CT胆管成像在疑诊胆道梗阻疾病中的应用

目的:探讨CT胆管成像(CTC)在疑诊胆道梗阻疾病中的应用价值。方法:对60例临床拟诊为胆道系统病变的病例行CT平扫及增强扫描,再用曲面重组、最低密度投影和多平面重组等方法重建出CT胆管成像(CTC)图像,结合两者作出诊断,与病理结果进行对照分析,计算CT+CTC对疑诊胆道梗阻病变的定位和定性诊断符合率。结果:胆管癌21例,胰腺癌18例,十二指肠乳头癌10例,胆管结石7例,胆总管囊肿3例,十二指肠乳头腺瘤1例。CT+CTC对疑诊胆道梗阻病变的定位和定性诊断符合率分别为100%和88.3%。结论:CT和CTC对疑诊胆道梗阻病变定位和定性诊断符合率高,具有良好的应用前景。     

小剂量托伐普坦联合呋塞米治疗急性心力衰竭合并利尿剂抵抗超高龄老年患者临床评价

目的观察小剂量托伐普坦联合呋塞米在急性心力衰竭合并利尿剂抵抗超高龄老年患者中应用的疗效及安全性。方法选取自2013年1月至2015年6月在广州军区总医院干诊科住院的24例急性心力衰竭超高龄老年患者,平均年龄(94.16±7.03)岁。在维持长期治疗方案并强心、扩血管、改善肾灌注或(和)纠正低蛋白血症基础上,予呋塞米100~160 mg/d静脉泵注治疗5 d后,24 h尿量仍少于800 ml,在此治疗基础上加用托伐普坦7.5 mg/d口服7 d。观察记录患者每日的血压、心率、中心静脉压、尿量、心衰体征及不良事件。定期检查肝、肾功能,N末端B型脑钠肽前体(N-pro-BNP)及电解质,进行疗效及安全性评估。结果所有患者24 h尿量在治疗后48~72 h明显增加,治疗第3天尿量由(668.7±108.7)ml显著增加至(1 989.8±289.7)ml,差异有统计学意义(P<0.01)。治疗结束时,心衰症状明显改善,中心静脉压由(18.9±2.3)cm H2O显著下降至(12.6±1.3)cm H2O,差异有统计学意义(P<0.01);N-pro-BNP由(13 385.3±7 545.9)pg/ml显著下降至(4 995.4±2156.2)pg/ml,差异有统计学意义(P<0.01);血肌酐由(171.8±57.5)μmol/L显著下降至(121.7±48.8)μmol/L,差异有统计学意义(P<0.01);所有患者均未发生高钠血症,无明显口渴;1例患者出现肝损害。结论小剂量托伐普坦联合呋塞米能够显著增加急性心力衰竭合并利尿剂抵抗超高龄老年患者的尿量,有效纠正心力衰竭症状,对其的救治具有临床意义。     

Ultrasound in suspected obstruction complicating renal transplantation

The findings of regular ultrasound examination of 439 renal transplants in 419 patients performed during a 16-year period were reviewed to determine the significance of collecting system dilatation. Dilatation was observed in 80 cases. 34 of these proving to be obstructed. Pelvic dilatation was an insignificant finding except when appearing within a month of transplantation. One third of cases developing pelvic dilatation within a month showed progressive dilatation with obstruction subsequently confirmed. The majority of cases developing unheralded dilatation of pelvis and calyces were obstructed and all such patients require further investigation. Recurrence of dilatation following relief of obstruction was associated with recurrent obstruction in eight of nine cases. Consideration of ultrasound appearances allows more critical selection of patients for further investigation when dilatation is seen.     

Roscoe Miller award. Fatty-meal sonography for evaluating patients with suspected partial common duct obstruction

We evaluated the efficacy of fatty-meal sonography for identifying patients with partial common duct obstruction. The test consisted of initial control measurements of common duct diameter followed by repeated measurements every 15 min for 60 min after a fatty meal consisting of Lipomul (1.5 ml/lb). The rationale proposed for the fatty-meal test is that in the presence of partial common duct obstruction, fat-induced increases in bile flow related to increased circulating levels of cholecystokinin are associated with an increase in the diameter of the common duct. Initial analysis of our data indicated that a change in diameter of +/- 1 mm was within the range of measurement error or possibly physiologic variation. In 44 control subjects (24 without a gallbladder), the common duct diameter either remained unchanged, showed an insignificant change of +/- 1 mm, or decreased (greater than or equal to 2 mm). The common duct diameter never showed an increase of more than 1 mm. The results of fatty-meal sonography in 47 patients with suspected partial common duct obstruction were negative in all 28 true-negative cases (specificity, 100%) and were positive (common duct increased by greater than or equal to 2 mm) in 14 of 19 true-positive cases (sensitivity, 74%). Thus, in this study a positive test finding always indicated partial common duct obstruction. Of the true-positive cases, fatty-meal sonography correctly identified seven of eight patients with cryptic obstructive sphincter-of-Oddi dysfunction (stenosis or dyskinesia) and five of nine patients with commun duct stones. We conclude that fatty-meal sonography is a useful noninvasive screening test for evaluating patients with suspected partial common duct obstruction.     

Venous thromboembolism: additional diagnostic value and radiation dose of pelvic CT venography in patients with suspected pulmonary embolism

Purpose

To assess the additional diagnostic value of indirect CT venography (CTV) of the pelvis and upper thighs performed after pulmonary CT angiography (CTA) for the diagnosis of venous thromboembolism (VTE).

Materials and methods

In a retrospective analysis, the radiology information system entries between January 2003 and December 2007 were searched for patients who received pulmonary CTA and additional CTV of the pelvis and upper thighs. Of those patients, the radiology reports were reviewed for the diagnosis of pulmonary embolism (PE) and deep venous thrombosis (DVT) in the pelvic veins and veins of the upper thighs. In cases with an isolated pelvic thrombosis at CTV (i.e. which only had a thrombosis in the pelvic veins but not in the veins of the upper thigh) ultrasound reports were reviewed for the presence of DVT of the legs. The estimated radiation dose was calculated for pulmonary CTA and for CTV of the pelvis.

Results

In the defined period 3670 patients were referred to our institution for exclusion of PE. Of those, 642 patients (353 men, 289 women; mean age, 65 ± 15 years, age range 18–98 years) underwent combined pulmonary CTA and CTV. Among them, PE was found in 227 patients (35.4%). In patients without PE CTV was negative in all cases. In patients with PE, CTV demonstrated pelvic thrombosis in 24 patients (3.7%) and thrombosis of the upper thighs in 43 patients (6.6%). Of those patients 14 (2.1%) had DVT in the pelvis and upper thighs. In 10 patients (1.5%) CTV showed an isolated pelvic thrombosis. Of those patients ultrasound reports were available in 7 patients, which revealed DVT of the leg veins in 5 cases (1%). Thus, the estimated prevalence of isolated pelvic thrombosis detected only by pelvic CTV ranges between 1–5/642 patients (0.1–0.7%). Radiation dose ranges between 4.8 and 9.7 mSv for additional CTV of the pelvis.

Conclusion

CTV of the pelvis performed after pulmonary CTA is of neglectable additional diagnostic value for the detection of VTE, because the additional radiation dose is high and isolated pelvic DVT is very rare. Venous imaging of the legs (preferably by radiation-free ultrasound) is sufficient for the diagnosis of underlying DVT in patients with suspected PE.     

Food-stimulated cholescintigraphy as a supplement to ERC in patients with suspected bile flow obstruction. A preliminary study

Cholescintigraphy after food stimulation was carried out in 40 patients (13 patients with biliary enteric bypass, 14 patients with bile duct stenosis, demonstrated by ERC, 5 patients with endoprothesis and 8 patients with clinically suspected post-cholecystectomy syndrome. Biliary-bowel transit time of one hour or less was considered to be normal. In patients with biliary enteric bypass 11 had a normal transit time; however, one with a concomitant anastomotic leakage, and 2 patients had prolonged transit time and a significant obstruction by the anastomosis. All 14 patients with demonstrated biliary stricture had normal transit time. In 5 patients with endoprothesis, 2 had prolonged transit time in spite of patent endoprothesis. Finally, in the 8 patients with suspected post-cholecystectomy syndrome, 4 had normal sphincter of Oddi manometry and normal transit time, and 4 had abnormal sphincter of Oddi manometry, but only one with prolonged transit time. It is concluded that in patients with biliary enteric bypass (hepatico-jejunostomia) or biliary strictures a biliary-bowel transit time of one hour will be discriminatory between normal and abnormal conditions. This is in contrast to patients with endoprothesis and suspected sphincter of Oddi dysmotility, where a transit time of one hour only will have limited predictive value.     

Multislice CT cholangiography using thin-slab minimum intensity projection and multiplanar reformation in the evaluation of patients with suspected biliary obstruction: preliminary experience

Thirty-three patients with suspected biliary obstruction were prospectively evaluated with multislice CT cholangiography using thin-slab minimum intensity projection (MinIP) and multiplanar reformation (MPR) to determine its usefulness and to compare with the comparative studies of endoscopic retrograde cholangiography (ERC), magnetic resonance cholangiography (MRC), or percutaneous transhepatic cholangiography (PTC). CT cholangiography made correct diagnoses in all biliary obstructions except in two patients with common bile duct stones. The correspondence with the comparative study was 93.9%. Multislice CT cholangiography may be favorable in noninvasive evaluation of biliary obstructions.     

Bronchography in patients with suspected lung malignancy

Bronchography and flexible fiberoptic bronchoscopy (FFB) were performed on 95 patients with suspected lung malignancy. Finally, 66 of 95 lesions turned out to be malignant and 29 benign. Bronchographic diagnosis was correct in 46 of 66 cases of cancer (70%) but gave a false negative result in 20 malignant lesions and a false positive result in four benign lesions of which three had pulmonary tuberculosis and one hamartoma of the lung. It is concluded that bronchography is rarely indicated in central malignant lesions. In peripheral lesions bronchographic findings for malignancy are unreliable or negative.     

Radioimmunodetection in patients with suspected ovarian cancer

Twenty-five patients, having either unilateral ovarian tumors of unknown etiology or suspected of having ovarian cancer recurrence were investigated by the method of immunoscintigraphy to rule out primary and/or metastatic tumor sites. Four-hundred micrograms of the tumor-associated monoclonal mouse antibody HMFG-2, raised against human milk fat globulin membranes and labeled with 123I, were used for each patient to display the tumor sites by external scintigraphy. The dose ranged between 0.5 and 2.2 mCi, the specific activity between 1.25 and 5.5 mCi per mg of antibody. Nineteen of the patients underwent operations a few days after immunoscintigraphy. The remaining six patients were investigated by transmission computed tomography (TCT) to establish the presence or absence of tumor of the imaging. In 22 of the 25 cases the scintigraphic results correlated with the situation found at the subsequent operation, or by TCT, respectively, as well as with the histological diagnosis of the tumor type. Overall, there were just two false-negative and one false-positive scan report, the latter due to faulty reading of the scintigrams. Sixteen out of 18 tumor sites in 25 patients could be revealed by immunoscintigraphy, the smallest one being 1.5 cm in diam. In four of the patients immunoscintigraphy was the only noninvasive investigation method that could reveal the malignant tumor sites prior to the operation.     

Low dose computed tomography in suspected acute renal colic

AIM: To evaluate whether computed tomography (CT) of the renal tract in suspected renal colic using reduced exposure factors maintains diagnostic accuracy. METHODS: Prospective multi-centre cohort study. Patients with suspected renal colic were examined using computed tomography (CT) of the renal tract followed by intravenous urography (IVU) in four different centres with five different CT systems. RESULTS: Sixty-nine patients with suspected renal colic had CT of the renal tract followed by IVU. CT was performed with reduced exposure factors, giving a mean CT effective dose of 3.5 (range 2.8-4.5) mSv compared with 1.5 mSv for IVU. Ureteric calculi were detected in 43 patients: CT and IVU detected 40 (93%) ureteric calculi. CT identified other lesions causing symptoms in five patients and identified renal calculi in 24 patients. IVU identified renal calculi in six patients and made false positive diagnosis of renal calculi in seven patients. Mean examination time for CT was 5 minutes and for IVU was 80 minutes. CONCLUSION: CT examination at reduced exposure factors maintains the diagnostic accuracy recorded in other series.     

A head phantom study for intraocular dose evaluation of 64-slice multidetector CT examination in patients with suspected cranial trauma

Purpose

In cases of suspected cranial trauma, cranial CT examinations should be performed to rule out pathology. There are some methods available for reducing intraocular doses; however, it is difficult for the operators to conduct the necessary measurements because of restrictions in time and patient mobility, especially in high-energy trauma cases. Therefore, we performed a head phantom study for intraocular dose evaluation of 64-slice multidetector CT examination in patients with suspected cranial trauma.

Materials and methods

Assuming that the orbitomeatal (OM) line and bed were vertical, a head phantom was tilted from 10 degrees caudally to 25 degrees cranially at 5-degree intervals. At each tilted position, the phantom was examined using a 64-section multidetector CT device using three acquisition protocols. Intraocular doses during each examination were measured using small dosimeters.

Results

Assuming that the OM line and bed were vertical, intraocular doses varied between 52 and 140%, 17-138%, and 90-142% during helical, non-helical, and helical CT angiographic examinations, respectively. Intraocular doses increased when the phantom was tilted cranially.

Conclusion

If possible, the best way to reduce the intraocular dose is by angling the gantry cranially, tilting the head of each patient caudally and adopting a non-helical acquisition method. During procedure, the acquisition angle should be angled cranially more than 0 degrees based on the OM line. The estimation of intraocular dose using the acquisition angle and displayed volumetric CT dose index might be useful to evaluate the deterministic effect risks and to inform patients about the associated risks.     

Perfusion SPECT in patients with suspected pulmonary embolism

Purpose

Ventilation/perfusion tomography (V/P_SPECT), with new interpretation criteria and newer tracers for ventilation imaging, has markedly improved the diagnostic yield in acute pulmonary embolism (PE). Here, we evaluated the diagnostic performance of perfusion SPECT (P_SPECT) without ventilation imaging.

Methods

We studied 152 patients with clinically suspected PE who had been examined with both V/P_SPECT and multidetector computed tomographic angiography (MD-CTA). The diagnosis or exclusion of PE was decided by the referring clinician based on both the V/P_SPECT and/or MD-CTA findings in combination with the clinical findings. P_SPECT images were retrospectively examined by a physician with experience in the interpretation of planar perfusion scans who was blinded to clinical, V/P_SPECT and MD-CTA data. P_SPECT images were interpreted without the aid of chest radiography. All the patients who were deemed to have PE were given anticoagulant therapy.

Results

Of the 152 patients, 59 (39 %) received a final diagnosis of PE, and 19 (32 %) had associated cardiopulmonary diseases such as pneumonia, COPD, or left heart failure. P_SPECT correctly identified 53 (90 %) of the 59 patients with PE. The specificity was 88 of 93 (95 %). None of the P_SPECT images was rated nondiagnostic. P_SPECT yielded an overall diagnostic accuracy of 93 % (95 % confidence interval, CI, 87–96 %). At the observed PE prevalence of 39 %, the positive and negative predictive values of P_SPECT were 91 % (95 % CI, 80–97 %) and 94 % (95 % CI, 86–97 %), respectively.

Conclusion

In managing critically ill patients, P_SPECT might be a valid alternative to V/P_SPECT or MD-CTA since it was able to identify most patients with PE with a low false-positive rate and no inconclusive results.     

Bile duct: analysis of percutaneous transluminal forceps biopsy in 130 patients suspected of having malignant biliary obstruction

PURPOSE: To evaluate percutaneous transluminal forceps biopsy in patients suspected of having a malignant biliary obstruction. MATERIALS AND METHODS: One hundred thirty consecutive patients (82 men and 48 women; mean age, 59 years) with obstructive jaundice underwent transluminal forceps biopsy during or after percutaneous transhepatic biliary drainage. The lesions involved the common bile duct (n = 58), common hepatic duct (n = 39), hilum (n = 14), ampullary segment of the common bile duct (n = 11), right or left intrahepatic bile duct (n = 5), or the entire extrahepatic bile duct (n = 3). In each patient, three to five specimens (mean, 4.1 specimens) were taken from the lesion with 5.4-F biopsy forceps. The final diagnosis for each patient was confirmed with pathologic findings at surgery, additional histocytologic data, or clinical and radiologic follow-up. Statistical analysis was performed with the chi(2) test; a P value < or =.05 was considered to indicate a significant difference. RESULTS: Ninety-eight of 130 biopsies resulted in correct diagnoses of malignancy. Five biopsy diagnoses proved to be true-negative. There were 27 false-negative diagnoses and no false-positive diagnoses. The diagnostic performance of transluminal forceps biopsy in malignant biliary obstructions was as follows: sensitivity, 78.4%; specificity, 100%; and accuracy, 79.2%. Sensitivity of biopsy in the 82 patients with cholangiocarcinoma was higher than in the 43 patients with malignant tumors other than cholangiocarcinoma (86.6% vs 62.8%, P <.005). Sensitivity was significantly lower in the ampullary segment of the common bile duct than in other sites (P <.01). No major complications related to the biopsy procedures occurred. CONCLUSION: Percutaneous transluminal forceps biopsy is a safe procedure that is easy to perform through a transhepatic biliary drainage tract. It provides relatively high accuracy in the diagnosis of malignant biliary obstructions.     

双源CT双能量扫描在肝脏病变中的应用价值

目的 探讨双源CT(DSCT)双能量扫描对肝脏病变的诊断价值及限度.方法 将53例B超拟诊肝脏占位患者行上腹部普通平扫(TNE)及三期增强扫描(动脉期、双能量门静脉、延迟期).双能量扫描后自动生成80 kV、140 kV以及120 kV加权图像.数据导入工作站的虚拟平扫(VNE).从图像定性评估(肿瘤可见度、图像噪声、诊断接受度)及定量数值(脏器平均CT值、图像噪声、对比噪声比)比较VNE与TNE的图像质量;判断VNE能否取代TVE、80 kV图像中病变的微小血供、双能量纯(彩)碘图、以及感兴趣区(ROI)分解CT值的诊断作用.最后,对比TNE与VNE的有效辐射剂量.结果 53例中有7例在80 kV中较140 kV及120 kV加权图像更清晰显示肿瘤内血管.VNE肿瘤可见度、诊断接受性显著低于、噪声显著高于TNE(P<0.05).TNE及VNE平均CT值分别为:肝实质(58.5±5.6) HU、(58.2±6.7) HU(P=0.226);肝占位(38.8±8.1) HU、(37.4±8.3) HU(P<0.05).VNE图像噪声及对比噪声比显著高于TNE(P<0.001).超出的肝边缘及伪影对诊断无影响,除4例外,VNE均能取代TVE.纯(彩)碘图直观展示病变血供范围及程度,ROI可分解平扫及碘增强的CT值.TNE与VNE有效剂量:(3.38±0.55) mSv,(3.36±0.90) mSv(P>0.05).结论 双源CT双能量80 kV较常规CT对病变血供更敏感,其后处理功能对病变定性诊断有一定作用.VNE图像质量较TNE差,但可取代之并减少辐射剂量.     

Volume expanded diuretic renography in the postnatal assessment of suspected uretero-pelvic junction obstruction.

Controversy surrounds the role of 99mTc-diethylenetriamine pentaacetic acid renography in suspected uretero-pelvic junction obstruction in early life. Accordingly, we retrospectively reviewed 18 patients (28 hydronephrotic kidneys) with a mean age of 2 mo (range: 1 wk-6 mo) who underwent a total of 36 scans using intravenous volume expansion (10 ml/kg) and furosemide diuresis (1 mg/kg). Initial scans were classified as obstructed, not obstructed or indeterminate using differential renal function, furosemide washout T 1/2 and visual assessment of tracer clearance. Those initially classified as obstructed (n = 8) have been surgically confirmed. In the indeterminate (n = 6) and nonobstructed (n = 14) groups, three and two kidneys, respectively, developed obstruction on progress scans. Mean follow-up in the nonsurgical patients was approximately 9 mo (range: 4-17 mo). A total of 13 kidneys had developed obstruction by renographic criteria, and to date 12 have surgical confirmation. Our data indicate that: (1) scans classified as obstructed correlate well with surgery; (2) an initial classification of indeterminate or nonobstructed does not exclude later development of obstruction; and (3) serial scans correctly stratify children with possible uretero-pelvic junction obstruction.