Biomedical subjects

H B Pan

Publications and source records attributed to H B Pan.

At least 37 records · Page 2Linked to original sources

PubMed1999

Recurrent inverted papilloma: diagnosis with pharmacokinetic dynamic gadolinium-enhanced MR imaging.

BACKGROUND AND PURPOSE: Dynamic gadolinium-enhanced MR imaging has been used successfully to identify post-treatment recurrence or postoperative changes in rectal and cervical carcinoma. Our purpose was to evaluate the usefulness of dynamic gadolinium-enhanced MR imaging for distinguishing recurrent inverted papilloma (IP) from postoperative changes. METHODS: Fifteen patients with 20 pathologically proved lesions (recurrent IP, 12; fibrosis or granulation tissue, eight) were enrolled in the study. Three observers, blinded to pathologic results, independently evaluated conventional MR images, including T1-weighted (unenhanced and postcontrast), proton-density-weighted, and T2-weighted spin-echo images. Results then were determined by consensus. Dynamic images were obtained using fast spin-echo sequences at 5, 30, 60, 90, 120, 150, 180, and 300 seconds after the injection of gadolinium-diethylene-triamine penta-acetic acid. Time-signal intensity curves of suspected lesions were analyzed by a pharmacokinetic model. The calculated amplitude and tissue distribution time were used to characterize tissue, and their values were displayed as a color-coded overlay. RESULTS: T2-weighted images yielded a sensitivity of 67%, a specificity of 75%, and an accuracy of 70% in the diagnosis of recurrent IP. Contrast-enhanced T1-weighted images yielded a sensitivity of 75%, a specificity of 50%, and an accuracy of 65%. Pharmacokinetic analysis showed that recurrent IP had faster (distribution time, 41 versus 88 seconds) and higher (amplitude, 2.4 versus 1.2 arbitrary units) enhancement than did fibrosis or granulation tissue. A cut-off of 65 seconds for distribution time and 1.6 units for amplitude yielded a sensitivity of 100% and a specificity of 100% for diagnosing recurrent IP. CONCLUSION: Dynamic MR imaging can differentiate accurately recurrent IP from postoperative changes and seems to be a valuable diagnostic tool.

Adult↗

PubMed1999

Detection and assessment of circle of Willis aneurysms in acute subarachnoid hemorrhage with three-dimensional computed tomographic angiography: correlation with digital substraction angiography findings.

In this retrospective study, we examined the usefulness of computed tomographic angiography (CTA) for the detection and assessment of circle of Willis aneurysms in patients with acute nontraumatic subarachnoid hemorrhage (SAH), using selective digital substraction angiography (DSA) as the gold standard. Thirty-five patients who presented with acute, nontraumatic SAH, diagnosed on the basis of unenhanced computed tomography or lumbar puncture findings or both, underwent both CTA and DSA. The CTA images were interpreted for the presence, location, size, and shape of the aneurysm, presence of a neck, and relationship of the aneurysm to adjacent arterial branches. The CTA and DSA images were then compared, with the latter images serving as the gold standard. DSA revealed 37 aneurysms in 32 patients and ruled out intracranial aneurysms in the remaining three. The sensitivity and specificity of CTA for aneurysm detection were 97% and 100%, respectively. The size of the smallest aneurysm shown was 4 mm, and the largest aneurysm was 21 mm. The size and lobularity of the aneurysms estimated from CTA images corresponded well with those estimated from DSA images. In addition, CTA provided a three-dimensional representation of the aneurysmal lesion, which was considered useful for surgical planning. Our results confirm the accuracy of CTA in comparison with DSA. Because of its reliability, minimal invasiveness, and rapidity, CTA may become the technique of choice for neuroradiologic work-up of SAH patients. DSA then would be used to diagnose intracranial aneurysms only in selected, questionable cases.

Acute Disease↗

PubMed1998

Primary intracranial leiomyoma: case report.

We present a case of intracranial parenchymal leiomyoma in a 20-year-old woman with a chief complaint of numbness and a painful sensation over the right limbs for several years. CT and MRI revealed an intensely enhancing calcified mass. The patient was well, without recurrence, 2 years after surgery.

Adult↗

PubMed1998

Contracture of the deltoid muscle: imaging findings in 17 patients.

OBJECTIVE: A retrospective review of the MR images and radiographs of 26 shoulders in 17 patients suffering from contracture of the deltoid muscle was used to establish the characteristic imaging findings. MATERIALS AND METHODS: Deltoid muscle contractures in 26 shoulders in 17 patients encountered over a 4-year period are reported. The history of intramuscular injection and clinical symptoms and signs are detailed. Imaging studies including routine radiographs (24 shoulders), MR images (25 shoulders), and computed arthrotomograms (two shoulders) were reviewed. On MR images, the winging angle of the scapula (angle between the axis of the scapular body and the coronal plane of the chest) and the diameter of the lesion were measured and compared with data derived from 24 age-matched control subjects. RESULTS: Diagnostic MR features of deltoid muscle contracture include fibrotic cord in the deltoid muscle, especially its middle portion, extending from the superior acromial surface to the deltoid tuberosity, and winging of the scapula (increased winging angle of the scapula). Characteristic radiographic features include abduction contracture, winging of the scapula, lateral down-sloping of the acromial process, and a superior acromial enthesophyte. CONCLUSION: MR images are sensitive and accurate in the diagnosis of contracture of the deltoid muscles. Characteristic features also allow accurate routine diagnosis on radiographs.

Arm↗

PubMed1998

Intracranial cystic cavernous angioma: a case report.

We present a case of cystic cavernous angioma in an 18-year-old woman with the chief complaint of acute onset of seizures. Computed tomography (CT) and magnetic resonance (MR) imaging revealed a tumor with a slightly enhanced solid calcified portion and a large cystic portion. The patient was well without recurrence 6 months after surgery. The importance of MR imaging in the differential diagnoses is emphasized.

Adolescent↗

PubMed1997

Percutaneous transsplenic catheterization of the portal venous system.

PURPOSE: To evaluate the safety and feasibility of transsplenic portal vein catheterization. MATERIAL AND METHODS: Under ultrasonic guidance, percutaneous transsplenic splenic vein catheterization was performed in 17 patients. Two of the patients had minimal and 5 moderate ascites. In 11 patients, the platelet counts were over 50000/mm3 and the coagulation time normal or mildly prolonged, while 6 patients had either platelet counts of less than 50000/mm3 or moderately prolonged coagulation level. RESULTS: Transsplenic portal catheterizations were successfully performed in 16 of the 1/patients (one failed because of small splenic size). Procedure-related complications occurred in 3 patients with 2 requiring one unit of packed RBC transfusion. The third patient accumulated minimal fluid in the left pleural space. Imaging studies within one week of the procedure were made in 8 patients. These examinations revealed an intrasplenic hematoma in 2 patients. One patient had a small amount of hemoperitoneum. No major complications occurred. CONCLUSION: Transsplenic portal venous catheterization is a safe and feasible procedure.

Adult↗

PubMed1997

Correlation of high-resolution CT and pulmonary function in bronchiolitis obliterans: a study based on 24 patients associated with consumption of Sauropus androgynus.

OBJECTIVE: An outbreak of Sauropus androgynus-associated bronchiolitis obliterans occurred in Taiwan in the summer of 1995. We undertook a study of the correlation between high-resolution CT findings and pulmonary function testing in patients from this outbreak. MATERIALS AND METHODS: We evaluated inspiratory-expiratory high-resolution CT scans of 24 patients with S. androgynus-associated bronchiolitis obliterans. The presence of bronchiectasis was assessed by two visual scores (a bronchial dilatation score and a bronchiectasis extent score). Extent of air-trapping was assessed visually and given a score. We also used computer software to assess the extent of air-trapping and generate scores of dynamic attenuation. Spirometry, plethysmography, and diffusion capacity of each patient were also obtained. RESULTS: All four scores had statistically significant correlation with forced expiratory volume in 1 sec (FEV1) (p < .05 for both bronchiectasis scores; p < .001 for both air-trapping scores). The two air-trapping scores had statistically significant correlation with forced vital capacity and diffusion capacity. We found the scores for dynamic attenuation had the greatest correlation with FEV1 (r = .85). We also found that mosaic attenuation was notable on expiratory CT scans alone in nine patients (type 1 air-trapping) and on both inspiratory and expiratory CT scans in 15 patients (type 2 air-trapping). In the latter group, FEV1 was significantly lower (p < .01). CONCLUSION: Findings from high-resolution CT of air-trapping were more important than findings of bronchiectasis when correlating pulmonary function with S. androgynus-associated bronchiolitis obliterans. Type 2 air-trapping suggested a more severe air-flow obstruction than did type 1. Scores for quantitative attenuation generated by computer software were helpful in assessing air-trapping and correlating it with pulmonary function. These findings may apply to patients with bronchiolitis obliterans from other causes.

Adult↗

PubMed1997

Disseminated miliary cerebral candidiasis.

We present a case of disseminated intracranial infection by Candida albicans in a 5-year-old girl who had fever and a change of consciousness after surgery for complex congenital heart malformation. MR imaging revealed multiple small ring-enhancing hemorrhagic abscesses. One year after antifungal treatment, the abscesses and ventriculomegaly were almost completely resolved. The patient was discharged in a stable but vegetative condition.

Amphotericin B↗

PubMed1996

Azygos blood flow in cirrhosis: measurement with MR imaging and correlation with variceal hemorrhage.

PURPOSE: To evaluate magnetic resonance (MR) measurement of azygos blood flow (ABF) in assessment of risk of variceal hemorrhage in cirrhosis. MATERIALS AND METHODS: ABF in 50 patients with cirrhosis and 20 healthy control subjects was evaluated with phase-contrast cine MR imaging at the transaxial subcarinal plane. Group 1 included nine patients with cervical-drainage varices draining into brachiocephalic vein; group 2 included 41 patients with varices draining into azygos vein and was subdivided as group 2A, 15 patients with variceal hemorrhage, and group 2B, 26 without variceal hemorrhage. RESULTS: Azygos flow rate and velocity were increased in patients compared with that in control subjects. ABF in group 2A was faster than that in group 2B (cutoff, 15 cm/sec; sensitivity, 80%; specificity, 89%). Group 1 had ABF close to that of group 2B, but variceal hemorrhage occurred in seven of nine patients in group 1 versus 15 of 41 patients in group 2 (78% vs 37%; P = .029). CONCLUSION: Patients with cirrhosis with cervical-drainage varices or ABF greater than 15 cm/sec may have higher risk for variceal hemorrhage.

Azygos Vein↗

PubMed1996

Obstructive jaundice caused by calcified portal venous thrombosis: a case report.

One case of bile duct obstruction because of calcified thrombosis of the portal vein is described. The patient had received splenectomy 20 years previously. He was admitted for fever, right upper abdominal pain and jaundice. The initial sonography and computed tomography showed dilatation of bilateral intrahepatic ducts and common bile duct with adjacent calcified portal vein mimicking common bile duct stones. Endoscopic retrograde cholangio-pancreatography showed external compression of the common bile duct by the calcified portal vein. Because of the patient's poor liver condition, biliary endoprosthesis was performed to relieve obstruction. This was an indication that the possibility of portal venous thrombosis should be included in the differential diagnosis of patients with obstructive jaundice who had previously received splenectomy.

Aged↗

PubMed1996

Computed tomography in the diagnosis of organic bowel obstruction.

BACKGROUND: This study examined the usefulness of computed tomography (CT) scan for cases of organic intestinal obstruction, with two simple criteria. METHODS: One hundred and thirteen patients with clinical suspicion of bowel obstruction were referred for CT scans. A line was drawn between the dilated proximal, and the collapsed distal bowels. A careful search was conducted on this line for obstructive lesions. The results were reported to be organic obstruction if there was an abrupt change of caliber (Criterion I) or a soft tissue mass around the dilated bowel (Criterion II). The judgement based on the CT findings. RESULTS: Eighty-eight cases proved to have bowel obstruction. With Criterion I, the sensitivity was 59.1%, and specificity, 88% with Criterion II, the sensitivity was 56.3% and specificity 100%. If either of them was considered to be a positive sign of organic obstruction, the sensitivity was 100%, the specificity 88% and the accuracy 97.3%. The nature of the obstructions were precisely predicted in 76 patients (86%). CONCLUSIONS: With these two simple criteria, CT scan can achieve high accuracy and is a recommendation in virtually every instance when intestinal obstruction is suspected.

Adult↗

PubMed1996

Experience with transjugular intrahepatic portosystemic shunts for gastroesophageal variceal bleeding.

BACKGROUND: Variceal bleeding is a major life-threatening complication of cirrhosis of the liver. Transjugular intrahepatic portosystemic shunts (TIPS) have been accepted as an effective method for portal decompression. Experiences here with the use of TIPS for control of gastroesophageal variceal bleeding is presented. METHODS: Sixteen TIPS procedures were performed for 15 patients who suffered from intractable gastroesophageal variceal bleeding. Nine cases (60%) were hepatitis-related cirrhosis of liver, four (27%) were alcoholic liver cirrhosis and two were cryptogenic in origin. Liver function tests revealed four patients were Child-Pugh's classification A, five were B and six, C. Twelve cases had received failed endoscopic management of varices; and one patient had recurrent variceal bleeding after devascularization. TIPS procedure was performed electively in nine cases and, as an emergency in six cases. RESULTS: Fifteen of the 16 TIPS procedures attempted were successfully performed. The technically successful rate was 94% (15/16), but two cases with successful TIPS procedure expired at the end of the procedure from hypovolemic shock and acute respiratory distress, respectively; thus the completely successful rate was 81% (13/16), The initial bleeding control rate was 83% (5/6) for the six patients with active bleeding. Portal venous pressure was significantly decreased from 30.8 +/- 5.8 mmHg before TIPS to 21.7 +/- 6.0 mmHg after the procedure (P < 0.01) and the porto-systemic pressure gradient also significantly decreased from 23.0 +/- 3.6 mmHg to 11.9 +/- 2.7 mmHg after TIPS (P < 0.01). Recurrent variceal bleeding was noted in four patients (33%) and that was managed by percutaneous transluminal angioplasty (PTA) of shunt, placement of additional stent, second TIPS procedure and a devascularization operation. Hepatic encephalopathy was noted in three patients (25%) after TIPS. CONCLUSIONS: TIPS is an effective method to control variceal bleeding caused by portal hypertension, especially when endoscopic or surgical management has failed or is contraindicated.

Adult↗

PubMed1994

Transcatheter arterial embolization with or without cisplatin treatment of hepatocellular carcinoma. A randomized controlled study.

BACKGROUND: This randomized controlled study was objectively designed to evaluate the utility cisplatin (50 mg) in transcatheter arterial embolization (TAE) for treatment of hepatocellular carcinoma (HCC). METHODS: From May 1991 to July 1993, 46 patients were included in the study. All had a pathologic verification of HCC. Clinically, all of the patients were considered inoperable. However, these patients satisfied eligibility criteria for TAE. The patients were divided into two groups by random sampling. In group I, 22 patients received TAE with the regimen of cisplatin (50 mg) mixed with Lipiodol 5-15 ml followed by gelfoam pieces. In group II, 24 patients, as a controlled group, used the regimen of Lipiodol and gelfoam (Spongostan Film, Ferrosan, Denmark) pieces only, without adding any anticancer drug. The two groups were evaluated by a series of imaging studies and various clinical examinations before and after TAE. Subsequently, TAE was performed every 2 or 3 months for all patients until there was no visible tumor, or the patient could not sustain further TAE, or the patient died. RESULTS: In group I, TAE was administered 61 times (average 28 times for each patient), and in group II, 73 times (average 3 times for each patient). The 1-year and 2-year survival rates of group I were 52.5% and 26.2%, and group II were 72.5% and 39.5%. Statistically, there was no significant difference in survival curves and survival rates between these two groups. Tumor response rate of group I was 68% (15/22) and group II was 67% (16/24). There was no significant difference in tumor response between these two groups. The liver and renal function studies after TAE also showed no significant difference between these two groups. CONCLUSIONS: Based on this controlled study, the authors conclude that the addition of cisplatin does not enhance the therapeutic effect of TAE for treatment of HCC.

Adult↗

PubMed1993

[Hematometra in patients with cervical cancer--its CT presentation and clinical significance].

Cervical cancer is the most common gynecologic malignancy in Chinese. Clinical staging has been traditionally used in cervical cancer, according to international Federation of Gynecology and Obstetrics (FIGO) staging classification. Computed tomography was an adjunctive modality for detecting paraaortic lymph nodes in preoperative evaluation. But CT has failed to accurately define the extent of parametrial and vaginal invasion. Here, an attempt has been made to define indirect clues alerting to invasive cervical cancer. Hematometra can be seen in CT as a dilated uterine cavity with retention of significant fluid. The incidence of hematometra was 5% (5/101) in control group, and 26% (22/84) in cervical cancer. Hematometra cannot be more specific for cervical cancer, with an accuracy of 64%, sensitivity of 82% and specificity of 61%. Hematometra was found to have a statistically high relationship with high cancer staging and uterine invasion. The Chi-square values were 14.8 (P < 0.005) in high cancer staging, and 19.8 in uterine invasion. The accuracy of hematometra was 65% in high cancer staging, and 74% in uterine invasion. Hematometra was more common in postmenopause women, with accuracy elevated to 80% for uterine invasion. This is probably related to senile atrophy or endophytic growth of the cervix into the uterus as well as to hormone replacement. These were five false positive instances of hematometra, all unrelated to cervical cancer. They presented with marked fluid and a solid mass in the uterine cavity, and included endometrial adenocarcinoma, uterine myoma and leiomyosarcoma. None of cervical cancer showed a solid mass in a dilated uterine cavity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

[Acute abdomen with intraperitoneal bowel perforation-demonstration by CT scan].

Ninety-eight cases of surgically proved bowel perforation in VGH-Kaohsiung within one year were reviewed. Among them, 25 patients received abdominal CT scans before operation. Free gas or fluid could be demonstrated with CT scan in 80% of cases though sometimes the fluid was too scanty to be well recognized. Local abscess formation with or without tumor mass lesion (n = 3), local fluid accumulation (n = 1) and negative CT findings (n = 1) constituted the remaining 20% of cases. The recognition of perforation sites depended on direct evidences of perforation such as ulceration, abscess formation and tumor mass lesion (32%), or indirect evidences including hematoma formation, dependent extraluminal gas accumulation and phlegmonous reaction (12%). An inexplicable localized extraluminal fluid accumulation might also suggest a possibility of hollow organ perforation and lead to the recognition of perforation site in the absence of free gas (4%). Absence of extraluminal fluid or gas can not completely rule out the possibility of hollow organ perforation (4%). Massive free air, especially with an air-fluid level, suggested a possibility of upper abdominal perforation. The perforation hole located at the anterior wall of stomach produced more free gas than that located at posterior wall. Air-fluid levels could never be identified in the cases of lower gastrointestinal perforations. Local bowel wall thickening and the distribution of free gas contributed little to the recognition of perforation site. Extravasation of oral contrast media sometimes led to the diagnosis of gastrointestinal perforation but was not necessary to be noted around the perforation hole and did little contribution to the perforation site recognition.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen, Acute↗

PubMed1991

Hepatic microabscesses caused by Escherichia coli--US and CT appearance.

Hepatic microabscesses have been described in immunosuppressed patients. However, there has been no previous report concerning hepatic microabscesses caused by Escherichia coli (E. coli). Recently, we experienced a 75-year-old male patient who had suffered from fever and upper abdominal pain for 4 days. His laboratory tests revealed an increased erythrocyte sedimentation rate (55 mm/hr), the white cell count was 7500/cumm with 82% segmented leukocytes, minimally elevated serum alkaline phosphatase and serum glutamic-pyruvic transaminase. Ultrasonography (US) showed multiple tiny hypo- or nearly anechoic lesions (3-8mm) diffusely scattered in both hepatic lobes. Some lesions were too small to be demonstrated and only distal acoustic enhancement posterior to the lesions could be noted. Contrast-enhanced computed tomography (CT) scan subsequently demonstrated the tiny hypodense and cystic lesions and confirmed the US diagnosis of microabscesses. Cultures of blood and liver aspirates showed E. coli. Although US and CT appearance of hepatic microabscesses caused by E. coli may be characteristic, it is not specific. Differential diagnosis should include multiple biliary hamartomas, and definite diagnosis should be made by needle aspiration.

Aged↗

PubMed1990

Ultrasonographic demonstration of duplication cyst of the ileum.

The enteric duplication cyst is a term applied to an anomaly of the gut which presents as a cystic structure with a mucosal lining predominantly similar to that of the adjacent alimentary tract. It may be either due to an embryologic error in normal canalization or errors in the embryologic connection between the developing gut and neural tube, as a part of the split notochord syndrome. The preoperative diagnosis of a duplication cyst is difficult to make on the basis of conventional radiologic study including barium swallowing gastrointestinal series. With the wide application of ultrasound in the detection and evaluation of pediatric abdominal masses, an intra-abdominal cystic lesion may be encountered and the differential diagnoses may be difficult or impossible. We hereby report a case of duplication cyst of the ileum in which we believe its sonographic appearance is of certain value or even diagnostic in this pathology.

Child↗

PubMed1989

Serum amylase, isoamylase, and lipase in the acute abdomen. Their diagnostic value for acute pancreatitis.

We evaluated the diagnostic value of serum amylase, isoamylase, and lipase for the diagnosis of acute pancreatitis from sera of patients with acute abdominal pain. Comparison was first made in condition A between 32 patients with image-proven pancreatitis and 414 patients with nonpancreatic acute abdomen (the control group), then in condition B, between 62 pancreatitis patients with or without image proof and the control group. We found (a) that patients with image-proven pancreatitis suffer a more severe clinical course than those without; (b) that the sensitivity, positive predictive value, and accuracy in condition B are higher than in condition A at any cutoff level; (c) that none of the enzyme assays is specific at the upper reference limit, but their diagnostic yields are much improved by raising cutoff levels to about three or four times the upper limit; and (d) that at these selected cutoff levels, amylase had a diagnostic value similar to p-isoamylase or lipase in both conditions (sensitivity 84% and 92% for amylase in conditions A and B, respectively; specificity 98% and 98%; positive predictive value 75% and 90%; negative predictive value 99% and 99%; accuracy 91% and 97%). In conclusion, at an appropriately selected cutoff level, amylase can be effectively used as the first-line test and isoamylase or lipase as adjunct tests for acute abdominal conditions.

Abdomen, Acute↗