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Biomedical subjects

S F Ko

Publications and source records attributed to S F Ko.

At least 55 records · Page 3Linked to original sources

Bronchial atresia associated with epibronchial right pulmonary artery and aberrant right middle lobe artery.

We report a case of bronchial atresia associated with an epibronchial right pulmonary artery (ERPA) and an aberrant right middle lobe artery (ARMLA). CT showed a branching opacity, which was hyperintense on MR images, in the anterior segment of the right upper lobe with segmental hyperinflation and the ERPA. At surgery, the ARMLA was found to originate from the ERPA, crossing the anterior aspect of the right upper lobe bronchus. It is postulated that the ARMLA might have interfered with the normal bronchial development, leading to the development of segmental bronchial atresia.

Abnormalities, Multiple↗

Cervical ecchordosis physaliphora: CT and MR features.

We report a case of cervical ecchordosis physaliphora in an elderly man who presented with hemihypoaesthesia and contralateral hemiparesis. MRI showed a well defined, non-enhancing extradural mass lesion on the dorsal surface of the odontoid process of the axis. The lesion was of intermediate signal intensity on T1 weighted images and of low signal intensity on T2 weighted images. CT showed a small bony defect on the adjacent cortex of the odontoid process. Recognition of the imaging features of ecchordosis physaliphora is helpful in suggesting the diagnosis and differentiating the lesion from chordoma.

Aged↗

Primary synovial sarcoma of the gastrocolic ligament.

A case of primary synovial sarcoma of the gastrocolic ligament is reported in a 37-year-old woman. CT showed an encapsulated intraabdominal cystic tumour with an amorphous solid component. Barium studies showed a mass at the gastrocolic ligament which elevated the gastric antrum and displaced the transverse colon downwards. This is the first report of synovial sarcoma formation in the gastrocolic ligament. This tumour may have originated from pluripotential mesenchyme.

Adult↗

Congenital bilateral cystic neuroblastoma with liver metastases and massive intracystic haemorrhage.

A case of bilateral cystic neuroblastoma with liver metastases in a newborn is reported. CT showed a 10 cm right suprarenal multicystic mass and numerous hepatic cystic masses with intracystic fluid-fluid levels. Multiple smaller cystic lesions were also present in the left adrenal gland. To our knowledge, the CT findings of neonatal bilateral cystic neuroblastoma with liver metastasis and massive acute intracystic haemorrhage has not been previously documented.

Female↗

Congenital Ewing's sarcoma of the humerus.

We report an extremely rare case of Ewing's sarcoma (ES) of the humerus in a Chinese neonate. Plain radiography and magnetic resonance imaging showed extensive neoplastic involvement of the humeral diaphysis and adjacent soft tissues, confirmed on histology and immunohistochemistry as being due to ES. This is the first report of congenital ES in a long bone. Since ultrasound at 20 weeks gestation showed a normal fetal skeleton, the ES may have begun to develop in the late middle or third trimester.

Bone Neoplasms↗

Thoracic neurilemomas: an analysis of computed tomography findings in 36 patients.

On computed tomography (CT), neurilemomas have generically been described as well-defined, round masses with heterogeneous contrast enhancement. The CT scans of 38 surgically proven thoracic neurilemomas in 36 patients were reviewed to characterize further the CT features of this tumor, with an emphasis on different enhancement patterns. Unenhanced CT was available in 32 patients; 10 tumors appeared isodense, and 22 tumors appeared slightly hypodense compared with chest wall muscle. Except for an intraosseous neurilemoma of the T8 vertebral body, which mimicked bone metastasis, the tumors could be categorized into five different patterns on CT after contrast enhancement. Twenty tumors (54.1%) revealed diffuse, but amorphous and inhomogeneous enhancement. Seventeen (45.9%) tumors appeared as masses with multiple hypodense or cystic areas. Of these 17, the pattern was somewhat radial enhancement (n = 6, 16.2%), peripheral enhancement with a large central hypodense area (n = 5, 13.5%), homogeneous hypodensity (n = 5, 13.5%), and central enhancement with peripheral hypodensity (n = l, 2.7%). Appreciation of various CT manifestations is important in the diagnosis of this tumor.

Adult↗

Lipoblastomatosis combined with intestinal neuronal dysplasia.

We report the case of a male infant with multifocal lipoblastomatosis and intestinal pseudo-obstruction for whom the pathologic findings of rectal biopsy were consistent with intestinal neuronal dysplasia. Lipoblastomatosis is a benign neoplasm of human fetal white adipose tissue that mainly occurs in infants and children. Intestinal neuronal dysplasia is a disorder that clinically mimics Hirschsprung's disease and that is pathologically characterized by parasympathetic hyperganglionosis of the enteric nervous system. To our knowledge, the combination of lipoblastomatosis and intestinal neuronal dysplasia has never been documented, and the gene mutations involved are completely different. In this case, therefore, we postulate that intestinal neuronal dysplasia may be secondary to either compression of the nerve tract or inhibition of bowel movement due to lipoblastomatosis.

Diagnosis, Differential↗

Preoperative embolization of meningiomas: comparison of superselective and subselective techniques.

We retrospectively compared the efficacy of preoperative superselective and subselective embolization for intracranial meningiomas. Between January and December 1996, 22 patients (7 men, 15 women, mean age 51 +/- 15.5 yr) underwent superselective embolization with 45 to 150 mm polyvinyl alcohol particles after superselective catheterization of the feeding vessels with a microcatheter system. Another 30 patients (12 men, 18 women, mean age 50 +/- 12.9 yr) underwent subselective embolization between January and December 1995 with 150 to 300 mm Gelfoam particles after catheterization of the terminal external carotid artery just proximal to the orifice of the maxillary artery with a 4- or 5-F angiocatheter. The mean intraoperative blood loss (918 versus 1450 mL, p < 0.05), amount of blood transfused (4.9 versus 7.5 units, p = 0.09), and surgical resection time (422 versus 529 min, p < 0.05) were all lower in the superselective group than in the subselective group, while the occurrence of fresh ischemic necrosis (59% versus 53%, p = 0.68), hemorrhage (77% versus 60%, p = 0.19), and embolic material (55% versus 13%, p < 0.05) on pathologic examination were higher in the superselective group. No procedure-related complications occurred in the superselective group, whereas two patients in the subselective group had postoperative scalp necrosis. Our findings show that superselective embolization is more effective than subselective embolization for preoperative endovascular devascularization of meningiomas, with significant reductions in intraoperative blood loss and surgery time. Preoperative embolization of meningiomas, if indicated, should be done with the superselective technique whenever feasible.

Adult↗

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS): a case report.

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare congenital disorder characterized by a massively enlarged urinary bladder without mechanical outlet obstruction and microcolon, as well as a hypoperistaltic bowel with normal ganglion cell distribution. We report one such case to discuss the findings of antenatal ultrasound and the radiologic and pathologic features of this condition.

Abnormalities, Multiple↗

Variations of the middle and inferior right hepatic vein: application in hepatectomy.

We evaluated the anatomic variations of the middle right hepatic vein (MRHV) and inferior right hepatic vein (IRHV) and their clinical application to the possibility of right subtotal hepatectomy. In 400 of normal livers studied with ultrasound, the IRHV was found to drain segment 6 of the liver and flow into the inferior vena cava (IVC) in 72 (18%) cases. In 22 (5.5%) cases, the MRHV was found to drain segment 5 of the liver and flow into the IVC. The size of the IRHV ranged from 0.1 cm to 0.8 cm with an average of 0.46 cm. For the MRHV, the sizes ranged from 0.1 cm to 0.9 cm with an average of 0.34 cm. In 10/79 (12.6%) cases the IRHV and in 4/ 22 (18.1%) cases the MRHV were bigger than the right hepatic vein (RHV). The distance between the RHV and IRHV ranged from 3 cm to 5 cm with an average of 3.7 cm. The distance between the RHV and MRHV ranged from 3 cm to 3.3 cm with an average of 3.1 cm. A hyperechoic edge, similar to that of the portal vein, was observed at the wall of the hypertrophic IRHV and was 0.3 cm or larger in size. Preoperative delineation of this complex venous anatomy is very important. It provides vital information in the preoperative evaluation needed before performing a right subtotal hepatectomy with preservation of segment 6 or segment 5 of the liver, and with RHV resection. Prior to undertaking a right hepatectomy, clamping the hypertrophic MRHV and IRHV electively may minimize intra-operative blood loss and extrahepatic spread of the malignancy.

Adolescent↗

Nasopharyngeal carcinoma: MRI and CT assessment.

Precise assessment of the extent of nasopharyngeal carcinoma (NPC) represents the basic step towards optimal treatment. We compared the capacity of CT and MRI in assessing the extent of NPC in 67 patients. MRI was superior to CT in demonstrating lesions in the retropharyngeal node, skull base, intracranial area, carotid space, longus colli muscle and levator palatini muscle. Of 25 cases in which retropharyngeal adenopathy was recognised only on MRI, seven had been reported as showing oropharyngeal involvement and 18 as primary extension to the carotid space on CT. MRI showed skull-base involvement in 40 patients compared with 27 on CT and intracranial involvement in 38 patients versus 24 on CT. There was not a single case in which skull base invasion was seen on CT but not on MRI. MRI enabled improved recognition of tumour infiltration of longus colli muscles (34 cases compared with 15 on CT). It allowed us to clarify 12 questionable sinonasal opacities on CT. Overall, T-staging was changed in 18 of 67 patients (26.9%), including upstaging in 15 cases and down-staging in 3 cases, after comparing CT with MRI. The nodel status was changed from negative on CT to positive on MRI in 4 of 67 patients (6%). We believe that MRI allows more accurate evaluation of the extent of NPC than CT and should be the primary mode of investigation.

Adolescent↗

CT angiography of intracranial aneurysms: advantages and pitfalls.

OBJECTIVE: To determine the clinical usefulness of computed tomography (CT) angiography in the evaluation of cerebral aneurysms. MATERIALS AND METHODS: From October 1994 through April 1996, 26 patients with 30 surgical proven intracranial aneurysms underwent both CT angiography and catheter cerebral angiography. The findings of the two methods were reviewed independently and then compared with each other. RESULTS: Comparing with catheter angiography, CT angiography was superior in demonstrating the aneurysmal neck in seven aneurysms but was inferior in one. The thrombosed part and calcification of aneurysms were clearly demonstrated on CT angiograms. CT angiography also aided in differentiating tight vascular loops from aneurysms. On CT angiograms, one posterior communicating arterial aneurysm was overlooked and another anterior choroidal artery aneurysm was misinterpreted as a posterior communicating artery aneurysm. Of note were two patients in whom the infundibulum of the orbitofrontal artery was misinterpreted as the anterior communicating artery aneurysm. CONCLUSION: CT angiography can compliment conventional catheter angiography for its better demonstration of the 3-dimensional anatomy. It can provide surgical information about the neck, calcification and thrombosed part of an aneurysm and its relation to adjacent structures. However, caution is advocated because CT angiography may fail to demonstrate small but important vessels such as posterior communicating, anterior choroidal and orbitofrontal arteries. Recognition of the limitations of CT angiography is important in minimizing interpretation errors.

Adult↗

MR imaging of thoracic neurilemmomas.

Magnetic resonance (MR) imaging features of 15 thoracic neurilemmomas were analyzed. Morphologically, five tumor patterns could be identified on MR imaging including: inhomogeneous masses (n = 8), thick-walled multiloculated masses (n = 2), thick-walled central cystic masses (n = 2), homogeneous cystic masses (n = 2) and a target pattern mass (n = 1). The signal characterization of thoracic neurilemmomas was variable, usually brighter on T2-weighted images, hyper- to hypo-intense on T1-weighted images and always enhancing. Histopathologically, the inhomogeneous masses were characterized by irregular distribution of hypercellular Antoni A and hypocellular Antoni B tissues with variable degrees of cystic, hemorrhagic, myxoid and hyaline degenerative changes. Enlargement of the cystic areas led to the development of thick-walled multiloculated masses while confluence of these cystic areas produced a central cystic pattern. Extensive myxoid or hyaline degeneration yielded homogeneous cystic tumors. Peripheral fibrinous changes and central Antoni B stroma contributed to a target pattern. Appreciation of the protean MR manifestations and understanding of the underlying histopathological changes of thoracic neurilemmomas are helpful in the diagnosis of this tumor.

Adult↗

CT findings at lupus mesenteric vasculitis.

PURPOSE: To describe the spectrum of early CT findings of lupus mesenteric vasculitis (LMV) and to assess the utility of CT in the management of this uncommon entity. METHODS: Abdominal CT was performed within 1-4 days (average 2.2 days) of the onset of severe abdominal pain and tenderness in 15 women with systemic lupus erythematosus. Prompt high-dose i.v. corticosteroid was administered in 11 patients after the CT diagnosis of LMV was made. CT was performed after abdominal symptoms subsided. RESULTS: Eleven cases revealed CT features suggestive of LMV including conspicuous prominence of mesenteric vessels with palisade pattern or comb-like appearance (CT comb sign) supplying focal or diffuse dilated bowel loops (n = 11), ascites with slightly increased peritoneal enhancement (n = 11), small bowel wall thickening (n = 10) with double halo or target sign (n = 8). Follow-up CT before high-dose steroid therapy revealed complete or marked resolution of the abnormal CT findings. CONCLUSION: CT is helpful for confirming the diagnosis of LMV, especially the comb sign which may be an early sign. Bowel ischemia due to LMV is less ominous than previously expected, and the abnormal CT findings were reversible when early diagnosis and prompt i.v. steroid therapy could be achieved.

Abdominal Pain↗

Unusual imaging presentations in renal transitional cell carcinoma.

PURPOSE: To report on unusual imaging presentations in renal transitional cell carcinoma (TCC). MATERIAL AND METHODS: Imaging studies of 140 cases of pathologically proven renal TCC were retrospectively studied with the focus on unusual presentations. RESULTS: Unusual imaging manifestations were found in 20 cases (14.3%). These findings were classified into 5 categories: perirenal abscesses or perirenal hematomas in 6 cases; parenchymal masses in 5; undue thickening of the hydronephrotic wall in 4; "tuberculoid" pyelograms in 3; and tumors with massive necrosis in 2. CONCLUSION: Deceptive imaging presentations may occur in renal TCC. Recognition of these presentations may help to prevent delay in diagnosis.

Abscess↗

Conservative management of early endometrial adenocarcinoma with repeat curettage and hormone therapy under assistance of hysteroscopy and laparoscopy.

We report a rare case of early-stage endometrial adenocarcinoma in a 22 year old nullipara with polycystic ovaries undergoing conservative treatment. Pretreatment evaluation including tumour grade, depth of myometrial invasion, tumour size, hormone receptor status and flow cytometric analysis indicated a favourable prognosis. The patient underwent repeat endometrial curettage and a 6 month period of therapy with megestrol acetate and tamoxifen. A combination contraceptive pill was then prescribed to ensure withdrawal of the menstrual cycle thereafter. Now, 1 year after the last curettage, there is no evidence of disease. During the treatment period, hysteroscopy allowed for a more precise approach in panoramically examining the tumour nest in the endometrial cavity, and the subsequent endometrial response to hormone therapy. Laparoscopy using bulldog clamps applied to the isthmic portion of the Fallopian tubes prevented i.p. spread of endometrial tissue from retrograde regurgitation during hysteroscopy. Laparoscopic ovarian electrocautery resulted in the reduction of abnormal hypervascularization on the surface of polycystic ovaries postoperatively but caused a peri-ovarian adhesion complication. It is interesting that this case posed a unique opportunity to demonstrate the tumour regression under the assistance of laparoscopy and hysteroscopy.

Adenocarcinoma↗