Biomedical subjects

S Jaovisidha

Publications and source records attributed to S Jaovisidha.

At least 19 recordsLinked to original sources

PubMed2001

Imaging of fungal, viral, and parasitic musculoskeletal and spinal diseases.

There are many nonbacterial infections that have musculoskeletal manifestations and radiologic findings. These infections produce a limited range of tissue responses, depending on the organism, the tissue compartment affected, and the immune competence of the host. Diagnosis is dependent on obtaining an appropriate travel or geographic history, the clinical and laboratory features, and on occasion the specific radiologic findings.

Humans↗

PubMed2001

False-negative meniscal tear in MR imaging using non fat-suppressed techniques.

Magnetic resonance (MR) imaging of menisci has a diagnostic accuracy of more than 90 per cent when the images are properly obtained. Errors in the interpretation of MR images may be related to many problems, resulting in false positive or false negative readings. We conducted this study to evaluate the prevalence of false negative results, using arthroscopy as gold standard. Matched MR imaging (performed before July 1997) and arthroscopic findings of the menisci in 63 consecutive patients were retrospectively reviewed separately by imaging planes and sequences used, by the site of tear, and by the site of meniscus (medial or lateral meniscus). The number and percentage of false-negative results were recorded. We found that with non fat-suppressed MR techniques, missed tear (false negative reading) of both menisci occurred predominantly in the meniscal body. The prevalence depends on imaging plane and sequence used. Among the techniques reviewed, sagittal T2-weighted (T2W) sequence had the highest prevalence of undetected meniscal tear.

Adolescent↗

PubMed2001

Humeral head ossification center in congenital heart disease.

The objective of this study was to evaluate the ossification (visualization) of proximal humeral ossification center (PHOC) which may indicate bone growth in infants with acyanotic and cyanotic congenital heart disease (HD) compared to normal infants. The medical records and chest radiographs within 3 months after birth of infants who were diagnosed as congenital HD by echocardiography or cardiac catheterization from 1989 to 1999 were reviewed. The PHOC was recorded from chest radiograph as presence or absence in every one-month interval since birth. In all cases, the corrected age of 0 month was defined as 40 weeks post conception. We used a study of 260 normal Korean infants as the normal population in this study. We found that from 67 cases enrolled in this study; 10 cases were excluded because of lack of complete medical records and sequential chest radiographs. In the remaining 57 cases, the average gestational age of the infants was 38.1 +/- 2.7 weeks and the average birth weight was 2860.5 +/- 597.7 grams. Female to male ratio was 1.28:1. The infants were classified by gestational age as term (75.4%) and pre-term (24.6%). Types of congenital HD were diagnosed from echocardiogram (96.5%) and cardiac catheterization (3.5%) of cases; and were divided as acyanotic HD (64.9%) and cyanotic HD (35.1%). The ossification of PHOC in acyanotic full-term infants at 0, 1, 2, and 3 months was 24.0 per cent, 32.0 per cent, 72.0 per cent and 88.0 per cent; in cyanotic full-term infants it was 27.8 per cent, 33.3 per cent, 77.8 per cent, and 94.4 per cent; and in acyanotic pre-term infants was 8.3 per cent, 8.3 per cent, 25.0 per cent, and 41.7 per cent, respectively. There were 2 cyanotic pre-term infants who did not show ossification of PHOC until 3 months. In full-term infants with both types of HD; the appearance of PHOC was significantly later than normal at 1 month corrected age (p = 0.000002) but not significant at 0, 2, and 3 months (p > 0.05); whereas, in pre-term infants with acyanotic HD, the appearance was later than normal at 1, 2, and 3 months (p = 0.02, p = 0.01, and p = 0.0002, respectively). We concluded that the ossification of PHOC is significantly later than normal in pre-term infants with congenital HD, but not significant in full-term infants with congenital HD.

Birth Weight↗

PubMed2000

Degenerative disk disease at lumbosacral junction: plain film findings and related MRI abnormalities.

Due to a wide range of normal disk space heights at lumbosacral (LS) junction, we conducted this study to evaluate how to diagnose degenerative disk disease (DDD) of LS junction and how much information we can obtain from plain radiography regarding this condition. We retrospectively reviewed lateral LS spine films and magnetic resonance (MR) imaging in 100 patients presented with low back pain. Anterior disk height (ADH) and posterior disk height (PDH) were directly measured from plain radiographs. Signs of DDD were recorded from both plain radiographs and MR imaging. We found that ADH < 11.3 mm or PDH < 5.5 mm indicate DDD at LS junction with 95 per cent confidence interval. When spondylolisthesis presented, disks were all degenerated. Endplate sclerosis had significant relative risk (p < 0.05) for lateral neural canal stenosis and disk herniation. No radiographic finding showed significant relative risk for nerve root compression.

Confidence Intervals↗

PubMed1998

An integrated approach to the evaluation of osseous tumors.

Modern treatment techniques for musculoskeletal neoplasms require significant imaging information to determine the nature and extent of tumors. The imaging investigation should be selected according to the information needed. Conventional radiographic techniques remain of fundamental importance in the analysis of bone tumors and tumor-like lesions, whereas advance imaging techniques such as CT and MR imaging can provide information regarding the extent of lesions.

Biopsy↗

PubMed1998

Influence of heterotopic ossification of the hip on bone densitometry: a study in spinal cord injured patients.

OBJECTIVE: To evaluate (1) the magnitude of falsely elevated bone density results caused by heterotopic ossification (HO) around the hip and (2) effect of age of patients when the measurement was taken, age of patients at injury, and age of injury (time since event) to the prevalence of HO. SUBJECTS AND METHODS: We blindly analyzed plain radiographs of the hip [(obtained within 1 month of dual energy X-ray absorptiometry (DEXA)] in 107 spinal cord injured (SCI) patients for HO and matched the result to the three regions of interest (ROI): the femoral neck, Ward's triangle, and the trochanter. The influence of HO on bone densitometric values was determined by the analysis of variance (ANOVA) and post-hoc analysis. RESULTS: Nineteen (18%) patients had HO; overlying the femoral neck (79%), trochanter (74%) and Ward's triangle (37%), respectively. Significant elevation of densitometric values (P < 0.05 or less) was observed in a various magnitude at each ROI, with the greatest elevation at Ward's triangle. The prevalence of HO was high when the patients were injured at age range of 20-39 years. CONCLUSIONS: HO around the hip can cause significantly elevated bone densitometry results at all ROIs, which can obscure underlying osteoporosis, leading to underestimation of fracture risk. Determination of bone density in this region with corresponding plain radiographs would be of help. In SCI patients, prevalence of HO was high when the age of patients at injury was 20-39 years.

Absorptiometry, Photon↗

PubMed1998

Elbow effusions: distribution of joint fluid with flexion and extension and imaging implications.

RATIONALE AND OBJECTIVES: The authors study the distribution of elbow joint fluid with flexion and extension of the joint and evaluate the imaging implications of such distribution. METHODS: Three cadaveric elbows were studied with radiography, ultrasonography, and magnetic resonance imaging after the incremental injections of 1 to 15 mL of saline solution into the elbow joint. Imaging was obtained with full flexion and extension of the joint. Anatomic sections were obtained for correlation. RESULTS: In flexion fluid initially collected posteriorly and, with larger quantities, anteriorly. In extension the anterior fat pad was pressed into its fossa and the posterior fat pad was displaced superiorly by the olecranon process. On lateral radiographs in elbow flexion a positive fat pad sign was seen with 5 to 10 mL of fluid in the joint. Sonography allowed identification of 1 to 3 mL of fluid posteriorly with the elbow flexed. Magnetic resonance imaging allowed identification of 1 mL of fluid, regardless of joint position and location. CONCLUSIONS: The distribution of joint fluid in the elbow is influenced by flexion and extension of the joint. Radiography is best performed in flexion. Sonography is more sensitive than radiography in diagnosing effusions, but should be performed along the olecranon fossa with the elbow flexed. Magnetic resonance imaging is most sensitive in identifying effusions, regardless of joint position or location.

Body Fluids↗

PubMed1998

Scoliosis in elderly and age-related bone loss: a population-based study.

Osteoporosis, a common metabolic condition resulting in reduced bone mass, causes significant morbidity in affected individuals by predisposing them to osteoporotic fractures. To determine the relationship of scoliosis and osteoporosis, dual-energy X-ray absorptiometry (DXA) scans of 493 men and 762 women were analyzed according to their scoliotic status. No association was observed in the few scoliotic men without osteoarthritis of the spine compared to nonscoliotic men. Without osteoarthritis, scoliotic women had significantly decreased bone mass of the total hip and the femoral neck (p < 0.05) compared to nonscoliotic women, whereas in spine, bone mass was also decreased compared to nonscoliotic women, but not statistically significant. This suggests that scoliosis associates with bone loss, and affected women may benefit from early institution of therapeutic measures.

Journal Article↗

PubMed1998

Detection of ankle effusions: comparison study in cadavers using radiography, sonography, and MR imaging.

OBJECTIVE: The purpose of this study was to compare radiography, sonography, and MR imaging in revealing ankle effusions in cadaveric specimens. MATERIALS AND METHODS: Known quantities of saline solution were instilled in increments into the ankle joints of three cadaveric specimens. Imaging was completed after each injection with the ankle in dorsiflexion, plantar flexion, and a neutral position. Imaging included radiography, sonography, and MR imaging. Three observers who were aware of possible joint fluid evaluated the images by consensus and determined the presence or absence of joint effusion. RESULTS: MR imaging revealed 1 ml of fluid within the anterior recess of the ankle in a neutral position and in plantar flexion and within the posterior recess in dorsiflexion. Sonography revealed 2 ml of fluid within the anterior recess in a neutral position and in plantar flexion. Radiography revealed 5 ml of fluid within the anterior recess in a neutral position. CONCLUSION: MR imaging, sonography, and lateral radiography, in order of decreasing sensitivity, revealed ankle effusion. The power to reveal with each technique is influenced by the precise position of the ankle.

Adipose Tissue↗

PubMed1998

The patellar tilt angle: correlation of MRI evaluation with anterior knee pain.

The purpose of this study was to analyze the degree of patella tilt and its correlation with the symptoms of anterior knee pain. We used magnetic resonance imaging (MRI) to measure the angle of patella tilt. The patients (n = 128) were classified into two groups. Group 1 (n = 78) included patients who had never had symptoms of anterior knee pain but had MRI for evaluation of the menisci and the ligaments. Group 2 (n = 50) included patients who had MRI for evaluation of anterior knee pain syndrome. Patients who had gross deformities like patellar dislocation, tricompartmental osteoarthritis, or inflammatory arthritis were excluded. The average patella tilt angle was 6.3 (SD = 3.9) and 12.8 (SD = 8.4) degrees, respectively, for the two groups of patients. Twenty-three patients in group 2 underwent arthroscopy because of failure of conservative treatment, and the average patella tilt angle in this subgroup was 16.4 degrees. Our study suggests that patella tilt angle is correlated with the symptoms of anterior knee pain, and indicated that the cause of pain came from the tight lateral retinaculum. In addition, MRI was found to be an accurate and reproducible method of measurement of the patellar tilt angle.

Adolescent↗

PubMed1997

Influence of spondylopathy on bone densitometry using dual energy X-ray absorptiometry.

Spinal cord injury (SCI), as well as other neuromuscular disorders, not only results in osteopenia but also induces various patterns of osseous, articular, and soft tissue alterations. In the spinal column, a variety of abnormalities occur. To evaluate the magnitude of discrepancy of bone densitometry results caused by spondylopathy in SCI patients, we analyzed anteroposterior (AP) radiographs of the lumbar spine [obtained within 1 month of dual energy X-ray absorptiometry (DXA)] in 116 SCI patients for various manifestations of spondylopathy, and matched the result to each vertebral level (L1, 2, 3, 4). The dataset was stratified by individual vertebra (totally 463 vertebrae) as valid (no demonstrable other abnormal density on plain radiograph except osteopenia), abnormal without, and abnormal with hardware. The influence of spondylopathy on bone densitometry results was determined by the analysis of variance (ANOVA) and post hoc analysis. Our results showed that 227 (49%) vertebrae were abnormal. Significant elevation (15%, 15%, 18%, 20%; P < 0.001-P < 0.05) of bone mineral density (BMD; g/cm2) was observed at all levels (L1, 2, 3, 4, respectively), particularly at those abnormal vertebrae without hardware compared with valid (no other abnormal density on radiograph except osteopenia (Table 1). The L4 level was most severely affected. We concluded that in SCI patients, owing to various secondary progressive skeletal abnormalities, particularly neuropathic spondylopathy, can have strongly and significantly elevated vertebral bone densitometry results, which can obscure underlying osteoporosis, leading to misinterpretation and underestimation of fracture risk. DXA, although characterized by improving spatial resolution, cannot replace radiography in establishing the magnitude of this skeletal pathology. Therefore, determination of bone density in this region with corresponding plain radiographs is highly recommended.

Absorptiometry, Photon↗

PubMed1997

Fibrolipomatous hamartoma: MR imaging findings.

OBJECTIVE: To analyze the MR imaging features of fibrolipomatous hamartoma (FLH) of nerves. DESIGN AND PATIENTS: MR imaging studies from six patients (three men and three women) were retrospectively reviewed by three musculoskeletal radiologists. In four patients, a biopsy of the nerve lesion was performed. In two patients, biopsy data were unavailable and the diagnosis was based on the clinical history combined with the MR imaging findings. RESULTS AND CONCLUSION: MR imaging demonstrated fusiform nerve enlargement that was caused by fatty proliferation and thickening of nerve bundles. Nerve bundles appeared as serpentine tubular structures, hypointense on both T1- and T2-weighted images. The degree of fatty proliferation varied among patients. In addition, significant variation in the distribution of fat along the course of the nerves was noted. In three patients, FLH followed the branching pattern of the nerves, a characteristic pathologic finding. In two patients, intramuscular fat deposition (biceps and tibialis posterior muscles) was present. MR imaging findings of FLH are typical, allowing a confident diagnosis. The variation of fatty proliferation among patients and involved nerves as well as the tendency of the abnormalities to follow the branching pattern of the nerves is well demonstrated with MR imaging. FLH may present as an isolated nerve lesion, may be associated with intramuscular fat deposition, or may occur as a feature of macrodystrophia lipomatosa (MDL).

Adult↗

PubMed1997

Hemophilic pseudotumor: spectrum of MR findings.

OBJECTIVE: To determine the MR imaging appearance of hemophilic pseudotumor (HP) and its clinical implications. DESIGN AND PATIENTS: Five hemophilic patients (aged 35-77 years) with 12 HPs in various anatomic locations were included in this study. The MR images were retrospectively evaluated for the appearance of the lesions and accompanying abnormalities, as well as their clinical implications. RESULTS AND CONCLUSION: MR images of all five patients (12 lesions) showed well-defined masses containing blood clots in various stages of organization surrounded by a fibrous capsule in subcutaneous fat or in intramuscular, interfascial, subperiosteal, and intraosseous locations. Intramuscular HP frequently had mural nodules. This is an almost unique appearance that is somewhat unexpected. MR imaging allowed determination of number, size, and extent of the lesions, evidence of neurovascular involvement, and accompanying musculoskeletal alterations. It is concluded that MR imaging not only is a sensitive and accurate method for detecting and diagnosing HP and providing useful information for therapeutic decision making, but can also be used to assess results of treatment by allowing evaluation of the evolution of blood products, the size of lesions in regions difficult to access by physical examination, and recurrent bleeding within a chronic lesion.

Adult↗

PubMed1997

Evolving stages of lipohemarthrosis of the knee. Sequential magnetic resonance imaging findings in cadavers with clinical correlation.

RATIONALE AND OBJECTIVES: Lipohemarthrosis, the presence of fat and blood in a joint cavity, exhibits several complex layers related to differences in specific component relaxation on magnetic resonance (MR) images. The authors investigated sequential changes in the appearance of lipohemarthrosis of the knee as demonstrated by MR imaging. METHODS: Sequential MR imaging over a 4-day period was performed on two cadaveric knees after intraarticular injection of blood from a volunteer and fat from a cadaveric tibia (50 mL of blood and 25 mL of fat in one knee and 15 mL of blood and 5 mL of fat in the other knee). The authors determined components in the joint based on MR signal behavior. Magnetic resonance imaging examinations of four patients with intracapsular fractures and lipohemarthroses of the knee were reviewed retrospectively. RESULTS: Sequential MR images of cadaveric knees showed serial changes representing progressive formation and lysis of blood clot. Several fluid-fluid levels (globules of fat at the interface between fat and blood) and entrapment of fat were early findings of lipohemarthrosis. Three different fluid levels appeared approximately 3 hours after injection of fresh blood and marrow fat. The 96-hour study demonstrated three distinct levels. CONCLUSIONS: Lipohemarthrosis demonstrates temporal changes on MR imaging related to stages of formation and lysis of blood clot.

Adult↗

PubMed1997

Correlation between ossification of the stylohyoid ligament and osteophytes of the cervical spine.

OBJECTIVE: To investigate the correlation between ligamentous ossification or osteophytes of the cervical spine and ossification of the styloid process and stylohyoid ligament, and to determine any relation between diffuse idiopathic skeletal hyperostosis (DISH) of the thoracic spine and ossification of the styloid process and stylohyoid ligament. METHODS: Four patients having cervical spine DISH, an elongated styloid process and/or variable patterns of stylohyoid ligament ossification, and clinical findings compatible with Eagle's syndrome are described. Cervical computed tomography scans of 100 patients who also had lateral radiographs of the thoracic spine were reviewed. Point biserial and Spearman rank correlation analysis, McNemar test, chi-squared test, and Fisher's exact test were used to determine correlation between elongation of the styloid process and/or ossification of the stylohyoid ligament and (1) ligamentous ossification or osteophytes of the cervical spine (the characteristic spinal manifestation of DISH), and/or (2) DISH of the thoracic spine. RESULTS: (1) Elongation of the styloid process and variable patterns of ossification of the proximal, middle, and distal parts of the stylohyoid ligament, and (2) enlargement of this ligament were significantly correlated with transverse and anteroposterior dimensions of ligamentous ossification or osteophytes of the cervical spine at various levels. The prevalence of such abnormalities of this process and ligament was not significantly different between the patients with and without thoracic spine DISH. CONCLUSION: Variable types of styloid process-stylohyoid ligament complex abnormalities have significant correlation with ligamentous ossification and osteophytes of the cervical spine.

Aged↗

PubMed1996

Association of gastrocnemius tendon calcification with chondrocalcinosis of the knee.

OBJECTIVE: Chondrocalcinosis of the knee is a common radiological finding in the elderly. However, visualization of chondrocalcinosis may be difficult in patients with advanced cartilage loss. The purpose of this study was to determine sensitivity, specificity, and accuracy of gastrocnemius tendon calcification that might serve as a radiographic marker of chondrocalcinosis in patients with painful knees. DESIGN AND PATIENTS: We prospectively evaluated 37 knee radiographs in 30 consecutive patients (29 men, 8 women; mean age 67 years, age range 37-90 years) with painful knees who had radiographic evidence of chondrocalcinosis. The frequency of fibrocartilage, hyaline cartilage, and gastrocnemius tendon calcification was determined. For a control group, we evaluated knee radiographs in 65 consecutive patients with knee pain (54 men, 11 women; mean age 59 years, age range 40-93 years) who had no radiological signs of chondrocalcinosis. The frequency of gastrocnemius tendon calcification in the control group was determined. RESULTS: Gastrocnemius tendon calcification was 41% sensitive, 100% specific, and 78% accurate in predicting chondrocalcinosis. The gastrocnemius tendon was calcified on 15 of 37 (41%) radiographs in the experimental group and on 0 of 67 radiographs in the control group. In the chondrocalcinosis group, 23 (62%) had posterior hyaline cartilage calcification, 14 (38%) had anterior hyaline cartilage calcification, 31 (84%) had medial meniscus calcification, and 36 (97%) had lateral meniscus calcification. CONCLUSIONS: Our results show that gastrocnemius tendon calcification is an accurate radiographic marker of chondrocalcinosis in patients with knee pain.

Adult↗

PubMed1996

Ventral sacroiliac ligament. Anatomic and pathologic considerations.

RATIONALE AND OBJECTIVES: The ventral sacroiliac ligament (VSL), which bridges the sacroiliac (SI) joint anteriorly, has been described as an important stabilizing structure of the joint, but no data exist regarding its assessment with routine and advanced imaging methods. The authors determine the imaging appearance of the normal and abnormal VSL using close anatomic-histologic-imaging correlation. METHODS: Eight and 10 cadaveric SI joints were examined with magnetic resonance imaging in axial and coronal planes, respectively; and in four computed tomography scanning in both planes was obtained. Anatomic sectioning with histologic correlation at levels corresponding to those of imaging planes was performed. Representative examples of diseases that produce abnormalities of the VSL and connective tissue about the SI joint were reviewed. RESULTS: Magnetic resonance images showed the VSL-anterior capsular complex as a hypointense, linear, or minimally curved structure of approximately 2 mm thickness traversing the SI joint anteriorly. The VSL could not be separated from the anterior joint capsule by imaging studies, but such differentiation by histology could be determined based upon the orientation of its collagen fibers. Any disease process that affects the ligament or the site of ligamentous attachment to bone produces characteristic imaging alterations.

Aged↗

PubMed1996

Tuberculous tenosynovitis and bursitis: imaging findings in 21 cases.

PURPOSE: To describe imaging features of tuberculous tenosynovitis and bursitis with various imaging methods. MATERIALS AND METHODS: Twenty-one patients with surgically and/or pathologically proved tuberculosis of the tendon sheaths or bursae were evaluated. Routine radiography, arthrography, computed tomography (CT), and magnetic resonance (MR) imaging were used in some or all of the patients. RESULTS: Twelve patients had tuberculous tenosynovitis, and nine had bursitis. Tuberculous tenosynovitis most commonly involved the tendon sheaths of the hand and wrist, whereas bursitis occurred most frequently about the hip, especially in the trochanteric bursa. All cases of tuberculous tenosynovitis or bursitis showed soft-tissue swelling on plain radiographs, with calcification demonstrated in three of nine (33%) cases. CT and MR imaging allowed evaluation of all forms of tuberculous tenosynovitis (hygromatous, serofibrinous, and fungoid forms), whereas tuberculous bursitis exhibited two patterns of involvement: either a distended bursa or multiple small abscesses. Contrast material-enhanced radiography (i.e., arthrography) helped delineate communication between the affected structures. CONCLUSION: All imaging methods can provide complementary information that is helpful for determination of therapy. MR imaging seems to be superior in evaluating the extent of the lesion, particularly in soft tissue.

Adolescent↗