Huan-Wu Chen

Multidetector computerized tomography urography is more accurate than excretory urography for diagnosing transitional cell carcinoma of the upper urinary tract in adults with hematuria.

PURPOSE It is debatable whether traditionally used excretory urography or the recently introduced multidetector computerized tomography urography is more accurate for diagnosing upper urinary tract transitional cell carcinoma. We compared accuracy measures of both methods for diagnosing upper urinary tract transitional cell carcinoma in adult patients with hematuria. MATERIALS AND METHODS We retrospectively analyzed consecutive adult patients with hematuria undergoing excretory urography and multidetector computerized tomography urography before any surgery, intervention or treatment from April 2004 to December 2006 in our hospital. The presence of upper urinary tract transitional cell carcinoma on excretory urography and multidetector computerized tomography urography was reviewed independently by 2 uroradiologists who were blinded to clinical information and other imaging results. Final diagnosis of upper urinary tract transitional cell carcinoma was confirmed by histological results. Measures of the diagnostic accuracy of excretory urography and multidetector computerized tomography urography for upper urinary tract transitional cell carcinoma were calculated and compared with reference to the final diagnosis. RESULTS Of 34 men and 26 women with hematuria (mean age 60.73 +/- 12.95 years) 19 (31.7%) had a final diagnosis of 24 upper urinary tract transitional cell carcinomas. The sensitivity, specificity and accuracy of excretory urography were 0.750, 0.860 and 0.849, respectively. In contrast, the sensitivity, specificity and accuracy of multidetector computerized tomography urography were 0.958, 1.000 and 0.996, respectively. Overall the area under the receiver operating characteristic curve for multidetector computerized tomography urography was significantly larger than that for excretory urography (0.978 vs 0.815, p = 0.005). CONCLUSIONS Multidetector computerized tomography urography is more sensitive, specific and accurate than excretory urography in the diagnosis of upper urinary tract transitional cell carcinoma in adult patients with hematuria. Therefore, multidetector computerized tomography urography rather than excretory urography should be the first choice noninvasive imaging modality for diagnosing upper urinary tract transitional cell carcinoma.

Contrast-enhanced multiphasic computed tomography for identifying life-threatening mesenteric hemorrhage and transmural bowel injuries.

BACKGROUND Active mesenteric hemorrhage and bowel perforation after blunt abdominal trauma warrant immediate surgical intervention. We investigate whether findings on multiphasic computed tomography (CT) can identify life-threatening mesenteric hemorrhage and bowel injuries. METHODS Within 1-year period, 106 patients underwent multiphasic CT for evaluation of blunt abdominal injuries. Images obtained at arterial phase, portal phase, and equilibrium phase were retrospectively reviewed with special focus on mesentery and bowel injuries. We compared the recorded findings with surgically proven active mesenteric hemorrhage and transmural bowel injuries. The diagnostic values and positive likelihood ratios of individual CT signs were calculated. RESULTS Mesenteric contrast extravasation had 73.5 positive likelihood ratio and 75% sensitivity for active mesenteric hemorrhage. Hemorrhage first appeared at arterial phase and portal phase was active and life threatening, different from a contained hemorrhage appeared only at equilibrium phase. For transmural bowel injuries, positive likelihood ratio of full-thickness bowel wall abnormality and extraluminal air was large at 32.5 and 26.9, respectively. However, increased mesenteric fat density and peritoneal fluid had high negative predictive value at 98.9 and 97.8. Mean radiodensity of peritoneal fluid in transmural bowel injuries was significantly lower (30 vs. 44 Hounsfield unit, p = 0.008). CONCLUSIONS Multiphasic CT is accurate in identifying life-threatening mesenteric hemorrhage and transmural bowel injuries.

Mesenteric vascular occlusion: comparison of ancillary CT findings between arterial and venous occlusions and independent CT findings suggesting life-threatening events.

Objective To compare the ancillary CT findings between superior mesenteric artery thromboembolism (SMAT) and superior mesenteric vein thrombosis (SMVT), and to determine the independent CT findings of life-threatening mesenteric occlusion. Materials and Methods Our study was approved by the institution review board. We included 43 patients (21 SMAT and 22 SMVT between 1999 and 2008) of their median age of 60.0 years, and retrospectively analyzed their CT scans. Medical records were reviewed for demographics, management, surgical pathology diagnosis, and outcome. We compared CT findings between SMAT and SMVT groups. Multivariate analysis was conducted to determine the independent CT findings of life-threatening mesenteric occlusion. Results Of 43 patients, 24 had life-threatening mesenteric occlusion. Death related to mesenteric occlusion was 32.6%. A thick bowel wall (p < 0.001), mesenteric edema (p < 0.001), and ascites (p = 0.009) were more frequently associated with SMVT, whereas diminished bowel enhancement (p = 0.003) and paralytic ileus (p = 0.039) were more frequent in SMAT. Diminished bowel enhancement (OR = 20; p = 0.007) and paralytic ileus (OR = 16; p = 0.033) were independent findings suggesting life-threatening mesenteric occlusion. Conclusion The ancillary CT findings occur with different frequencies in SMAT and SMVT. However, the independent findings indicating life-threatening mesenteric occlusion are diminished bowel wall enhancement and paralytic ileus.

Management of Complicated Lumbar Artery Injury After Blunt Trauma

STUDY OBJECTIVE Lumbar artery injury after blunt trauma is not frequently discussed. We review our experience with blunt lumbar artery injury management, especially alternative treatments in which embolization is not feasible. METHODS We reviewed our trauma registry for 8 years 8 months. We sought all patients who sustained blunt torso trauma and had lumbar artery injury detected by angiography. Variables collected included demographic data, trauma mechanism, vital signs in triage, Injury Severity Score, associated injuries, computed tomography results, angiography results, embolizations, and outcome. RESULTS Sixteen of the 3,436 patients in the trauma registry system had a blunt lumbar artery injury verified by angiography. For patients with lumbar artery injury, the mean Injury Severity Score was 38.6 (SD 12), and 10 (63%) of these 16 patients were in shock and 12 patients (75%) had closed head injuries. Angioembolization caused bleeding cessation in 11 patients but failed in 5 patients, who were treated conservatively. The overall mortality rate of patients with lumbar artery injury was 50%. CONCLUSION Lumbar artery injury in multiply injured patients with blunt trauma leads to a high mortality rate, especially if accompanied by head injury. Embolization often stops bleeding, but, if embolization is not feasible, conservative treatment without retroperitoneal surgery can be successful.

Diagnostic Performance on Low Dose Computed Tomography For Acute Appendicitis Among Attending and Resident Radiologists

Background Low-dose computed tomography (LDCT) techniques can reduce exposure to radiation. Several previous studies have shown that radiation dose reduction in LDCT does not decrease the diagnostic performance for appendicitis among attending radiologists. But, the LDCT diagnostic performance for acute appendicitis in radiology residents with variable training levels has not been well discussed. Objectives To compare inter-observer and intra-observer differences of diagnostic performance on non-enhanced LDCT (NE-LDCT) and contrast-enhanced standard dose CT (CE-SDCT) for acute appendicitis among attending and resident radiologists. Patients and Methods This retrospective study included 101 patients with suspected acute appendicitis who underwent NE-LDCT and CE-SDCT. The CT examinations were interpreted and recorded on a five-point scale independently by three attending radiologists and three residents with 4, 1 and 1 years of training. Diagnostic performance for acute appendicitis of all readers on both examinations was represented by area under receiver operating characteristic (ROC) curves. Inter-observer and intra-observer AUC values were compared using Jackknife FROC software on both modalities. The diagnostic accuracy of each reader on NE-LDCT was compared with body mass index (BMI) subgroups and noise using independent T test. Results Diagnostic performances for acute appendicitis were not statistically different for attending radiologists at both examinations. Better performance was noted on the CE-SDCT with a borderline significant difference (P = 0.05) for senior radiology resident. No statistical difference of AUC values was observed between attending radiologists and fourth year resident on both examinations. Statistically significant differences of AUC values were observed between attending radiologists and first year residents (P = 0.001 ~ 0.018) on NE-LDCT. Diagnostic accuracies of acute appendicitis on NE-LDCT for each reader were not significantly related to BMI or noise. Conclusion Attending radiologists could diagnose acute appendicitis accurately on NE-LDCT. Performance of senior residents on NE-LDCT is better than junior residents and comparable to attending radiologists.

Transcatheter Arterial Embolization of Traumatic Lumbar Artery Injury: Experience in One Institution

Transcatheter arterial embolization has been well recognized and popular for the management of traumatic lumbar artery injury (TLAI). Current evidence regarding the management of TLAI is still based on case reports and a few small series of studies. The purpose of the study is to evaluate the efficacy and results of embolotherapy in the management of lumbar artery trauma in our hospital, a 3000-bed tertiary hospital in the Northern Taiwan.We retrospectively recruited all patients who underwent angiography and transcatheter arterial embolization (TAE) for lumbar artery injury from April 2004 to December 2008. Angiographic images and procedural reports were reviewed to assess immediate results. Trauma mechanism, associated trauma, injury severity score, clinical outcomes and post-embolization complications were obtained by chart review.Of seventeen patients with lumbar artery injury who underwent angiography, selective embolization was performed in fourteen patients. AII fourteen patients exhibited immediate angiographic success. The overall mortality was 36% (5/14). However, there was only one suspected TLAI-related death. Two patients had minor neurological complaints in the follow-up period. No patient exhibited major neurological deficits or soft tissue complications.Traumatic lumbar arterial injury is an uncommon condition that requires a high index of clinical suspicion in the patients of retroperitoneal hemorrhage. According to the literature and our experience, TAE is a safe and effective method to achieve hemostasis.

Computed tomography arterial portography for assessment of portal vein injury after blunt hepatic trauma.

PURPOSE Intrahepatic portal vein injuries secondary to blunt abdominal trauma are difficult to diagnose and can result in insidious bleeding. We aimed to compare computed tomography arterial portography (CTAP), reperfusion CTAP (rCTAP), and conventional computed tomography (CT) for diagnosing portal vein injuries after blunt hepatic trauma. METHODS Patients with blunt hepatic trauma, who were eligible for nonoperative management, underwent CTAP, rCTAP, and CT. The number and size of perfusion defects observed using the three methods were compared. RESULTS A total of 13 patients (seven males/six females) with a mean age of 34.5±14.1 years were included in the study. A total of 36 hepatic segments had perfusion defects on rCTAP and CT, while there were 47 hepatic segments with perfusion defects on CTAP. The size of perfusion defects on CT (239 cm3; interquartile range [IQR]: 129.5, 309.5) and rCTAP (238 cm3; IQR: 129.5, 310.5) were significantly smaller compared with CTAP (291 cm3; IQR: 136, 371) (both, P = 0.002). CONCLUSION Perfusion defects measured by CTAP were significantly greater than those determined by either rCTAP or CT in cases of blunt hepatic trauma. This finding suggests that CTAP is superior to rCTAP and CT in evaluating portal vein injuries after blunt liver trauma.

Detection and characterization of traumatic bile leaks using Gd-EOB-DTPA enhanced magnetic resonance cholangiography

Expanding bile leaks after blunt liver trauma require more aggressive treatment than contained bile leaks. In this retrospective study approved by institution review board, we analyzed if non-invasive contrast-enhanced magnetic resonance cholangiography (CEMRC) using hepatocyte-specific contrast agent (gadoxetic acid disodium) could detect and characterize traumatic bile leaks. Between March 2012 and December 2014, written informed consents from 22 included patients (17 men, 5 women) with a median age of 24.5 years (IQR 21.8, 36.0 years) were obtained. Biliary tree visualization and bile leak detection on CEMRC acquired at 10, 20, 30, 90 minutes time points were independently graded by three radiologists on a 5-point Likert scale. Intraclass Correlation (ICC) was computed as estimates of interrater reliability. Accuracy was measured by area under receiver operating characteristic curves (AUROC). Biliary tree visualization was the best on CEMRC at 90 minutes (score 4.30) with excellent inter-rater reliability (ICC = 0.930). Of 22 CEMRC, 15 had bile leak (8 expanding, 7 contained). The largest AUROC of bile leak detection by three radiologists were 0.824, 0.914, 0.929 respectively on CEMRC at 90 minutes with ICC of 0.816. In conclusion, bile leaks of blunt liver trauma can be accurately detected and characterized on CEMRC.

Distal embolization versus combined embolization techniques for blunt splenic injuries: comparison of the efficacy and complications

Comparable failure rates of distal or proximal transcatheter arterial embolization (TAE) techniques for blunt splenic injuries have been reported. This study is to investigate the efficacy and complication of combining both TAE techniques. We included 26 patients of blunt splenic injuries for TAE therapy and randomized them into distal TAE and combined TAE groups. A prospective study was performed to compare their demographics, clinical parameters, hemograms, post-TAE splenic infarct volumes, splenic abscess and pancreatitis between the two groups. Of 26 patients, 17 received distal TAE, 9 received combined TAE. Their basic demographics, clinical parameters and hemograms did not differ. Mean systolic blood pressure of all patients was significantly elevated after TAE at 24 hours later. Three patients of distal TAE group had residual pseudoaneurysms in follow up. They were considered failures in distal TAE group as opposed to all successes in combined TAE group. The risk difference of failure of distal TAE was 17.6%. None developed post-TAE splenic abscess, massive splenic infarct or pancreatitis. The mean splenic infarct volume of distal TAE (10.9%) versus combined TAE groups (6.6%) was not significant (p = 0.481). Combined TAE is effective and safe to decrease the failure rates of non-operative management for blunt splenic injuries.

Route Selection for Percutaneous Cholecystostomy, Concerning Complications and Catheter Related Events

The purpose of this article is to compare the complication rates of imaging-guided percutaneous cholecystostomy (PC) between transperitoneal and transhepatic approaches. We performed a database search for patients who underwent imaging-guided percutaneous cholecystostomy from Dec., 2009 to Jun., 2012. Four hundred sixty-five patients were included in our study. These patients were subdivided into two groups by their catheter insertion route; transhepatic approach (group A; n=423) and transperitoneal approach (group B; n=42). Technical success, complications, gender, age, etiology, catheter size, and INR data were compared between the two groups retrospectively. Statistical analysis was performed using independent sample-t test for quantitative variables and chi-square test for qualitative data. The overall technical success rate was 98.49%. There were 7 failure attempts (1.51%), 6 in group A (1.42%) and 1 in group B (2.38%): 3 misplaced in the gallbladder (GB) fossa (all in group A), 2 found difficult penetration of gallbladder wall (one in group A and one in group B), and 2 were intolerant to proceed to whole procedure (all in group A). Complications included catheter dislodgement, hemorrhage, secondary infection (abscess along the catheter route), bile leakage induced peritonitis or biloma. Total complication rate of percutaneous cholecystostomy was 13.98% (65/465). The complication rates is 13% (55/423) in group A and 23.8% (10/42) in group B, p=0.054) .The most common complication in both groups was catheter dislodgement, followed by bile leakage induced peritonitis or biloma. No procedure related pneumothorax, hollow organ injury, procedure-related death were registered. There was no significant difference in the complication rate between transhepatic and transperitoneal approach of percutaneous cholecystostomy. Percutaneous cholecystostomy is a safe procedure and can be performed with similar complication rates in both groups of transhepatic and transperitoneal approach. Proper secure and aftercare of the drainage catheter is more important than route selection. Therefore, the radiologists should not hesitate to use transperitoneal approach if it is a relatively easy and quick approach route in irritable or uncooperative patients.