Biomedical subjects

K A Tong

Publications and source records attributed to K A Tong.

7 recordsLinked to original sources

PubMed2001

Spinal angiolipoma.

BACKGROUND: Spinal epidural angiolipoma is a rare cause of spinal cord compression. We present a case and review the clinical presentation, radiological appearance, pathological aspects and treatment of this distinct clinico-pathological entity. METHODS: A case of a 46-year-old woman with a five-month history of progressive myelopathy affecting her lower extremities is presented. CT and MRI revealed a large epidural fat-containing mass compressing the spinal cord dorsally at the T7-T8 level. A laminectomy was performed with gross total resection of the lesion. RESULTS: The patient's neurologic symptoms improved postoperatively. A two-year follow-up period has revealed no signs of tumor recurrence and no neurological deficit. CONCLUSION: The diagnosis of spinal angiolipoma should be considered in the differential diagnosis of spinal cord compression. Magnetic resonance imaging is the investigation of choice. The surgical objective is complete excision but, for anterior lesions involving bone, an overly aggressive approach should be tempered by an awareness of the overall indolent natural history of so-called "infiltrating" spinal angiolipomas that are only partially excised.

Adolescent↗

PubMed2001

A reliable method for measurement and normalization of pediatric hippocampal volumes.

A robust standardized method for segmentation, quantification, and normalization of pediatric hippocampal volumes using magnetic resonance imaging is presented. The method will find application in time course measurements of hippocampal volumes in pediatric patients who suffer from temporal lobe epilepsy and was tested prospectively on six control patients (13-60 mo of age). The un-normalized hippocampal volumes obtained using our segmentation method ranged from 3.85 to 6.38 mL, in agreement with previously published results. Inter- and intraobserver variability of the segmentation method was determined to be 13.3% and 2.8%, respectively. Four different methods of volume normalization were tested. Normalization is required to adjust for age-related increases in hippocampal volume. The normalization approach that seemed to compensate best for growth-related hippocampal volume changes was based on a simple estimation of intracranial volumes. This is the first report of a consistent and reliable method for segmentation and normalization of hippocampi from pediatric patients that can be used to study the progression of neurologic diseases in children.

Adolescent↗

PubMed2001

November 2000: 13 year old girl with back pain and leg weakness.

A 13 year-old girl presented with back pain and recurrent falls of one year, with more recent loss of ambulation and bladder control. Examination showed spasticity and a sensory level bilaterally at T8. CT and MRI scans showed an epidural soft tissue mass with spinal cord compression and destruction of the pedicle, transverse process and other portions of a mid-thoracic vertebral body. Histologic examination of the gross total resection showed a pigmented villonodular synovitis (PVNS). PVNS is most common in the knee and only 26 cases have been reported in the spine. Although vertebral bodies are rarely involved, it is important to include PVNS in the differential diagnosis of spinal lesions because of its tendency to recur locally if not totally resected.

Accidental Falls↗

PubMed1999

MR evaluation of vestibulocochlear anomalies associated with large endolymphatic duct and sac.

BACKGROUND AND PURPOSE: Large endolymphatic duct and sac (LEDS) is one of the most common anomalies seen in patients with congenital sensorineural hearing loss (SNHL), and is known to occur with other inner ear findings. Our purpose was to use high-resolution T2-weighted fast spin-echo (FSE) MR imaging to describe the features and prevalence of specific anomalies that occur in association with LEDS. METHODS: We retrospectively reviewed MR images of the inner ear obtained in 63 patients with LEDS and in 60 control subjects. We evaluated each image for features of cochlear and vestibular dysplasia, including deficiency of the cochlear modiolus, gross cochlear dysmorphism, asymmetry of the cochlear scalar chambers, enlargement of the membranous vestibule, gross vestibular dysmorphism, and abnormality of the semicircular canals (SCC). RESULTS: Cochlear anomalies were present in 76% of ears with LEDS. Modiolar deficiency, gross dysmorphism, and scalar asymmetry were seen in 94%, 71%, and 65% of abnormal cochleas, respectively. Vestibular abnormalities were present in 40% of ears with LEDS. Simple enlargement, gross dysmorphism, and distortion of the lateral SCC were seen in 84%, 16%, and 32% of abnormal vestibules, respectively. CONCLUSION: Coexistent cochlear anomalies, vestibular anomalies, or both are present in most ears with LEDS, and appear as a spectrum of lesions, ranging from subtle dymorphism to overt dysplasia. The presence of coexistent anomalies in LEDS affects treatment decisions and prognosis. Newer techniques of high-resolution FSE MR imaging provide a means of exquisite characterization of LEDS, as well as more sensitive detection of associated vestibulocochlear anomalies.

Cochlea↗

PubMed1997

Large vestibular aqueduct syndrome: a genetic disease?

OBJECTIVE: Our objective was to determine the familial incidence of large vestibular aqueduct syndrome (LVAS) detected by CT and MR imaging and to propose the genetic inheritance of LVAS. MATERIALS AND METHODS: We retrospectively reviewed cases of LVAS revealed by temporal-bone CT and MR imaging at the University of Utah Health Sciences Center. We interviewed 25 patients with LVAS regarding family history of hearing loss. Any family members with onset of hearing loss before 30 years old also underwent CT and MR imaging. The vestibular aqueduct (on CT scans) or the endolymphatic duct (on MR images) was measured at the midpoint of the distal limb. A measurement greater than 1.5 mm in diameter was considered abnormally large. Diagnosis of LVAS was made if the patient had hearing loss and positive imaging findings. RESULTS: Of the 25 patients, five were found to have familial involvement, resulting in subsequent study of eight additional symptomatic individuals. A total of 33 patients had positive CT or MR imaging findings. Twenty-nine underwent both studies, two underwent CT only, and two underwent MR imaging only. Among the 33 patients with LVAS, 39% familial occurrence was observed (13 patients). In four of the five different families, the involvement occurred among siblings in one generation. In one of the five families, the involvement occurred in two generations, affecting an uncle and a cousin of the patient. CONCLUSION: In patients with LVAS, a significant subgroup had familial involvement. Based on the pedigrees of the familial cases, the pattern was most consistent with autosomal recessive inheritance, although a smaller component of autosomal dominant or multifactorial inheritance may exist.

Deafness↗

PubMed1994

Asymptomatic myositis ossificans of the medial pterygoid muscles: a case report.

Traumatic myositis ossificans, also known as myositis ossificans circumscripta or fibrodysplasia ossificans circumscripta, is a form of dystrophic calcification leading to heterotopic ossification of intramuscular connective tissue. This is usually due to a single severe injury or repeated minor injuries to muscle, although cases without a history of injury have been reported. Heterotopic ossification is rare in the orofacial region, especially in the medial pterygoid muscles. A case of medial pterygoid myositis ossificans with unique computed tomography findings is described.

Aged↗

PubMedDate not supplied

Ocular melanoma.

Uveal melanoma is the second most frequent ocular malignancy after metastasis and the most common primary ocular malignant neoplasm in adults. The diagnosis is usually made from clinical examination and ocular ultrasound. CT and MR may be helpful for further evaluation.

Aged↗