Li-Jen Wang

Multi-Slice CT Angiography in Diagnosing Total Versus Near Occlusions of the Internal Carotid Artery Comparison With Catheter Angiography

Background and Purpose— To determine the accuracy of multislice computed tomographic (CT) angiography in diagnosing total versus near occlusions of the internal carotid artery (ICA). Methods— Fifty-seven ICA total or near occlusions identified by catheter angiography were studied with multislice CT angiography 1 to 3 days after catheter angiography. CT angiography in diagnosing total versus near occlusions was analyzed by 2 radiologists independently. The results were compared with those of catheter angiography. Results— Catheter angiography depicted 31 total occlusions, including 10 without a stump, 19 with a stump <2 cm, and 2 with a stump >2 cm. Among them, 22 had a downward extent of the retrograde ICA flow at or above the carotid siphon, 8 at the carotid canal, and 1 at the distal cervical ICA. Catheter angiography depicted 26 near occlusions, including 21 with a tight stenosis at the proximal third cervical ICA, 1 at the middle third, and 4 at the carotid canal or siphon. CT angiography correctly depicted all total and near occlusions. In total occlusions, the length of the stump and the retrograde flow were all accurately described by CT angiography. In near occlusions, the sites of tight stenoses were also correctly identified by CT angiography. Conclusions— Multislice CT angiography had an excellent correlation with catheter angiography in diagnosing total versus near occlusion of the ICA. It may be considered as a substitute of catheter angiography in confirming the ultrasonographic results in diagnosing total versus near occlusions of the ICA.

Mortality after successful transcatheter arterial embolization in patients with unstable pelvic fractures : Rate of blood transfusion as a predictive factor

BACKGROUND To determine the factors predictive of mortality in patients with unstable pelvic fractures after successful transcatheter arterial embolization. METHODS A retrospective study of pelvic fractures between May of 1995 and April of 1998 was performed. Of 507 patients, 17 who were unstable underwent embolization. The success rate of embolization and the mortality rate after successful embolization were reviewed. Predictive factors (contrast medium extravasation, initial blood pressure, Injury Severity Score, timing of external fixation, time to angiography, volume of blood transfusion, rate of blood transfusion) of the final outcome were statistically analyzed. RESULTS Embolization was 100% effective in stopping pelvic hemorrhage. The mortality of patients treated successfully with embolization was 17.6%. Among the predictive factors analyzed, only the rate of blood transfusion before embolization, 11.3 +/- 11.0 units/h (death) versus 3.2 +/- 1.9 units/h (survival) showed statistical significance with an odds ratio of 1.62 (95% confidence interval, 1.07-2.46). CONCLUSION The success rate of embolization was 100% in stopping arterial hemorrhage of unstable pelvic fractures. The survival rate after successful embolization was 82.4%. Patients who had rapid blood transfusion before embolization had a poor final outcome. The risk of dying increased by 62% for every 1 unit/h increase of transfusion rate.

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.

CT grading of blunt pancreatic injuries: prediction of ductal disruption and surgical correlation.

PURPOSE The purpose of our study was to devise a CT grading scheme for blunt pancreatic injuries (BPIs) and to apply it to predict the presence or absence of ductal disruption. METHOD We retrospectively reviewed CT scans of 22 patients with proven BPIs. We graded these injuries on CT (A, BI, BII, CI, and CII) based on the (a) presence or absence of pancreatic lacerations, (b) site of lacerations, and (c) depth of lacerations. CT grading was correlated with surgical findings for glandular and ductal injuries. RESULTS Main pancreatic ducts were intact in 2 patients with normal CT scans and in all grade A injuries (n = 10). Distal pancreatic ducts were disrupted in all grade B injuries (BI, n = 1; BII, n = 4). Of five grade C injuries, three CII injuries had disruption of proximal pancreatic duct, one CII injury had disruption of minor duct, and one CI injury had an intact ductal system. CONCLUSION CT grading of BPIs was useful in predicting ductal integrity or disruption. Ductal disruption was likely present if the pancreas appeared to have a transection or deep laceration on CT scans. It was accurate in grade A and B injuries. Overestimation could occur in grade CI and CII injuries.

CT features of genitourinary tuberculosis.

The genitourinary system is the most common site of extrapulmonary tuberculous infection. The diagnosis is difficult and often delayed. In this essay, we illustrate the CT features of the kidneys, ureters, bladder, prostate gland, and seminal vesicles caused by tuberculosis.

Hypoplasia of the internal carotid artery with intercavernous anastomosis.

Abstract We report a symptomatic case of unilateral hypoplasia of the internal carotid artery with an intercavernous anastomosis, a very rare developmental anomaly. The symptoms were caused by occlusion of the proximal middle cerebral artery which possibly related to the haemodynamic stress caused by the anomalous intercavernous anastomosis.

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.

Intracranial meningeal melanocytoma: CT and MRI

Abstract We report the MRI and CT findings of an intracranial meningeal melanocytoma (IMM) arising from Meckels cave and review the imaging characteristics of IMM. On CT, IMM constantly appear as well-circumscribed, isodense to slightly dense, extra-axial tumours with homogeneous contrast enhancement. This appearance is nonspecific and similar to that of meningiomas or small neuromas. On MRI, the signal of IMM is strongly related to the amount of melanin pigment: the more melanin, the more shortening of T1 and T2 relaxation times. Only when it shows as a homogeneous mass, bright on T1 and dark on T2 weighting, can a specific diagnosis of a melanin-containing tumour be made. However, this still cannot provide a distinction between IMM and malignant meningeal melanoma.

Multidetector-row computed tomography (CT) of blunt pancreatic injuries: can contrast-enhanced multiphasic CT detect pancreatic duct injuries?

BACKGROUND We examined patients of blunt trauma with contrast-enhanced multiphasic computed tomography (CT) and determined if it could detect pancreatic duct injuries. METHODS During a 17-month period, 95 patients of blunt abdominal trauma underwent multiphasic CT examinations. The CT grading scales of pancreatic injuries at parenchymal phase, portal venous phase, and equilibrium phase were recorded and compared with surgery, endoscopic retrograde cholangiopancreatography, or discharged diagnosis. The diagnostic values of multiphasic CT and interobserver agreements at different phases were computed. RESULTS Of the 95 patients, nine (9.5%) had pancreatic injuries (six with main duct injuries, three without main duct injuries). The interobserver agreement presented in kappa values between two radiologists regarding the integrity or disruption of the main duct were good at parenchymal phase (K = 0.73), portal venous phase (K = 0.64), and equilibrium phase (K = 0.68). The overall accuracies of multiphasic CT in detecting main duct injuries were 97.9% (parenchymal phase), 100.0% (portal venous phase), and 96.8% (equilibrium phase), respectively. The sensitivity (50.0%) and negative predictive value (96.7%) of equilibrium phase CT were the lowest among the three phases of CT scans. CONCLUSION The portal venous phase CT was the most accurate scan to detect pancreatic duct injuries. However, equilibrium phase CT might underestimate major pancreatic injuries. Multiphasic CT shows early promise in this clinical application and further multi-institutional studies to verify its accuracy and reveal the optimal CT methodology are needed.

Spinal MR findings in spontaneous intracranial hypotension

Abstract. Whole spine magnetic resonance (MR) imaging was used to evaluate the shape, size, signal intensity, and enhancement of the spinal spaces in a series of six patients with spontaneous intracranial hypotension (SIH). In all patients varying degrees of shrunken dural sacs, expanded extradural spaces with delayed homogeneous enhancement, and distended epidural venous plexuses were noted. In 83% (5/6) of patients, the MR signal of the expanded extradural space was similar to that of cerebrospinal fluid; 17% (1/6) showed an excessive fat deposit in the epidural space. Sixty-seven percent (4/6) of patients had a visible peridural membrane. After relief of the symptoms, one patient (1/4) showed persistence of the spinal abnormalities even though the brain abnormalities disappeared. In conclusion, the spinal MR findings of SIH, like its brain counterpart, are characteristic. In cases with clinical suspicion but without support from brain MR imaging, spinal MR imaging may be helpful in establishing the diagnosis.