T1-Staging for Urinary Bladder Cancer with the Stalk and Inchworm Signs with 3.0 Tesla MRI

Purpose@#To evaluate the diagnostic utility of the stalk and the inchworm sign on preoperative MRI for detecting superficial bladder cancers, and to compare the diagnostic performance between the stalk and the inchworm sign. @*Materials and Methods@#We retrospectively reviewed 240 patients (505 tumors) who had undergone radical cystectomy. The tumors were classified as follows: superficial or invasive tumors indicated by the stalk or inchworm sign on 3.0 Tesla MRI. We evaluated the diagnostic accuracy of the stalk and inchworm signs, by comparing each finding with the postoperative pathologic T stage. We compared diagnostic performance between them statistically. @*Results@#The stalk and inchworm signs showed high specificity (93% and 91%, respectively), positive predictive values (89% and 90%, respectively), and acceptable accuracy (70% and 74%, respectively), but low sensitivity (54% and 61%, respectively) and negative predictive values (60% and 63%, respectively). There was no statistically significant difference between the two signs (p > 0.05). @*Conclusion@#Superficial bladder cancers could be differentiated from invasive tumors using the stalk or inchworm sign on MRI.

T1-Staging for Urinary Bladder Cancer with the Stalk and Inchworm Signs with 3.0 Tesla MRI

Purpose@#To evaluate the diagnostic utility of the stalk and the inchworm sign on preoperative MRI for detecting superficial bladder cancers, and to compare the diagnostic performance between the stalk and the inchworm sign. @*Materials and Methods@#We retrospectively reviewed 240 patients (505 tumors) who had undergone radical cystectomy. The tumors were classified as follows: superficial or invasive tumors indicated by the stalk or inchworm sign on 3.0 Tesla MRI. We evaluated the diagnostic accuracy of the stalk and inchworm signs, by comparing each finding with the postoperative pathologic T stage. We compared diagnostic performance between them statistically. @*Results@#The stalk and inchworm signs showed high specificity (93% and 91%, respectively), positive predictive values (89% and 90%, respectively), and acceptable accuracy (70% and 74%, respectively), but low sensitivity (54% and 61%, respectively) and negative predictive values (60% and 63%, respectively). There was no statistically significant difference between the two signs (p > 0.05). @*Conclusion@#Superficial bladder cancers could be differentiated from invasive tumors using the stalk or inchworm sign on MRI.

Detection of Incidental Prostate Cancer or Urothelial Carcinoma Extension in Urinary Bladder Cancer Patients by Using Multiparametric MRI: A Retrospective Study Using Prostate Imaging Reporting and Data System Version 2.0

Purpose@#The study aimed to investigate the role of Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) in predicting incidental prostate cancer (PCa) or urothelial carcinoma (UCa) extension in urinary bladder (UB) cancer patients. @*Materials and Methods@#A total of 72 UB cancer patients who underwent radical cystoprostatectomy and 3 Tesla multiparametric MRI before surgery were enrolled. PI-RADS v2 ratings were assigned by two independent radiologists. All prostate specimens were examined by a single pathologist. We compared the multiparametric MRI findings rated using PI-RADS v2 with the pathologic data. @*Results@#Of the 72 UB cancer patients, 29 had incidental PCa (40.3%) and 20 showed UCa extension (27.8%), with an overlap for 3 patients. With a score of 4 as the cut-off value for predicting incidental PCa, the diagnostic accuracy was 65.3%, specificity was 90.7%, and positive predictive value (PPV) was 66.7%. The diagnostic accuracy for incidental UCa extension was 47.2%, specificity was 92.3%, and PPV was 83.3%. @*Conclusion@#Despite the low diagnostic accuracy, the PPV and specificity were relatively high. Therefore, PI-RADS v2 scores of 1, 2, or 3 may help exclude the probability of incidental PCa or UCa extension.

Changes in Cortical Auditory Evoked Potentials by Ipsilateral, Contralateral and Binaural Speech Stimulation in Normal-Hearing Adults

Objectives@#. Cortical auditory evoked potentials (CAEPs) have been used to examine auditory cortical development or changes in patients with hearing loss. However, there have been no studies analyzing CAEP responses to the different sound stimulation by different stimulation sides. We characterized changes in normal CAEP responses by stimulation sides in normal-hearing adults. @*Methods@#. CAEPs from the right auditory cortex were recorded in 16 adults following unilateral (ipsilateral and contralateral) and bilateral sound stimulation using three speech sounds (/m/, /g/, and /t/). Amplitudes and latencies of the CAEP peaks in three conditions were compared. @*Results@#. Contralateral stimulation elicited larger P2-N1 amplitudes (sum of P2 and N1 amplitudes) than ipsilateral stimulation regardless of the stimulation sounds, mostly due to the larger P2 amplitudes obtained, but elicited comparable P2-N1 amplitudes to bilateral stimulation. Although the P2-N1 amplitudes obtained with the three speech sounds were comparable following contralateral stimulation, the /m/ sound elicited the largest P2-N1 amplitude in ipsilateral stimulation condition due to the largest N1 amplitude obtained, whereas /t/ elicited larger a P2-N1 amplitude than/g/ in bilateral stimulation condition due to a larger P2 amplitude. @*Conclusion@#. Spectrally different speech sounds and input sides are encoded differently at the cortical level in normal-hearing adults. Standardized speech stimuli, as well as specific input sides of speech, are needed to examine normal development or rehabilitation-related changes of the auditory cortex in the future.

Value of imaging study in predicting pelvic lymph node metastases of uterine cervical cancer

PURPOSE: To evaluate the diagnostic accuracy of computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography/computed tomography (PET/CT) in predicting pelvic lymph node (LN) metastases in patients with cervical cancer. MATERIALS AND METHODS: From January 2009 to March 2015, 114 patients with FIGO stage IA1-IIB uterine cervical cancer who underwent hysterectomy with pelvic lymphadenectomy and took CT, MRI, and PET/CT before surgery were enrolled in this study. The criteria for LN metastases were a LN diameter ≥1.0 cm and/or the presence of central necrosis on CT, a LN diameter ≥1.0 cm on MRI, and a focally increased FDG uptake on PET/CT. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for pelvic LN metastases were estimated. RESULTS: The sensitivity, specificity, PPV, NPV, and accuracy for detection of pelvic LN metastases were 51.4%, 85.9%, 41.3%, 90.1%, and 80.3% for CT; 24.3%, 96.3%, 56.3%, 86.8%, and 84.6% for MRI; and 48.6%, 89.5%, 47.4%, 90.0%, and 82.9% for PET/CT, respectively. The sensitivity of PET/CT and CT was higher than that of MRI (p=0.004 and p= 0.013, respectively). The specificity of MRI was higher than those of PET/CT and CT (p=0.002 and p=0.001, respectively). The difference of specificity between PET/CT and CT was not statistically significant (p=0.167). CONCLUSION: These results indicate that preoperative CT, MRI, and PET/CT showed low to moderate sensitivity and PPV, and moderate to high specificity, NPV, and accuracy. More efforts are necessary to improve sensitivity of imaging modalities in order to predict pelvic LN metastases.

Middle Ear Surgery in Only Hearing Ears and Postoperative Hearing Rehabilitation

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate surgical interventions and hearing rehabilitation in patients with chronic middle ear disease of only hearing ears. SUBJECTS AND METHODS: Thirty-one patients with chronic middle ear disease of only hearing ears were enrolled in this retrospective study. Patients were classified into three groups according to the hearing level: groups A [pure tone audiometry (PTA) or =70). We evaluated hearing results and patterns of auditory rehabilitation. RESULTS: The main consideration for a surgical procedure was the presence of recurrent otorrhea and structural destruction. The reasons for surgical intervention in only hearing ears were otorrhea caused by chronic otitis media (68%), cholesteatoma (29%), and cholesterol granuloma (3%). The causes of contralateral deaf ears were chronic otitis media (81%) and sensorineural hearing loss (19%). Although there was hearing deterioration in some patients with severe hearing loss (PTA> or =70), all patients achieved dry ears after surgery and functional hearing using auditory rehabilitation. Hearing aids were used in most patients with moderate to moderately severe hearing loss and cochlear implants were used for auditory rehabilitation in patients with severe to profound hearing loss. CONCLUSIONS: Proper evaluation and indications for surgery in only hearing ears are important for successful eradication of inflammation and hearing preservation. Surgical interventions can achieve dry ear and enable further auditory rehabilitations using hearing aids and cochlear implantation.

Contrast-Induced Nephropathy in Patients Undergoing Intravenous Contrast-Enhanced Computed Tomography in Korea: A Multi-Institutional Study in 101487 Patients

OBJECTIVE: To evaluate the prevalence of known risk factors for contrast-induced nephropathy (CIN) and their association with the actual occurrence of CIN in patients undergoing intravenous contrast-enhanced computed tomography (CECT) in Korea. MATERIALS AND METHODS: Patients who underwent CECT in 2008 were identified in the electronic medical records of 16 tertiary hospitals of Korea. Data on demographics, comorbidities, prescriptions and laboratory test results of patients were collected following a standard data extraction protocol. The baseline renal function was assessed using the estimated glomerular filtration rate (eGFR). We identified the prevalence of risk factors along the eGFR strata and evaluated their influence on the incidence of CIN, defined as a 0.5 mg/dL or 25% increase in serum creatinine after CECT. RESULTS: Of 432425 CECT examinations in 272136 patients, 140838 examinations in 101487 patients met the eligibility criteria for analysis. The mean age of the participants was 57.9 +/- 15.5 years; 25.1% of the patients were older than 70 years. The prevalence of diabetes mellitus was 11.9%, of hypertension 13.7%, of gout 0.55% and of heart failure was 1.7%. Preventive measures were used in 40238 CECT examinations (28.6%). The prevalence of risk factors and use of preventive measures increased as the renal function became worse. A CIN was occurred after 3103 (2.2%) CECT examinations, revealing a significant association with decreased eGFR, diabetes mellitus, and congestive heart failure after adjustment. CONCLUSION: Risk factors for CIN are prevalent among the patients undergoing CECT. Preventive measures were seemingly underutilized and a system is needed to improve preventive care.

A Newly Designed Y-shaped Covered Stent in the Palliative Treatment of Hepatic Hilar Malignant Obstruction: Case Report

We report a case in an inoperable patient with the hilar malignant biliary obstruction treated palliatively by the use of a newly designed Y-shaped covered stent without interfering contra-lateral bile duct. We percutaneously inserted a newly designed Y-shaped covered stent into a biliary tree in an inoperable patient with Bismuth Type II cholangiocarcinoma. We checked tubograms, enhanced CT studies, and blood bilirubin levels before, one week after, and at every three month after the stenting, by observing closely the signs of clinical infection as well. The follow-up period was about 12 months. The placement of the Y-shaped covered stent was successful and resulted in adequate biliary drainage in the immediate post-procedural tubogram and in the follow-up abdominal CT. The serum bilirubin levels did not show elevation after the insertion of the Y-shaped covered stent.

Erratum: A Newly Designed Y-shaped Covered Stent in the Palliative Treatment of Hepatic Hilar Malignant Obstruction: Case Report

On page 97, the second author's name has been incorrectly spelled as So Yon Lee. The correct spelling is So Won Lee.

A Case of Ameloblastic Carcinoma in the Maxillary Sinus / 대한이비인후과학회지

Ameloblastoma is the most common benign odontogenic tumor of jaw, whereas ameloblastic carcinoma is extremely rare, aggressive odontogenic neoplasm of mandible and maxilla. Ameloblastic carcinoma is odontogenic malignancy that combines the histological features of ameloblastoma with cytological atypia regardless of metastasis. The clinical course is described as typically aggressive, with extensive local destruction and distant metastatic spread. Ameloblastic carcinoma has been found mostly in the mandible; however, its maxilla lesion has been reported less than 40 cases in the literature. We experienced a case of ameloblastic carcinoma in the maxillary sinus in a 43-year-old male presenting with right facial swelling. No evidence of recurrence was noted at a 5-year follow-up.

A Case of Dyspnea Caused by Local Botulinum Toxin Type A Injection / 대한내과학회지

Botulinum toxin type A is widely used for functional improvement of muscles and aesthetic plastic surgery. It paralyzes the injected muscle by inhibiting acetylcholine release from synapses of neuromuscular junctions. We herein report a case of progressive respiratory distress after botulinum toxin injection at both the gastrocnemius and soleus muscles. The patient also showed ptosis, dysphonia, dysphagia, and general weakness. Vocal cord dysfunction was observed by laryngoscopy. Other neurologic examination findings, including those of the physical examination, brain MRI, and Jolly's test, were normal. To our knowledge, this is the first report of botulinum toxin injection associated with dyspnea (MRC dyspnea scale, grade 3) in Korea.

Clinical Outcome of Fibromatosis of the Head and Neck Region / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Fibromatosis is an uncommon soft tissue mass lesion that can occur in all anatomic sites. Fibromatoses arising in the head and neck region comprises of approximately 5% of all fibromatoses, which is associated with an infiltrative growth pattern and thus results in difficulty in complete excision. The authors investigate the clinical characteristics of head and neck fibromatoses. SUBJECTS AND METHOD: Six cases of head and neck fibromatoses were analyzed from 1989 to 2011. The imaging and pathologicfindings, surgical management, and clinicaloutcomes were evaluated. RESULTS: Painless mass effect was the most common symptom. The accuracy of diagnostic tools including computed tomography, magnetic resonance imaging and fine needle aspiration biopsy were under 50%. Recurrence was observed in two patients who had undergone surgical excision during follow-up. Salvage surgery was performed in these patients. CONCLUSION: The aggressive excision of head and neck fibromatosis cannot be achieved easily. Vigilant follow-up with or without conservative surgical excision results in good disease control. Radiotherapy can be applied for inoperable or margin positive cases considering age or performance of patient.

Treatment Failure after Uterine Artery Embolization for Symptomatic Uterine Fibroids: Significance of Ovarian Arterial Collateral Vessels in Predicting the Outcome / 이화의대지

OBJECTIVES: To evaluate the treatment failure (TF) rate of leiomyoma after uterine artery embolization (UAE) for uterine leiomyomas in cases of the presence of anastomoses between the ovarian arteries (OA) and uterine arteries (UA). METHODS: The results of 163 consecutive UAE for uterine fibroid were reviewed. Mean patient age was 42.8 years (range, 25 to 57 years). TF was evaluated according to the anastomoses between OA and UA on pre-embolization angiography. Magnetic resonance images (MRIs) were obtained at 1~6 months or 12 months after UAE. MRIs were gadolinium (Gd)-enhanced images and/or T2-weighted images. MRIs exhibited focal enhancement portion on fibroid and evaluated the TF rate of the leiomyoma in patients of presence of anastomoses between OA and UA. RESULTS: Fifty six patients had anastomoses between UA and OA on pre-embolization angiography (56/163, 34.4%). Angiographic subtypes were type Ia (n=19), type Ib (n=16), type II (n=11) and type III (n=10). Of all patients, 10 patients showed the focal enhancements of the leiomyomas on follow-up enhanced MRIs (10/163, 6.1%). Three treatments failed in patients demonstrated type Ia (3/19, 15,8%). One had type Ib (1/16, 6.3%). Other 6 had no anastomoses. There was no TF rate difference between patients with communication (4/56, 7.1%) and without communication (6/107, 5.7%). However, TF rate in patients with type Ia communication (15.8%) was higher than that without communication (5.7%; P<0.05). CONCLUSION: Type Ia utero-ovarian anastomoses communication could be a contraindication for embolization treatment for leiomyoma.

Superior Canal Dehiscence Patients Have Smaller Mastoid Volume than Age- and Sex-Matched Otosclerosis and Temporal Bone Fracture Patients

BACKGROUND AND OBJECTIVES: The purpose of the study was to compare the mastoid air-cell volume of the patients with superior semicircular canal dehiscence syndrome (SCDS) and that of the control patients with otosclerosis and temporal bone (TB) fracture. SUBJECTS AND METHODS: Ten patients with SCDS were enrolled and 10 patients with bilateral otosclerosis and TB fracture were selected as control groups by age and sex matching. To measure the mastoid air-cell volume, 3D reconstruction software was used. RESULTS: In 10 patients with SCDS, the mean age was 44.5 years, ranging from 16 to 79 years (M : F=4 : 6). Mean mastoid air-cell volume in the SCDS side was 3319.9 mm3, whereas 4177.2 mm3 in the normal side (p=0.022). Mean mastoid air-cell volume in the right side of otosclerosis patients was 6594.3 mm3 and it was not different from 6380.5 mm3 in the left side (p=0.445). Mean mastoid air-cell volume in normal side of TB fracture was 6477.2 mm3. The mastoid air-cell volume in the SCDS side was significantly smaller than that of otosclerosis and TB fracture patients (p=0.009, p=0.002, respectively). The mastoid air-cell volume in the normal side of SCDS was significantly smaller than that of TB fracture (p=0.019), but not significant with that of otosclerosis (p=0.063). CONCLUSIONS: Our findings revealed that the mastoid air-cell volume in the SCDS side was significantly smaller than control group, which suggest that the decreased mastoid pneumatization is closely related to the generation of SCDS.

Superior Canal Dehiscence Patients Have Smaller Mastoid Volume than Age- and Sex-Matched Otosclerosis and Temporal Bone Fracture Patients

BACKGROUND AND OBJECTIVES: The purpose of the study was to compare the mastoid air-cell volume of the patients with superior semicircular canal dehiscence syndrome (SCDS) and that of the control patients with otosclerosis and temporal bone (TB) fracture. SUBJECTS AND METHODS: Ten patients with SCDS were enrolled and 10 patients with bilateral otosclerosis and TB fracture were selected as control groups by age and sex matching. To measure the mastoid air-cell volume, 3D reconstruction software was used. RESULTS: In 10 patients with SCDS, the mean age was 44.5 years, ranging from 16 to 79 years (M : F=4 : 6). Mean mastoid air-cell volume in the SCDS side was 3319.9 mm3, whereas 4177.2 mm3 in the normal side (p=0.022). Mean mastoid air-cell volume in the right side of otosclerosis patients was 6594.3 mm3 and it was not different from 6380.5 mm3 in the left side (p=0.445). Mean mastoid air-cell volume in normal side of TB fracture was 6477.2 mm3. The mastoid air-cell volume in the SCDS side was significantly smaller than that of otosclerosis and TB fracture patients (p=0.009, p=0.002, respectively). The mastoid air-cell volume in the normal side of SCDS was significantly smaller than that of TB fracture (p=0.019), but not significant with that of otosclerosis (p=0.063). CONCLUSIONS: Our findings revealed that the mastoid air-cell volume in the SCDS side was significantly smaller than control group, which suggest that the decreased mastoid pneumatization is closely related to the generation of SCDS.

The Primary Patency of Percutaneous Transluminal Angioplasty in Hemodialysis Patients With Vascular Access Failure

BACKGROUND AND OBJECTIVES: Dysfunction of arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) contributes significantly to morbidity and hospitalization in the dialysis population. We evaluated the primary patency of AVFs following percutaneous transluminal angioplasty (PTA) in haemodialysis patients. SUBJECTS AND METHODS: We performed 231 interventions in 118 patients with a mean age of 62.1+/-12.9 years. We performed 122 interventions in 53 AVG patients (44.9%), and 109 interventions in 65 AVF patients (55.1%). If there was thrombosis of the vascular access, urokinase was administered and/or thrombus aspiration was performed. The stent was inserted when balloon dilatation did not expand sufficiently or elastic recoil occurred. RESULTS: For the 118 patients, the median patency time was 10.45+/-10.29 months at 92 months of follow-up. The primary patencies for stenotic AVFs at 6, 12, 24, 36, 48, and 60 months were 63.4%, 41.4%, 17.0%, 9.7%, 7.3%, and 2.4%, respectively. The primary patencies for AVGs at 6, 12, 24, and 36 months were 36.9%, 19.5%, 10.8%, 2.1%, respectively, and were obtained by means of the Kaplan-Meier analysis (log rank=6.42, p<0.05). The median patency time was 11.0 months and 4.45 months in the non-thrombus and thrombus groups, respectively. The complication rate was 1.73% (4/231); two cases of pseudoaneurysms and two cases of extravasation were detected. All therapy failures (5/231) occurred in thrombotic lesions of AVGs and were treated surgically. CONCLUSION: PTA is an efficacious method for the correction of stenosis of AVFs for hemodialysis, thus prolonging the patency of the fistulas.

Blood Vessel Regeneration using Human Umbilical Cord-derived Endothelial Progenitor Cells in Cyclophosphamide-treated Immune-deficient Mice

Endothelial cells are a vital constituent of most mammalian organs and are required to maintain the integrity of these tissues. These cells also play a major role in angiogenesis, inflammatory reactions, and in the regulation of thrombosis. Angiogenesis facilitates pulp formation and produces the vessels which are essential for the maintenance of tooth homeostasis. These vessels can also be used in bone and tissue regeneration, and in surgical procedures to place implants or to remove cancerous tissue. Furthermore, endothelial cell regeneration is the most critical component of the tooth generation process. The aim of the present study was to stimulate endothelial regeneration at a site of acute cyclophosphamide (CP)-induced endothelial injury by treatment with human umbilical cord-derived endothelial/mesenchymal stem cells (hEPCs). We randomly assigned 16 to 20-week-old female NOD/SCID mice into three separate groups, a hEPC (1 x 10(5) cells) transplanted, 300mg/kg CP treated and saline (control) group. The mice were sacrificed on days 5 and 10 and blood was collected via the abdominal aorta for analysis. The alanine transaminase (ALT), aspartate aminotransferase (AST), serum alkaline phosphatase (s-ALP), and albumin (ALB) levels were then evaluated. Tissue sections from the livers and kidneys were stained with hematoxylin and eosin (HE) for microscopic analysis and were subjected to immunohistochemistry to evaluate any changes in the endothelial layer. CP treatment caused a weight reduction after one day. The kidney/body weight ratio increased in the hEPC treated animals compared with the CP only group at 10 days. Moreover, hEPC treatment resulted in reduced s-ALP, AST, ALT levels compared with the CP only group at 10 days. The CP only animals further showed endothelial injuries at five days which were recovered by hEPC treatment at 10 days. The number of CD31-positive cells was increased by hEPC treatment at both 5 and 10 days. In conclusion, the CP-induced disruption of endothelial cells is recovered by hEPC treatment, indicating that hEPC transplantation has potential benefits in the treatment of endothelial damage.

A Pig to Canine Auxiliary Hepatic Xenotransplantation Model: Prevention of Hyperacute Rejection via Blocking the Kupffer Cells and Regulating the Complement Family

PURPOSE: We designed a pig to canine liver xenotransplantation model to study the diverse immunologic and hemodynamic consequences that follow xenotransplantation and hyperacute rejection. METHODS: The animals were divided into two groups: the cobra venom factor and Gadolinium chloride treatment group (CVF+Gd group) (3 cases) and the control group (3 cases). The donor pig's whole liver was harvested, and then the harvested pig's whole liver was transplanted into a dog after the dog underwent left hepatectomy. After reperfusion of the graft, blood samples were taken 20, 40 and 60 minutes after reperfusion, and the liver, lung and kidney tissues were taken 1 hour after reperfusion. RESULTS: In the control group, the grafts showed a patchy hypoperfused liver surface and it felt rubbery solid compared to the CVF+Gd group. The serum total protein, albumin, fibrinogen and platelets decreased abruptly and there were no significant differences between the two groups. The serum PT, PTT and FDP were increased in both groups and the CVF+Gd group showed a more obtuse slope than the control group. We could not find any intravascular pathologic changes on the microscopic findings of the graft. Only scant intravascular fibrin deposition was found. Hepatocellular vacuolization and sinusoidal dilatation were also found. There were patches of necrosis without any zonal distribution, intrasinusoidal neutrophil sequestration and interstitial hemorrhage. These findings were milder in the CVF+Gd group. CONCLUSION: The pig to canine partial auxiliary liver xenotransplantation model is feasible and it is a good model before starting to perform pig to primate liver xenotransplantation. In the CVF+Gd group, pathologic findings like patch hepatocyte necrosis etc. were less severe. As there were no corresponding vascular pathologic findings, these findings are not the direct effect of CVF and gadolinium treatment, and so other factors like Ischemia- reperfusion injury should be considered.

Efficacy of Preoperative US Vascular Mapping for Arteriovenous Fistula in Patients with Hemodialysis

PURPOSE: The purpose of this study is to assess the efficacy of preoperative US vascular mapping to predict postoperative patency of the arteriovenous fistula for hemodialysis. MATERIALS AND METHODS: Sixty-six patients who underwent hemodialysis for end-stage renal failure (M: F=34:32, mean age, 58.8 years) were observed prospectively from January 2001 to April 2003. The patients were divided into two groups: the vascular mapping group and the control group. A comparative analysis of the re-operation rate between the two groups was determined by use of the chi-square rest, efficacy of preoperative US vascular mapping according to the type of surgery. A comparative analysis of the secondary patency after percutaneous transluminal angioplasty was determined by the use of Fischer exact test, and a comparative analysis of the diminution of patency during the follow-up periods was determined by the use of the Log-rank test. In the mapping group, the diameters of intraoperatively selected vessels were investigated and compared with the recommended diameter on preoperative US vascular mapping determined statistically by the use of Fisher's exact test. RESULTS: The preoperative US vascular mapping group had relatively lower re-operation rates (11.8%) than the control group (28.1%) (p=0.09). The preventive role of US vascular mapping is more effective in decreasing the re-operation rate for a native arteriorvenous fistula (7.4%) than for a synthetic arteriovenous graft (25.9%) (p=0.06). For patients that had an interventional procedure, the failure rate to obtain a secondary patency was smaller than in the mapping group (33.3%), compared with the control group (46.3%) (p=0.37). Patients in the mapping group had a higher patency than the control group patients for a native arteriovenous fistula (92.0%) and a synthetic arteriovenous graft (71.4%) at one year following surgery (p=0.10, p=0.79). The arteriovenous fistulas in the mapping group had a higher patency for both a native arteriovenous fistula (16.6%) and a synthetic arteriovenous graft (22.2%), which was statistically significant (p=0.01, p=0.03). CONCLUSION: Preoperative US vascular mapping is considered to be a useful technique for the preoperative evaluation of an arteriovenous fistula and to contribute to maintaining its postoperative patency and reducing the rate of repeated surgery.

Comparison of CT Urography and Intravenous Urography in Patients with Hematuria

PURPOSE: We wanted to compare CT urography (CTU) with using multi-detector row CT (MDCT) and intravenous urography (IVU) for diagnosing the causes of hematuria. MATERIALS AND METHODS: From January 2003 to March 2004, IVU and CTU were obtained in 48 patients. We evaluated the causes of hematuria in 34 of 48 patients. The IVU images were obtained by the conventional method. The CTU images were routinely obtained before intravenous contrast injection, and at 2 and 5 minutes after intravenous contrast injection. In case of delayed excretion of contrast by the kidneys, the delayed CT scans were obtained at 120 minutes after contrast injection. All the CT images, including the axial and 3D coronal reformatted CTUs with using software as well as conventional IVU images, were reviewed by two radiologists working in consensus. We decided if urinary stone existed or not and we looked for the indirect signs such as hydronephrosis or delayed excretion, etc. We also observed if it was possible to determine the mass, ureteral stricture and enhancement of the ureteral wall, etc. We calculated sensitivity, specificity, positive predictive value and negative predictive value for each modality to diagnose urinary stone. We compared the detection rate according to the phases of CTU. RESULTS: We confirmed the presence of urinary tract stones in 27 of 34 patients who had undergone both IVU and CTU. We diagnosed ureteritis in 1, transitional cell carcinoma in 5 and acute pyelonephritis in 1 of the remaining 7 patients. The urinary stones were detected in fifteen patients on both IVU and CTU (15/27, 55.6%). We detected the urinary stones on CTU, but not IVU, in twelve patients (12/27, 44.5%). The sensitivity to detect the urinary stones was 100% (27/27) on CTU and 55.6% (12/27) on IVU respectively. The specificity was 100% (7/7) on IVU and CTU, respectively. The positive predictive value was 100% (15/15) on IVU and 100% (27/27) on CTU, respectively. The negative predictive value was 36.8% (7/19) on IVU and 100% (7/7) on CTU. Precontrast CTU demonstrated the urinary stones in all 27 patients (100%, 27/27). On the other hands, urinary stones were detected in 19 patients (19/27, 70.4%) and 8 patients (8/27, 29.6%) at 2 and 5 minutes on CTU, respectively. CONCLUSION: CTU is superior to IVU to diagnose the causes of hematuria such as urinary tract stone or extrarenal lesion. Precontrast CTU is the most useful modality for the detection of the urinary tract stone of the other enhanced CTUs.