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Biomedical subjects

M M Teng

Publications and source records attributed to M M Teng.

At least 19 recordsLinked to original sources
PubMed2001

Pneumocephalus secondary to septic thrombosis of the superior sagittal sinus: report of a case.

Pneumocephalus secondary to septic superior sagittal sinus thrombosis (SSSST) is extremely rare. We report computed tomography (CT) findings in a 63-year-old man with SSSST caused by the gas-forming organism Klebsiella pneumoniae. The patient presented with fever, chills, general weakness, and spontaneous progressive swelling of the right frontoparietal scalp. CT revealed a gas-containing abscess over the right frontoparietal subgaleal region and in the superior sagittal sinus. Surgical drainage of the subgaleal abscess was performed and blood and pus cultures grew Klebsiella pneumoniae. The patient died of sepsis on the 6th day of hospitalization.

Humans↗
PubMed2001

Aneurysms of the fenestrated basilar artery treated with Gulielmi Detachabe Coils: case report.

Multiple aneurysms at the site of a basilar artery fenestration (BAF) are extremely rare. We report a case of BAF in association with two aneurysms successfully treated with Guglielmi Detachable Coils (GDCs). A 42-year-old male presented with subarachnoid hemorrhage and consciousness change. Angiograms of the vertebrobasilar artery demonstrated fenestration of the proximal basilar artery associated with two aneurysms. Embolization of aneurysms was done by using GDCs. Aneurysms were almost completely obliterated with preservation of the flow and lumen of the vertebrobasilar system. The patient remains asymptomatic at clinical follow-up of 18 months.

Adult↗
PubMed2001

Endovascular embolization of carotid-cavernous fistula using the posterior communicating artery approach: a case report.

We report a case of direct carotid-cavernous fistula complicated with occlusion of internal carotid artery (ICA) at attempted endovascular obliteration via ICA and subsequent successful embolization via the posterior communicating artery (PCoA) approach. After a thorough understanding of vascular anatomical alterations associated with initial technical failure with detachable balloons, a microcatheter was navigated to the fistula site via the vertebro-basilar-PCoA to the distal cavernous segment of the left ICA. Embolization of the fistula was performed with deposition of three platinum microcoils. Angiograms after embolization showed complete disappearance of the fistula. There was no procedural complication and no recurrence of fistula at one-year clinical follow up.

Adult↗
PubMed2001

Image evaluation of suprazygomatic masticator space lesions.

In order to understand lesions involving the suprazygomatic masticator space (SZMS) demonstrated on computered tomography (CT) or magnetic resonance (MR) images, we collected 45 cases of lesions in SZMS. There were hematomas in 26 cases, tumors in 16 cases, and abscesses in 3 cases. The location of these lesions in compartments of the SZMS and adjacent structures was analyzed. Most commonly hematoma was found in the deep loose connective tissue (80.8%), followed by the superficial dense connective tissue (61.5%). Only 2 SZMS hematoma involved the superficial fat pad. Five patients had air accumulation in the SZMS, and all were in the deep fat pad and with maxillary sinus fracture. Of the sixteen cases which were tumors, 12 were extended from adjacent structures, and four were primary tumor. In cases of tumor, compartments of SZMS involved most frequently were temporal muscles (15 of 16 cases), followed by deep fat pad (8 of 16 cases). The connective tissue layer of SZMS is a communication pathway for superficial spread of infection, hematoma, or tumor invasion to or from the scalp and face. Compartments of deep fat pad and temporal muscle are also pathways for the spread of disease to or from the face, intracranium and orbit. The primary tumors in infratemporal fossa and SZMS are rare. Malignant tumors in SZMS usually come from surrounding spaces.

Adolescent↗
PubMed2001

Sequential MR studies of a patient with white matter disease presenting psychotic symptoms: ADEM versus single-episode MS.

Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) are both demyelinating white matter disorders. It is difficult to differentiate ADEM from single episode MS because of the similar clinical presentation, cerebral spinal fluid (CSF) analysis, histological finding and magnetic resonance image (MRI) appearance. We report an ADEM case with unusual clinical presentations of predominant psychiatric symptoms, and relatively long disease course. Initially, we were not able to distinguish it from single episode MS. By means of sequential MR images followed up 2 years and spectroscopy studies, and the dramatic clinical improvement after corticosteroid therapy, ADEM was diagnosed as the disease entity of this patient. In this case report we will present the MR findings of this patient and discuss the differentiation between the ADEM and MS.

Adult↗
PubMed2001

Percutaneous transluminal angioplasty as an adjunct to treat the carotid-cavernous fistula.

We report a case of the direct carotid-cavernous fistula (CCF) with high-grade stenosis of the internal carotid artery (ICA) and treatment via the transarterial route after percutaneous transluminal angioplasty (PTA). A 46-year-old man was found to have a CCF after a motorcycle accident. Transarterial embolization was attempted, but it failed due to stenosis of the left cervical ICA. After the procedure of PTA for dilatation of the stenotic ICA, the fistula was successfully obliterated by detachable balloon subsequently. There were no complications or recurrence of the fistula at the three-year clinical follow up.

Angioplasty, Balloon↗
PubMed2001

Magnetic resonance imaging appearance of intradural spinal lipoma.

Intradural spinal lipoma not associated with spinal dysraphism is a rare tumor often presenting with nonspecific symptoms and indolent clinical course. Its intradural location and fat component is the key for proper preoperative diagnosis, which could hardly be made by traditional imaging studies including plain film and myelography. Both CT and MRI can reveal the fat component of the tumor, but MRI is superior to CT in demonstrating its relationship with adjacent normal nerve tissue. We report a 32-year-old man who had back pain for years and the symptom progressed rapidly in recent two months. MRI revealed an intradural tumor at T12 level with high signal intensity on both T1- and T2-weighted images. The signal intensity dropped dramatically with fat saturation technique, which confirmed fat as its main component. The patient received surgery and the tumor was proved to be an intraspinal lipoma.

Adult↗
PubMed2000

Hereditary haemorrhagic telangiectasia: hepatic lesions demonstrated with colour Doppler and power Doppler sonography.

Visceral vascular abnormalities in patients with hereditary haemorrhagic teleangiectasia (HHT) include teleangiectasis, arteriovenous fistula (AVF), and aneurysms. Sonographic findings and colour Doppler ultrasound (CDU) features of HHT in the liver have been described in a few reports. Presented here is the CDU finding of liver with HHT involvement in two patients, aged 52 and 29 years, respectively. Power Doppler sonography was also performed in the first patient in whom both CDU and power Doppler sonography could demonstrate the abnormal vascular channels in the liver. In the second patient, aneurysms in the left hepatic lobe and of the splenic artery were noted. Angiography was performed in both patients and confirmed the abnormal vascular lesions demonstrated by CDU and/or power Doppler sonographic findings.

Adult↗
PubMed2000

Imaging of invasiveness of pituitary adenomas.

The purpose of our study was to examine the tumor size, imaging invasiveness of the pituitary macroadenomas (PMA) and to evaluate the directions of PMA spread. One hundred and thirty-five patients with PMA were examined with MRI and/or CT for pre-operative evaluation. We retrospectively reviewed the CT and MRI to identify tumor size, extension and to evaluate the directions of tumor spread. One hundred and seventeen patients (87%) had suprasellar extension with compression of optic apparatuses, twelve patients (9%) had extension of tumor upward to hypothalamus and third ventricle. Infrasellar extension via the floor of the sella and sphenoid sinus was found in thirty-eight patients (28%), and further downward extension to ethmoid sinus, nasopharynx and/or skull base was depicted in five patients (4%). Twenty-two patients (16%) had lateral invasion to the cavernous sinus and associated cranial nerves. Temporal and frontal extensions were depicted in seven patients (5%) and six patients (4%), respectively. Five patients (4%) had posterior subtentorial extension to posterior fossa. Histologically, only two patients showed microscopic invasive features. There was no correlation between histologic features and imaging invasiveness. The PMA had the potential of multi-directional extension. This experience indicated any type of pituitary adenoma could invade surrounding structures. Suprasellar invasion was the most common direction of pituitary adenoma spread, followed by infrasellar, lateral, anterior and posterior routes.

Adenoma↗
PubMed2000

Endovascular embolization of intractable epistaxis.

BACKGROUND: We undertook this study to define the role of angiography and endovascular embolization in the treatment of patients with intractable epistaxis. METHODS: A series of 19 patients with massive intractable epistaxis, all treated with endovascular embolization were reviewed. There were 15 males and four females ranging in age from 18 to 70 years, with a mean age of 38 years. The predisposing factors of intractable epistaxis were head and neck tumors (n = 11), idiopathic symptoms (n = 3), surgical complications (n = 2), arteriovenous malformation of the face (n = 1), thrombocytopenia (n = 1) and trauma (n = 1). Polyvinyl alcohol (PVA) particles and gelfoam plugs were used as embolic agents in 11 patients for devascularization; detachable balloons with N-butyl-2-cyanoacrylate (NBCA) were used in four patients for vascular occlusion; NBCA and/or coils were used in four patients in the carotid and subclavian arteries for obliteration of pseudoaneurysms. RESULTS: Complete cessation of epistaxis was achieved in all 19 patients immediately after embolization. Seven patients had also undergone surgical tumor removal at two to five days after embolization. Two patients experienced mild to moderate facial pain on the first day after the procedure, but the symptoms later subsided. No significant complication or recurrence was observed in 18 patients. One patient with advanced hypopharyngeal carcinoma died two weeks after embolization due to another episode of massive epistaxis. Clinical follow-up for these patients was 15 days to eight years, with a mean of 41 months. CONCLUSIONS: Therapeutic endovascular embolization of intractable epistaxis is both efficient and safe. It should be considered as the primary treatment modality in intractable epistaxis.

Adolescent↗
PubMed2000

Cavernous sinus gas.

Gas within the cavernous sinus is an unusual finding. We report three patients who demonstrated gas in the cavernous sinus on computerized tomography (CT). The clinical information of these patients was reviewed for the possible source of the gas and the symptoms induced by the gas. Cavernous sinus gas was seen in two patients with sphenoid sinus fracture and in one patient after intravenous fluid infusion. None of the patients had symptoms referable to the cavernous sinus gas, but one patient had a grave prognosis due to trauma. Identification of cavernous sinus gas on CT and correlation with the clinical information is mandatory for further management.

Adult↗
PubMed2000

Aberrant cervical carotid artery.

Aberrant cervical carotid artery is an uncommon anomaly. Because this anomaly can lie in close proximity to the midline of the posterior part of the pharynx, it poses a significant risk during both major pharyngeal tumor resection and less extensive procedures such as tonsillectomy, adenoidectomy and palatopharyngoplasty. Five cases of aberrant cervical carotid artery were encountered and diagnosed using computerized tomography. In all five cases, the anomalous finding did not correlate with the presenting symptoms. Computerized tomographic images of these cases are provided. A review of the literature and the embryology of the aberrant carotid artery are presented. Awareness of the anomaly by radiologists and surgeons is essential to avoid accidental injury to the vessel during surgery.

Adult↗
PubMed2000

Double-balloon technique for embolization of carotid cavernous fistulas.

Embolization of a carotid cavernous fistula (CCF) by means of a detachable balloon is an established method for treating CCFs while preserving a patent parent internal carotid artery (ICA). However, failure to embolize the CCF may occur on a few occasions, such as when the balloon cannot pass through the fistula into the cavernous sinus by blood flow, or when the inflated balloon in the cavernous sinus retracts to the carotid artery. Under these circumstances, the ICA may have to be sacrificed in order to treat the CCF. Herein we describe a double-balloon technique for embolization of a CCF. By applying this technique, we successfully treated nine of 11 CCFs, without compromise of the parent ICA when the conventional one-balloon technique failed.

Balloon Occlusion↗
PubMed2000

Fat in the cerebral falx.

BACKGROUND: Fat within the cerebral falx is commonly encountered in our daily practice but has never been characterized and reported. The purpose of this study was to determine the incidence of fat within the cerebral falx and to identify its clinical features. METHODS: The cerebral falx was prospectively imaged in 1,570 consecutive brain computed tomographic scans and its features characterized. Cerebral magnetic resonance imaging was done in some patients. RESULTS: Of the 1,570 cases studied, 115 revealed a small amount of fat in the cerebral falx. This fat had a purely negative Hounsfield value. It produced a high signal on both T1- and T2-weighted magnetic resonance images. There was no calcified component. The fat was seen most commonly in aged patients. No related symptoms were noted. CONCLUSIONS: Among the patients studied, fat in the cerebral falx had an incidence of 7.3%. It is an incidental finding in adults and requires no further evaluation or treatment.

Adolescent↗
PubMed2000

Computed tomography and magnetic resonance imaging characteristics of giant pituitary adenomas.

PURPOSE: The purpose of this study was to characterize the computed tomography (CT) and magnetic resonance (MR) imaging features of giant pituitary adenoma (GPA) and to demonstrate the pathways of the spread of GPA. METHODS: CT and/or MR imaging scans of 356 patients evaluated preoperatively for single pituitary tumor were reviewed. Fourteen tumors (4%) fulfilled the radiologic criteria for GPA. There were 10 male and four female patients, ranging in age from 22 to 71 years (mean, 52 yr). We retrospectively reviewed the CT and MR imaging scans of these patients to characterize tumor appearances and identify the pathways of tumor extension. RESULTS: Thirteen tumors (93%) extended upward to the suprasellar cistern, and/or hypothalamus and third ventricle. Infrasellar extension through the sellar floor and sphenoid sinus to the skull base, or to the ethmoid sinus or the nasopharynx, was identified in seven patients (50%). Eight patients (57%) had lateral invasion to the cavernous sinus. Temporal and frontal extension was apparent in seven patients (50%) and six patients (43%), respectively. Five patients (36%) had posterior subtentorial extension to the posterior fossa. Histologically, only two GPAs showed invasive features. There was no correlation among histologic features, pituitary hormone concentrations, and evidence of tumor aggressiveness on CT and MRI scans. CONCLUSIONS: GPA has the potential for widespread, multi-directional extension. Our results indicate that any type of pituitary adenoma, regardless of its endocrinologic activity, may invade surrounding structures. Suprasellar invasion is the most common pathway of tumor spread, followed by infrasellar, lateral, anterior, and posterior routes.

Adenoma↗
PubMed1999

Aberrant left brachiocephalic vein: CT imaging findings and embryologic correlation.

Computed tomography was utilized to evaluate aberrant left brachiocephalic vein (ALBCV), an infrequently discussed congenital vascular anomaly among Chinese people. Associated vascular variation and possible embryonic correlation are discussed. Since 1990, a total of 14 cases of ALBCV have been reported in patients receiving CT scan of chest, and was mainly an incidental diagnosis. One case was confirmed angiographically and two others were confirmed by magnetic resonance imaging. Emphasis was placed on the entry of the azygos vein into the superior vena cava (SVC), the length of the SVC, and the presence of other cardiovascular abnormalities. Of the 14 cases of ALBCV, the level of azygos vein entry was higher than the origin of the SVC in 7 cases: 4 were approximately the same level and 3 were lower. The average length of the SVC was approximately 5. 6 cm shorter than that of the general population, which is approximately 7.0 cm. Three cases had associated vascular anomaly. Most cases of ALBCV had azygos vein drainage level higher than or equal to the origin of the SVC. Right-sided aorta is one of the causes giving rise to the ALBCV during embryonic development. The CT scan remains a definitive diagnostic modality for ALBCV.

Adolescent↗
PubMed1999

Positron emission tomography scan in cortical visual loss in patients with organophosphate intoxication.

OBJECTIVE: To determine the cerebral metabolism of patients with cortical visual loss. DESIGN: Two observational case studies. TESTING: Two patients who survived acute organophosphate poisoning with respiratory failure experienced severe visual loss despite relatively normal ophthalmic examination results. Magnetic resonance imaging of the brain revealed no abnormality of the visual system in either patient. Positron emission tomography (PET) was performed in these 2 patients and in 12 normal subjects with fluorine-18 fluorodeoxyglucose (FDG) as a tracer to measure cerebral glucose metabolism for the estimation of neurologic deficit in the visual cortex. MAIN OUTCOME MEASURES: The FDG uptake values were measured as nanoCurie per cubic centimeters of tissue (nCi/cc). The relative uptake index in visual cortex was computed as the ratio of uptake of FDG in each region of visual cortex to that of cerebellum (regional visual cortex/cerebellum). RESULTS: Hypometabolism was observed in the visual cortex of both patients. The relative uptake index of FDG in visual cortex (visual cortex/cerebellum) was significantly decreased in those patients compared with normal subjects. CONCLUSIONS: In patients with cortical visual loss, conventional neuroimaging techniques can fail to visualize damage that can be detected by PET scanning, and PET analysis may be helpful in estimating the metabolic deficit of visual cortex and in establishing the organic nature of cortical visual loss in these patients.

Adult↗