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Chi-Ming Lee

Publications and source records attributed to Chi-Ming Lee.

At least 19 recordsLinked to original sources
PubMed2006

Using positron emission tomography to facilitate CNS drug development.

Positron emission tomography (PET) is a non-invasive technology of nuclear medicine that has sensitivity for tracing low picomolar concentrations of radiolabeled molecules in the human body. Radiolabeling a new drug to high specific radioactivity facilitates a detailed mapping of its distribution to crucial organs in humans after the administration of a "microdose" (< 1 microg), for which limited toxicology documentation is required. For drugs directed at the CNS, this method is particularly useful for confirming exposure to the brain. A different approach is to develop suitable radioligands for quantitative PET studies of drug binding to target proteins and subsequently to correlate receptor occupancy with pharmacodynamic responses. To follow disease progression and to monitor the outcome of new treatments, PEt also facilitates longitudinal studies of biomarkers of pathophysiology such as amyloid plaque load in Alzheimer's disease. Finally, combining genomic knowledge with PET neuroreceptor imaging is expected to facilitate the search for genetic predictors of drug response.

Animals↗
PubMed2006

Gastrointestinal stromal tumor of the prostate: a case report and literature review.

We report a case of gastrointestinal stromal tumor (GIST) of the prostate in a 75-year-old man with dysuria and urinary retention. Digital rectal examination revealed a markedly enlarged prostate. The serum level of prostate-specific antigen was 0.2 ng/dL. Imaging studies showed an expanded prostate, measuring 6.7 x 5.6 x 5.5 cm, with heterogeneity in contrast enhancement. No metastatic disease was found. The pathologic diagnosis of prostatic GIST was made based on characteristic morphological features, immunoprofiles, and molecular analysis. The possibility of secondary involvement by a rectal GIST was excluded by radiological and intraoperative findings. To our knowledge, this is the second case of a primary GIST of the prostate reported in the literature.

Adenocarcinoma↗
PubMed2006

Differential diagnosis of cystic lymphangioma of the pancreas based on imaging features.

Lymphangioma is a benign tumor, which is a consequence of lymphatic malformation with blockage of lymphatic flow. Most lymphangiomas occur in the neck and axillary region, and < 1% occur in the mesentery or retroperitoneum. Lymphangiomas arising from the pancreas are extremely rare. We report the case of a 34-year-old woman with cystic lymphangioma of the pancreas without major symptoms or signs. A 6 x 6 cm intra-abdominal cystic mass was incidentally revealed by sonography during a health examination. It is always a challenge to differentiate the lesion from other possible cystic-like pancreatic neoplasms. Differential diagnosis of cystic lymphangioma from other cystic-like tumors of the pancreas can be performed based on their imaging characteristics, including presence of septa, cystic or wall calcification, soft tissue, wall thickness, single or multiple loculation, and dilatation of the pancreatic duct. Post-gadolinium magnetic resonance imaging is excellent in defining the origin of intra-abdominal cystic mass and intracystic septa.

Adult↗
PubMed2006

Retrospective study of the total insertion period of peripherally inserted central catheter: discussion of anti-thrombogenic surface and other biomaterial requirements.

A retrospective study of patients' records on reviewing the purpose of venous catheter insertion (chemotherapy, blood transfusion, antibiotics or parenteral nutrition); total period of insertion; reason for catheter removal. 120 admitted patients who received fluoroscopic guide PICC (4-French single lumen silicone rubber catheter) insertions into distal SVC via antecubital region of forearm. We retrospectively review human factors including the patients' laboratory data of pre- and post-insertion, total insertion period and reasons for withdrawal. The important human factors that affect the clinical outcome of PICC were also evaluated. The results indicated that the most common complications were wound oozing, phlebitis, occlusion, infection and leaking. Persistent wound oozing for over 3-day-period is the higher incidence of complication. It also demonstrated a surprisingly high ratio (> 77%) in those patients with thrombocytopenia and leukemia. In this group, persistent low platelet counts could be noted, the ratio of failure (remove PICC within 3 days) is 10% and there is 40% decrease insertion period (< 30 days). Prospectively, it is worthwhile to choose new material or new technology of surface coating of PICC, to decrease consumption of platelet thrombogenic proteins and to maintain normal coagulate function of human bodies.

Catheterization, Central Venous↗
PubMed2005

Balthazar computed tomography severity index is superior to Ranson criteria and APACHE II scoring system in predicting acute pancreatitis outcome.

AIM: Acute pancreatitis (AP) is a process with variable involvement of regional tissues or organ systems. Multifactorial scales included the Ranson, Acute Physiology and Chronic Health Evaluation (APACHE II) systems and Balthazar computed tomography severity index (CTSI). The purpose of this review study was to assess the accuracy of CTSI, Ranson score, and APACHE II score in course and outcome prediction of AP. METHODS: We reviewed 121 patients who underwent helical CT within 48 h after onset of symptoms of a first episode of AP between 1999 and 2003. Fourteen inappropriate subjects were excluded; we reviewed the 107 contrast-enhanced CT images to calculate the CTSI. We also reviewed their Ranson and APACHE II score. In addition, complications, duration of hospitalization, mortality rate, and other pathology history also were our comparison parameters. RESULTS: We classified 85 patients (79%) as having mild AP (CTSI <5) and 22 patients (21%) as having severe AP (CTSI > or =5). In mild group, the mean APACHE II score and Ranson score was 8.6+/-1.9 and 2.4+/-1.2, and those of severe group was 10.2+/-2.1 and 3.1+/-0.8, respectively. The most common complication was pseudocyst and abscess and it presented in 21 (20%) patients and their CTSI was 5.9+/-1.4. A CTSI > or =5 significantly correlated with death, complication present, and prolonged length of stay. Patients with a CTSI > or =5 were 15 times to die than those CTSI <5, and the prolonged length of stay and complications present were 17 times and 8 times than that in CTSI <5, respectively. CONCLUSION: CTSI is a useful tool in assessing the severity and outcome of AP and the CTSI > or =5 is an index in our study. Although Ranson score and APACHE II score also are choices to be the predictors for complications, mortality and the length of stay of AP, the sensitivity of them are lower than CTSI.

APACHE↗
PubMed2005

Difficulty with diagnosis of malignant pancreatic neoplasms coexisting with chronic pancreatitis.

Chronic pancreatitis is a relatively common disease. We encountered two different cases of belatedly demonstrated pancreatic carcinoma featuring underlying chronic pancreatitis. The first case was one that was highly suspected as that of a malignancy based upon imaging study, but unfortunately, it could not be confirmed by intra-operative cytology at that time. Following this, the surgeon elected to perform only conservative bypass surgery for obstructive biliary complication. Peritoneal carcinomatosis was later noted and the patient finally died. The second case, a malignant mucinous neoplasm, was falsely diagnosed as a pseudocyst, based upon the lesion's sonographic appearance and associated elevated serum amylase levels. After suffering repeated hemoptysis, the patient was found to exhibit lung metastasis and peritoneal seeding. We reviewed some of the literature, including those studies discussing chronic pancreatitis predisposing to a malignant change. These two case analyses illustrate clearly that the diagnosis for such conditions, which is simply based upon imagery or pathological considerations may end up being one of a mistaken malignancy. Some of our suggestions for the treatment of such malignancies as revealed herein include, total pancreatomy for univocal mass lesion, and needle aspiration of lesion-contained tissue for amylase, CA199 and CEA levels for a suspicious cystic pancreatic mass.

Chronic Disease↗
PubMed2005

Post-radiation survival time in hepatocellular carcinoma based on predictors for CT-determined, transarterial embolization and various other parameters.

AIM: In this retrospective study of unresectable hepatocellular carcinoma (HCC), we have investigated the efficacy of CT-derived parameters, laboratory measurements, clinical assessment and associated transarterial embolization (TAE) as predictors of post-radiotherapy survival time. METHODS: Sixty-six patients diagnosed with unresectable HCC that had undergone radiotherapy at two medical university hospitals in Taipei were enrolled in the study. Using multivariant analysis, pre-treatment parameters including tumor number and CT confirmation of PVT and ascites were compared. Multivariant analysis was also used for comparison of the mean pretreatment values for laboratory measurements, including alpha-fetoprotein, direct/total bilirubin and GOT/GPT levels, and clinical history of chronic hepatitis across the three survival-time categories. The chi2 was used to test the significance of the relationship between survival time and TAE procedure. The P values for the above tests were deemed statistically significant where P<0.05. RESULTS: Portal vein thrombosis (P = 0.032) and ascites (P<0.05) were negative predictors of post-radiation survival time. Low-grade liver cirrhosis (A or B), lower tumor volume and low levels of AFT, GOT/GPT, and total bilirubin were predictors of longer post-radiation survival time (P<0.05). CONCLUSION: The CT and clinical and laboratory assessment provide a reference for, and enable estimation of, probable survival times in HCC patients after radiotherapy. Tumor volume, severity of liver cirrhosis, status with respect to portal vein thrombosis and ascites and AFT, GOT/GPT and total bilirubin values were significant predictors of survival in this study.

Ascites↗
PubMed2005

Anatomic and technical skill factor of gastroduodenal complication in post-transarterial embolization for hepatocellular carcinoma: a retrospective study of 280 cases.

AIM: To reduce the possibility of gastroduodenal complications. The purpose of this retrospective study was to survey the literature and compare and discuss the incidence of post-transarterial embolization (TAE) gastroduodenal complications. METHODS: We found reports describing 280 cases of hepatocellular carcinoma with TAE procedures done during the past 4 years and selected all of them for our study. Amongst these cases, 86 were suspected of suffering gastroduodenal complications within one month of post-TAE treatment. Fifteen of these cases were proved by pan-endoscopy to have gastroduodenal erosions or ulcerations. We reviewed the angiographic pictures in patient records to evaluate the possibility that anatomic and technical skill factors could explain the complications. RESULTS: Amongst the 15 cases, 9 were primary lesions of the antrum and prepylorus; 4 had duodenal ulcer or erosions; 2 had mid-body lesions; none showed a lesion at the fundus or cardia region. Three cases had not received TAEs using our ideal method, and may be associated with possible regurgitation of gel-foam pieces into the right or left gastric arteries. Two cases involved sub-selective embolization at a distal point on the hepatic artery; one case was found by angiography to have complete occlusion of the celiac trunk. CONCLUSION: Comparing our results with past cases of post-TAE gastroduodenal complications, we surmise that our relatively low incidence (5.3%) of gastric complications might be explained by our concerted efforts to improve our technical skills in multi-sequential, selective and super-selective approaches to the embolization of tumor vessels.

Abdomen↗
PubMed2004

A case of atypical caudate lobe hemangioma mimicking hepatocellular carcinoma: CT and angiographic manifestations.

We report a case of caudate lobe hemangioma with an atypical CT enhancement pattern. In the present case, hemangioma exhibited a very subtle discontinuous peripheral rim enhancement at the post-enhanced arterial phase, and the peripheral enhanced zone had a moderately increased enhancement degree and with widened enhancement thickness during the portal-phase and delayed-phase. The slow enhancement rate for this caudate lobe hemangioma was due to sluggish perfusion by the small feeding arteries of caudate lobe branches as demonstrated by angiography.

Carcinoma, Hepatocellular↗
PubMed2004

Gastrointestinal stromal tumor: Computed tomographic features.

AIM: Gastrointestinal stromal tumor (GIST) is a rare type of cancer. Computed tomography (CT) is an imaging modality of choice for diagnosing GIST. The aim of this retrospective study was to review the CT imaging features of 17 GIST patients. METHODS: From 1995 to 2003, there were 47 patients with pathologically proven GISTs at our hospital. Of these, 17 patients underwent preoperative CT. We collected and analyzed these CT images. The CT imaging features included tumor diameter, number and location, tumor margin, location of metastasis, hounsfield units of tumor and effect of contrasts. In addition, we also recorded the surgical findings, including complications, tumor size and location for comparative analysis. RESULTS: The results showed that 12 (70%) tumors were located in the stomach and five (30%) were located in the jejunum mesentery. GISTs were extraluminal in 12 (70%) patients. The tumor margins of 13 (76%) tumors were well defined and irregular in four (24%). The effect of contrast enhancement on GIST CT imaging was homogenous enhancement in 13 (76%) and heterogeneous enhancement in four (24%). The hounsfield units (HU) were 30.41 +/-5.01 for precontrast images and postcontrast hounsfield units were 51.80 +/- 9.24. CONCLUSION: The stomach was the commonest site of GIST occurrence among our patients. The CT features of GIST were well-defined tumor margins, homogenous enhancement on postcontrast CT images.

Adult↗
PubMed2004

Magnetic resonance cholangiopancreatography of anatomic variants of the biliary tree in Taiwanese.

BACKGROUND AND PURPOSE: Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive method for evaluating the hepatobiliary system. This study investigated the anatomic variants of the biliary tree in Taiwanese using MRCP. METHODS: 170 patients with abdominal or liver diseases underwent diagnostic MRCP over the 29-month study period. We identified the type of biliary tree variants in 130 patients. RESULTS: The imaging findings showed that the most common biliary tree variants were type I and type IIA, which together comprised 70% of all variants. Type I is a triple confluence, which is an anatomy characterized by simultaneous emptying of the right posterior segment duct, right anterior segment duct, and left hepatic duct into the common hepatic duct. Type IIA involves drainage of the right posterior segment duct into the right anterior segment duct to form the right hepatic duct, and then confluence with the left hepatic duct to form the common hepatic duct. There was a mean percentage of 10 to 20% among the 7 types of variants identified. CONCLUSION: Comparison of these findings with previous investigation indicates that biliary tract structure shows racial and ethnic variation.

Bile Ducts↗
PubMed2003

Intense uptake of [F-18]-fluoro-2 deoxy-D-glucose in active pulmonary tuberculosis.

FDG PET is well recognized for its utility in cancer workup. Nonetheless, the differentiation between malignant and benign pulmonary lesions by FDG PET is challenging. The authors report three proved cases of pulmonary tuberculosis in acute active and open stages. The activities and extents of infection were demonstrable in FDG PET, which could not be observed in either chest radiograph or computed tomography.

Adult↗
PubMed2003

Neurofibroma with increased uptake of [F-18]-fluoro-2 deoxy-D-glucose interpreted as a metastatic lesion.

We report a patient with a solitary spinal neurofibroma in the posterior mediastinum interpreted as a metastatic tumor. A 46-year-old female with rectal cancer who had undergone operation and subsequent adjuvant chemotherapy two years previously was referred to our department for a follow-up whole body FDG-PET study. PET scan revealed a mass with increased uptake of FDG (SUV = 4.6) in the posterior mediastinum. MRI examination showed a dumbbell neurogenic tumor originating from the intercostal nerve at T6 level. A subsequent CT-guided biopsy demonstrated a neurofibroma.

Diagnosis, Differential↗
PubMed2003

F-18 fluorodeoxyglucose positron emission tomography in pulmonary cryptococcoma.

Cryptococcosis is not uncommon. Potential interpretation pitfalls should be kept in mind when fluorodeoxyglucose (FDG) positron emission tomography (PET) is used for differentiating pulmonary nodules and for discriminating infection from malignancy, especially in areas where the prevalence of granulomatous infection is high and in immunocompromised patients. In this case, a nodular mass was shown on chest radiography and computed tomographic (CT) scanning. A consolidated infection or a bronchioloalveolar carcinoma was suspected because the CT scan showed air bronchograms within the mass and another perihilar infiltration. The FDG PET scan clearly delineated the lesion and had intermediately high glucose uptake (standard uptake value, 3.8-4.0), which led to the exclusion of the possibility of bronchioloalveolar carcinoma because most of these tumors had normal or mildly increased FDG accumulation. Cryptococcoma was finally diagnosed. Hence, the CT scan and FDG PET played complementary roles in the differential diagnosis of this nodular mass.

Cryptococcosis↗