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Tze-Yu Lee

Publications and source records attributed to Tze-Yu Lee.

18 recordsLinked to original sources

MDCT angiography for evaluation of the complete vascular tree of hemodialysis fistulas.

OBJECTIVE: The purpose of our study was to assess the clinical feasibility of MDCT angiography for evaluating hemodialysis arteriovenous fistulas (AVFs). MATERIALS AND METHODS: MDCT angiography of the complete vascular trees of 36 failing AVFs or AVF-related complications (20 native and 16 polytetrafluoroethylene graft AVFs) was reviewed. The numbers and degrees of stenoses at the anastomoses, graft loops, and draining and central veins and the presence of aneurysms or thrombosis were recorded. Wilcoxon's signed rank test was used to compare the findings of MDCT angiography with those of digital subtraction angiography (DSA) (n = 10), surgery (n = 22), or both (n = 4) performed within 2-6 days. Kappa statistics were used to correlate the clinical feasibility of MDCT angiography assessed by two reviewers. RESULTS: Among the 14 AVFs examined with both MDCT angiography and DSA, no significant difference was seen in the detection and grading (p = 0.317 to > 0.999) of stenoses at various segments of the entire vascular tree. Among the 36 AVFs examined, MDCT angiography also showed no significant difference from DSA or surgery in revealing vascular stenoses, aneurysms, and thromboses from the supplying artery to central veins (p = 0.317 to > 0.999). Overall, the sensitivity, specificity, positive and negative predictive values, and accuracy of MDCT angiography in lesion detection were 98.7%, 97.5%, 98.8%, 97.2%, and 98.3%, respectively. High image quality with superb interobserver correlation (kappa = 0.809 to > 0.999) validated the clinical feasibility of MDCT angiography for assessing AVFs. CONCLUSION: MDCT angiography is clinically feasible for evaluating the complete vascular tree of failing AVFs and in showing uncommon complications, including brachial aneurysms and central vein lesions.

Adult↗

Effects of heart rate on motion artifacts of the aorta on non-ECG-assisted 0.5-sec thoracic MDCT.

OBJECTIVE: Our aim was to evaluate the effects of heart rate on aortic motion artifacts on 0.5-sec non-ECG-assisted thoracic MDCT. MATERIALS AND METHODS: A total of 124 non-ECG-assisted thoracic MDCT scans with satisfactory simultaneous ECG data were reviewed. Scans were grouped according to patient heart rates (beats per minute [bpm]: group A, 46-55; B, 56-65; C, 66-75; D, 76-85; E, 86-95; and F > 95). The groups were compared regarding the presence, locations, and spatial distributions of pulsation artifact, number of slices affected, maximum amplitude of pulsation, continuity of artifact, and the presence of superior vena cava (SVC) pseudoflaps. RESULTS: Of the 124 scans, 114 (91.9%) had aortic motion artifacts, with prevalence ranging from 85.3% (66-75 bpm) to 100% (65 bpm or less). Of the 114 motion artifacts, all affected the ascending aorta, 105 (92.1%) involved the left anterior and right posterior aspects of the aortic circumference, and 106 (93%) were associated with SVC pseudoflaps. Group B had significantly greater numbers of images with artifacts (p < 0.001-0.006), greater artifact amplitudes (p < 0.001-0.002), and a higher continuity trend for the artifacts (p = 0.003-0.194) than did the other five groups. CONCLUSION: Aortic motion artifacts are frequently seen on thoracic MDCT, especially in patients with heart rates of 65 bpm or less. The presence of a SVC pseudoflap is helpful for distinguishing artifacts from dissection. If aortic disease is suspected, then measures to reduce motion artifact, such as ECG-gating, should be considered.

Aorta, Thoracic↗

Contracture of the deltoid muscle: sonographic evaluation with MRI correlation.

OBJECTIVE: This article evaluates the sonographic features of deltoid contracture (DC) with MRI correlation. MATERIAL AND METHODS: Two reviewers evaluated the imaging features in 22 painful shoulders of 20 patients with a sonographic diagnosis of DC and a subsequent confirming MRI study. The sonographic and MRI findings with regard to the lesion extent (assessed by a 3-point scale: 1 = less than or equal to one third of the longitudinal deltoid length involved, 2 = greater than one third and less than or equal to two thirds involved, and 3 = greater than two thirds involved), transverse lesion morphologic appearance, and maximal transverse diameter measured were compared with kappa statistics and Wilcoxon's signed rank test, respectively. RESULTS: Compared with MRI, there were two false-positive diagnoses of DC on sonography. Among the 20 true-positive diagnoses, sonography showed good agreement with MRI in assessing the lesion extent (kappa = 0.796, p < 0.001). Three sonographic lesion morphologic patterns for hyperechoic lesions (I = with multiple < 8-mm hypoechoic spots, II = heteroechoic lesions with predominant 8-15-mm hypointense areas, and III = > 15-mm calcified nodules, respectively) showed excellent agreement with three MRI lesion patterns (I = multiple < 8-mm hypointense spots, II = predominant 8-15-mm hypointense areas, and III = > 15-mm hypointense nodules, respectively) (kappa = 0.921, p < 0.001). However, the maximum lesion diameters appeared significantly larger on sonography than on MRI (2.8 +/- 0.6 cm vs 2.0 +/- 0.8 cm, mean +/- SD; p < 0.001), which was plausibly ascribed to the better sonographic delineation of hyperechoic immature fibrotic tissues. CONCLUSION: Sonography is helpful for evaluating DC and correlates well with MRI.

Adult↗

Severe acute respiratory syndrome: prognostic implications of chest radiographic findings in 52 patients.

PURPOSE: To retrospectively assess prognostic implications of radiographic findings in severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: Radiographic findings were reviewed by two radiologists for 52 patients with SARS. On each radiograph, each lung was separated into upper, middle, and lower zones. A four-point scale was used to score extent of SARS-related lesions in each zone; points from all zones were added for a cumulative score. Patient sex, age, comorbidities, duration of developing lesions, lesion score for each radiograph, need for mechanical ventilation, and percentage of lung affected were compared between patients who died (n = 20) and survivors (n = 32). Continuous and categorical variables were analyzed with Mann-Whitney test and Fisher exact or chi(2) test, respectively. RESULTS: Survival and mortality groups showed no significant differences with respect to patient sex, duration of SARS-related lesions, development of lesion shifting, and acute respiratory distress syndrome. Patients who died were significantly older (mean +/- standard deviation, 56.9 years +/- 17.2 vs 40.4 years +/- 16.6; P =.002) and had higher frequency of comorbid lung illnesses (nine of 20 vs two of 32, P =.001), maximal lesion extent score of 7 or higher (20 of 20 vs five of 32, P <.001), involvement of four or more lung zones (17 of 20 vs four of 32, P <.001), bilateral lung involvement (19 of 20 vs 14 of 32, P <.001), need for mechanical ventilation (18 of 20 vs two of 32, P <.001), and higher percentage of affected areas (41.5% +/- 8.6 vs 16.4% +/- 10.0, P <.001) than those of survivors. CONCLUSION: On chest radiographs, maximal SARS-related lesion extent score of 7 or higher is a strong predictor of mortality, especially in patients with comorbid lung illnesses and involvement of four or more lung zones.

Adult↗

Testicular dislocation: an uncommon and easily overlooked complication of blunt abdominal trauma.

STUDY OBJECTIVE: We report testicular dislocation as an unusual complication of blunt abdominal trauma. METHODS: The computer data bank of Chang Gung Memorial Hospital was searched for the period from 1987 to 2002, and 1,967 male patients with blunt abdominal trauma were admitted to the emergency department. Among these patients, records of 9 patients associated with testicular dislocation were collected. A retrospective review of the clinical records, abdominal computed tomography (CT) results, and subsequent scrotal sonograms was jointly performed by 2 radiologists, an emergency physician, and a trauma surgeon. RESULTS: Of these 9 patients (age range 6 to 53 years; mean 23 years), 7 patients were in motorcycle crashes, 1 patient had explosive injury, and 1 patient had seat belt injury. Associated testicular dislocation was initially missed in all patients. CT for evaluating blunt abdominal trauma revealed liver lacerations in 2 patients and pancreatic fracture, pancreatitis, bowel perforation, pubic bone fracture, and contralateral inguinal hernia in 1 each. Typical CT findings of testicular dislocation (empty scrotum and displaced testis) were retrospectively seen in 7 patients, but prompt CT diagnosis of testicular dislocation was achieved only in 3 patients, who were subsequently treated with closed manual reduction, obviating surgery. In the remaining 2 patients, CT examination did not include the scrotum and testicular dislocation, which was diagnosed by subsequent sonography. Delayed diagnosis occurred in 6 patients (duration 3 to 60 days; mean 19 days). Five of the patients underwent orchiopexy, and 1 underwent orchiectomy. CONCLUSION: In blunt abdominal trauma patients, associated testicular dislocation is easily overlooked. A complete physical examination in the trauma patient, including palpation of both testes, is strongly recommended.

Abdominal Injuries↗

Castleman disease of the pleura: experience with eight surgically proven cases.

BACKGROUND: Castleman disease of the pleura is unusual, and we present our experience with eight surgically proven cases. METHODS: Between 1980 and 2002, 8 patients (7 women and 1 man; age range, 20 to 53 years; mean, 26.5 years) with surgically proven, pleural Castleman disease (six hyaline vascular type, one plasma cell type, and one mixed type) were encountered. Their clinical, imaging, and surgical findings were reviewed. RESULTS: Five patients were asymptomatic, 1 had dyspnea, 1 had cough, and 1 experienced chest discomfort. Chest radiography showed a well-circumscribed interlobar, cardiophrenic, or paraaortic mass in 6 patients, a massive effusion in 1, and a focal diaphragmatic bulge in 1. Six tumors showed varying degrees of contrast enhancement (10 to 95 HU; mean, 46 HU) on computed tomography. Three cases appeared as well-defined, heterogeneously hyperintense pleural masses on magnetic resonance imaging. The masses varied in size from 3 to 10 cm (mean, 5.2 cm). Five masses greater than 5 cm had prominent pleural arterial blood supply and severe adhesions requiring thoracotomy and resection of nearby structures for radical tumor excision. Blood loss from patients varied between 100 and 850 mL (mean, 620 mL). No tumor recurrence was noted during follow-up (range, 1 to 16 years; mean, 6.5 years). CONCLUSIONS: Pleural Castleman disease predominately affects young women and manifests as a well-circumscribed mass with a varying degree of contrast enhancement on computed tomography and heterogeneity on magnetic resonance imaging. Tumors greater than 5 cm have profuse pleural blood supplies and severe adhesion necessitating open thoracotomy and resection of neighboring structures. Radical resection can produce a satisfactory outcome.

Adult↗

Small bowel intussusception in symptomatic pediatric patients: experiences with 19 surgically proven cases.

Nineteen cases of surgically proven symptomatic pediatric small bowel intussusceptions (SBI) were retrospectively reviewed. Clinical presentations included vomiting (89.5%), abdominal pain and/or irritable crying (89.5%), fever (52.6%), bloody stools (26.3%), palpable abdominal masses (15.8%), hematemesis (10.5%), jaundice (5.3%), and seizures (5.3%). The duration between symptom onset and hospitalization ranged between 20 and 336 hours (average 75.8 hours). Two patients with suspected appendicitis and small bowel obstruction were operated on promptly. Sonograms revealed target lesions (average diameter 2.9 cm) suggestive of intussusception in 13 out of 17 patients, with 10 lesions located in the paraumbilical or left abdominal regions. Barium enemas in 12 of these 13 patients demonstrated no colonic lesions. Diagnosis and surgery were delayed in 16 patients (average delay = 32 hours). The remaining 1 patient with positive sonographic findings underwent early surgery after computed tomographic (CT) confirmation of SBI. Surgery revealed ileoileal intussusceptions in 11 patients, jejunojejunal in 4, jejunoileal in 3, and duodenojejunal in 1. Eight patients had lead points. Bowel complications (ischemia, necrosis, or perforation) occurred in 8 patients. The duration between symptom onset and surgery in patients with bowel complications was significantly longer than for patients without complications (p = 0.0026). In conclusion, delayed diagnosis and surgical treatment in symptomatic pediatric patients with SBI were common, leading to a high rate (42%) of bowel complications. Sonographic demonstration of a 2-3 cm target lesion, especially if paraumbilical or left abdominal, is suggestive of SBI and may obviate the need for a barium enema; however, CT is helpful for confirming SBI. In symptomatic SBI, once diagnosed, early surgical referral is strongly recommended.

Adolescent↗

Clinically occult isolated right iliac mycotic aneurysm with duodenal involvement in a diabetic elderly man: multislice CT diagnosis.

A diabetic old man presented with vague abdominal discomfort and intermittent tarry stools for 2 days and gastric ulcers with bleeding was diagnosed after endoscopy. Multislice computed tomography (MSCT) clearly depicted an isolated right iliac mycotic aneurysm with retroperitoneal extension and duodenal involvement. Timely operation and effective antibiotic treatment resulted in complete recovery. To our knowledge, this is the first report of an isolated mycotic iliac artery aneurysm (IAA) complicated with an aneurysmo-duodenal fistula induced by Klebsiella pneumoniae.

Abdominal Pain↗

Imaging features of atypical thoracic Castleman disease.

The imaging features of 16 cases of pathologically proven atypical thoracic Castleman disease (CD) were retrospectively reviewed. Thirteen out of 16 tumors originated from atypical locations, including eight from the pleura and one each from the axilla, supraclavicular fossa, intercostal space, pericardium, and lung. Six out of 16 tumors revealed atypical enhancement, including poor CT enhancement in three tumors, target-like CT enhancement in two tumors, and concentric MR enhancement pattern in one tumor. These atypical enhancement patterns were histopathologically corresponded to various degrees of degeneration, necrosis, and fibrosis.

Adult↗

Sudden cardiac arrest during computed tomography examination: clinical findings and "dense abdominal veins" on computed tomography.

We report imaging findings in five patients who had sudden cardiac arrest during contrast-enhanced computed tomography (CT). We observed strikingly dense abdominal veins, variable degrees of arterial enhancement, and poor abdominal visceral enhancement. Comparison with a control group of 30 patients revealed a statistically significant increase in mean enhancement of the abdominal veins (including the inferior vena cava, bilateral renal veins, and major tributaries of the hepatic vein) (Kruskal-Wallis test, P< 0.05). These patients lacked any clear cause of cardiac arrest, and the arrest may have been related to an adverse reaction to contrast medium. Despite resuscitation, two patients died and three convalesced. In summary, sudden cardiac arrest is characterized by "dense abdominal veins" on CT in the absence of the cardiac pump function. This effect was presumably the result of forced reflux and stagnation of contrast medium in the abdominal veins without any dilution with the circulating blood, leading to a markedly dense appearance of these venous structures.

Abdomen↗

Massive hemobilia.

BACKGROUND/AIMS: Massive hemobilia is a relatively rare, but potentially life-threatening cause of upper gastrointestinal hemorrhage. We report our experiences in the treatment of 15 cases of massive hemobilia with different underlying pathologies. METHODOLOGY: Massive hemobilia is defined as a patient with blood discharge from the biliary tree and requiring whole blood transfusion for at least 4 u (1 u = 250 cc). Fifteen such patients were collected during an 8.5-year period (from January 1986 to July 1994), and the clinical courses of these patients were retrospectively reviewed. RESULTS: Among these 15 patients, 11 were males and 4 were females. Age distribution was from 33 to 78 years old. Mean age was 59.7 years. The cause of hemobilia included: percutaneous transhepatic biliary drainage in 7 patients, surgical trauma in 3, choledochoscopic extraction of biliary calculi in 1, pancreatic cancer in 1, radiotherapy for cholangiocarcinoma in 1, after operation for biliary lithiasis in 1, and rupture of the pseudoaneurysm in 1. In 11 patients, hemobilia was first noted by bleeding from percutaneous transhepatic biliary drainage tube (n = 10) or T-tube (n = 1). Three patients had hemobilia during choledocholithotomy. The other one was diagnosed by choledochoscopy. Treatment included pitressin infusion from angiographic catheter in one patient, transarterial embolization in 1, hepatic artery ligation in 1, hepatic artery ligation and transarterial embolization in 1, choledochotomy or choledocholithotomy in 2, and blood transfusion only in 9. Two of the four mortality cases had underlying malignancy. CONCLUSIONS: The most common cause of massive hemobilia was percutaneous transhepatic biliary drainage procedures. Eight cases were successfully treated with blood transfusion only. Transarterial embolization, hepatic artery ligation and open drainage were effective non-surgical and surgical procedures, but the former two procedures might not be successful if sudden and severe hemobilia developed, or when an aberrant hepatic artery existed. Main hepatic artery had better been isolated before removal of the percutaneous transhepatic biliary drainage tube during operation.

Adult↗

Splenic abscess: diagnosis and management.

BACKGROUND/AIMS: To evaluate the usefulness of a combination of computed tomography and sonography for splenic abscess diagnosis and management determination. METHODOLOGY: From January 1986 to June 1999, 30 patients of pyogenic splenic abscess were collected in our hospital. Computed tomograms of the spleen were performed on all of the patients, and abdominal sonographies were performed on 26 of them. The imaging findings of all the patients were reviewed with respect to the clinical presentations, predisposing factors, infective organisms, method of treatment and clinical outcome. RESULTS: The clinical triad of splenic abscess was the main presentation of the 30 patients; it included fever (92%), left upper abdominal pain (77%) and leukocytosis (66%). Infective bacteria were identified in 19 patients, and the most offending bacteria were aerobes (82.6%). The radiological findings included single abscess were found in 16 patients and multiple abscesses were noted in 14 patients. The computed tomography and sonography findings included abnormal gas content (6 cases), progressive enlargement of lesion (6 cases), subcapsular extension of lesion (6 cases), extracapsular fluid collection (8 cases) and cystic lesion (7 cases). 59% of the cases had at least one of the above imaging findings. With the combination of the clinical triad and the imaging findings, the diagnostic rate rose up to 86.7%. CONCLUSIONS: Although splenic abscess is rare, it has a high mortality rate if there is delay in diagnosis and treatment. With the combination of computed tomography, sonography and clinical features, early diagnosis and treatment can be made. Percutaneous drainage for single abscess and splenectomy for multiple abscesses are the safe and effective treatment choice. The computed tomography and sonography appearance of splenic abscess is a valuable predictor of outcome of splenic abscess drainage. Medical treatment alone was definitely insufficient.

Abscess↗

Hepatic focal nodular hyperplasia: the "star sign" on gadolinium-enhanced magnetic resonance angiography.

BACKGROUND/AIMS: This study aimed at presenting the three-dimensional gadolinium-enhanced magnetic resonance angiography findings of hepatic focal nodular hyperplasia with angiographic correlation. METHODOLOGY: Three patients (one had abdominal pain, two were asymptomatic) with liver mass or nodules in the liver revealed on ultrasound underwent three-dimensional gadolinium-enhanced magnetic resonance angiography. Catheter angiography was available for correlation in all three cases. Other imaging studies including conventional magnetic resonance imaging in three patients, computed tomography in two and scintigraphy scan in one were reviewed. Surgical resection and biopsy were performed in one and two patients respectively. RESULTS: The ultrasound, computed tomography, magnetic resonance and scintigraphy findings were non-specific for focal nodular hyperplasia in all three patients. However, gadolinium-enhanced magnetic resonance angiography demonstrated tumor vessels radiating from its center to the periphery, which corresponded to the spokes of the characteristic "spoke-wheel" pattern on catheter angiography, producing the so called "star sign," that may suggest the diagnosis of focal nodular hyperplasia. Histopathologic examinations revealed focal nodular hyperplasia. CONCLUSIONS: This report highlights the usefulness of gadolinium-enhanced magnetic resonance angiography in the diagnosis of hepatic focal nodular hyperplasia by demonstrating the "star sign" and that computed tomography, scintigraphy, and catheter angiography may thus be obviated in such instances.

Adolescent↗