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Biomedical subjects

T S Chung

Publications and source records attributed to T S Chung.

50 records · Page 3Linked to original sources
PubMed1983

Multiple primary carcinoma of the lung.

The risk of developing multiple primary lung carcinoma is rare (1.07%) but increases with time following resection of the first primary lesion. Eight well-documented cases are reported along with a review of 351 cases reported in the literature. The interval between metachronous lesions ranged from 9 months to 17 years. Surgical resection remains the preferred treatment of resectable nonsmall cell carcinoma, with 5 year survival of 11%. All patients with lung carcinoma should be followed-up for the rest of their lives because of the possible occurrence of a second primary.

Adenocarcinoma↗
PubMed1980

Distant metastases of carcinoma of tonsillar region: a study of 475 patients.

The records of 471 patients with carcinoma of the tonsillar region seen at the Veterans Administration Medical Center, Hines, Illinois, have been reviewed to determine the incidence and location of distant metastases. All patients were male and with histologically proved diagnosis. Seventy-two patients (15%) of 471 and 33(29%) of 115 patients who underwent autopsy were found to have distant metastases. Squamous cell carcinoma was by far the most common cell type (88%); however lymphoepithelioma showed the highest incidence of distant metastases. Lung, liver, and bone were the most common anatomical sites of involvement, and thorough work-up of these organs is highly recommended before initiating definitive treatment and during follow-up care.

Bone Neoplasms↗
PubMed1976

Benign hydroarthrosis of knee in patients with spinal cord injury.

Swelling of the knee joint occurred in 8 of 35 patients with spinal cord injury; in seven of the eight patients the swelling developed within the first eight months after injury. Six of the eight patients had flaccid paraplegia. None of the patients showed any constitutional or local changes other than swelling. No laboratory evidence of inflammation could be detected. Swelling disappeared in two to six weeks and no sequelae were noted. Although trauma appeared to be the most likely cause of the swelling. Only one of four joints showed hemarthrosis on aspiration.

Adult↗
PubMed1975

Pneumatic orthosis PILOT STUDY;.

The pneumatic orthosis is potentially a substitute or replacement for conventional long-ler and under outer clothing. Pneumatic tubes are incorporated into the orthosis and may be inflated at will by the patient. In a preliminary test it was found to be lighter, more comfortable and cosmetically more acceptable than conventional braces. This paper presents the results of the first pilot study of the orthosis in the United States, conducted by the New York Medical College--Bird S. Coler Hospital Department of Rehabilitation Medicine, using 11 patients with different levels of cord transection. The orthosis was tested for its effect in the following areas: pulmonary function, blood chemistries to determine calcuyn function and phosphorus metabolic retention or loss; spasticity; urinary tract studies; skin; systemic blood pressure and pulse; physical comfort; and effect of temperature and humidity on patient. Wearing time was increased daily until a patient tolerated a minimum of one hour of inflation and six to eight hours of deflation comfortably without negative results. All the patients tested tolerated daily use of the pneumatic orthosis up to six to eight hours with no harmful effect on the skin. It did not interfere with healing of existing decubiti. Use of the pneumatic orthosis prevented postural hypotension in all tested cases, facilitated urinary outflow, increased vital capacity and reduced spasms related to postural changes.

Activities of Daily Living↗
PubMedDate not supplied

Effects of inner water volume on the peculiar surface morphology of microspheres fabricated by double emulsion technique.

Poly(D,L-lactide-co-glycolide) (PLG, 65:35) was used to encapsulate bovine serum albumin (BSA) using a water-in-oil-in-water (W/O/W) double emulsion solvent extraction technique. To investigate the effects of an inner water/oil ratio on microsphere characteristics, microspheres were fabricated using four different formulations with a fixed oil volume of 12ml and the inner aqueous phase volume of 0.2ml, 0.3 ml, 0.4ml or 0.5 ml, respectively. Spherical microspheres were obtained after collection by filtration for formulations employing any of the four different inner water/oil ratios. However, microspheres with smaller inner water volumes tend to collapse after vacuum drying. The surface of the formulation with a higher inner water/oil ratio was shown to possess many more pores than that of the formulations with lower inner water/oil ratios. These pores may facilitate the water withdrawal during vacuum drying. Furthermore, microspheres with the lowest inner water/oil ratio (1/60) had higher initial burst release due to its larger surface area. However, microspheres with the highest inner water volume yield a faster release profile of BSA due to interconnected voids within microspheres and more pores on the surface. Therefore, the inner water/oil ratio is a crucial factor in the W/O/W double emulsion technique affecting the morphology and release kinetics of the resulting microspheres.

Drug Delivery Systems↗
PubMedDate not supplied

MRI of carotid angiopathy after therapeutic radiation.

OBJECTIVE: Our goal was to assess whether significant secondary atherosclerotic changes from radiation can be detected on SE MR of the neck. MATERIALS AND METHODS: Pre- and postradiation MR scans of 16 patients with head and neck malignancies were studied randomly, independently, and blindly by two readers to determine the frequency of narrowing of the carotid arterial lumen and obliteration of the carotid space within the carotid sheath. RESULTS: Interval narrowing of either the common, internal, or external carotid artery lumen was seen in 108 of 192 (56%) of vessels evaluated on postradiation MR scans compared with preradiation studies. The differences in the grades of vessel luminal diameter were statistically significant (p < 0.05 for one reader and p < 0.0001 for the other reader). Among the 16 patients, 3 patients had vessels with a critical degree of stenosis, newly appearing on postradiation scans. Seven of 16 patients had diffuse obliteration of the planes within the carotid space. CONCLUSION: The incidence of accelerated atherosclerosis from therapeutic radiation may be greater than expected in nonirradiated patients. Magnetic resonance scans are an effective, noninvasive method for this type of follow-up.

Aged↗
PubMedDate not supplied

Application of magnetization transfer imaging for intracranial lesions of tuberous sclerosis.

PURPOSE: Our goal was to assess the effectiveness of magnetization transfer imaging (MTI) and the usefulness of the magnetization transfer ratio (MTR) in tuberous sclerosis (TS). METHOD: T2- and T1-weighted SE images with saturation pulse on/off before and after gadolinium enhancement in 10 patients with TS were obtained. The numbers of subependymal nodule (SEN), cortical tuber, and white matter (WM) abnormality detected on T1-, proton density, T2-, and MT T1-weighted SE images were compared. The contrast-to-noise ratio (C/N) on T1-, MT T1-, Gd T1-, and Gd MT T1-weighted SE images and MTR (1-Msat/MO) on each set of saturation/nonsaturation images for each lesions were calculated. Mean MTRs (mMTRs) of WM and gray matter (GM) from seven normal volunteers were also obtained. RESULTS: MT T1-weighted SE images always depicted all lesions seen on conventional MRI and allowed depiction of more SENs (n = 80), cortical tubers (n = 197), and WM abnormalities (n = 82) than did T1-weighted (n = 58/85/33), proton density (n = 41/108/36), or T2-weighted (n = 48/121/46) SE images. The best C/N was obtained from Gd MT T1-weighted SE images in SENs and from MT T1-weighted SE images in other lesions. mMTRs of normal WM and GM were 36.43 and 29.42%, respectively. Cortical tubers and WM abnormalities had measured MTRs that were statistically equal to MTRs of GM in normal subjects (p < 0.005). MTRs of SENs showed lower mean (25.55%) and greater diversity (SD +/- 5.30), compared with MTRs of other lesions and normal GM and WM. One SEN with MTR of 20.72% was pathologically confirmed to be subependymal giant cell astrocytoma (SGCA). Nine SENs had measured MTR below 20.72% and six nodules among these were located in the region of the foramen of Monro, which is the characteristic location of SGCA. CONCLUSION: MTI may be effective in detecting all cranial lesions of TS. MTR may increase the specificity of MRI because it can differentiate the histopathologic subtypes and track and evolution of SEN into SGCA.

Adolescent↗
PubMedDate not supplied

CT findings of laryngeal tuberculosis: comparison to laryngeal carcinoma.

PURPOSE: Our goal was to describe the appearance of laryngeal tuberculosis using CT, with the intent of identifying features distinguishing laryngeal tuberculosis and carcinoma. METHOD: CT scans of 12 patients with laryngeal tuberculosis were analyzed retrospectively. Clinical symptoms, laryngoscopic exams, and presence of pulmonary tuberculosis on chest radiographs were also reviewed. RESULTS: In laryngeal tuberculosis, bilateral involvement was noted in nine patients (75%), while unilateral involvement was seen in three (25%). Diffuse thickening of the free margin of the epiglottis was a characteristic and frequent finding in tuberculosis (n = 6, 50%). No deep submucosal infiltration of the preepiglottic and paralaryngeal fat spaces was seen even when there was extensive involvement of the laryngeal mucosa. Cartilage destruction was not found in any case. CONCLUSION: Characteristic CT findings of laryngeal tuberculosis include bilateral involvement, thickening of the free margin of the epiglottis, and good preservation of the preepiglottic and paralaryngeal fat spaces even in the presence of extensive mucosal involvement. By comparison, laryngeal carcinoma presented unilateral involvement, infiltration of the preepiglottic and paralaryngeal fat spaces by a submucosal mass, cartilage destruction, and extralaryngeal invasion.

Adult↗
PubMedDate not supplied

Fate of stroke patients transferred to a long-term rehabilitation hospital.

The rehabilitation outcome of 25 elderly hemiplegic patients discharged from the rehabilitation facilities of an acute general hospital and admitted to a long-term facility hospital was evaluated. Only those patients who had been on a rehabilitation program and were discharged after an average of 11 weeks because of lack of progress or severity of their functional and/or neurological disability were considered for this study. Twenty-two patients were wheelchair bound on admission and severely dependent in most self-care activities. Improvement in function and performance occurred in ten patients, while 13 patients remained unchanged. Among the improved patients, eight became ambulatory and independent in activities of daily living (ADL), eight became independent from a wheel-chair level, and eight returned home or to the community. The average stay of the patients in the chronic rehabilitation care facility was seven months, although all the patients reached their maximum level of performance within six months. It appears from this study that some hemiplegic patients require a long and intensive rehabilitation program.

Cerebrovascular Disorders↗
PubMedDate not supplied

Application of spatial modulation of magnetization to cervical spinal stenosis for evaluation of the hydrodynamic changes occurring in cerebrospinal fluid.

OBJECTIVE: To evaluate the hydrodynamic changes occurring in cerebrospinal fluid (CSF) flow in cervical spinal stenosis using the spatial modulation of magnetization (SPAMM) technique. MATERIALS AND METHODS: Using the SPAMM technique, 44 patients with cervical spinal stenosis and ten healthy volunteers were investigated. The degree of cervical spinal stenosis was rated as low-, intermediate-, or high-grade. Lowgrade stenosis was defined as involving no effacement of the subarachnoid space, intermediate-grade as involving effacement of this space, and high-grade as involving effacement of this space, together with compressive myelopathy. The patterns of SPAMM stripes and CSF velocity were evaluated and compared between each type of spinal stenosis and normal spine. RESULTS: Low-grade stenosis (n = 23) revealed displacement or discontinuity of stripes, while intermediate- (n = 10) and high-grade (n = 11) showed a continuous straight band at the stenotic segment. Among low-grade cases, 12 showed wave separation during the systolic phase. Peak systolic CSF velocity at C4-5 level in these cases was lower than in volunteers (p <.05), but jet-like CSF propulsion was maintained. Among intermediate-grade cases, peak systolic velocity at C1-2 level was lower than in the volunteer group, but the difference was not significant (p >.05). In high-grade stenosis, both diastolic and systolic velocities were significantly lower (p <.05). CONCLUSION: Various hydrodynamic changes occurring in CSF flow in cervical spinal stenosis were demonstrated by the SPAMM technique, and this may be a useful method for evaluating CSF hydrodynamic change in cervical spinal stenosis.

Cervical Vertebrae↗
PubMedDate not supplied

The role of functional MR imaging in patients with ischemia in the visual cortex.

BACKGROUND AND PURPOSE: Functional MR (fMR) imaging is based on changes in regional blood flow. The purpose of this study was to evaluate the role of fMR imaging for detection of a vascular compromised status in the occipital lobe in patients with ischemia in the visual cortex. METHODS: We performed fMR imaging in seven control subjects and seven patients with symptoms and signs of visual cortical transient ischemia and/or infarct. fMR imaging was performed using a gradient-echo sequence with the 2D fast low-angle shot technique. An axial slice including both visual cortices was selected, and stimulation of the visual cortex was performed using a red photostimulator. The number of activated pixels in each primary visual cortex area were counted and an asymmetry ratio [AR (%) = 100 x (R-L)/(R+L)/2] was calculated. Patients and control subjects underwent visual field examination, conventional MR imaging, and vascular imaging (MR angiography in all patients and control subjects, conventional catheter angiography in two patients). fMR imaging results were compared with the results of a visual field examination, conventional MR imaging, and vascular imaging. RESULTS: fMR imaging of the patients showed significant activation asymmetry (P <.05) compared with that of control subjects. Vascular abnormalities in the posterior circulation were found in all seven patients. By conventional MR imaging, five patients were found to have infarction in the occipital lobe and the remaining two patients showed no abnormality. In visual field examination, six of the seven patients showed homonymous hemi- or quadrantanopsia suggesting postchiasmic abnormalities, and the remaining patient had normal findings. fMR imaging showed decreased activity in the visual cortices corresponding to vascular abnormalities (seven of seven patients), permanent infarction (five of seven patients), or visual field defect (six of seven patients). Two patients with normal conventional MR imaging had vascular lesions in the posterior circulation, and fMR imaging showed decreased activity in the corresponding visual cortices. One patient with normal visual field examination had multifocal stenosis in the posterior cerebral artery without infarction, and fMR imaging showed decreased activity in the corresponding visual cortex. CONCLUSION: fMR imaging of the visual cortex may be a sensitive method for the detection of vascular-compromised status in the occipital lobe.

Adult↗
PubMedDate not supplied

Transient MR signal changes in patients with generalized tonicoclonic seizure or status epilepticus: periictal diffusion-weighted imaging.

BACKGROUND AND PURPOSE: Our purpose was to investigate transient MR signal changes on periictal MR images of patients with generalized tonicoclonic seizure or status epilepticus and to evaluate the clinical significance of these findings for differential diagnosis and understanding of the pathophysiology of seizure-induced brain changes. METHODS: Eight patients with MR images that were obtained within 3 days after the onset of generalized tonicoclonic seizure or status epilepticus and that showed seizure-related MR signal changes had their records retrospectively reviewed. T1- and T2-weighted images were obtained of all eight patients. Additional diffusion-weighted images were obtained of five patients during initial examination. After adequate control of the seizure was achieved, follow-up MR imaging was performed. We evaluated the signal changes, location of the lesions, and degree of contrast enhancement on T1- and T2-weighted images and the signal change and apparent diffusion coefficient (ADC) on diffusion-weighted images. We also compared the signal changes of the initial MR images to those of the follow-up MR images. RESULTS: The initial MR images revealed focally increased T2 signal intensity, swelling, and increased volume of the involved cortical gyrus in all eight patients. The lesions were located in the cortical gray matter or subcortical white matter in seven patients and at the right hippocampus in one. T1-weighted images showed decreased signal intensity at exactly the same location (n = 6) and gyral contrast enhancement (n = 4). Diffusion-weighted images revealed increased signal intensity at the same location and focally reduced ADC. The ADC values were reduced by 6% to 28% compared with either the normal structure opposite the lesion or normal control. Follow-up MR imaging revealed the complete resolution of the abnormal T2 signal change and swelling in five patients, whereas resolution of the swelling with residual increased T2 signal intensity at the ipsilateral hippocampus was observed in the other two patients. For one of the two patients, hippocampal sclerosis was diagnosed. For the remaining one patient, newly developed increased T2 signal intensity was shown. CONCLUSION: The MR signal changes that occur after generalized tonicoclonic seizure or status epilepticus are transient increase of signal intensity and swelling at the cortical gray matter, subcortical white matter, or hippocampus on periictal T2-weighted and diffusion-weighted images. These findings reflect transient cytotoxic and vasogenic edema induced by seizure. The reversibility and typical location of lesions can help exclude the epileptogenic structural lesions.

Adolescent↗
PubMedDate not supplied

Results of transvenous embolization of cavernous dural arteriovenous fistula: a single-center experience with emphasis on complications and management.

BACKGROUND AND PURPOSE: To describe the results of transvenous embolizations of cavernous dural arteriovenous fistua (cDAVF) with an emphasis on identifying the incidence, characteristics, and management strategies associated with the complications of transvenous embolization of cDAVFs. METHODS: Fifty-six consecutive patients who were treated by transvenous embolization for cDAVFs were reviewed. The approach routes, angiographic results, complications, and clinical outcome were assessed. RESULTS: Retrograde inferior petrosal sinus (n = 36), transfacial vein (n = 7), transcontralateral intercavernous sinus (n = 4), and direct superior ophthalmic vein (n = 3) approaches were used. Angiographic results showed complete occlusion (n = 29), nearly complete occlusion (n = 13), and incomplete occlusion (n = 14). Complications associated with the procedures were cranial nerve palsy (n = 6), venous perforation (n = 3), and brain stem congestion (n = 2). The cranial nerve signs resolved with conservative treatment. Venous perforations were managed by coil embolizations at the site of the tear with no significant neurologic sequelae. One case of brain stem congestion resulted in hemiplegia after conservative treatment. The other case showed venous congestion as a result of rerouting of the shunted flow after venous embolization that was successfully managed by covered stent deployment for occlusion of the residual feeders. Clinical follow-up data were available in 46 patients. Complete resolution or improvement of symptoms was seen in 42 patients (91%). CONCLUSIONS: Cavernous DAVFs may be effectively treated by transvenous embolization. However, the procedure can be associated with various complications, some of which can potentially result in significant morbidity. Prompt diagnosis of the complications with appropriate management strategies is mandatory for a safe procedure.

Adult↗