Accuracy of office-based ultrasonography of the shoulder for the diagnosis of rotator cuff tears.

BACKGROUND: This prospective multi-institutional study was designed to define the accuracy of ultrasonography, when performed in an orthopaedic surgeon's office, for the diagnosis of rotator cuff tears. METHODS: An anatomic diagnosis and a treatment plan were made on the basis of office-based shoulder ultrasonography, physical examination, and radiographs for ninety-eight patients (ninety-nine shoulders) with a clinical diagnosis of a rotator-cuff-related problem. The results of the ultrasonographic studies were then compared with the results of magnetic resonance imaging and the operative findings. RESULTS: Office-based ultrasonography led to the correct diagnosis for thirty-seven (88%) of forty-two shoulders with a full-thickness rotator cuff tear or both full and partial-thickness tears, twenty-six (70%) of thirty-seven shoulders with a partial-thickness rotator cuff tear only, and sixteen (80%) of twenty shoulders with normal tendons. In no case was the surgical approach (open or arthroscopic) that had been planned on the basis of the ultrasonography altered by the operative findings, but the operative finding of a full-thickness tear resulted in an arthroscopic cuff repair in four shoulders. Magnetic resonance imaging led to the correct diagnosis for forty (95%) of forty-two shoulders with a full-thickness rotator cuff tear or both full and partial-thickness rotator cuff tears, twenty-seven (73%) of thirty-seven shoulders with only a partial-thickness tear, and fifteen (75%) of twenty shoulders with normal tendons. There were no significant differences between magnetic resonance imaging and ultrasonography with regard to the correct identification of a full-thickness tear or its size. The sensitivity of ultrasonography for detecting tear size in the anterior-posterior dimension was 86% (95% confidence interval, 71% to 95%), and that of magnetic resonance imaging was 93% (95% confidence interval, 81% to 99%) (p = 0.26). The sensitivity of ultrasonography for detecting tear size in the medial-lateral dimension was 83% (95% confidence interval, 69% to 93%), and that of magnetic resonance imaging was 88% (95% confidence interval, 74% to 96%) (p = 0.41). CONCLUSIONS: A well-trained office staff and an experienced orthopaedic surgeon can effectively utilize ultrasonography, in conjunction with clinical examination and a review of shoulder radiographs, to accurately diagnose the extent of rotator cuff tears in patients suspected of having such tears. Errors in diagnosis made on the basis of ultrasonography most often consist of an inability to distinguish between partial and full-thickness tears that are approximately 1 cm in size. In this study, such errors did not significantly affect the planned surgical approach.

Evaluation of posterior tibial pathology: comparison of sonography and MR imaging.

OBJECTIVE: To compare the results of sonographic (US) and magnetic resonance (MR) imaging in detecting pathology of the posterior tibial tendon (PTT) in patients with PTT dysfunction. DESIGN: Twenty-two ankles that were clinically suspected by the orthopedic surgeon to have PTT dysfunction were evaluated with US (10 MHz linear-array transducer) and 1.5 T MR examinations within the same day. The US and MR studies were conducted and interpreted by two sonologists and two musculoskeletal radiologists who were masked to the results of the other study. Four patients had bilateral studies. Classic clinical findings were utilized as a standard reference in staging PTT dysfunction. PATIENTS: Eighteen women (mean age 61 years, age range 39-86 years). RESULTS: Based on a commonly accepted staging system for PTT dysfunction, 6 ankles were classified as stage I, 11 ankles as stage II, and 5 ankles as stage III. All stage I ankles were interpreted as having an intact PTT by both MR imaging and US. In the stage II and III tendons, MR imaging demonstrated PTT tears in 12 of 22 examinations, including 11 partial tears and 1 complete tear. US demonstrated PTT tears in 8 of 22 examinations, including 8 partial tears and no complete tears. The findings of US and MR imaging were consistent in 17 of 22 cases (77%). The five inconsistencies were as follows: in 4 cases, US reported tendinosis when MR imaging interpreted partial tears (no change in management); in one case, US diagnosed a partial tear when MR reported a complete tear of the PTT (no change in management because the clinical findings were more consistent with a partial tear). CONCLUSIONS: In this study, US and MR imaging of the PTT were concordant in the majority of cases. US was slightly less sensitive than MR imaging for PTT pathology, but these discrepancies did not affect clinical management.

Power Doppler assessment of vascular changes during fracture treatment with low-intensity ultrasound.

OBJECTIVE: To study the use of power Doppler sonography for assessing changes in vascularity during treatment of fracture sites with low-intensity ultrasound. METHODS: In 6 dogs (3 pairs), subcutaneous dissection of the midshaft of the ulna allowed symmetrical osteotomies to be made with a reciprocation saw. Three dogs were treated and 3 were used as controls. The fracture site was subjected to 1.5-MHz low-intensity ultrasound (30 mW/cm2) for 20 minutes daily from a therapeutic ultrasonic device. Gray scale sonography was performed to evaluate the fracture site. Power Doppler sonography was used to assess flow patterns at the fracture site and surrounding soft tissue. A sonographic contrast agent was administered intravenously. The dose was 0.2 mL/kg. RESULTS: Power Doppler sonography showed an increase in flow around the fracture site in the treated dogs compared with that in control dogs. Color pixel values on day 7 were 3-fold higher in treated legs than control legs and on day 11 were 33% higher in treated legs than control legs. Enhancement after contrast agent administration was consistently higher in treated legs than control legs. CONCLUSIONS: Power Doppler sonography showed increased vascularity around the fracture sites in treated dogs with and without contrast agent administration.

Comparing contrast-enhanced ultrasound to immunohistochemical markers of angiogenesis in a human melanoma xenograft model: preliminary results.

This study compared contrast-enhanced ultrasound (US) measures of tumor neovascularity with molecular markers of angiogenesis in a human melanoma xenograft model. A total of 14 mice were implanted with a human melanoma cell line (WM-9) in the thigh. After 2 to 3 weeks, a tumor, approximately 12 mm in diameter, developed. The US contrast agent Optison (Mallinckrodt, St. Louis, MO) was injected in a tail vein (dose: 0.4 to 0.6 mL/kg). Power Doppler and pulse-inversion harmonic imaging (HI) were performed with an Elegra scanner (Siemens Medical Systems, Issaquah, WA) and a 7.5 MHz linear array. Frame-rates of 30 Hz and 0.5 Hz (intermittent imaging) were used for pulse-inversion HI. After surgical removal, specimens were sectioned in the same planes as the US images. Immunohistochemical stains for endothelial cells (CD31), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and cyclooxygenase-2 (COX-2) were performed. Two observers graded the stains (for intensity and percent area), and two other observers graded the US imaging modes (for fractional tumor neovascularity) on the same scale from 0 to 3. Of the 14 mice, 4 failed for technical reasons (i.e., n = 10). Linear regressions indicated statistically significant correlations between percent area stained with COX-2 and power Doppler (r = -0.789; p < 0.01), as well as intermittent pulse-inversion HI (r = -0.795; p < 0.05). There was a trend toward significance between percent area stained with VEGF and intermittent pulse-inversion HI (r = -0.720; 0.05 < p < 0.10). No other comparisons were significant. In conclusion, contrast-enhanced US measures of tumor neovascularity in a human melanoma xenograft model appear to provide a noninvasive marker of angiogenesis corresponding to expression of COX-2. However, the sample size of this study is small and, until further studies have been conducted, these conclusions are preliminary.

Contrast-enhanced two- and three-dimensional sonography for evaluation of intra-abdominal hemorrhage.

OBJECTIVE: To determine whether a contrast agent enhances sonographic detection of bleeding sites in the abdomen and whether contrast-enhanced three-dimensional sonography provides additional information compared with contrast-enhanced two-dimensional sonography. METHODS: Bleeding sites were created within the livers (n = 3), spleens (n = 5), and kidneys (n = 3) of 3 dogs. A sonographic contrast agent with vascular and parenchymal enhancement capabilities was administered intravenously at a dose of 0.02 mL/kg. Before and after each contrast agent injection, the bleeding sites were imaged with two- and three-dimensional sonography in gray scale harmonic imaging and color flow modes. Sonographic findings were compared with gross pathologic findings. RESULTS: Noncontrast-enhanced sonography was not able to show the specific location of the active bleeding in any of the organs evaluated. The contrast agent enhanced the sonographic detection of blood flow in normal vessels and extravasated blood from damaged vessels or organs in all cases. Intrasplenic and intrahepatic hematomas were better identified on delayed imaging sequences because there was marked enhancement of the normal parenchyma, whereas the hematomas remained unenhanced. Reconstructed three-dimensional sonography showed spatial relationships of the bleeding sites and surrounding structures. Gross pathologic findings were consistent with the contrast-enhanced sonographic results. CONCLUSIONS: Contrast-enhanced sonography improves the detection and evaluation of abdominal bleeding sites. Contrast-enhanced three-dimensional sonography appears to provide additional information when compared with two-dimensional sonography.

Hepatic tumor detection: MR imaging and conventional US versus pulse-inversion harmonic US of NC100100 during its reticuloendothelial system-specific phase.

PURPOSE: To compare conventional ultrasonography (US) and magnetic resonance (MR) imaging with contrast agent-enhanced US for detection of VX-2 liver tumors in rabbits. MATERIALS AND METHODS: Conventional gray-scale liver US was performed in 65 rabbits, 38 of which had VX-2 hepatic tumor implants. Twenty minutes after contrast agent injection, gray-scale pulse-inversion harmonic US images of the liver-specific phase were obtained. Following sacrifice of the animals, T1- and T2-weighted MR imaging was performed at 4-mm intervals. Pathologic analysis was performed as the reference standard. The capability of each imaging modality to correctly depict tumor presence or absence and the number of tumors was compared. RESULTS: Conventional US correctly depicted the presence or absence of tumors in 54 rabbits, for an accuracy of 83%, sensitivity of 71%, and specificity of 100%. With contrast-enhanced US, accuracy increased to 92% (60 correct cases); sensitivity, to 87%; and specificity, to 100%. MR imaging facilitated 56 correct diagnoses, for an accuracy of 86%, sensitivity of 82%, and specificity of 93%. There was a marginally significant difference between US with and US without contrast agent (P =.07) but not between MR imaging and contrast-enhanced US (P > or = .34). When the numbers of correctly detected tumors were compared, contrast-enhanced US performed significantly better than MR imaging (P =.02) and conventional US (P =.04). CONCLUSION: There was no significant difference between contrast-enhanced US and MR imaging in the detection of hepatic tumors, whereas contrast-enhanced US had the highest accuracy (92%) of the three modalities studied.