Accuracy of ultrasound and oral cholecystography in assessing the number and size of gallstones: implications for non-surgical therapy.

Prior to non-surgical therapy of gallstones it is important to assess their number and size. In order to evaluate the accuracy of ultrasound (US) and oral cholecystography (OCG) in counting and measuring gallstones, a prospective blind study was conducted to compare the results of US (n = 99) and OCG (n = 36), either alone or in combination (n = 34), with the number and size of gallstones retrieved after cholecystectomy. The number of gallstones was accurately estimated by US and OCG in 74% and 69% of the cases, respectively. In assessing the presence of up to three, five or 10 gallstones both US and OCG proved reliable. In measuring the size of gallstones, there was 19% accuracy with US compared with only 3% with OCG. With an accepted measurement error of 3 mm these values increased to 80% for US and 44% for OCG. US proved more reliable than OCG in discriminating gallstones smaller or larger than 10 mm and smaller or larger than 20 mm, but with US, detection of gallstones larger than 30 mm was problematic. Both US and OCG underestimated gallstone size. The combination of both techniques did not significantly improve the assessment of either number or size of gallstones compared with the results obtained with US or OCG alone. It is concluded that (1) both US and OCG have some limitations in assessing the number and size of gallstones, (2) the combination of both examinations does not improve accuracy, and (3) patient selection for non-surgical treatment of gallstones can be started by US alone.     

The value of ultrasound in predicting non-visualization of the gall-bladder on OCG: implications for imaging strategies in patient selection for non-surgical therapy of gallstones

Gall-bladder visualization on oral cholecystography (OCG) is required for most non-surgical therapies of gallstones. In this study we attempted to establish sonographic criteria which will predict non-visualization of the gall-bladder on OCG. For this purpose we compared the results of ultrasound (US) and OCG in 171 patients with gallstones being assessed for non-surgical therapy. Sonographic criteria for non-visualization were a contracted gall-bladder and stone impaction in the gall-bladder neck or cystic duct. In detecting findings which predict non-visualization on OCG, US had a sensitivity of 78.3% and a specificity of 97.6%. The predictive values were: positive findings 92.3% and negative findings 92.4%. The overall accuracy was 92.4%. We conclude that US can be used as a first step in selecting patients for non-surgical therapy and if US indicates a contracted gall-bladder, 11% of the patients can be excluded from further diagnostic imaging.     

Comparison of ultrasonography and oral cholecystography in biliary lithotripsy. I. Screening patients

Ultrasound and oral cholecystography (OCG) are both used to evaluate candidates for biliary lithotripsy. Some investigators have suggested abandoning the OCG, believing that sufficient screening information can be obtained from ultrasound. This study compares ultrasound and OCG in assessing the size and number of gallstones, both in vitro and in vivo. In the in vitro model, 35 gallstones, divided into 20 groups, were separately suspended in dilute contrast media in a phantom, and examined by ultrasound and simulated OCG by each of three gastrointestinal radiologists. In the in vivo study, the ultrasound and OCG examinations from 53 patients were independently reviewed by three radiologists. The number and size of the stones were recorded in both studies. In the in vitro study, the stone size was measured within 2 mm of the actual size by OCG in 23/35 stones (66%) and by ultrasound in 4/35 stones (11%). The correct number of stones was determined by OCG in 19/20 groups (95%), and by ultrasound in 14/20 (70%). In the in vivo study, all readers saw the same number of stones in 40/50 (80%) patients by OCG and 33/49 (67%) patients by ultrasound. Statistical analyses revealed correlation coefficients for OCG greater than those for ultrasound in each comparison. The size of the largest stone was within 2 mm by all readers in 26/51 (51%) of patients by OCG and 20/47 (43%) patients by ultrasound. Oral cholecystography is more reliable than ultrasound for the determination of size and number of stones in patients being screened for biliary lithotripsy.     

Comparison of ultrasonography and oral cholecystography in lithotripsy. II. Determining retreatment

Both ultrasonography (US) and oral cholecystography (OCG) are being used to evaluate patients after extracorporeal shock wave lithotripsy (ESWL) for gallstones. Criteria for retreatment after the initial ESWL are usually related to the size of the residual fragments. This study examines the efficacy of ultrasound and OCG for determining both the size and number of stone fragments in the gallbladder in an in vitro model and in patients. Ultrasonography and OCG examinations using an in vitro ESWL phantom with ten groups of stones, and on 39 patients, were reviewed independently by three radiologists to determine both the size and number of stone fragments. For the in vitro study, the three readers estimated the correct number of fragments, or the next closest range, in 87% of observations by OCG and in 43% by US. The size of the largest fragment was measured within 1 mm of its actual size in 87% of observations by OCG and 20% by US. Correlation coefficients for the mean measurements of the three readers versus the actual fragment size and number were greater for OCG than for US. For the in vivo study, the three readers agreed in 47% of the OCG versus 32% of US examinations with respect to the number of fragments, and in 65% of OCG compared to 40% of US studies with respect to size of the largest fragment. Multiple statistical analyses demonstrate that these differences are statistically significant. A discrepancy among the readers concerning whether a patient was eligible for retreatment occurred in 15% of OCG as compared to 45% of US studies. Both the in vivo and in vitro studies indicate that there is more interobserver reproducibility for OCG than for US, and that OCG is more reliable in making the decision concerning patient eligibility for retreatment following lithotripsy.     

Predicting gallstone composition with CT: in vivo and in vitro analysis

Chemical composition of gallstones is of major importance in selecting patients for nonsurgical therapy. In a combined in vivo and in vitro study of predictive potential, 50 patients undergoing cholecystectomy were evaluated with computed tomography (CT) and either plain abdominal radiography or oral cholecystography (OCG). The largest stone surgically removed from each patient was subjected to in vitro CT and chemical analysis. The authors found an inverse relationship between CT attenuation numbers and cholesterol content and a good positive correlation between CT attenuation numbers and calcium content. In vivo CT analysis improved sensitivity, specificity, accuracy, and positive and negative predictive values compared to plain abdominal radiography and OCG in detection of cholesterol stones. Using their prediction rule (a CT number smaller than 140 HU indicates a pure cholesterol gallstone), the authors correctly classified gallstones in 17 (84%) of another 20 patients. In vivo CT analysis can enable reliable prediction of gallstone composition and should play an important role in the selection of patients for nonsurgical treatment.     

Oral cholecystography vs gallbladder sonography: a prospective, blinded reappraisal

In a prospective, blinded study of 205 patients, oral cholecystography (OCG) and sonography were compared in terms of how well each screened patients for gallbladder diseases. Among 23 patients who had pathologic confirmation of the diagnosis at cholecystectomy, OCG correctly diagnosed 20 cases (87%) while sonography diagnosed 18 (78%). Among 54 patients with an abnormal OCG and/or sonogram, OCG detected 47 (87%) while sonography detected 44 (81%). These small differences in detection rates were not statistically significant. On the basis of these results, we cannot conclude that either sonography or OCG has a diagnostic advantage in screening patients for gallbladder disease. The large numbers of false-negative examinations found on both sonography and OCG suggest that in a patient with persistent symptoms, the alternative study should be performed if the first examination is negative.     

The value of sonography in determining cystic duct patency.

A prospective blinded comparison of ultrasonography (US) and oral cholecystography (OCG) was performed in 100 patients with symptomatic gall-stones to determine whether US would enable an accurate assessment of cystic duct patency to be made. Patency of the cystic duct was defined as gall-bladder opacification on OCG or a greater than 20% decrease in gall-bladder volume by US post-fatty meal. The ellipsoid method of volume measurement was used. Any patient who had a non-opacified gall-bladder on OCG but a greater than 20% volume decrease on US had cholescintigraphy performed (DISIDA). Oral cholecystography demonstrated cystic duct patency in 88 patients (88%), and fatty-meal gall-bladder US met the specified study criteria for patency in 86 patients (86%). False negative results were identified in four of the OCG and in six of the US examinations. The results of this study indicate that gall-bladder sonography with a post-fatty meal contraction of greater than 20% is a very accurate predictor of cystic duct patency. A contraction of less than 20%, however, cannot be considered a reliable predictor of cystic duct occlusion.     

A rational approach to the investigation of the gallbladder

A technique for the investigation of suspected non-acute gallbladder disease is described. It is based on properly conducted oral cholecystography (OCG) augmented, when necessary, by ultrasonic examination of the gallbladder (UCG) during the patient's same visit. This regimen has been applied successfully for 5 years; the results of a recent year's work are presented and discussed. Only 12.2% of patients required both investigations and, using the OCG technique described, in only 1.1% of cases was the gallbladder inadequately opacified when subsequent UCG was normal. This approach involves no increase in work-load and provides the referring clinician with objective evidence of the presence or absence of disease following a single visit by the patient to the X-ray department.     

Interventional radiologic alternatives to cholecystectomy

It has been estimated that 20 million people in the United States have gallstone disease. The choice of the optimal management strategy for a patient with symptomatic gallstones in the 1990s will take into account the clinical status of the patient, the characteristics of the gallstones, and the patient's preference. Only patients whose doctors understand the advantages and disadvantages of the newer methods can make properly informed choices. When interventional radiologic alternatives to cholecystectomy are being contemplated, one approach is to first consider the patient's clinical presentation (acute or nonacute) and then their risk of death after cholecystectomy (low or high). Figure 5 shows an algorithmic approach to the management of gallbladder stones based on this concept. This algorithm also can be used as a framework for discussion of treatment options with any individual patient.     

飞行人员胆囊结石的空中B超观察

旨在观察飞行中胆囊结石有无位移及能否诱发空中突然失能。采用日本SDL－32型B超诊断仪，对16名飞行人员胆囊结石患者进行了地面及空中观察。结果表明，地面观察未见胆囊结石有明显位移；跟班飞行观察，从飞机爬升经巡航到下滑几个阶段内，胆囊结石保持原位不动者9例（共有块状结石7枚，泥沙状结石3堆），其中结石位于胆囊颈部3例、胆囊体部6例，为滞留型；结石发生了位移者7例（共有块状结石13枚），其中结石由胆囊颈部降到胆囊体部者4例、由胆囊体部落到胆囊底部者2例，在胆囊体部前后壁间横向移位者1例，为游移型。游移型结石有可能速入胆道，引起突然失能，危及飞行安全，应密切观察。     

Cholelithiasis in the morbidly obese: diagnosis by US and oral cholecystography

Forty-two morbidly obese patients underwent cholecystectomy at the time of gastroplasty, primarily for prophylactic reasons. Preoperatively, 37 patients underwent ultrasonography (US) of the gallbladder and oral cholecystography, four US only, and one oral cholecystography only. There was one indeterminate US study (2.4%) and one indeterminate oral cholecystogram (2.7%). At US study, gallstones were detected in six of the eight patients with gallstones (sensitivity = 75%), and the gallbladders of all 32 patients without gallstones were categorized as normal (specificity = 100%). The gallstones not identified measured 1-2 mm in diameter. Oral cholecystographic study enabled detection of gallstones in three of the seven patients with gallstones (sensitivity = 43%) and categorized as normal all 30 gallbladders without gallstones (specificity = 100%). The gallstones not seen were small and included those not detected by US. The results suggest that US is equal or superior to oral cholecystography for detection of cholelithiasis in obese patients.     

Percutaneous Biliary Interventions: Inside and Outside the Box: Gallbladder: Role of Interventional Radiology

Percutaneous cholecystostomy is an established procedure for the management of patients with acute cholecystitis and with significant medical comorbidities that would make laparoscopic cholecystectomy excessively risky. In this review, we will explore the role of percutaneous cholecystostomy in the management of acute cholecystitis as well as other applications in the management of biliary pathology. The indications, grading, technical considerations, and postprocedure management in the setting of acute cholecystitis are discussed. In addition, we will discuss the potential role of percutaneous cholecystostomy in the management of gallstones and biliary strictures, in establishing internal biliary drainage, and in a joint setting with other clinicians such as gastroenterologists in the management of complex biliary pathology.     

Diagnosis of gallstone composition in magnetic resonance imaging: in vitro analysis.

OBJECTIVE: To elucidate the cause of the signal intensity of gallstones on magnetic resonance (MR) images and to determine whether MR imaging would enable the prediction of the composition of gallstones. MATERIALS AND METHODS: 50 gallstones removed by cholecystectomy from 50 patients were used for in vitro study. All 50 gallstones were examined by MR imaging using a body phantom. After imaging, all gallstones were cut into two pieces, and the MR appearances were compared with their cross-sections. Chemical analysis was subsequently performed on 32 gallstones. RESULTS: On T2-weighted (T2W) images, 24 of 50 gallstones showed high signal intensities only in their center. These central high intensities seen on T2W images corresponded to the clefts filled with fluid within gallstones. In 45 of 50 gallstones there were high signal intensity areas in central and/or peripheral regions on T1-weighted (T1W) images. On T1W images, not only the clefts within gallstones but also other regions were seen as high intensity, and these regions had a brown to black color, coarse structure, and contained much copper. CONCLUSION: MR imaging can visualize the structures and compositions of gallstones in detail.     

血清8种胆固醇脂肪酸与胆囊结石成因分析

为分析胆结石形成与胆固醇脂肪酸的关系,采用气相色谱法(HPLC)测定结石组59例、非结石组43例血清中8种胆固醇脂肪酸含量。经统计学处理,发现20:5、20:4、18:2、14:0、18:1均有显著差异,认为肥胖及高胆固醇血症是胆囊结石的高危因素。     

MRI of gallstones with different compositions

OBJECTIVE: Gallstones are usually recognized on MRI as filling defects of hypointensity. However, they sometimes may appear as hyperintensities on T1-weighted imaging. This study investigated how gallstones appear on MRI and how their appearance influences the detection of gallstones. MATERIALS AND METHODS: Gallstones from 24 patients who had MRI performed before the removal of the gallstones were collected for study. The gallstones were classified either as cholesterol gallstone (n = 4) or as pigment gallstone (n = 20) according to their gross appearance and based on analysis by Fourier transform infrared spectroscopy. MRI included three sequences: single-shot fast spin-echo T2-weighted imaging, 3D fast spoiled gradient-echo T1-weighted imaging, and in-phase fast spoiled gradient-echo T1-weighted imaging. The signal intensity and the detection rate of gallstones on MRI were further correlated with the character of the gallstones. RESULTS: On T1-weighted 3D fast spoiled gradient-echo images, most of the pigment gallstones (18/20) were hyperintense and all the cholesterol gallstones (4/4) were hypointense. The mean ratio of the signal intensity of gallstone to bile was (+/- standard deviation) 3.36 +/- 1.88 for pigment gallstone and 0.24 +/- 0.10 for cholesterol gallstone on the 3D fast spoiled gradient-echo sequence (p < 0.001). Combining the 3D fast spoiled gradient-echo and single-shot fast spin-echo sequences achieved the highest gallstone detection rate (96.4%). CONCLUSION: Based on the differences of signal intensity of gallstones, the 3D fast spoiled gradient-echo T1-weighted imaging was able to diagnose the composition of gallstones. Adding the 3D fast spoiled gradient-echo imaging to the single-shot fast spin-echo T2-weighted sequence can further improve the detection rate of gallstones.     

胆囊结石化学类型的计算机辅助诊断

探讨胆囊结石化学类型与各影像学特征的关系，并建立简便而有效的体外预测结石化学类型的方法。     

长期服用抗精神病药物患者胆结石患病情况及其影响因素

目的探讨长期服用抗精神病药物的精神疾病患者胆结石患病情况及其影响因素。方法对94例住院精神病患者（患者组）及154例健康体检者（对照组）进行B超检查,同时观察体重指数、血糖及病期等指标。结果胆结石检出率：患者组为25.5%（其中男23.72%,女28.57%）,对照组为6.49%（其中男6.89%,女5.56%）。患者组体重指数和血糖方面高于对照组,差异具有统计学意义。结论长期服用抗精神病药物的精神病患者胆结石发生率明显高于正常人群,其原因可能与服用抗精神病药物后患者活动减少,体重增加,糖、脂质代谢异常以及胆囊收缩功能下降等因素有关。     

Sensitivity of ultrasonography for detecting gallstones

Previous studies have overestimated the accuracy of ultrasonography for the diagnosis of gallstones by neglecting the systematic checking of false negative findings. In the present series only 80% of 331 cases of gallstones seen at autopsy had been detected by ultrasonography. The most frequent reason for a false negative finding was the small size of the gallstones.     

Spontaneous resolution of cholelithiasis in infants

Follow-up sonographic studies of five infants whose initial sonograms had displayed evidence for the diagnosis of cholelithiasis demonstrated spontaneous resolution of the gallbladder defects. These defects may have been caused by tumefactive sludge with acoustic shadowing. Whether sludge or gallstones are being imaged, in the absence of other clinical or imaging evidence of biliary tract disease, conservative (i.e., nonsurgical) management and serial sonograms are recommended.     

Combined surgical and radiologic intervention for complicated cholelithiasis in high-risk patients

Ultrasound-guided surgical cholecystostomy with local infiltration anesthesia was combined with radiologic removal of gallstones in 36 elderly patients with acute calculous gallbladder disease who were considered to be at high risk due to multiple coexisting diseases. At cholecystostomy, the fundus of the gallbladder was sutured to the anterior abdominal wall resulting in a short surgical track to the gallbladder. This permitted early percutaneous stone removal through the cholecystostomy track under fluoroscopic guidance. All gallstones were removed in 31 of 36 patients, for an overall success rate of 86%. The success rate was 97% for gallbladder stones, 86% for cystic duct stones, and 63% for common bile duct stones that were removed by traversing the cystic duct. The treatment in the five patients in whom radiologic stone removal was incomplete or unsuccessful consisted of elective cholecystectomy in three, with common bile duct exploration in two of these; endoscopic sphincterotomy and stone extraction in one; and expectant management in one. There were no deaths or serious complications. This technique has thus proved safe and effective in these 36 high-risk patients.