Pamela J. Lund

Ultrasonographic imaging of the hand and wrist in rheumatoid arthritis

ObjectiveTo assess ultrasound findings in patients with rheumatoid arthritis affecting the hand and wrist compared to normal volunteers.DesignMetacarpophalangeal and carpal articulations were imaged ultrasonically. Two readers reviewed static images for synovial, cartilaginous, and bony abnormalities using severity and probability scales. Ultrasound findings were correlated with disease activity.PatientsTen normal volunteers and 29 patients with known rheumatoid arthritis.ResultsSynovial abnormalities and erosions were most commonly identified in the rheumatoid hand and wrist (p<0.01). Criteria used for normal and abnormal cartilage did not predict normal and disease states. Significant differences in synovial abnormalities and erosions were observed between the inactive and mildly active disease groups as well as the active and mildly active disease groups (p<0.01).ConclusionUltrasound can detect abnormalities of the hand and wrist in patients with rheumatoid arthritis compared to normal volunteers. Normal articular anatomy is well demonstrated ultrasonically.

How the new hologic hip normal reference values affect the densitometric diagnosis of osteoporosis

Abstract: In February 1997, Hologic supplied new software to all QDR dual-energy X-ray absorptiometry (DXA) machines replacing the previous femoral normative reference database with the NHANES III normative data. In addition to changing the normative database (and therefore T-scores) for all regions of the hip, the new software has changed the primary region of interest from the femoral neck to the total hip. In the present study we examined how these changes influence the densitometric diagnosis of osteoporosis in a large clinical referral population (n= 2311, mean age 62.7 years). The patients had spine and hip DXA performed at either of two centers using a Hologic QDR-2000 over a 4-year period. T-scores were derived for each patient using both previous and current young normal reference databases. Intraindividual differences in T-scores were calculated. The prevalence of osteoporosis based on the two normative databases and the difference between the prevalence was calculated for each skeletal site. The average paired difference between current and previous T-scores at femoral neck is 0.64, the difference increasing with age. Using the new normative database, the percentage of osteoporotic patients decreases from 49% of all patients at the femoral neck to 28% at the femoral neck and 20% at the total hip. In conclusion, the densitometric diagnosis of osteoporosis will be affected in a significant proportion of women as a result of the implementation of the new hip normative database supplied by Hologic. Whether this will translate into fewer patients being treated remains to be seen.

Gas-filled lipid bilayers as ultrasound contrast agents

Unger E, Shen D, Fritz T, Kulik B, Lund P, Wu G-L, Yel-lowhair D, Ramaswami R, Matsunaga T. Gas-filled lipid bilayers as ultrasound contrast agents. Invest Radiol 1994;29: S134–S136.

Differences in Time to Interpretation for Evaluation of Bone Radiographs with Monitor and Film Viewing

RATIONALE AND OBJECTIVES The authors evaluated how observers search hard-copy versus soft-copy images to determine why viewing times are longer for images displayed on a monitor. METHODS Twenty-seven nonconsecutive bone-trauma computed radiographs were collected from the routine emergency practice. Eye positions of three bone radiologists and three orthopedic surgeons were recorded as they searched images on a view box and digital images at a workstation. RESULTS Overall viewing time was longer for images displayed on a monitor. Time to first fixate a lesion and true-negative dwell times were significantly longer with the monitor than with the film. Absolute numbers of clusters and dwell times were greater for diagnostic image areas on the monitor than on the film. Twenty percent of the clusters for images viewed on the monitor were on the image-processing menu. CONCLUSION The amount and type of information that is processed during search is different when images are viewed on a monitor rather than on film.

Receiver operating characteristic evaluation of computer display of adult portable chest radiographs.

RATIONALE AND OBJECTIVESThe suitability of using an image console monitor for interpretation of adult portable chest radiographs was evaluated with receiver operating characteristic (ROC) analysis and subjective techniques. METHODSRadiologists read 80 chest images, once on a display monitor and once on computed radiography film, for the presence or absence of pneumothorax or atelectasis. Judgments of correct or incorrect positions of tubes and lines were reported, and total viewing time was recorded. RESULTSA statistically significant difference was found in favor of monitor reading for detection of pneumothoraces. Atelectasis detection also was higher with monitor reading, but the difference did not reach statistical significance. Tube/line judgments were equivalent for both modes. Total viewing time was approximately 1 minute longer per image with the monitor. CONCLUSIONSViewing computed radiography images on a workstation monitor does not seem to affect diagnostic accuracy compared with film viewing. Preset image defaults tailored to the individual radiologist could decrease total viewing time to acceptable levels.

Gas-filled liposomes as echocardiographic contrast agents in rabbits with myocardial infarcts.

RATIONALE AND OBJECTIVES The authors evaluated gas-filled liposomes as echocardiographic contrast agents in rabbits with myocardial infarcts. METHODS Ten rabbits underwent ligation of the left anterior descending coronary artery. Five animals underwent echocardiography before and after production of myocardial infarct (MI) and four animals had post-MI imaging only. In either case, images were obtained before and after injection of a single dose of 1 mL of gas-filed liposomes. Three radiologists blinded to clinical information reviewed the pre- and postcontrast images and assessed endomyocardial border definition, wall motion, confidence levels for normal versus abnormal wall motion and visualization of papillary muscle and mitral valve. RESULTS Postcontrast scans showed significant improvement (P < .05) in endomyocardial border definition, visualization of wall motion, papillary muscle and mitral valve as well as increased reader confidence level. CONCLUSIONS These results are encouraging and suggest that gas-filled liposomes may be a useful contrast agent for echocardiography.

Gas fIIIed lipid bilayers as imaging contrast agents

AbstractGas bubbles are highly efficient reflectors of sound and are therefore useful as contrast agents for diagnostic ultrasound. In general, in order to pass through the pulmonary circulation and provide contrast for the systemic circulation the gas bubbles must be of defined diameter and stabilized by a coating material. Our group has developed gas bubbles which are stabilized within lipid bilayers. These bubbles may be formed with stable size and gas content. In vivo studies in rabbit and porcine models show sustained ventricular enhancement, increased arterial doppler signal following intravenous injection and myocardial perfusion enhancement following injection into the aortic root of pigs. Preliminary toxicity studies suggest that the therapeutic index (LD50 dose divided by imaging dose) is greater than 400 to 1. For therapy, these agents may be used to increase the capture of ultrasonic energy for hyperthermia to augment local tissue heating. An exciting new class of agents based upon gas fIIIed ...

Comparison of conventional and computed radiography: Assessment of image quality and reader performance in skeletal extremity trauma

RATIONALE AND OBJECTIVES Reader performance and image quality wee assessed for standard film, computed film, and computer monitor radiography viewing formats in the evaluation of skeletal extremity trauma. MATERIALS AND METHODS Three radiologists and three orthopedic surgeons interpreted 27 skeletal radiographs obtained with equivalent technical parameters. Readers evaluated standard film, computed film, and computer monitor formats randomly for fracture and soft-tissue abnormalities. Sessions were videotaped, and eye motion was recorded. RESULTS No statistically significant differences were found between image formats for true-positive or false-positive findings of trauma indicators. Findings were classified as false-negative based on eye position fixation times. Search errors (lesion not fixated) accounted for 21.7%, 20.6% and 17.1% of false-negative errors with the computer monitor, computed film, and standard film formats, respectively. Combined recognition errors and decision errors were 78.3%, 79.4%, and 82.9%, respectively. Viewing times were longest for the computer monitor images (P < .001). Image quality, contrast, and sharpness were rated highest for computed radiographs (P = .001). Radiologists had a higher true-positive decision rate than orthopedic surgeons (P = .03). CONCLUSION No statistically significant differences were seen in reader performance among viewing formats. The computed film format received the highest quality rating, and workstation viewing times were longest.

Magnetic resonance imaging in coccidioidal arthritis

Abstract Objective. The authors assessed the MRI findings of appendicular coccidioidal arthritis. Design. T1- and T2-weighted MR images of affected joints, both with and without intravenous gadopentetate dimeglumine, were performed in nine adult patients (ten studies) and evaluated by three masted readers, using a four-point certainty scale for: synovial abnormality, articular cartilage loss, subarticular bone loss, abnormal marrow signal, enhancement of osseous and articular structures, and assessment of disease activity. Findings were correlated with biopsy results or clinical course. Results. Eight patients had active and one had inactive arthritis, involving the knee (five patients), ankle (two patients), and elbow (one patient). Synovial complex was the most common finding in active arthritis (P<0.025). Cartilage and subarticular bone loss were seen 56% and 89% of patients with active disease, respectively. Abnormal marrow signal was uncommon (two patients). All cases showed synovial and/or osseus enhancement. Conclusions. MRI findings in coccidiodal arthritis are described. Enhancement of thickened synovium and erosions was seen after intravenous gadopentetate.

Femoral neck buttressing : a radiographic and histologic analysis

Abstract Objective. To examine the incidence, radiographic and histologic findings of medial femoral neck buttressing in a consecutive group of patients undergoing total hip arthroplasty. Design. Biomechanical parameters were evaluated on standard anteroposterior pelvic radiographs of 113 patients prior to hip replacement surgery. Demographic information on all patients was reviewed and histologic evaluation was performed on specimens obtained at the time of surgery. Results. The incidence of medial femoral neck buttressing was found to be 50% in a consecutive series of patients undergoing total hip arthroplasty. The incidence was slightly higher in women (56% vs 41%). Patients with buttressing had increased neck-shaft angles and smaller femoral neck diameters than were seen in patients without buttressing. Histologic evaluation demonstrated that the buttress resulted from deposition bone by the periosteum on the femoral neck in the absence of any evidence of femoral neck fracture. Conclusion. It would appear that femoral neck buttressing occurs in response to increased joint reactive forces seen at the hip being transmitted through the femoral neck. The increased joint reactive force can be related to the increased neck shaft angle seen in patients with buttressing.