Review of Innovative Ultrasound Techniques forthe Diagnosis of Musculoskeletal Injury

Natasha M. Werpy, DVM, Diplomate ACVR*; and Laura Axiak, DVM

Ultrasound examination with the use of standard ultrasound and angle contrast (on- and off-beamangles) ultrasound techniques, as well as imaging the non–weight bearing limb or changing limbposition, can contribute valuable information to the diagnosis of musculoskeletal injury. In addition,these techniques may facilitate visualization of an injury by use of ultrasound after magneticresonance imaging examination. Therefore, the lesion can subsequently be monitored with ultra-sound. Authors’ address: 9418 SW 67th Drive, Gainesville, FL 32608; e-mail: equinedxim@yahoo.com.*Corresponding and presenting author. © 2013 AAEP.

1. Introduction

Multiple imaging modalities are available to aid inthe diagnosis of tendon and ligament injury.1 Of-ten, a combination of modalities is used to fullycharacterize musculoskeletal injury. With the ad-vancement and increasing availability of computedtomography (CT) and magnetic resonance imaging(MRI), diagnoses are commonly made through theuse of advanced imaging after negative ultrasono-graphic or radiographic studies are performed.Retrospectively, with knowledge of the location andcharacter of the lesion, many injuries can subse-quently be identified through the use of ultrasonog-raphy or radiography. This process contributes tothe development of improved imaging skills, and, incertain cases, the diagnosis can be subsequentlyachieved with the use of ultrasound and/or radio-graphs without the benefit of advanced imaging.CT and MRI may require general anesthesia and asignificant financial investment from the client.Ultrasonography is readily accessible, cost-effective,and can easily be performed in the field. Thesequalities make it a highly advantageous imaging

modality and facilitate its use for sequential exam-inations. Sequential examinations are extremelyuseful to assess lesions over time and healing re-sponses on the basis of administered therapeutics.However, ultrasound is extremely operator-depen-dent, relying on the training, skill, and operatorexperience to obtain diagnostic images. Edu-cated ultrasonographers understand how the ul-trasound beam propagates in normal tissue ascompared with abnormal tissue. They are able todifferentiate injury from artifact and have a prac-tical knowledge of the limitations of ultrasound asan imaging modality.2 The purpose of this re-view is to describe the use of angle contrast (on-and off-beam angles) ultrasound techniques, todiscuss the interpretation of these images, and todemonstrate the benefits of comparing images ac-quired with the limb in weight bearing and non–weight bearing positions. These ultrasoundtechniques will be presented in combination withother modalities to provide a better appreciation ofultrasonographic capabilities and how they can beused for the diagnosis of musculoskeletal injury.

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NOTES

Anatomic VariationThe most reliably identified tendon and ligamentinjuries through the use of ultrasound include en-largement, enthesopathies, and hypoechogenicityindicating inflammation, edema, and/or fiber disrup-tion. These injuries can be described by the struc-ture involved, their exact locations, the extent ofinjury, and amount of damage. Anatomic knowl-edge of the structures being examined in both thetransverse and longitudinal planes is essential forthe diagnosis of these injuries and to recognize ar-tifacts. A successful ultrasonographer is familiarwith the normal anatomic appearance (size, shape,position, and textural quality) of each structure ex-amined as well as any anatomic variations.3

Tendons and ligaments are of similar compositionand differ in their structural orientation. The fi-bers are more uniformly distributed in tendons andare more multi-directional in ligaments.4 Normalanatomic variation in the fiber orientation withinligaments causes non-uniform echogenicity on ultra-sound examination, such as in the collateral liga-ments of the distal interphalangeal joint (Fig. 1).5,6

This variation in fiber orientation also causes magicangle artifact within ligaments on MR images.5,7

When regions of decreased echogenicity are identi-fied in collateral ligaments with multi-directionalfibers, multiple ultrasound beam angles are thenused at the same level to create echogenicity in thedifferent fiber bundles (Fig. 2). In addition, com-parison to the contralateral limb can be helpfulwhen attempting to differentiate normal anatomicvariation from a clinically significant abnormality.

Identification of Lesions After Advanced ImagingIn most cases, once a lesion has been identifiedthrough the use of advanced imaging, it can readilybe determined if the lesion should be visible throughthe use of traditional imaging modalities. This pro-cess increases our knowledge of anatomy and iden-tifies structures or artifacts that can preventvisualization of a lesion when traditional imagingmodalities are used. Retrospectively evaluatingthese lesions with the use of ultrasonography leadsto the development of new skills and techniques.In certain cases, this process allows the diagnosis ofthese lesions going forward, without the benefit ofadvanced imaging. Several innovative ultrasoundtechniques have been validated through the use ofadvanced imaging and correlating the anatomic ap-pearance of structures with gross and histologicevaluation.

Anisotropy: Understanding the Influence ofUltrasound Beam AngleFiber disruption and fluid accumulation in tendonsand ligaments can be apparent with ultrasound.In contrast, other types of fiber injury can remainechogenic on ultrasound images despite clinicallysignificant abnormalities. This discrepancy in thediagnostic capability of ultrasound during certain

stages or types of injury may result in an ultrasoundappearance that is not markedly different from nor-mal, which can make certain types of injury chal-lenging to diagnose with the use of this modality.Tissue echogenicity is determined by the acousticproperties (acoustic impedances) of that tissue.Variations in the acoustic properties and the result-ing changes in echogenicity are used to differentiatenormal and injured tissues.8

The term “anisotropic” in regard to ultrasonogra-phy simply means that the tissue exhibits differentacoustic impedances when imaged at different an-gles. This principle is illustrated when imaging theflexor tendons in the transverse plane. When theprobe angle is adjusted proximally or distally toobtain maximum echogenicity, the anisotropic prop-erties of the tendons are demonstrated (Fig. 3).Obtaining a quality image in tissues of varyingacoustic impedances is dependent on the ability of

Fig. 1. Frontal plane section of the foot at the level of the distalinterphalangeal joint collateral ligament. The varying orienta-tion of fibers in the collateral ligament of the distal interphalan-geal can be seen from the origin (bracket) on the middle phalanxand as the ligament extends distally to the insertion (box) at thefossae of the distal phalanx. In addition, there is variation in thefiber orientation at the level of the middle phalanx (within thebracket). These anatomic characteristics affecting the appear-ance of this ligament are imaged with ultrasound, MRI, and CT.

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Fig. 3. Transverse ultrasound images of the superficial and deep digital flexor tendons at the level of the metacarpus thatdemonstrate the principle of anisotropy, or the dependency of echogenicity on beam angle. A, Ultrasound beam is perpendicular tothe tendons creating diffuse echogenicity within the tendon. B, Ultrasound beam is off-angle or oblique incidence to the tendons.In this image, the echogenicity of the tendons are reduced compared with that in A. However, the tendon margins remain echogenic.Medial is to the left of each image.

Fig. 2. Transverse ultrasound images (A, C) of a collateral ligament of the distal interphalangeal joint at the level of the middlephalanx with two different beam orientations and the corresponding MR images at the same level (B, D). On the ultrasound images,the central aspect of the ligament changes in echogenicity on the basis of the ultrasound beam angle. The appearance is represen-tative of bundles of fibers with different orientations. This difference in fiber bundle orientation also results in the changes in signalintensity present on the MR images when the position of the limb is altered. The recognition of this ultrasound appearance was theresult of the initial identification of the different fiber bundle orientation on MRI. Therefore, MRI was used to develop a moreaccurate method for evaluation of ultrasound images of the collateral ligaments of the distal interphalangeal joint at this level.Dorsal is to the left of each image.

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the ultrasonographer to appropriately adjust themachine and settings (transducer, frequency, depth,

focal zones, and gain). In addition, altering thedirection of the beam angle is necessary to assess

Fig. 4. Transverse ultrasound images (A, B) of the hind proximal suspensory ligament that were acquired with the horse resting onits toe. The beam was directed toward the plantar margin of the third metatarsal bone by use of on-angle (A) and off-angle (B)ultrasound beam orientations. C, Corresponding MR image at the same level. Note the adipose tissue and muscle bundles remainechogenic regardless of beam angle. Similar to that shown in Fig. 3, the ligament fibers are echogenic when the ultrasound beam ison-angle or perpendicular to the long axis of the tendon and are subsequently reduced in echogenicity when the ultrasound beam isoff-angle. The peripheral margin of the ligament is visible when the ultrasound beam is off-angle.

Fig. 5. Probe position and resulting ultrasound images for angle contrast (on- and off-beam angles) ultrasound technique whenimaging the proximal suspensory ligament in the forelimb. A, Ultrasound beam is perpendicular to the proximal suspensoryligament in the metacarpus. B, Corresponding transverse ultrasound image of the suspensory ligament by use of this perpendicularbeam angle. C, Ultrasound beam is oblique incidence to the proximal suspensory ligament. A change in hand position with anglechange is required to achieve this image. D, Corresponding transverse ultrasound image of the suspensory ligament with thisoff-angle technique. Note the hypoechogenicity in the ligament fibers of image D and the hyperechogenicity of the muscle and fatbundles in the suspensory ligament regardless of beam angle (B, D).

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the normal anatomy and to identify pathologicchange. On the basis of the principles of aniso-tropy, the off-angle or oblique-incidence ultrasoundtechnique can be used in structures with compli-cated anatomy to further elucidate the nature of thetissue and any associated anatomic characteristicsas well as to aid in the diagnosis of pathologicchange.9 This technique and how it can be used toidentify normal anatomy and diagnose musculo-skeletal injury is discussed below.

Standard Ultrasound TechniqueUltrasound has traditionally been the imaging mo-dality of choice for diagnosing most soft-tissue inju-ries because it is non-invasive, cost-effective, andeasily accessible. The standard ultrasound tech-nique has been described for the equine distal limbin scholarly veterinary publications and text-books.1,10–16 The majority of musculoskeletal im-aging in the equine distal limb is performed with alinear transducer.17 The ultrasound probe is

placed on the palmar or plantar surface of the limbwith the beam oriented perpendicular to the longi-tudinal axis of the tendons or ligaments of interestwith the limb in a weight bearing position. In ad-dition, transverse images are obtained. The size,shape, margins, and echogenicity of the structuresshould be evaluated and a measurement system,with the use of distance (cm) or zones, should beused to obtain images at regular intervals. Com-parison to the contralateral limb is a critical step inmost cases, even those with obvious injury in theprimary limb. This system will facilitate sequen-tial examinations. In certain cases, the medial andlateral extent of the tendons and ligaments cannotbe imaged in the same field of view, and theprobe should be directed toward the medial andlateral aspects of the structure to obtain peripheralmargin images.

The standard ultrasound technique (single-beamangle with the limb in a weight bearing position)

Fig. 6. Transverse ultrasound images of the proximal suspensory ligament in the forelimb. Ultrasound beam is perpendicular to theproximal suspensory ligament at 3 cm (A) and 4 cm (C) distal to the accessory carpal bone. Corresponding transverse ultrasoundimages at 3 cm (B) and 4 cm (D) distal to the accessory carpal bone with the ultrasound beam at an oblique incidence angle and MRimages at the same level overlying these images. Note the hypoechogenicity in the ligament fibers (B, D) and hyperechogenicity ofthe muscle and fat in the suspensory ligament (A–D). There is decreased echogenicity in the dorsal aspect of the suspensoryligaments (A, C) with the ultrasound beam perpendicular to the longitudinal axis of the ligament. This appearance varies amonghorses with normal suspensory ligaments, and in this horse it is more marked than is typical. This appearance should not beconfused with injury and may be the result of relaxation artifact. However, the dorsal aspect of the ligament is most frequentlyaffected by injuries. Therefore, the dorsal aspect of the ligament should be carefully evaluated, and regions of decreased echogenicityshould be assessed in conjunction with lobe size, shape, and margins along with comparison to the opposite limb.

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does not always demonstrate important anatomicfeatures of tendons and ligaments. This techniquewas selected to create maximum echogenicity in thestructure, to prevent decreased echogenicity causedby variations in beam angle (anisotropy) that couldbe mistaken for a lesion. In addition, this tech-nique was designed to prevent relaxation artifactfrom causing false decreases in echogenicity thatcould be mistaken for a lesion. However, decreasedtension on certain structures may actually increasethe conspicuity of lesions. The angle contrast ul-trasound technique uses perpendicular and obliquebeam (on- and off-beam) angles to identify bundlesof fibers with different orientations. This technique,along with changes in limb position and weightbearing, can be used to identify abnormalities thatare less apparent or not visible with the standardtechnique.

Angle Contrast Ultrasound Technique(On- and Off-Beam Angles)The angle contrast (on- and off-beam angles) ultra-sound technique is typically used after examinationwith the standard ultrasound technique. To per-form the angle contrast ultrasound technique, theultrasound beam is placed at perpendicular andoblique angles of incidence relative to the longitudi-nal axis of the tendon or ligament fibers. Toachieve an oblique incidence image, the ultrasoundbeam is first positioned perpendicular to the tendonor ligament to create maximum echogenicity, andthis image is saved and compared with an obliqueincidence image at the same level (Fig. 4). To cre-

ate the oblique incidence image, the probe angle isthen changed by moving the probe cable proximallyor distally, depending on the structure being imagedand the specific region of interest (Fig. 5). The leastamount of angle that results in decreased echogenic-ity of the tendon or ligament fibers should be used.The shape, size, and location of the imaged structureand any other anatomic landmarks, such as osseousmargins, in the oblique incidence image should becompared with the original perpendicular beam an-gle image. The shape, size, and location of the softtissue and osseous structures should match in thetwo different images to ensure that similar levels ofthe tendon or ligament are being evaluated and canthen be compared. The angle contrast ultrasoundtechnique has been incorporated as part of the stan-dard examination in all musculoskeletal examina-tions by the author.

This technique has proven to be effective whenimaging the suspensory ligament through the use ofultrasound. It facilitates differentiating regions offibers from adipose tissue and muscle (Fig. 6).9

Anisotropic properties of tendon and ligament fibersdiffer from that of adipose tissue and muscle. Mus-cle echogenicity is much less dependent on beamangle compared with tendon and ligament fibers.Adipose tissue echogenicity is not dependent onbeam angle. Regions of adipose tissue, and, to alesser extent, muscle, will remain echogenic regard-less of beam angle. In contrast, tendon and liga-ment fibers will become hypoechogenic when thebeam angle is not perpendicular to the longitudinal

Fig. 7. Transverse ultrasound images of the third metacarpal bone with the fetlock flexed. A, The dorsal aspect of the lateral condyleof the third metacarpal bone has a clearly defined hypoechogenic line of articular cartilage (white arrow) with a smooth osseousmargin. B, The medial condyle of the third metacarpal bone has an irregular articular surface (red arrow) and osseous margin.In addition, the region of the articular cartilage is echogenic, indicating cartilage abnormality such as fibrosis or degeneration.These findings were not evident with the limb in a weight bearing position.

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axis of the tendon or ligament fibers. By use ofvariations in the ultrasound beam angle, regions ofscarring and injury in soft-tissue structures can beidentified. Scarring is echogenic regardless of ul-

trasound beam angle. Areas of fiber disruption areanechoic regardless of beam angle. Therefore, com-paring the echogenicity of soft tissues structureswith on-beam angle (perpendicular) and off-beam

Fig. 8. Transverse ultrasound images of the cranial aspect of the medial meniscus. A, Weight bearing image shows two regions ofdecreased echogenicity in the distal aspect of the medial meniscus with an irregular tibial margin. B, Non–weight bearing imageshows enlargement and coalescence of the previously identified regions of abnormality with a further decrease in echogenicityconsistent with presence of fluid and fiber loss, indicating a tear in the medial meniscus.

Fig. 9. Ultrasound (A) and MR (B, C) images of an 11-year-old Dutch Warmblood mare that presented for right forelimb lamenesslocalized to the digital sheath. No significant soft tissue lesions were identified on initial ultrasound examination. High-field MRIwas performed under general anesthesia of the left fore fetlock region and revealed abnormalities in the deep digital flexor tendon andstraight sesamoidean ligament with associated synovial proliferation. A, On retrospective ultrasound examination, these abnormal-ities could be identified after flexion of the limb and manual displacement of the ergot. B, MR image at the level of the injuries.C, Localizer image denoting the slice position relative to the ergot. Note that tissue manipulation of the ergot is necessary to fullyexamine the tendons at the level of the fetlock. Medial is to the left of each image.

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angle (oblique) ultrasound beam orientations can beused to characterize regions of pathologic changefrom normal anatomic variation.14

Limb Position, Tissue Manipulation, and Probe PressureLimb position can affect visualization of certainstructures. When examining the palmar or plantarsoft tissues at the level of the pastern and the foot,have the horse standing squarely on all four limbsand then place the foot of interest caudal from thissquare stance to facilitate examination. Visualiza-tion of the medial aspect of the elbow with ultra-sound can be greatly improved with the limbextended. The degree of extension is variable.The location of the lesion or area of interest withinthis region of the elbow will affect the degree ofextension that is necessary. In contrast, examina-tion of the medial aspect of the stifle is best per-formed with the limb placed squarely underneaththe body. When the limb is positioned forward orbehind, the vertical visualization of certain struc-tures of the stifle is limited.

Evaluating the limb in weight bearing and non–weight bearing positions can provide additional in-formation and aid the diagnosis of pathologic

change. In certain anatomic regions, standard andangle contrast ultrasound techniques can be com-bined with changes in weight bearing and tissuemanipulation to achieve more information. This isespecially true when imaging the front and hindlimb suspensory ligaments. Placing the limb in anon–weight bearing position has many advantages.The decreased tension in the flexor tendons allowsmanipulation of their position. They can be manip-ulated to create a wider skin surface for the ultra-sound probe, increasing visualization of the medialand lateral aspects of the ligaments (Fig. 4). Vas-culature that may have been creating artifact withthe limb in a weight bearing position can often bemanipulated to decrease the amount of artifact.In addition, this process decreases the depth be-tween the probe and the suspensory ligament, whichoften allows use of a higher frequency that increasesimage resolution.

For ultrasonographic examination of the proximalmetacarpal region, the limb is placed in a non–weight bearing position with the lower leg sus-pended and minimal carpal flexion while themetatarsal region can be examined with the horse

Fig. 10. A, Transverse ultrasound image of the straight sesamoidean ligament at the level of the junction with the intersesamoideanligament. B, Corresponding magnetic resonance image at the same level. C, Localizer image. This lesion appeared smaller whenimaged with the limb in a weight bearing position and was more difficult to visualize. With the limb in a non–weight bearing position,the lesion size was similar when comparing ultrasound and MR images and the lesion was readily identified.

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resting on the toe, in most cases. Once images ofthe proximal metacarpus have been obtained, thecarpus can be flexed further to maintain a morecomfortable position. When imaging the proximalmetatarsal region, placing the limb of interest in anon–weight bearing position (resting on the toe) canallow flexor tendon manipulation. However, in-creased limb flexion results in greater tendon laxity,which can be beneficial when tendon manipulationcannot be adequately performed with the horse rest-ing on its toe.

A complete ultrasonographic examination of jointsoften requires imaging the joint in flexion after ex-amination of the joint in a weight bearing position.When examining the fetlocks and carpi, joint flexionallows visualization of regions of the joint that arenot accessible with ultrasound when the limb is in aweight bearing position. This position aids in iden-tification of the dorsal articular surfaces of the me-dial and lateral condyles of the third metacarpalbone in the fetlock (Fig. 7). This examination is anexcellent adjunct to radiographs, especially if anabnormality is suspected on the basis of radio-graphic appearance. In the stifle joint, flexion ofthe limb is required to examine the cranial tibialmeniscal ligaments and to identify certain types ofmeniscal tears. This can often be achieved with thehorse resting on its toe. However, visualization ofthe distal margin of the medial femoral condyle andthe distal aspect of the cranial cruciate ligament isbest achieved with more pronounced joint flexion.In addition, small meniscal tears may become moreapparent, revealing the maximum extent of theirmargins with greater joint flexion. After evalua-tion with the horse resting on its toe, it is best toreevaluate any findings with more pronounced flex-

ion of the joint. This technique is used to deter-mine if the findings change with different limbpositions or degree of flexion. Examination of thestifle joint with the limb in weight bearing and non–weight bearing positions allows protrusion of themeniscus to be more easily identified. In manycases, the meniscus will be further displaced outsidethe joint margins with the limb in a weight bearingposition and then will return within the joint spacewith the limb in a non–weight bearing position.Ultrasonographic examination can be used to reli-ably identify the menisci, collateral ligaments, cra-nial meniscal ligaments, and the distal portion ofthe cranial cruciate ligaments.18

In general, a lack of tension in soft-tissue struc-tures can increase the visibility of lesions, especiallywhen adjacent fluid can enter regions of fiber dis-ruption. Although this has been shown repeatedlywhen evaluating meniscal tears in the stifle (Fig. 8),reduced pressure can also aid in the diagnosis ofsoft-tissue injury in other anatomic regions. Thebenefit of this technique is somewhat related to le-sion configuration. However, it appears to increasethe conspicuity of many different types of injuriesbeing diagnosed with ultrasound. Longitudinalsplits and margin tears are substantially affected bythis technique. This premise has developed fromcomparing ultrasound and MRI images of lesions.Although there are certain types of injury that canbe identified with MRI that will not be evident onultrasound images, other lesions, especially thosewith fiber disruption, should be evident with ultra-sound if the structure is accessible. When MRI le-sions with fiber disruption are identified, they mayappear smaller when imaged with ultrasound.This can occur when the periphery of the lesion is

Fig. 11. Transverse ultrasound images of a tear in the lateral aspect of the superficial digital flexor tendon both acquired with thelimb in a non–weight bearing position. A, The ultrasound probe is positioned such that it is in contact with the skin sur-face. However, no pressure is applied to the probe and the tear is quite evident. B, With pressure on the ultrasound probe, the tearin the superficial digital flexor tendon appears smaller, is less conspicuous, and does not obviously extend through the plantar margin.This injury was less evident with the limb in a weight bearing position.

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less severely affected and will therefore be moreapparent on MR images when compared with ultra-sound images. However, in certain cases, this dis-

crepancy appears to be the result of differences intension on the basis of weight bearing. These dif-ferences are most apparent when comparing recum-

Fig. 12. Transverse ultrasound images at the level of the pastern made with the limb in a non–weight bearing position. Possibleadhesions exist between the deep digital flexor tendon and the straight sesamoidean ligament in the left forelimb distally (A, B) andmore proximally (C, D). Ballottement can be used to determine if adhesions are present. Digital pressure on the sheath can displacestructures. Fluid completely separates the deep digital flexor tendon and the straight sesamoidean ligament (B) after ballottementand manipulation of the fluid in the digital sheath. However, the deep digital flexor tendon and the straight sesamoidean ligamentdo not separate in the more proximal image (D) indicating adhesion formation. The proximal images (C, D) of the deep digital flexortendon are off-angle.

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bent MR images with standing ultrasound images.In these cases, the lesions are more similarly sizedand shaped when MR images obtained in a recum-bent horse are compared with ultrasound imageswith the limb in a non–weight bearing position.

Comparison of MRI and ultrasound images alsoreveals lesions in anatomic regions that are ultra-sound accessible. However, additional steps mustbe taken to adequately visualize these regions withultrasound if these regions have not been part of thestandard ultrasound examination previously. Thepalmar or plantar fetlock under the ergot is one ofthese regions. At the level of the ergot, there aremany important anatomic structures on midline,such as the straight and intersesamoidean liga-ments and the cruciate ligaments. This region canbe obscured by the ergot and is more challengingbecause of the curvature of the limb and ligamentsat this level. Complete examination of the regioncan require both flexion and tissue manipulation(Fig. 9). Flexion results in relaxation of the palmaror plantar soft tissues, whereas manipulation of theergot allows visualization of these midline struc-tures. Lesions of the straight sesamoidean liga-ment at the junction with the intersesamoideanligament are frequently identified retrospectively af-ter MRI with the use of this technique (Fig. 10).Regions that may not have been specifically imagedwith previous ultrasound include fibers of the hindsuspensory ligament that extend proximally to thefourth tarsal bone. This area demonstrates injuryon MRI images and is ultrasound accessible. Inthis case, adjusting the proximal anatomic limits ofa hind suspensory ligament ultrasound study willfacilitate identification of lesions in this region.

As previously discussed, limb position and tensionon soft-tissue structures can affect the visibility oflesions. In addition, probe pressure can also mark-edly affect the visibility of certain lesions. Changesin the amount of probe pressure at the region ofinterest can be used to increase the conspicuity ofcertain lesions (Fig. 11). Alterations in probe pres-sure in combination with tissue manipulation are abenefit, especially when evaluating the digitalsheath. With the limb in a non–weight bearing po-sition, digital pressure can be used to force fluid intodifferent regions of the sheath to aid in determiningthe presence or absence of adhesion formation(Fig. 12).

Summary and ConclusionsAlthough ultrasound has limitations compared withadvanced imaging, the continued development of in-novative techniques will aid the diagnosis of muscu-loskeletal injury in horses. Advanced imaging

provides the best method for the development ofthese techniques and furthers our educational pro-cess about imaging and the pathologic changes as-sociated with musculoskeletal injury.

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