcium level were included (11 uric acid stones, 2 calcium oxalate stones and 12 mixture stones of uric acid and calcium oxalate). Of all, 18 renal stones accepted alkalization therapy except for 5 lower urinary tract stones and 2 stones of unknown position. With well-matched composition, 61 adult urinary stones were included as controls. Every stone was scanned by helical CT (80 kV/120 kV, 300 mA, pitch 0.625 mm) and the highest CT-attenuation value measured. CT-attenuation values of MRUC increased gradually from uric acid stones, mixture stones to calcium oxalate stones, but were always lower than the values of controls. Furthermore, a strong positive correlation was found between stone CT-attenuation value and stone calcium level (n = 25, r (80kV) = 0.883, p = 0.000; r (120kV) = 0.855, p = 0.000). Compared with alkalization-therapy-alone group, stone CT-attenuation values and stone calcium level in the comprehensive-therapy group were significantly greater (CT(80kV) 1,057 ± 639 vs. 172 ± 61 HU, p = 0.001; CT(120kV) 783 ± 476 vs. 162 ± 60 HU, p = 0.001; Ca 19.83 ± 7.48% vs. 1.30 ± 1.51%, p = 0.000). Fisher's exact test suggested that the stones with higher CT-attenuation values tended to resist alkalization when 400 HU served as the cutoff value (P (80kV) = 0.002, P (120kV) = 0.000). In conclusion, the study was the first to illustrate that the CT-attenuation value could reflect calcium level in MRUC and found that stones with higher CT-attenuation value were not amenable to alkalization because they probably contained greater calcium. For those patients, we believe that comprehensive therapy will be the best choice.     

Urolithiasis in Okinawa, Japan: A relatively high prevalence of uric acid stones

AIM: The aim of the present study was to investigate the composition of urinary tract stones in patients from Okinawa, the most southern island group of Japan. METHODS: The study was conducted by 12 hospitals in Okinawa. A total of 1816 urinary tract calculi were obtained from 1816 patients (1323 males; 493 females). The patients had a mean age of 53 +/- 15.3 years (mean +/- SD). The calculi were examined to determine their chemical composition. Stone samples were analyzed by computed infrared spectrophotometer. RESULTS: Pure stones comprised 58.4% of the total, with calcium oxalate stones accounting for 40% (21% monohydrate [whewellite]; 6.6% dihydrate [weddellite]; and 12.4% combined monohydrate and dihydrate stones), uric acid/urate stones for 9.6%, calcium phosphate stones for 5.1%, and struvite stones for 3.7%. The other 41.6% of the stones consisted of calcium oxalate mixed with other components. The male-to-female ratio was 2.7:1. CONCLUSION: In our series, calcium oxalate stones accounted for 81.6% of the urinary tract calculi, while uric acid/urate stones accounted for 15.8%. Uric acid stones, predominantly the anhydrous and/or dihydrate forms, showed a relatively high prevalence. Calcium oxalate stones, predominantly in the form of whewellite, showed a high prevalence among pure calculi; while the predominant combinations among mixed calculi were weddellite + calcium phosphate and whewellite + uric acid/urate.     

Analysis of spontaneously passed urinary tract stones

Most studies on epidemiology, composition, and recurrence of renal calculi include both spontaneously passed calculi and those retrieved after surgical manipulation or shock wave lithotripsy. The present study exclusively focused on epidemiology, composition, and recurrence of spontaneously expelled stones in patients from North and East Mallorca (Spain) which represents a geographically specific non-urban region of a developed country. The study involved 136 patients who spontaneously passed 205 renal calculi. All calculi were classified and sub-classified according to composition after macroscopic and microscopic examination. We also analyzed prevalence, gender, age, and stone recurrence rate over a period of 3 years. The peak incidence of spontaneously stone passage is within the fourth to sixth decade. Overall male to female ratio was 3/1. Calcium oxalate was the most prevalent composition (64.8%) followed by uric acid (25.3%), mixed stones (5.3%) and calcium phosphate calculi (4.3%). Uric acid stones were the most recurrent (50%) followed by calcium oxalate monohydrate papillary calculi (26.4%), calcium oxalate monohydrate un-attached calculi (19.2%), calcium oxalate dihydrate calculi (18.3%), calcium phosphate calculi (14%), and mixed calculi (12.5%). In conclusion, spontaneously passed stones in Mallorcan population have similar epidemiology, composition, and recurrence rate from that found in other developed countries. Calcium oxalate stones are largely the most spontaneously passed type of calculi and uric acid stones are the most frequently recurred. These findings are also found to be similar to those reported in previous studies examining both spontaneously and non-spontaneously passed stones.     

Computed tomography and composition of renal calculi

Summary The attenuation values of computed tomography were studied in 50 recovered renal calculi of more than 10 mm in diameter, in the hope of determining the composition of calculi in situ. The attenuation value of various calculi (mean±s.d.) in a 5 mm slice with a maximal rectangular region of interest was as follow (Hounsfield units); mixed calcium oxalate and phosphate 1,555±193 (n=22), magnesium ammonium phosphate 1,285±284 (n=18), calcium oxalate 1,690 (n=1), calcium phosphate 1,400 (n=2), cystine 757±114 (n=5) and uric acid 480 (n=2). Attenuation values ranging from 500 to 1,600 overlapped for various calculi, except those composed of uric acid calculi. There was no correlation between the attenuation value and the mineral content such as calcium or magnesium per unit weight of calculus. The mineral content per unit volume seemed to be attributable to the attenuation value. From the present results we conclude that the determination of calculous composition by the attenuation value is possible only for oxalate calculi of more than 1,600 and uric acid calculi of less than 500 attenuation value, provided that the proper CT slice location, the region of interest and the appropriate calculus size can be determined.     

体外冲击波碎石成功治疗肾结石的多因素分析

目的 确定病人和结石在非增强螺旋CT上的特点,预言2种体外冲击波碎石后的结果:结石分散状态(游离状态)或体外碎石成功.方法 回顾性分析200个相连续的用体外震波碎石治疗的肾结石患者.患者年龄、性别、结石侧别、体表面积、体重、结石最大容积、结石的平均CT值、结石密度、皮肤到结石距离,肾内结石的位置,研究这些潜在的预测因子.患者非肾脏、输尿管、膀胱手术后钙化,在第6周时拍腹部平片确定结石的分散状态,体外冲击波碎石成功者:结石残留碎片小于4mm.结果 发现肾内结石的位置是唯一一个预测体外碎石后结石分散状态的因子.肾盂、肾盂输尿管交界处结石清除率要高于肾盏结石;上盏或中盏结石清除率要高于下盏.结石大小、平均CT值和结石的位置能够预测体外震波碎石的成功率.小结石和低CT值结石更容易被击碎,在肾盏结石中更高的离散状态和体外碎石的成功率发现与更短的皮肤-结石距离有关,肾盂结石和肾盂输尿管交界处结石排除在分析之外.结论 结石的位置是体外震波碎石后获得结石离散状态最重要的因素,非增强螺旋结石特点:诸如结石大小、平均密度、结石肾内位置是体外震波碎石成功的重要预测因子.

Abstract：

Objectives To determine the patient and noncontrast computed tomography (NCCT) stone characteristics that predict either of 2 extracorporeal shock wave lithotripsy (ESWL) outcomes: stone - free (SF)status or ESWL success. Methods The records of 200 consecutive patients with nephrolithiasis treated with ESWL were reviewed. Patient age, sex, stone laterality, body surface area, body mass index, maximal stone dimension,mean stone Hounsfield units (HU), stone Hounsfield density, skin- to- stone distance (SSD), and intrarenal stone location were studied as potential predictors. Patients with no calcifications on postoperative kidneys, ureters,and bladder (KUB) at 6 weeks were defined as SF. ESWL success was defined as SF or remaining stone fragments less than 4 mm. Results lntrarenal stone location was found to be the only predictor of SF status. Renal pelvic/ureteropelvic junction (UPJ) stones cleared better than calyceal stones, and upper/middle calyceal stones cleared better than lower calyceal stones. Stone size, mean HU, and location predicted ESWL fragmentation success. Smaller stones and stones with lower mean HU levels were more successfully fragmented. Higher SF and ESWL success rates were found with a shorter SSD among calyceal stones when renal pelvic/UPJ stones were excluded from analysis. Conclusions Stone location is the most important factor in achieving SF status after ESWL. NCCT stone characteristics such as stone size, mean HU, and intrarenal location are important predictors of ESWL success.     

上尿路结石复发原因分析及其治疗(附42例报告)

目的:探讨泌尿系结石复发的原因及其处理措施。方法:回顾性分析2005年1月～2010年5月在我院接受治疗的42例上尿路复发结石患者临床资料,并对其尿石成分进行分析,对血、尿理化指标及代谢指标进行检测。结果:术后复发结石成分中,与原发结石成分相同者34例;与原发结石成分不同者8例,其中1例为尿流改道术后(草酸钙结石变为尿酸结石),1例为ESWL术后(草酸钙结石变为尿酸结石),3例为开放取石术后(草酸钙结石变为感染结石及尿酸结石),2例为输尿管碎石取石术后(尿酸结石变为感染结石)。在血、尿理化检测中,糖尿病8例,尿路感染7例,肥胖6例,甲状旁腺机能亢进3例。结论:根据复发性尿路结石的临床特点及诱发因素,采取针对性措施,选择合理的治疗方式,可以提高治疗效果。     

Spectrum of stone composition: structural analysis of 1050 upper urinary tract calculi from northern India

BACKGROUND: The purpose of the present paper was to study the spectrum of stone composition of upper urinary tract calculi by X-ray diffraction crystallography technique, in patients managed at All India Institute of Medical Sciences. METHODS: Between 30 April 1998 and 31 March 2003, a total of 1050 urinary calculi (900 renal, 150 ureteric) were analyzed. The stone fragments were collected after extracorporeal shock-wave lithotripsy, or retrieval by endoscopic (percutaneous nephrolithotomy, ureterorenoscopy), laparoscopic and various open surgical procedures. The structural analysis of the stones was done using X-ray diffraction crystallography. RESULTS: Four types of primary and three secondary X-ray diffraction patterns were obtained. The primary patterns were as follows. Pattern A, well organized crystalline structure; pattern B, moderately organized crystalline structure; pattern C, poorly organized crystalline structure; pattern D, very poorly organized crystalline structure. The three secondary patterns mainly highlighted the mixed variety of stones. These patterns were further analyzed and compared with standard X-ray diffraction (powder) photographs. Of the 1050 stones analyzed, 977 (93.04%) were calcium oxalate stones, out of which 80% were calcium oxalate monohydrate (COM) and 20% were calcium oxalate dihydrate (COD). Fifteen were struvite (1.42%) and 19 were apatite (1.80%). Ten were uric acid stones (0.95%) and the remaining 29 (2.76%) were mixed stones (COM + COD and calcium oxalate + uric acid, calcium oxalate + calcium phosphate, and calcium phosphate + magnesium ammonium phosphate). A total of 89.98% of staghorn stones were made of oxalates (COM/+COD) and only 4.02% were struvite. CONCLUSION: Urinary stone disease in the Indian population is different from that in Western countries, with a larger percentage of patients having calcium oxalate stones, predominantly COM. Also, the majority of staghorn stones (89.98%) were made of oxalates.     

Determination of the chemical composition of urinary calculi by noncontrast spiral computerized tomography

Various techniques for noncontrast spiral computerized tomography (NCCT) were utilized for the determination of the Hounsefield unit (HU) values of various types of urinary calculi with the aim of determining the best technique for distinguishing various stones compositions. A total of 130 urinary stones, obtained from patients who underwent open surgery, were scanned with a multidetector row scanner using 1.25 mm collimation at two energy levels of 100 and 120 kV at 240 mA. Two post-scanning protocols were used for the HU value assignment, tissue and bone windows, for both kV values. In both protocols, three transverse planes were defined in each stone, one near the top, one in the middle, and one near the bottom. Three regions of interest (ROI) were obtained in each plane. The absolute HU value was determined by three methods: the mean of the nine ROI, the mean of the central three ROI, and the central ROI in the middle plane. Determination of the stones composition was performed using the absolute HU value measured at 120 kV, the dual CT values (HU values at 100 kV–HU values at 120 kV), and HU values/stone volume ratio (HU density). All stones were analyzed by x-ray diffraction to determine their chemical composition. After the exclusion of groups with few calculi, 47 pure stones [25 uric acid (UA), 15 calcium oxalate monohydrate (COM), seven struvite], and 60 mixed stones [15 COM 60–90%+hydroxyl apatite (HA), 14 COM 40–90%+UA, 21 UA+COM <40%, ten mixed struvite+COM+hydroxyl apatite] were included in the statistical analysis. From the least to the most dense, the pure stone types were UA, struvite, COM. Mixed UA+COM<40% calculi were less dense but insignificantly different from pure UA, while when the COM ratio was 40% their density became higher than and significantly different from pure UA, and less than but not significantly differentiated from pure COM. Mixed COM+HA were the most dense stones. Using the absolute HU values at 120 kV and HU density, we could distinguish, with statistical significance, all pure types from each other, pure UA from all mixed calculi except UA+COM <40%, pure COM from mixed UA+COM <40%, and pure struvite from all mixed stones except mixed struvite stones. Dual CT values were not as good as absolute HU values and HU density in the determination of stone composition. These results demonstrate that absolute HU values and HU density derived from CT scanning using a small collimation size could uncover statistically significant differences among all pure and most of the mixed urinary stones. This permits more accuracy in the prediction of stone composition. Moreover, this technique permits diagnostic conclusions on the basis of single CT evaluation.     

Comparison of urinary stone and stent encrustation: biochemical analysis

PURPOSE: To compare biochemical analysis of stent encrustation with that of urinary stones from the same patient. PATIENTS AND METHODS: Any patient presenting from February to December 2000 with a symptomatic ureteral or renal calculus that necessitated stenting and delayed calculus retrieval was enrolled in the study. The stent and stone were sent to the same laboratory for qualitative and semiquantitative chemical analysis. A total of 50 stents and matched calculi were available for comparison; four stents were excluded because they had insufficient encrustation for analysis. RESULTS: Two patients had open ureterolithotomy; the remainder were treated by endoscopic or percutaneous means. Every stone containing calcium oxalate had a stent that was positive for calcium oxalate. Four uric acid stones were available for comparison, and three of the four matched stents tested positive for uric acid. CONCLUSION: Biochemical analysis of urinary stent encrustation is a good predictor of urinary stone composition, especially for calcium oxalate-containing stones. Uric acid stent encrustation is likely to occur in patients with uric acid stones.     

Essential arterial hypertension and stone disease.

BACKGROUND: Cross-sectional studies have shown that nephrolithiasis is more frequently found in hypertensive patients than in normotensive subjects, but the pathogenic link between hypertension and stone disease is still not clear. METHODS: Between 1984 and 1991, we studied the baseline stone risk profile, including supersaturation of lithogenic salts, in 132 patients with stable essential hypertension (diastolic blood pressure of more than 95 mm Hg) without stone disease and 135 normotensive subjects (diastolic blood pressure less than 85 mm Hg) without stone disease who were matched for age and sex (controls). Subsequently, both controls and hypertensives were followed up for at least five years to check on the eventual formation of kidney stones. RESULTS: Baseline urine levels in hypertensive males were different from that of normotensive males with regards to calcium (263 vs. 199 mg/day), magnesium (100 vs. 85 mg/day), uric acid (707 vs. 586 mg/day), and oxalate (34.8 vs. 26.5 mg/day). Moreover, the urine of hypertensive males was more supersaturated for calcium oxalate (8.9 vs. 6.1) and calcium phosphate (1.39 vs. 0.74). Baseline urine levels in hypertensive females were different from that of normotensive females with regards to calcium (212 vs. 154 mg/day), phosphorus (696 vs. 614 mg/day), and oxalate (26.2 vs. 21.7 mg/day), and the urine of hypertensive females was more supersaturated for calcium oxalate (7.1 vs. 4.8). These urinary alterations were only partially dependent on the greater body mass index in hypertensive patients. During the follow-up, 19 out of 132 hypertensive patients and 4 out of 135 normotensive patients had stone episodes (14.3 vs. 2.9%, chi-square 11.07, P = 0.001; odds ratio 5.5, 95% CI, 1.82 to 16.66). Of the 19 stone-former hypertensive patients, 12 formed calcium calculi, 5 formed uric acid calculi, and 2 formed nondetermined calculi. Of the urinary factors for lithogenous risk, those with the greatest predictive value were supersaturation of calcium oxalate for calcium calculi and uric acid supersaturation for uric acid calculi. CONCLUSIONS: A significant percentage of hypertensive subjects has a greater risk of renal stone formation, especially when hypertension is associated with excessive body weight. Higher oxaluria and calciuria as well as supersaturation of calcium oxalate and uric acid appear to be the most important factors. Excessive weight and consumption of salt and animal proteins may also play an important role.     

ACCURATE DETERMINATION OF CHEMICAL COMPOSITION OF URINARY CALCULI BY SPIRAL COMPUTERIZED TOMOGRAPHY

Purpose

Choice of efficacious clinical management of symptomatic renal calculi can be facilitated by ascertaining the precise chemical composition of the calculus. Spiral computerized tomography (CT) is becoming a frequently used radiographic examination to establish the diagnosis and severity of calculus disease. Our objective for this study was to determine the precision of spiral CT in identifying the chemical composition of 6 different types of urinary calculi with region of interest measurements using spiral CT.

Materials and Methods

A total of 102 chemically pure stones were separated into 6 groups. The stones along with phantoms containing butter (fat) and jello (water) were mounted vertically in the scanner gantry. Then 1 mm. thickness scanning was performed with a high speed scanner at the 2 energy levels of 80 and 120 kV. The determination of the chemical composition was performed using the absolute CT value measured at 120 kV. and the dual kilovolt CT values measured at 80 and 120 kV. Hounsfield unit at 80 kV. - Hounsfield unit at 120 kV.).

Results

The absolute CT value measured at 120 kV. was able to identify precisely the chemical composition of uric acid, struvite and calcium oxalate stones. It was imprecise in differentiating calcium oxalate from brushite stone and struvite from cystine stone. However, dual kilovolt CT value was able to differentiate these latter stones with statistical significance (p <0.03). Uric acid stones were easily differentiated from all other stones using the absolute CT value.

Conclusions

This study demonstrates that the chemical composition of urinary calculi can be accurately determined by CT scanning in an in vitro setting.     

232例湖北地区泌尿系结石红外光谱成分分析

目的：分析湖北地区泌尿系结石化学成分的构成,为本地区结石的防治提供依据。方法：采用结石红外光谱自动分析系统对2011年11月～2012年8月期间收集到的湖北地区泌尿系结石232例进行成分分析。结果：232例结石中,各成分的检出率为：一水草酸钙（COM）85．34％,二水草酸钙（COD）62．93％,碳酸磷灰石（CA）24．14％,无水尿酸（UA）12．93％,二水磷酸氢钙（PH）4．31％,磷酸铵镁（MAP）6．90％,黄嘌呤1．29％,胱氨酸（CYS）1．29％,方解石0．86％,尿酸铵（AU）0．86％。含草酸钙成分结石86．21％,含磷酸钙成分结石28．45％,含磷酸铵镁成分结石6．90％,含尿酸成分结石13．79％,含胱氨酸成分结石1．29％。混合成分结石181例（78．02％）,尿路结石发病男性多于女性,男女比例为3．14：1。结论：湖北地区泌尿系结石以混合性结石为主,COM检出率最高,其次为COD。结石成分分析对于结石的防治有重要意义。     

复杂性肾结石化学成分分析(附84例报告)

目的 :分析复杂性肾结石化学成分特点 ,为预防其复发提供依据。方法 :对 84例在我院行微经皮肾镜取石术的复杂性肾结石患者 (纳入标准为鹿角形结石、单肾或双肾多发性结石且最大结石直径 >2 .5cm)进行结石化学成分分析 ,同时收集相关临床资料。结果 :80例 (95 .2 % )为含钙混合性结石和感染结石 ,其中草酸钙加磷酸钙 30例 (35 .7% ) ;草酸钙加尿酸 14例 (16 .7% ) ;草酸钙加磷酸钙加尿酸 10例 (11.9% ) ,草酸钙加磷酸钙加胱氮酸 1例 ;含钙结石并发感染结石 14例 (16 .7% ) ;感染结石 11例 (13.1% )。 4例 (4 .8% )为单一成分。结论 :体积较大的复杂性肾结石成分复杂 ,生长过程中常多种病因参与 ,应加强其病因诊断和针对多种病因采用积极的预防性治疗     

Difference in urinary stone components between obese and non-obese patients

The prevalence and incidence of urinary stone disease have been reported to be associated with body weight and body mass index (BMI). The aim of the study was to determine the difference in stone components among different BMI groups in patients with urolithiasis. Between Dec 2005 and Jan 2008, 907 urinary calculi were collected and analyzed by infrared spectroscopy. Most of the stones had been passed spontaneously, and some were collected during surgical manipulations. The data on patients’ gender, age, BMI at diagnosis, and stone composition were collected. The patients were classified as normal weight (18.5≤ BMI <24), overweight (24≤ BMI <27), or obese (BMI ≥27). Of the 907 patients with urinary stone disease, 27.7% had normal weight, 33.5% were overweight, and 38.8% were obese. The prevalence of calcium oxalate stones in the normal weight, overweight, and obese groups were 23.1, 30.6, and 34.9%, respectively (P = 0.002), and the prevalence of uric acid stones in the different groups was 2.8, 7.2, and 7.7%, respectively (P = 0.002). The prevalence of calcium oxalate and uric acid stones, but not that of calcium phosphate stones, increased with body size. There was a significant correlation between BMI and uric acid stones in the overweight and obesity groups, with odds ratios of 3.28 and 4.35, respectively. The prevalence and incidence of urinary stone disease were found to be associated with BMI. The percentage of uric acid and calcium oxalate stones was higher in obese than in non-obese patients. There was no apparent difference in the prevalence of calcium phosphate stones between obese and non-obese patients.     

2015~2018年达州市尿路结石患者人口学特征及结石化学成分分析

目的对2015~2018年四川省达州地区尿路结石患者人口学特征及结石化学成分进行分析。方法选择2015年1月至2018年12月四川省达州市中西医结合医院进行治疗的583例尿路结石患者,经体外振动波碎石、手术、自排等方式获得结石标本583份进行研究。所有患者入组后均采集性别、年龄、居住地等一般资料,获取结石标本后以结石红外光谱自动分析系统对其化学成分进行分析。结果583例患者中单纯性结石289例(49.75%),二重混合性结石288例(49.40%),三重混合性结石6例(1.03%)。从结石成分分布上看草酸钙占比最高,为94.00%,其次是磷酸磷灰石37.04%、尿酸及尿酸铵14.92%。女性患者磷酸铵镁占比为4.31%,明显高于男性的1.35%(P<0.05)。其他成分不同性别患者分布情况差异无统计学意义(P>0.05)。60岁以下的患者结石成分为草酸钙占比为96.69%,明显高于60岁及以上者的89.55%(P<0.05)。其他成分不同年龄段患者分布情况差异无统计学意义(P>0.05)。城镇居民患者草酸钙、磷酸磷灰石占比分别为96.69%、40.38%,均明显高于农村居民的89.82%、28.74%(P<0.05)。其他成分不同居住环境患者分布情况差异无统计学意义(P>0.05)。结论四川达州地区尿路结石患者结石化学成分易草酸钙为主,其次为磷酸磷石灰石、尿酸及尿酸铵。不同性别、年龄、居住环境对尿路结石化学成分分布有一定的影响。     

Clinical utility of computed tomography Hounsfield characterization for percutaneous nephrolithotomy: a cross-sectional study

Background

Computed Tomography (CT) is considered the gold-standard for the pre-operative evaluation of urolithiasis. However, no Hounsfield (HU) variable capable of differentiating stone types has been clearly identified. The aim of this study is to assess the predictive value of HU parameters on CT for determining stone composition and outcomes in percutaneous nephrolithotomy (PCNL).

Methods

Seventy seven consecutive cases of PCNL between 2011 and 2016 were divided into 4 groups: 40 (52%) calcium, 26 (34%) uric acid, 5 (6%) struvite and 6 (8%) cystine stones. All images were reviewed by a single urologist using abdomen/bone windows to evaluate: stone volume, core (HUC), periphery HU and their absolute difference. HU density (HUD) was defined as the ratio between mean HU and the stone’s largest diameter. ROC curves assessed the predictive power of HU for determining stone composition/stone-free rate (SFR).

Results

No differences were found based on the viewing window (abdomen vs bone). Struvite stones had values halfway between hyperdense (calcium) and low-density (cystine/uric acid) calculi for all parameters except HUD, which was the lowest. All HU variables for medium-high density stones were greater than low-density stones (p?<?0.001). HUC differentiated the two groups (cut-off 825 HU; specificity 90.6%, sensitivity 88.9%). HUD distinguished calcium from struvite (mean?±?SD 51?±?16 and 28?±?12 respectively; p?=?0.02) with high sensitivity (82.5%) and specificity (80%) at a cut-off of 35 HU/mm. Multivariate analysis revealed HUD?≥?38.5 HU/mm to be an independent predictor of SFR (OR?=?3.1, p?=?0.03). No relationship was found between HU values and complication rate.

Conclusions

HU parameters help predict stone composition to select patients for oral chemolysis. HUD is an independent predictor of residual fragments after PCNL and may be fundamental to categorize it, driving the imaging choice at follow-up.

     

Renal tract calculi: comparison of stone size on plain radiography and noncontrast spiral CT scan

BACKGROUND AND PURPOSE: Noncontrast spiral CT (NCCT) has emerged as the investigation of choice in patients presenting with renal-tract calculi. As management guidelines are based on stone size measured on plain radiography of the kidneys, ureters, and bladder (KUB), it is important to assess the accuracy of stone size measured on NCCT compared with KUB films. PATIENTS AND METHODS: The NCCT and KUB studies obtained from 24 patients (27 stones) presenting to the emergency department at a major metropolitan hospital were analyzed randomly and independently by two urologists and one uroradiologist. The NCCT scans were assessed separately from the KUB films. Only size in greatest dimension and stone location were recorded. RESULTS: The stone size was 2 to 38 mm on NCCT scans and 2 to 46 mm on KUB films. The mean stone size was 6.773 +/- 6.146 mm and 7.747 +/- 7.866 mm, respectively (P = 0.0398; Student's t-test). Almost three fourths (70%) of the stones were larger on KUB films than they were on NCCT scans, with a mean difference -0.974 mm (95% confidence interval -5.652, 3.703) for NCCT. CONCLUSION: Spiral CT underestimates stone size by approximately 12% compared with KUB films. This error may impact stone management as outlined in guidelines published by the American Urological Association, particularly for stones about 5 mm in greatest dimension. These patients may initially be managed conservatively when intervention would be more appropriate.     

佛山市顺德地区原住居民与外来居民尿路结石成分差异性分析

目的分析广东佛山市顺德地区原住居民与外来居民尿路结石成分的差异性。方法选取顺德区新容奇医院泌尿外科2017年1月~2019年1月收治的300例尿路结石患者,根据居民来源分为原住居民组150例及外来居民组150例,利用红外光谱结石检测仪对尿路结石成分进行分析和比对。结果原住居民组含钙结石占比、纯尿酸结石占比高于外来居民组,感染性结石占比低于外来居民组,差异有统计学意义(P0.05),其他结石占比差异无统计学意义(P0.05);原住居民组中一水草酸钙占比高于原住居民组,差异有统计学意义(P0.05),二水草酸钙、一水草酸钙+二水草酸钙尿酸铵、无水尿酸、一水尿酸钠以及二水尿酸占比与外来居民组数值相当,差异无统计学意义(P0.05)。结论顺德地区原住居民与外来居民尿路结石成分存在较大差异性。