Chen-Chih Huang

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.

Diagnostic Accuracy of Transitional Cell Carcinoma on Multidetector Computerized Tomography Urography in Patients With Gross Hematuria

PURPOSE We analyzed the diagnostic value of multidetector computerized tomography urography for transitional cell carcinoma in patients with gross hematuria. MATERIALS AND METHODS All consecutive adult patients with gross hematuria who underwent multidetector computerized tomography urography in a 23-month period were prospectively enrolled. Transitional cell carcinoma and its location on multidetector computerized tomography urography were recorded at a prospective reading with knowledge of the pertinent history and at a retrospective reading while blinded to all information. Histological evidence of transitional cell carcinoma served as the gold standard for final diagnosis. Patients who were lost to followup, refused biopsy/surgery for clinically suspicious neoplasms or had negative diagnostic evaluation but a followup of less than 1 year were excluded from study. We analyzed the diagnostic value of multidetector computerized tomography urography for transitional cell carcinoma by location with reference to final diagnosis. RESULTS A total of 139 patients were eligible for study, of whom 24 were excluded from analysis. There was no difference in demographic features between included and excluded patients. Of the 115 included patients 60 had a final diagnosis of a total of 77 transitional cell carcinomas in the renal pelvis, ureter or bladder. Overall sensitivity, specificity and accuracy of multidetector computerized tomography urography for diagnosing transitional cell carcinoma were 0.857, 0.980 and 0.963 at the retrospective reading, and 0.961, 0.988 and 0.984 at the prospective reading, respectively. Multidetector computerized tomography urography had the highest accuracy for diagnosing renal transitional cell carcinoma and the lowest sensitivity for detecting ureteral transitional cell carcinoma. CONCLUSIONS Multidetector computerized tomography urography is an accurate, noninvasive imaging modality for diagnosing transitional cell carcinoma in patients with gross hematuria. However, careful assessment of the ureter for multidetector computerized tomography urography is required for detecting ureteral transitional cell carcinoma.

Necrotic stercoral colitis: importance of computed tomography findings.

AIM To study the computed tomography (CT) signs in facilitating early diagnosis of necrotic stercoral colitis (NSC). METHODS Ten patients with surgically and pathologically confirmed NSC were recruited from the Clinico-Pathologic-Radiologic conference at Chang Gung Memorial Hospital, Taoyuan, Taiwan. Their CT images and medical records were reviewed retrospectively to correlate CT findings with clinical presentation. RESULTS All these ten elderly patients with a mean age of 77.1 years presented with acute abdomen at our Emergency Room. Nine of them were with systemic medical disease and 8 with chronic constipation. Seven were with leukocytosis, two with low-grade fever, two with peritoneal sign, and three with hypotensive shock. Only one patient was with radiographic detected abnormal gas. Except the crux of fecal impaction, the frequency of the CT signs of NSC were, proximal colon dilatation (20%), colon wall thickening (60%), dense mucosa (62.5%), mucosal sloughing (10%), perfusion defect (70%), pericolonic stranding (80%), abnormal gas (50%) with pneumo-mesocolon (40%) in them, pericolonic abscess (20%). The most sensitive signs in decreasing order were pericolonic stranding, perfusion defect, dense mucosal, detecting about 80%, 70%, and 62.5% of the cases, respectively. CONCLUSION Awareness of NSC and familiarity with the CT diagnostic signs enable the differential diagnosis between NSC and benign stool impaction.

Evaluation of renal function of angiomyolipoma patients after selective transcatheter arterial embolization.

Background:Angiomyolipoma patients may have renal insufficiency before selective transcatheter arterial embolization (TAE) or may undergo subsequent surgery after TAE. Therefore, this retrospective study examined our experience with TAE or TAE and subsequent surgery on renal function of angiomyolipoma patients with and without preexisting renal insufficiency. Methods:25 patients who had undergone TAE for renal angiomyolipoma over a 7-year period were reviewed. The 25 patients were grouped according to whether or not they had undergone further surgery. Preexisting renal insufficiency was compared between the 2 groups. The TAE and surgery group was further subdivided into 2 subgroups according to total nephrectomy or not. The TAE-alone group was further subdivided into 2 subgroups by presence of preexisting renal insufficiency or not. In each group and subgroup, pre-TAE and post-TAE renal function, including serum creatinine and creatinine clearance were compared. Results:TAE rather than TAE and surgery was more likely chosen in the presence of preexisting renal insufficiency (6/13 versus 1/12, P = 0.035). In TAE-alone patients, no statistical differences were noted between serum creatinine and creatinine clearance before and after TAE. Conversely, TAE and surgery patients who had undergone total nephrectomy rather than nephron-sparing surgery differed significantly in preand post-TAE serum creatinine (0.77 versus 1.07, P = 0.014) and creatinine clearance (98.1 versus 70.7, P = 0.032). Conclusions:This study demonstrated that TAE alone for treating renal angiomyolipomas was able to preserve renal function, despite the presence of mild preexisting renal insufficiency. Conversely, surgery after TAE, particularly total nephrectomy, should be avoided whenever possible.

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.

Urothelial Carcinoma of the Native Ureter in a Kidney Transplant Recipient

A 56-year-old woman who underwent cadaveric kidney transplantation 44 months earlier had hydronephrosis of the left native kidney diagnosed on routine sonography. She also had chronic urinary tract infection but not gross microscopic hematuria. History included diabetes mellitus, gout, hypertension and hyperlipidemia. Left retrograde pyelography (RP) showed complete obstruction of the left native proximal ureter (part A of figure, arrow). Multidetector computerized tomography urography (MDCTU) revealed a fork sign at the left proximal ureter (part B of figure, arrow) and a spindle sign at the left middle ureter (part B of figure, arrowheads), suggesting urothelial carcinoma (UC). Although urine cytology was negative for malignancy, left ureteroscopy revealed a proximal ureteral mass subsequently proved on biopsy to be UC. The patient underwent bilateral nephroureterectomy with bladder cuff excision. Histological examination confirmed UC in the left native proximal and middle ureter with periureteral fat invasion. The patient died of brain and bone metastases 8 months after surgery, although there was no clinical or radiological evidence of metastasis at surgery. In Taiwan kidney transplant recipients have a reported 4.1% incidence of UC involving greater than 90% of the native upper urinary tract. 1 The most common presentation is gross hematuria followed by chronic urinary tract infection or microscopic hematuria. Mean SD time from transplantation to UC diagnosis is 48.2 49.6 months. UC is usually diagnosed at cystoscopy or on RP. Approximately 50% of patients have hydronephrosis on sonography, of whom 23% have positive urine cytology. MDCTU accurately diagnosed UC in patients with gross hematuria and detected more UC of the native upper urinary tract in kidney transplant recipients than RP. 2 Nonetheless, a careful search for imaging signs suggestive of UC throughout the entire native upper urinary tract is necessary and important on MDCTU to achieve a correct diagnosis because these native upper tracts are small and poorly functioning.

Predictors of Clinically Significant Residual Stones for Renal Stones after Percutaneous Nephrolithotomy

The aim of this study is to analyze the predictors of clinically significant residual stones (CSRS) after percutaneous nephrolithotomy (PCNL). Between March 2006 and January 2008, all consecutive patients with renal stones undergoing percutaneous creation and dilatation of renal access by radiologists for subsequent scheduled PCNL were reviewed. Patients who have completed the whole procedure of PCNL were included in this study. We reviewed clinical characteristics and the follow-up plain radiograph of the kidney, ureter and bladder for assessing CSRS in each patient. The relationships of clinical characteristics and CSRS were analyzed by univariate analysis and multivariate analysis. Univariate analysis showed larger stone size, less body mass index, presence of prior open nephrolithotomy and staghorn stone were significantly associated with CSRS. Multivariate analysis showed that stone size, prior open nephrolithotomy and their interaction were significant predictors of CSRS. In patients with prior open nephrolithotomy, the probability of CSRS is as high as 62.5% even in small (＜ 3 cm) renal stones. On the other hand, the probability of CSRS in patients without prior open nephrolithotomy increases rapidly with increasing stone size despite a much lower baseline probability. When the stone sizes are larger than 6 cm, the CSRS probability in patients without prior open nephrolithotomy becomes as high as 92.3%, which is much higher than that (50.0%) of patients with prior open nephrolithotomy. In conclusion, stone size, prior open nephrolithotomy and their interaction should be taken into account for selecting patients undergoing PCNL.