A nonhuman primate model of age-related bone loss: a longitudinal study in male and premenopausal female rhesus monkeys

Aging is associated with gradual bone loss in men and premenopausal women, with an accelerated rate of loss after menopause in women. Although many studies have investigated bone loss due to surgically induced estrogen depletion, little is known regarding normal age-related changes in bone mass in animal models. We used dual-energy X-ray absorptiometry (DXA) to measure bone mineral density (BMD), bone mineral content (BMC), and projected area (PA) at four skeletal sites over 4 years in 20 premenopausal female (8-23 years) and 29 male (8-27 years) rhesus monkeys (Macaca mulatta). Forearm BMD declined with age in both male and female monkeys. Lean mass was positively associated with BMD at all sites in males and with the distal radius in females. Serum osteocalcin declined and urinary cross-links increased with age in males but not females. Serum 25-hydroxyvitamin D concentrations decreased with age in females, and a similar trend was observed in males. In conclusion, an age-related decline in forearm BMD was observed in male and female rhesus monkeys. Total body BMC declined over time in older females, with a similar trend in males. Changes in markers of bone turnover with age were also observed in male monkeys. The results of this longitudinal study suggest that the rhesus monkey is a potential model for age-related changes in the human skeleton.

Interpretation of Emergency Department radiographs: a comparison of emergency medicine physicians with radiologists, residents with faculty, and film with digital display

OBJECTIVE

We determined the relative value of teleradiology and radiology resident coverage of the emergency department by measuring and comparing the effects of physician specialty, training level, and image display method on accuracy of radiograph interpretation.

MATERIALS AND METHODS

A sample of four faculty emergency medicine physicians, four emergency medicine residents, four faculty radiologists, and four radiology residents participated in our study. Each physician interpreted 120 radiographs, approximately half containing a clinically important index finding. Radiographs were interpreted using the original films and high-resolution digital monitors. Accuracy of radiograph interpretation was measured as the area under the physicians' receiver operating characteristic (ROC) curves.

RESULTS

The area under the ROC curve was 0.15 (95% confidence interval [CI], 0.10-0.20) greater for radiologists than for emergency medicine physicians, 0.07 (95% CI, 0.02-0.12) greater for faculty than for residents, and 0.07 (95% CI, 0.02-0.12) greater for films than for video monitors. Using these results, we estimated that teleradiology coverage by faculty radiologists would add 0.09 (95% CI, 0.03-0.15) to the area under the ROC curve for radiograph interpretation by emergency medicine faculty alone, and radiology resident coverage would add 0.08 (95% CI, 0.02-0.14) to this area.

CONCLUSION

We observed significant differences between the interpretation of radiographs on film and on digital monitors. However, we observed differences of equal or greater magnitude associated with the training level and physician specialty of each observer. In evaluating teleradiology services, observer characteristics must be considered in addition to the quality of image display.

Genealogy construction in a historically isolated population: application to genetic studies of rheumatoid arthritis in the Pima Indian

PURPOSE

Due to the characteristics of complex traits, many traits may not be amenable to traditional epidemiologic methods. We illustrate an approach that defines an isolated population as the "unit" for carrying out studies of complex disease. We provide an example using the Pima Indians, a relatively isolated population, in which the incidence and prevalence of Type 2 diabetes, gallbladder disease, and rheumatoid arthritis (RA) are significantly increased compared with the general U.S. population. A previous study of RA in the Pima utilizing traditional methods failed to detect a genetic effect on the occurrence of the disease.

METHODS

Our approach involved constructing a genealogy for this population and using a genealogic index to investigate familial aggregation. We developed an algorithm to identify biological relationships among 88 RA cases versus 4,000 subsamples of age-matched individuals from the same population. Kinship coefficients were calculated for all possible pairs of RA cases, and similarly for the subsamples.

RESULTS

The sum of the kinship coefficient among all combination of RA pairs, 5.92, was significantly higher than the average of the 4,000 subsamples, 1.99 (p < 0.001), and was elevated over that of the subsamples to the level of second cousin, supporting a genetic effect in the familial aggregation. The mean inbreeding coefficient for the Pima was 0.00009, similar to that reported for other populations; none of the RA cases were inbred.

CONCLUSIONS

The Pima genealogy can be anticipated to provide valuable information for the genetic study of diseases other than RA. Defining an isolated population as the "unit" in which to assess familial aggregation may be advantageous, especially if there are a limited number of cases in the study population.

The retained intrapericardial sponge: value of the lateral chest radiograph

OBJECTIVE

Our objective was to identify reasons for the difficulty in diagnosing retained intrapericardial sponges and to determine ways to improve diagnostic accuracy.

CONCLUSION

All three intrapericardially retained sponges were in the posterior pericardium, a region not visible to the surgeon. Radiographic detection of the sponges on standard anteroposterior projections is difficult because of exposure factors, other confusing linear markers, and metallic densities such as sternal sutures. However, knowledge of the typical location of a lost sponge and use of lateral radiographic projections may aid in early detection of this rare complication.

Establishing the level of digitization for wrist and hand radiographs for the third National Health and Nutrition Examination Survey

In the third National Health and Nutrition Examination Survey (NHANES III) conducted by the National Center for Health Statistics, Centers for Disease Control and Prevention, radiographs of the hands and knees were taken of participants 60 years and older as part of the study of arthritis and musculoskeletal conditions. The purpose of the study was to decide the digitizing resolution to be used for these radiographs. A set of wrist and hand radiographs (N = 49) was graded by two radiologists for degree of bone erosions and served as a "gold standard." The radiographs were then digitized at three resolution levels; low-resolution 150 microns (2001 x 1634 x 12 bit matrix); intermediate-resolution 100 microns (3000 x 2400 x 12 bit matrix); and high-resolution 50 microns (4900 x 3000 x 12 bit matrix). A comparison of the digital images versus the gold standard reading was made at the three resolutions by two radiologists. Kappa statistics suggested fair (K > .4) to excellent (K > .75) agreement between the gold standard and the images at all levels. Intraclass correlation coefficient suggested high agreement between readers (ICC > .5), with minimal individual reader effect. Variance component estimates showed that the major contribution (78-83%) to scoring came from variability in the images themselves, not from the readers. The 100 microns resolution was selected over the 150 and 50 microns on the basis of practical considerations such as storage requirements, display time, and easier manipulation of the digital images by the readers.

Rheumatoid arthritis in the Pima Indians: the intersection of epidemiologic, demographic, and genealogic data

OBJECTIVE

To describe the clinical features and familial distribution of rheumatoid arthritis (RA) in the Pima Indians.

METHODS

From 1965 through 1990, all cases of RA as defined by the American College of Rheumatology (formerly, the American Rheumatism Association) 1987 criteria or all cases of seropositive, erosive disease as defined by the Rome criteria were identified in individuals who were age 20 years and older and were of 50% or more Pima/Tohono-O'odham heritage. Radiographs were reviewed by 2 musculoskeletal radiologists who were blinded to case status. Kinship coefficients were used to evaluate familial aggregation.

RESULTS

Eighty-eight RA cases were identified from this population-based sample. Over 66% of the cases had seropositive disease, over 60% had erosive disease, and over 40% had subcutaneous nodules. Of the 88 RA cases, 40 were members of families with more than 1 RA case. The remainder were simplex cases.

CONCLUSION

In this population, clinical markers of severe RA were present in a majority of cases. The presence of familial aggregation for RA in the Pima Indians suggests underlying genetic factors in disease pathogenesis.

Utilization of computed tomography in patients hospitalized with community-acquired pneumonia

The objective of the study was to assess the frequency of the use of chest computed tomography in 385 adults hospitalized with community-acquired pneumonia and determine whether the computed tomography examinations yielded additional diagnostic information. Also, if additional information was obtained, the study determined whether it changed the patient's treatment plan.

Familial aggregation of osteoarthritis: data from the Baltimore Longitudinal Study on Aging

OBJECTIVE

To evaluate the familial aggregation of osteoarthritis (OA) in a cohort of healthy volunteers drawn from a community setting.

METHODS

Hand radiographs obtained between 1978 and 1991 and bilateral standing knee radiographs obtained between 1984 and 1991 were read for changes of OA, using Kellgren-Lawrence (K-L) scales. The hand sites were distal interphalangeal (DIP) joints, proximal interphalangeal (PIP) joints, and first carpometacarpal (CMC1) joints. For each joint group, the presence of OA in at least 1 joint in a joint group, the number of affected digits in each joint group, and the sum of the K-L grade across all joints were analyzed. Polyarticular OA was recorded if there were OA findings in 2 of 3 hand joint groups plus 1 or both knees. Data from 167 families with hand radiographs, 157 families with knee radiographs, and 148 families with both hand and knee radiographs were analyzed for sib-sib correlations.

RESULTS

After adjustment for age, sex, and body mass index, clinically relevant sib-sib common correlations were found for OA of the DIP, PIP, and CMC1 joints, for OA at 2 or 3 hand sites, and for polyarticular OA (r = 0.33-0.81) when OA was defined according to the number of affected joints or as the sum of the K-L grade across all joints.

CONCLUSION

These results from a cohort of volunteers drawn from a community setting and ascertained without regard to OA status demonstrate familial aggregation of OA and contribute to the evidence for heritability of OA.

Experimental testing of a DEXA-derived curved beam model of the proximal femur

This study was designed to test whether, using curved beam theory, a structural model of the proximal femur derived from two-dimensional dual energy x-ray absorptiometry could be used to predict femoral strength in an experimental simulation of a fall on the greater trochanter. A set of 22 fresh cadaveric femoral specimens were scanned with use of two-dimensional dual energy x-ray absorptiometry and then were tested to failure in a materials testing system, under three-point loading, with the ground impact vector aligned within the plane and along the bisector of the femoral neck-shaft angle. Failure locations generally corresponded to stress peak locations predicted by the curved beam model. Predicted failure loads correlated well with measured failure loads for femoral neck fractures (r=0.89; percent SE of estimate=23%) and some-what less well for intertrochanteric fractures (r=0.83; percent SE of estimate=29%). Overall predictions for failure load calculated from the maximum stress peak value over both locations corresponded to measured failure loads with an r value of 0.91 (percent SE of estimate=21%). This kind of structural approach to the analysis of data for hip bone mass has the potential to provide mechanistic interpretations of the statistical associations frequently shown between conventional bone mineral measures and either hip fracture risk in vivo or bone strength in vitro.

The value of immediate cytologic evaluation for needle aspiration lung biopsy

RATIONALE AND OBJECTIVES

The authors evaluate the role of immediate cytologic evaluation (ICE) with fine-needle aspiration biopsy (FNAB) for lung lesions at highest risk for pneumothorax.

METHODS

A prospective randomized study was conducted of 80 patients with lung lesions surrounded by aerated parenchyma undergoing FNAB with and without ICE (47 and 33 patients, respectively). An analysis of needle passes, procedure time, complications, specimen adequacy, diagnostic yield, and accuracy of procedure was made.

RESULTS

There was an increased number of needle passes with ICE (> or = three passes: 23% [11 biopsies] versus 3% [1 biopsy]; P = 0.01). Fluoroscopic procedures took longer with ICE (median time: 15 versus 9 minutes; P = 0.002) with no difference in complication rates. Specimen adequacy was similar (74% and 64%) and the procedure was diagnostic in 79% (37 biopsies) with ICE and in 70% (33 biopsies) without ICE. There were no significant differences in the sensitivity, specificity, or accuracy of the biopsy.

CONCLUSIONS

Immediate cytologic evaluation improved results marginally with increased procedure time and needle passes. Immediate cytologic evaluation may be most useful for lesions at lowest risk of complications to assure that a second procedure is not required.

Observer variation in the detection of acetabular bone deficiencies

To determine observer variation in the detection of acetabular bone deficiencies, 42 pairs of frontal (AP) and lateral hip radiographs and CT studies for total hip arthroplasty patients obtained within an average of 4 weeks of each other were reviewed separately by five radiologists and one orthopedic surgeon. Interobserver variations were calculated for each individual reading the films using kappa values. The individual film readings were then compared with a consensus reading of the CT data. When separate observers were analyzed, agreement on plain film readings was slight to fair (av. kappa = 0.1440 +/- 0.1047). The individual observers were not able to give readings which were very consistent with the CT consensus reading, resulting in a low sensitivity (65%) and specificity (74%) for acetabular defect classification with plain radiographs. The identification of acetabular bone defects from the AP and lateral views of the hip is highly subjective and variable from observer to observer.

Axial and hip bone mineral density and radiographic changes of osteoarthritis of the knee: data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

To examine the relationship between axial and hip bone mineral density (BMD) and radiographic changes of knee osteoarthritis (OA).

METHODS

BMD of the lumbar spine and/or right hip was measured, using dual photon absorptiometry, in 402 men and 247 women in the Baltimore Longitudinal Study of Aging who had bilateral standing knee radiographs taken between 1984 and 1991. Radiographs were read for features of OA using Kellgren-Lawrence and reliable individual feature scales. The relationship between BMD and radiographic changes of OA was examined using multiple linear regression adjusting for age, body mass index, and smoking. Additional analyses with adjustment for menopausal status and estrogen replacement therapy were performed in a subset of women.

RESULTS

Adjusted mean lumbar spine BMD was higher in subjects with knee osteophytes in both sexes: 1.23 +/- 0.02 vs 1.18 +/- 0.01 g/cm2 (p = 0.02) in men, and 1.12 +/- 0.02 vs 1.08 +/- 0.01 g/cm2 (p = 0.07) in women. There were no differences in levels of adjusted hip BMD by presence of any radiographic features of OA in either men or women.

CONCLUSION

These results show that both men and women with radiographic changes of knee OA, specifically osteophytosis, have higher levels of adjusted spine but not hip BMD.

One hundred consecutive thymectomies for myasthenia gravis

BACKGROUND

Between June 1997 and November 1993, 100 consecutive thymectomies for myasthenia gravis were performed at University of North Carolina Hospitals in Chapel Hill.

METHODS

A consistent, planned protocol involving preoperative, intraoperative, and postoperative care was followed. All thymectomies were performed through a median sternotomy with removal of all visible thymus and perithymic fat in the anterior mediastinum.

RESULTS

There was no perioperative mortality or longterm morbidity. Mean postoperative hospital stay was 6.3 days (range, 3 to 18 days). Ninety-six percent of the patients were extubated the day of the operation, and all patients were extubated within 24 hours. Mean postoperative intensive care unit stay was 1.2 days (range, 1 to 4 days). After a mean follow-up of 65 months (range, 1 to 199 months), 78% of all patients are improved by at least one modified Osserman classification when their current status is compared with their worst preoperative disease severity. In fact, 69% of patients with mild disease preoperatively (class I, II, or III maximal severity) are in pharmacologic remission (asymptomatic without regular medication), whereas 29% of patients with severe disease (class IV or V) are in remission (p = 0.0001).

CONCLUSIONS

Our programmatic approach to thymectomy through a sternotomy has shown minimal morbidity and mortality. It is beneficial to myasthenics at both ends of the age and severity spectrum.

Case report: Phrenic artery injury--a rare complication of percutaneous needle lung biopsy

The phrenic artery is a small vessel that is not often visualized on CT and is at risk of injury during biopsy of low lung lesions. This may result in haemoperitoneum that will not be evident on post-biopsy chest X-rays. We present a patient with a bleeding tendency who had this unusual complication following a needle aspiration lung biopsy.

Fluid-fluid levels in injured knees: do they always represent lipohemarthrosis?

PURPOSE

To determine if fluid-fluid levels on horizontal-beam radiographs of posttraumatic knee joints always represent lipohemarthrosis.

MATERIALS AND METHODS

The files of 41 patients with tibial plateau fracture were reviewed retrospectively. Twelve with fluid-fluid levels on radiographs who underwent computed tomography (CT) or magnetic resonance (MR) imaging were selected; CT attenuation and MR signal intensity patterns were used to assess fluid-fluid levels. Simulated hemarthrosis and lipohemarthrosis underwent plain radiography, CT, and MR imaging.

RESULTS

Eight patients showed no evidence of fat in the supernatant fluid with either CT (n = 7) or CT and MR imaging (n = 1). Fluid levels resulted from blood separating into cellular elements and supernatant serum. Four patients showed evidence of lipohemarthrosis with either CT (n = 3) or MR imaging (n = 1); in one of these patients, a double fluid-fluid level could be demonstrated retrospectively on plain radiographs.

CONCLUSION

Single fluid-fluid levels in posttraumatic knee joints do not necessarily represent a lipohemarthrosis. Double fluid-fluid levels are a more specific finding.

Association of hand and knee osteoarthritis: evidence for a polyarticular disease subset

OBJECTIVE

To examine the association between hand and knee osteoarthritis (OA) in a community based population.

METHODS

Radiographs of 695 participants aged > or = 40 years in the Baltimore Longitudinal Study of Aging were read for changes of OA, using Kellgren-Lawrence grade > or = 2 as the case definition.

RESULTS

Logistic regression analyses, adjusting for age, gender and body mass index, revealed a significant association between OA in the knee and the following joint groups: distal and proximal interphalangeal (DIP, PIP) and Hand2 (OA in two or more hand joint groups) for grade 2-4 and grade 3-4 disease, and the first carpometacarpal (CMC1) joint for grade 3-4 disease.

CONCLUSION

There is an association between OA in hand sites and the knee. The strength of the associations increases with increasing disease severity. For the PIP site, there is a trend toward increasing strength of association for increasing numbers of affected joints and bilateral disease.

Depiction of pelvic fractures using 3D volumetric holography: comparison of plain X-ray and CT

OBJECTIVE

The goal of this study was to demonstrate the feasibility and test the diagnostic performance of a new technology, 3D volumetric holography, for imaging pelvic fractures. The management of pelvic fractures may be complex, and advanced imaging studies such as CT are frequently indicated. Multiplanar CT reformations and 3D renderings provide clinically useful and complementary display of the directly acquired CT data. With the recent availability of volumetric multiple exposure holograms, produced from serial image data, it is now possible to produce true 3D images of the pelvis. In the hologram, one may view the CT data in 3D or as individual planar slices constituting the whole 3D pelvis. The diagnostic performance of the volumetric multiple exposure holograms was tested against routine radiography, CT, and 3D volumetric CT reconstructions.

MATERIALS AND METHODS

Routine radiography and CT were performed in 15 patients with suspected pelvic fractures. Volumetric multiple exposure holograms and 3D volumetric CT reconstructions were created from the CT data. Axial and multiplanar reformation CT images were used as the standard for fracture, diastasis, and intraarticular fragment detection.

RESULTS

Radiograms detected 39 of 50 of the fractures and diastases and no intraarticular fragments. The 3D CT reconstructions and the holograms viewed as 3D objects alone missed two small fractures of the anterior column and one hip with intraarticular bone fragments. When the volumetric multiple exposure holograms were viewed as a 3D object and as individual planar slices constituting the whole, their results were the same as the standard.

CONCLUSION

Volumetric multiple exposure holograms were as sensitive and specific as axial CT and multiplanar reformations in detecting fracture pathology. By containing and making available, from one image, both planar and 3D information, volumetric multiple exposure holograms detected subtle anatomical features that were hidden by overlapping structures in the radiographs and the 3D CT images.

Association of radiographic features of osteoarthritis of the knee with knee pain: data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

To examine the association between self-reported knee pain and radiographic features of osteoarthritis (OA) of the knee.

METHODS

A sample of participants in the Baltimore Longitudinal Study of Aging (452 Caucasian males and 223 Caucasian females) completed questionnaires and underwent a standing radiograph of both knees at the same biennial visit between 1984 and 1989. Radiographs were interpreted using both the Kellgren-Lawrence and individual features scales. Odds ratios were calculated for the association of radiographic features with knee pain after adjustment for age, sex, and body mass index.

RESULTS

Overall, 156 (23%) persons reported ever having knee pain, and 104 (15%) reported current knee pain (within the previous year). Both ever knee pain and current knee pain were significantly associated with the presence of definite knee OA (Kellgren-Lawrence grade > or = 2) and with the presence of all individual features. There was a direct relationship between all measures of severity of radiographic OA and knee pain.

CONCLUSION

These data demonstrate that radiographic features of knee OA are significantly associated with knee pain. The data also support the continued use of the Kellgren-Lawrence grading scale for defining knee OA in population studies.

Pulmonary nodules: effect of increased data sampling on detection with spiral CT and confidence in diagnosis

PURPOSE

To compare spiral computed tomography (CT) with interscan spacing of 4-5 mm versus 8-10 mm for detection rate and level of confidence in diagnosis of pulmonary nodules.

MATERIALS AND METHODS

Four radiologists (two junior and two senior faculty members) retrospectively reviewed 67 spiral CT studies with one to six nodules per study. Every second image was masked, which resulted in 8-mm sections every 8 or 10 mm; then all images reconstructed every 4 or 5 mm were reviewed. Lesions were classified as definite, probable, or possible.

RESULTS

Narrow interscan spacing yielded more lesions overall (583 vs 566, P < .025) and more definite lesions and fewer equivocal lesions (482 vs 431 and 101 vs 135, respectively; P < .055). The greatest effects were in the reduction of possible lesions (50 vs 88, P < .001) and in the reduction of false-positive diagnoses made by less experienced radiologists.

CONCLUSION

Increased reconstruction frequency of spiral CT volume data sets improves detection of pulmonary nodules and enhances confidence in the diagnosis.

Interpretation of emergency department radiographs by radiologists and emergency medicine physicians: teleradiology workstation versus radiograph readings

PURPOSE

To compare accuracy of interpretation by radiologists and emergency medicine physicians of conventional radiographs and digitized images on a workstation.

MATERIALS AND METHODS

One author selected 120 radiographs from the radiology department library, including 62 musculoskeletal, 20 abdominal, and 38 chest examinations. Analog radiographs were digitized. There were 60 positive and 60 control cases. Positive cases demonstrated clinically important disease and had a high degree of diagnostic difficulty. Thirty-one cases were judged to be critical to the patient's immediate care, requiring prompt accurate interpretation. Four groups of readers were used: staff radiologists and emergency medicine physicians and second-year radiology and emergency medicine residents.

RESULTS

All reader groups performed better when interpreting conventional radiographs than digitized images. Differences in favor of radiograph reading were statistically significant for overall accuracy related to all cases and to critical cases (P < .05, one-tailed test).

CONCLUSION

Results with the teleradiology system were found unacceptable for primary interpretation of the spectrum of radiographs seen in an emergency department.

Differentiation of benign and malignant musculoskeletal tumors: potential pitfalls with MR imaging

Magnetic resonance (MR) imaging is the most sensitive and accurate imaging technique for evaluation of musculoskeletal tumors. With increasing clinical experience, however, an overlap between the classic characteristics of benign and malignant tumors is frequently observed. In a prospective analysis of 87 consecutive cases of musculoskeletal tumors, the malignancy of skeletal lesions was correctly assessed with MR imaging in 55% of the cases. In 39% of the cases, the malignancy of skeletal lesions was overestimated with MR imaging. Correlation with plain radiography is extremely important in such cases and would have resulted in correct assessment of 73% of the skeletal lesions. For soft-tissue lesions, a large variability is found in the benign versus malignant appearances of lesions on MR images, with poor correlation between classic benign characteristics and the benignity of the lesion (17% of cases). The exceptions are hemangiomas and lipomas, which have characteristic appearances on MR images. Knowledge of potentially misleading appearances of musculoskeletal tumors on MR images allows more accurate diagnosis of such tumors.

The association of body weight, body fatness and body fat distribution with osteoarthritis of the knee: data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

To examine the association of body weight, body fatness, and body fat distribution with osteoarthritis (OA) of the knee.

METHODS

Bilateral standing knee radiographs, taken between 1985 and 1991, of 465 Caucasian men and 275 Caucasian women subjects aged 40 and above in the Baltimore Longitudinal Study of Aging were read by one investigator for grade of OA using Kellgren-Lawrence scales. Measures of obesity, assessed at same visit as the last radiograph during this interval, included body mass index, percent body fat, and body fat distribution.

RESULTS

Both men and women with definite knee OA had higher age adjusted mean levels of body mass index, while women only had higher age adjusted mean levels of percent body fat. Both women and men in the highest tertile of body mass index had significantly increased odds of both definite and bilateral knee OA; women in the middle and highest tertile of percent body fat had significantly increased odds of both definite and bilateral knee OA, and men in the highest tertile of waist-hip ratio had significantly increased odds of bilateral knee OA. After adjusting for body mass index, however, the association of percent body fat and waist-hip ratio with knee OA in women and men, respectively, was no longer significant.

CONCLUSION

These data further extend observations that body weight is associated with both definite and bilateral knee OA in both sexes, and support a stronger contribution of mechanical as opposed to systemic factors to explain this association.

Upper extremity bone mass and osteoarthritis of the knees: data from the Baltimore Longitudinal Study of Aging

To examine the association of upper extremity bone mass with osteoarthritis (OA) of the knee, bilateral standing knee radiographs, taken between 1985 and 1991, in 430 Caucasian male and 266 Caucasian female subjects aged 40 years and above in the Baltimore Longitudinal Study of Aging, were read by one investigator for grade of OA using Kellgren-Lawrence scales. Several measures of upper extremity bone mass, size, and density, including combined cortical thickness (CCT), total width and percentage of cortical area of the second metacarpal, and bone mineral content (BMC), width, and density of the distal third of the left radius measured with single photon absorptiometry, were assessed at the same visit. In univariate analyses, men and women with definite knee OA were significantly older, men had significantly greater radial width, and women had significantly lower bone mass as measured by both CCT and BMC. After adjustment for age and body weight, however, men with knee OA had significantly higher BMC and radial width while neither of these measures of upper extremity bone mass and size was significantly associated with the presence of definite knee OA in women. Neither measure of upper extremity bone density was significantly associated with definite knee OA in either sex. These data suggest that, although men (but not women) with definite knee OA have significantly higher levels of adjusted radial bone mass and size, subjects with knee OA do not have significantly higher levels of adjusted bone mineral density at either upper extremity site.

The relationship of age and gender to prevalence and pattern of radiographic changes of osteoarthritis of the knee: data from Caucasian participants in the Baltimore Longitudinal Study of Aging

The aim of this study was to estimate the prevalence and pattern of radiographic changes of osteoarthritis (OA) of the knee by age and gender in Caucasian participants in the Baltimore Longitudinal Study of Aging. Bilateral standing weight-bearing radiographs of the knee in 547 male and 351 female subjects (aged 20 and above) were read for changes of knee OA using Kellgren-Lawrence and individual features scales. Prevalence of definite (Kellgren-Lawrence grade > or = 2 changes) knee OA increased with advancing age in both sexes. Approximately 50 percent in both sexes showed bilateral involvement. Men aged 59 and below were more likely to have unilateral impairment than men aged 60 and above; no such differences were found in females. These data demonstrate that age and gender influence both the prevalence and pattern of radiographic changes of knee OA.

Serum levels of insulin-like growth factor in subjects with osteoarthritis of the knee. Data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

To examine the relationship between serum levels of insulin-like growth factor 1 (IGF-1) and osteoarthritis (OA) of the knee.

METHODS

Serum IGF-1 levels were compared in 162 male and 101 female subjects age > or = 20 stratified by presence of radiographic changes of OA of the knee.

RESULTS

Mean serum IGF-1 levels were significantly lower in subjects with knee OA; however, after adjustment for age-related changes in IGF-1 levels, these differences were no longer significant.

CONCLUSION

These data fail to support the hypothesis that serum IGF-1 levels are reduced in subjects with OA of the knee independent of the known age-related changes in these levels.

Appendicular bone mass and osteoarthritis of the hands in women: data from the Baltimore Longitudinal Study of Aging

OBJECTIVE

The association of appendicular bone mass with hand osteoarthritis (OA) was studied in 238 Caucasian female participants aged 40 and above in the Baltimore Longitudinal Study of Aging.

METHODS

Bilateral hand radiographs taken between 1978 and 1991 were read for grade of OA using Kellgren-Lawrence scales. Two measures of appendicular bone mass, percent cortical area of the second metacarpal and bone mineral density of the distal radius measured with single photon absorptiometry, were assessed at the same visit.

RESULTS

Bivariate analyses showed that increasing grade of hand OA was associated with increasing age and decreasing bone mass as measured by both techniques. After adjustment for age and body mass index, however, neither of these measures of appendicular bone mass remained significantly associated with grade of hand OA.

CONCLUSION

Our data fail to support the hypothesis that increased appendicular bone mass is associated with hand OA in women.

Skeletal complications of radiation therapy

Radiation therapy is an important modality in the treatment of a wide variety of neoplasms. Skeletal complications of radiation therapy include alterations in bone growth, radiation osteitis with secondary stress fractures, and radiation-induced sarcoma. Routine follow-up of patients who are asymptomatic may show radiation changes that must be differentiated from recurrent disease. In symptomatic patients who are examined for metastatic disease, imaging findings may suggest stress fractures related to prior radiation therapy or, rarely, radiation-induced tumors. Correlation of the clinical presentation, radiation ports, and radiologic findings will often help in the differential diagnosis in these patients.

CT evaluation of amyloidosis: spectrum of disease

Amyloidosis is a rare systemic disease caused by extracellular deposition of an insoluble protein. Although it is usually seen in a systemic form, 10%-20% of cases can be localized. Systemic amyloidosis is subclassified into an idiopathic primary form and a secondary or reactive form. Patients with primary amyloidosis have no underlying condition or disease. Men are affected more than women, and the mean age at presentation is 55-60 years. Some causes of secondary amyloidosis are multiple myeloma (10%-15%), rheumatoid arthritis (20%-25%), tuberculosis (50%), or familial Mediterranean fever (26%-40%). Radiographic studies of 90 patients with biopsy-proved primary or secondary amyloidosis were reviewed. Computed tomographic (CT) scans demonstrated a wide spectrum of disease in the cardiothoracic, gastrointestinal, genitourinary, and musculoskeletal systems. Amyloid deposition simulated both inflammatory and neoplastic conditions. Amorphous or irregular calcifications were occasionally identified within the amyloid deposit. Definitive diagnosis requires biopsy confirmation, as CT findings are nonspecific.

Angioleiomyoma involving the sciatic nerve--CT demonstration. Case report

An angioleiomyoma adjacent to the sciatic nerve was responsible for an 11-year history of pain and dysfunction in the sciatic nerve distribution, which required numerous therapeutic procedures and intermittent use of narcotic analgesics. Diagnosis was finally made when results of a sciatic nerve block suggested possible mechanical compression of the nerve and computed tomography examination of the pelvis was extended further caudal than usual, demonstrating the tumor adjacent to the sciatic nerve near the ischial tuberosity. Only one previous case of nerve dysfunction due to impingement by an angioleiomyoma has been reported.

Reliability of grading scales for individual radiographic features of osteoarthritis of the knee. The Baltimore longitudinal study of aging atlas of knee osteoarthritis

RATIONALE AND OBJECTIVES

The authors present an atlas of individual radiographic features of osteoarthritis of the knee and evaluate the inter- and intra-reader reliability of trained readers using this atlas.

METHODS

Four trained readers graded 30 standing anterior-posterior knee radiographs for eight selected features of osteoarthritis (medial and lateral osteophytes, joint space narrowing, and sclerosis; osteophytes of the tibial spines and chondrocalcinosis) as well as the Kellgren-Lawrence global scale. Inter- and intra-reader reliability were calculated using intraclass correlation coefficients.

RESULTS

For all features except sclerosis and osteophytes of the tibial spines, inter-reader reliability ranged from 0.63 to 0.83, whereas intra-reader reliability ranged from 0.82 to 0.95.

CONCLUSION

Using this atlas, trained readers are reliable in measuring the presence and severity of individual radiographic features of osteoarthritis of the knee. This atlas should be useful in clinical and epidemiologic studies of osteoarthritis of the knee.

Subtle orthopedic fractures: teleradiology workstation versus film interpretation

The purpose of this study was to evaluate whether radiologists perform equally well with plain radiographs or digitized images displayed on a video monitor in interpretation of difficult orthopedic trauma cases. Interpretations with film and those made from a teleradiology system with spatial resolution of 2.35 line pairs per millimeter were compared in 120 difficult cases, 60 with the selected abnormality (ie, fracture or dislocation) and 60 that were control cases. Seven senior radiology residents and one radiology fellow each interpreted 60 randomly ordered cases with the teleradiology system (1,280 x 1,024-pixel monitors) and 60 cases with the original radiographs. The overall accuracy of the readers was 80.6% for film interpretations and 59.6% for teleradiology screen readings (P < .001). Sensitivity was 78.5% for film and 48.8% for on-screen images (P < .001), and specificity was 83.2% for film and 72.3% for on-screen images (P < .025). Receiver operating characteristic analysis showed rejection of the null hypothesis in favor of film interpretation (P < .0049). It was concluded that the teleradiology system was not acceptable for primary diagnostic interpretation of difficult fracture cases.

Obesity and osteoarthritis of the hands in women

The association of obesity and body fat distribution with hand osteoarthritis was studied in 317 Caucasian female subjects aged 40 years and above in the Baltimore Longitudinal Study of Aging. Bilateral hand radiographs taken between 1978 and 1991 were read by one investigator for grade of osteoarthritis using Kellgren-Lawrence scales. Possible risk factors, assessed at same visit as the first radiograph during this interval, included age and measures of obesity, per cent body fat, and fat distribution. Results of bivariate analyses showed that increasing grade of hand osteoarthritis was associated with increasing age, greater mean levels of waist-hip ratio and per cent body fat; there was no association with body mass index. After adjustment for age, however, none of these independent variables remained significantly associated with grade of hand osteoarthritis. These data fail to support hypotheses that measures of obesity are associated with hand osteoarthritis in women independent of their known age-related changes.

Effect of image display on the quality of multiplanar reconstruction of computed tomography data

RATIONALE AND OBJECTIVES

The objective of this study is to determine whether the use of edge-enhancement post-processing filters was useful in the computed tomographic (CT) multiplanar evaluation of skeletal trauma.

METHODS

The group consisted of a series of 10 cases of skeletal trauma (3 cases of acetabular fractures, 3 cases of tibial plateau fractures, and 4 cases of ankle fractures). All patients had a CT scan using a scan protocol of 4-mm collimation and 3-mm interscan interval. All transaxial images were reconstructed with both a standard algorithm and with an edge-enhancement filter. The images from each group were then reconstructed into coronal and sagittal planes. Three individuals independently reviewed each case and compared image pairs to determine whether images using an edge-enhancement filter were of better or worse quality than standard images.

RESULTS

The reviewers found the images with edge-enhancement to be equal to or superior to images reconstructed with a standard algorithm, regardless of the image plane chosen. This bias was especially true in cases of hip and ankle trauma.

CONCLUSIONS

When CT supplemented by multiplanar imaging is used in patients with skeletal trauma, image data reconstruction should be done with an edge-enhancement filter to optimize image detail.

Denervation of the immature porcine lung impairs normal airway development

Reimplantation or allotransplantation of the immature porcine left lower lobe results in long-term functional dynamic airway obstruction that is associated with abnormally small distal airways. We have attributed this small airway size to bronchoconstriction resulting from chronic denervation rather than to impaired airway growth. To further investigate these findings, we transplanted mature left lower lobes from adult pigs into young piglets after left pneumonectomy. After approximately 12 weeks of somatic growth, the lobes were harvested and fixed through the airways with formalin. Cross-sectional areas of terminal, noncartilaginous airways from the lung periphery were traced on a video monitor. Five groups were examined: control innervated mature left lower lobes, innervated left lower lobes subjected to compensatory growth after left upper lobectomy at approximately 9 weeks of age, mature left lower lobe transplants, reimplanted immature left lower lobe autografts, and transplanted immature left lower lobe allografts. Unlike the immature porcine lobe, transplantation of the mature porcine lobe does not result in abnormally small airways. The small airways seen after transplantation or reimplantation of the immature porcine lobe are likely, therefore, to be due to impaired airway development and not to bronchoconstriction caused by denervation.

Comparison of helical and serial CT with regard to three-dimensional imaging of musculoskeletal anatomy

To test the hypothesis that helical computed tomographic (CT) scans provide three-dimensional images as good as or better than those provided by serial CT, two objects were used to study the effects of helical CT: an angled cylindrical bone phantom and a human cadaveric femur specimen with a simulated fracture 1 mm wide. Both objects were immersed in a water bath, and a series of helical and serial CT scans were obtained with various parameters. Volumetric rendering was applied to the resultant data sets to create three-dimensional images, which three radiologists reviewed in a blinded manner to rate their fidelity, accuracy, and diagnostic usefulness. As expected, the images obtained with thin collimation and small intersection spacing or slow table movement were considered superior. Helical and serial CT data acquired with similar parameters were similar in quality, but helical CT is approximately five times faster than serial CT; hence, it is possible to use thinner collimation and obtain more sectional data with helical CT.

Growth potential of porcine reduced-size mature pulmonary lobar transplants

The use of mature pulmonary lobes for pediatric lung transplantation has recently been described. Successful application of this technique could help alleviate the pediatric donor lung shortage. Whether an already mature lobe can grow by forming new alveolar units after transplantation into a developing recipient is not known. We therefore measured functional residual capacity, fixed lung volume and weight, alveolar size and air space volume percent, and total number of alveoli in mature left lower lobe porcine lung transplants 12 weeks after transplantation into growing piglets. Comparisons were made with nontransplanted mature left lower lobes to determine if functional or morphologic growth had occurred after transplantation. The transplanted and control lobes were all taken from 6-month-old animals (mean body weight 105 +/- 4 kg). Recipients of the transplanted lobes were 9 weeks old and weighed 22 +/- 2 kg. By the end of the 12-week holding period, the recipient animals increased their body weight approximately fourfold (85 +/- 4 kg). No significant differences were seen in functional residual capacity or morphologic analysis of total alveolar number and alveolar size between the transplanted and nontransplanted lobes (p = not significant). Although the reduced-size mature porcine lobar transplants did not display a significant increase in either functional residual capacity or total alveolar number, there was significant growth of the transplanted mature lobes as determined by fixed volume and total lobar weight (p < or = 0.05 versus control animals).

Computed tomography appearance of bone metastases of leiomyosarcoma

Bone lesions in leiomyosarcoma are uncommon. When encountered, they are usually a late manifestation of disease seen in the setting of widespread systemic metastases. We present five cases of metastatic leiomyosarcoma, including one in which a bone lesion predated detection of a primary gastric leiomyosarcoma and one in which bone metastases signaled disease recurrence. Computed tomography in 14 of 16 osseous leiomyosarcomas demonstrated a lytic, non-expansile pattern.

Phantom for use in lung biopsy training

A phantom to assist in the teaching of fluoroscopically guided transthoracic needle biopsy of pulmonary lesions was designed. The phantom was constructed of an aluminum and rubber skeleton, wood hemidiaphragms and heart, and foam rubber lungs and was covered with foam rubber. Modeling clay was used to simulate lesions. The authors believe the phantom is of value in helping increase the confidence and proficiency of the radiologist during the first few biopsy procedures with an actual patient.

Tumoral calcinosis causing bone erosion in a renal dialysis patient

Tumoral calcinosis is a rare disorder manifest by large calcific periarticular masses. Associated bone destruction has been described previously only once. The radiographic and computed tomographic (CT) findings of bone erosion in a case of tumoral calcinosis in a renal dialysis patient are presented. Although the presence of bone destruction may suggest a neoplasm, it does not exclude the diagnosis of tumoral calcinosis.

Sex differences in geometry of the femoral neck with aging: a structural analysis of bone mineral data

The greater hip fracture rate among elderly women is generally ascribed to differences in femoral neck strength between the sexes. Strength of a given bone is a function of both its material properties and the magnitudes of mechanical stresses within it. This study examined the hypothesis that these apparent strength differences between the sexes are due to dissimilarities in the restructuring of the femoral neck with age, which result in higher stresses in elderly women. Using Hip Strength Analysis, a computer program developed by the authors, femoral neck cross-sectional geometric properties for stress analyses were derived from bone mineral image data of 409 community living, white subjects ranging from 19 to 93 years of age. Though both sexes show declines in femoral neck bone mineral density (BMD) and cross-sectional area with age, only females show a decline in the cross-sectional moment of inertia (CSMI, a geometric index of bone rigidity). The lack of decline in male CSMI appears to be a result of a small but significant increase in femoral neck girth. Similar age-related changes have been observed in the femoral shaft by others. The net effect of these observed changes is that mechanical stresses in the femoral neck of females appear to increase at three times the rate per decade of those of males. These results lend support to the hypothesis that the higher fracture rate in elderly women is due, at least in part, to elevated levels of mechanical stress, resulting from a combination of greater bone loss and less compensatory geometric restructuring with age.

Articular and diaphyseal remodeling of the proximal femur with changes in body mass in adults

Proximal femoral dimensions were measured from radiographs of 80 living subjects whose current body weight and body weight at initial skeletal maturity (18 years) could be ascertained. Results generally support the hypothesis that articular size does not change in response to changes in mechanical loading (body weight) in adults, while diaphyseal cross-sectional size does. This can be explained by considering the different bone remodeling constraints characteristic of largely trabecular bone regions (articulations) and largely compact cortical bone regions (diaphyses). The femoral neck shows a pattern apparently intermediate between the two, consistent with its structure. When the additional statistical "noise" created by an essentially static femoral head size is accounted for, the present study supports other studies that have demonstrated rather marked positive allometry in femoral articular and shaft cross-sectional dimensions to body mass among adult humans. Body weight prediction equations developed from these data give reasonable results for modern U.S. samples, with average percent prediction errors of about 10%-16% for individual weights and about 2% for sample mean weights using the shaft dimension equations. When predicting body weight from femoral head size in earlier human samples, a downward correction factor of about 10% is suggested to account for the increased adiposity of very recent U.S. adults.