Objective—To determine the detailed computed tomography (CT) anatomy of the metacarpophalangeal (MCP) joint in healthy horses.
Sample Population—10 cadaveric forelimbs from 10 adult horses without orthopedic disease.
Procedures—CT of the MCP joint was performed on 4 forelimbs. In 1 of the limbs, CT was also performed after intra-articular injection of 30 mL of contrast medium (40 mg of iodine/mL). Transverse slices 1-mm thick were obtained, and sagittal and dorsal planes were reformatted with a slice thickness of 2 mm. The CT images were matched with corresponding anatomic slices from 6 additional forelimbs.
Results—The third metacarpal bone, proximal sesamoid bones, and proximal phalanx could be clearly visualized. Common digital extensor tendon; accessory digital extensor tendon; lateral digital extensor tendon; superficial digital flexor tendon (including manica flexoria); deep digital flexor tendon; branches of the suspensory ligament (including its attachment); extensor branches of the suspensory ligament; collateral ligaments; straight, oblique, and cruciate distal sesamoidean ligaments; intersesamoidean ligament; annular ligament; and joint capsule could be seen. Collateral sesamoidean ligaments and short distal sesamoidean ligaments could be localized but not at all times clearly identified, whereas the metacarpointersesamoidean ligament could not be identified. The cartilage of the MCP joint could be assessed on the postcontrast sequence.
Conclusions and Clinical Relevance—CT of the equine MCP joint can be of great value when results of radiography and ultrasonography are inconclusive. Images obtained in this study may serve as reference for CT of the equine MCP joint.
Objective—To compare clinical usefulness of ultrasonography versus radiography for detection of fragmentation of the dorsal aspect of the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints in horses.
Animals—36 horses with fragmentation of the MCP (n = 19) and MTP (29) joints.
Procedures—In all joints, radiography (4 standard projections) and ultrasonography were performed prior to arthroscopic examination and fragment removal. Number and location of fragments identified radiographically and ultrasonographically were compared with arthroscopic findings.
Results—Radiographic and arthroscopic findings were in agreement with respect to both number and location of fragments in 21 of the 48 (44%) joints. Ultrasonographic and arthroscopic findings were in agreement with respect to number and location of fragments for 46 of the 48 (96%) joints. In the remaining 2 joints, arthroscopy revealed additional fragments that were not identified ultrasonographically. When ultrasonographic findings were compared with radiographic findings, more fragments were seen ultrasonographically in 3 joints and fewer fragments were seen ultrasonographically in 1 joint. Ultrasonographic findings also confirmed the absence (4 joints) or presence (3 joints) of fragmentation at the dorsoproximal aspect of the joint that had been suspected on the basis of radiographic findings. Ultrasonography was also able to determine the location of the fragments in the joints where this was not possible radiographically.
Conclusions and Clinical Relevance—Results of the present study suggested that ultrasonography was a useful method for determining the number and location of fragments in horses with dorsal fragmentation of the MCP or MTP joint.
Objective—To compare computed tomography (CT) images of equine tarsi with cross-sectional anatomic slices and evaluate the potential of CT for imaging pathological tarsal changes in horses.
Sample—6 anatomically normal equine cadaveric hind limbs and 4 tarsi with pathological changes.
Procedures—Precontrast CT was performed on 3 equine tarsi; sagittal and dorsal reconstructions were made. In all limbs, postcontrast CT was performed after intra-articular contrast medium injection of the tarsocrural, centrodistal, and tarsometatarsal joints. Images were matched with corresponding anatomic slices. Four tarsi with pathological changes underwent CT examination.
Results—The tibia, talus, calcaneus, and central, fused first and second, third, and fourth tarsal bones were clearly visualized as well as the long digital extensor, superficial digital flexor, lateral digital flexor (with tarsal flexor retinaculum), gastrocnemius, peroneus tertius, and tibialis cranialis tendons and the long plantar ligament. The lateral digital extensor, medial digital flexor, split peroneus tertius, and tibialis cranialis tendons and collateral ligaments could be located but not always clearly identified. Some small tarsal ligaments were identifiable, including plantar, medial, interosseus, and lateral talocalcaneal ligaments; interosseus talocentral, centrodistal, and tarsometatarsal ligaments; proximal and distal plantar ligaments; and talometatarsal ligament. Parts of the articular cartilage could be assessed on postcontrast images. Lesions were detected in the 4 tarsi with pathological changes.
Conclusions and Clinical Relevance—CT of the tarsus is recommended when radiography and ultrasonography are inconclusive and during preoperative planning for treatment of complex fractures. Images from this study can serve as a CT reference, and CT of pathological changes was useful.
Objective—To determine effectiveness of infusion of
1 and 2% enilconazole for treatment of nasal and
sinusal aspergillosis, respectively, in dogs.
Animals—26 client-owned dogs with aspergillosis.
Procedure—All dogs had typical clinical signs of
aspergillosis and rhinoscopically visible intrasinusal or
intranasal fungal plaques associated with turbinate
destruction. During rhinoscopy, affected nasal cavities
and frontal sinuses were debrided meticulously.
Nineteen dogs (group A) were treated with 1% enilconazole
by use of a modified noninvasive infusion
procedure. Seven dogs (group B) were treated with
2% enilconazole via catheters that were placed via
endoscopic guidance into the frontal sinuses. All dogs
underwent follow-up rhinoscopy for determination of
further treatment until cure was established.
Results—Age, disease duration, clinical score, and
rhinoscopic score were similar for both groups before
treatment. In group A, 17 of 19 dogs were cured; 9,
6, and 2 dogs were cured after 1, 2, or 3 treatments,
respectively. The remaining 2 dogs were euthanatized
before the end of the treatment protocol. In
group B, all dogs were cured; 6 dogs and 1 dog were
cured after 1 or 2 treatments, respectively. Only
minor adverse effects such as nasal discharge, epistaxis,
and sneezing developed.
Conclusions and Clinical Relevance—After extensive
rhinoscopic debridement, 1 and 2% enilconazole
infused into the nasal cavities and the frontal sinuses,
respectively, were effective for treatment of
aspergillosis in dogs. Intrasinusal administration via
endoscopically placed catheters appeared to require
fewer infusions for success. Follow-up rhinoscopy is
strongly advised. (J Am Med Vet Assoc 2002;221:1421–1425)
Objective—To use computed tomography (CT) and
magnetic resonance imaging (MRI) to provide a
detailed description of the nasal cavities and paranasal
sinuses in clinically normal mesaticephalic dogs.
Animals—2 clinically normal Belgian Shepherd Dogs
that weighed 25 and 35 kg, respectively.
Procedure—The first dog was anesthetized and positioned
in ventral recumbency for CT and MRI examinations,
and transverse slices were obtained from the
caudal part of the frontal sinuses to the nares. For MRI,
T1-weighted, T2-weighted, and proton-density
sequences were obtained. The second dog was anesthetized
and positioned in dorsal recumbency with the
head perpendicular to the table, and CT and MRI examinations
were again conducted. At the completion of
the MRI examination, each dog received an IV injection
of heparin and then was euthanatized. A 4% solution of
formaldehyde was perfused IV immediately after each
dog was euthanatized. The skull was prepared, decalcified,
embedded with gelatin, and sectioned into 5-mmthick
sections by use of a stainless-steel knife. Each
anatomic section was photographed and compared
with the corresponding CT and MRI views.
Results—Structures on the CT and MRI views
matched structures on the corresponding anatomic
sections. The CT scans provided good anatomic detail
of the bony tissues, and MRI scans were superior to
CT scans for determining soft-tissue structures.
Conclusions and Clinical Relevance—CT and MRI
provide a means for consistent evaluation of all structures
of the nasal cavities and frontal sinuses. Both
techniques could be useful for evaluation of diseases
that affect the nasal region. (Am J Vet Res 2003;64:1093–1098)
Objective—To determine radiographic vertebral ratio values representing vertebral canal stenosis in Doberman Pinschers with and without clinical signs of caudal cervical spondylomyelopathy (CCSM).
Animals—Doberman Pinschers with (n = 81) and without (39) signs of CCSM.
Procedures—All dogs underwent lateral survey radiography of the cervical vertebral column. Five specific measurements were made at C3 through C7, and from those data, 3 ratios were calculated and analyzed for use in diagnosis of CSSM: canal height-to-vertebral body height ratio (CBHR), canal height-to-vertebral body length ratio (CBLR), and caudal vertebral canal height-to-cranial vertebral canal height ratio (CCHR). The CBHR and CBLR were considered indicators of vertebral canal stenosis, and CCHR described vertebral canal shape.
Results—Compared with Doberman Pinschers without CCSM, mean CBHR and CBLR values were significantly smaller for Doberman Pinschers with CCSM; for CBHR, this difference was evident at each assessed vertebra. The CCHR value for C7 was significantly larger in dogs with CCSM. Receiver operating characteristic statistics did not identify a threshold point that had combined high sensitivity and specificity sufficient to differentiate between Doberman Pinschers with and without CCSM.
Conclusions and Clinical Relevance—Doberman Pinschers with CCSM had vertebral canal stenosis combined with a funnel-shaped vertebral canal at C7 significantly more often than did Doberman Pinschers without CCSM. Despite these significant differences, no reliable threshold ratio values were identified to differentiate groups of dogs.
Objective—To determine the feasibility of quantitative contrast-enhanced ultrasonography (CEUS) for detection of changes in renal blood flow in dogs before and after hydrocortisone administration.
Procedure—Dogs were randomly assigned to 2 treatment groups: oral administration of hydrocortisone (9.6 mg/kg; n = 6) or a placebo (5; control group) twice a day for 4 months, after which the dose was tapered until treatment cessation at 6 months. Before treatment began and at 1, 4, and 6 months after, CEUS of the left kidney was performed by IV injection of ultrasonography microbubbles. Images were digitized, and time-intensity curves were generated from regions of interest in the renal cortex and medulla. Changes in blood flow were determined as measured via contrast agent (baseline [background] intensity, peak ntensity, area under the curve, arrival time of contrast agent, time-to-peak intensity, and speed of contrast agent transport).
Results—Significant increases in peak intensity, compared with that in control dogs, were observed in the renal cortex and medulla of hydrocortisone-treated dogs 1 and 4 months after treatment began. Baseline intensity changed similarly. A significant increase from control values was also apparent in area under the curve for the renal cortex 4 months after hydrocortisone treatment began and in the renal medulla 1 and 4 months after treatment began. A significant time effect with typical time course was observed, corresponding with the period during which hydrocortisone was administered. No difference was evident in the other variables between treated and control dogs.
Conclusions and Clinical Relevance—Quantitative CEUS allowed detection of differences in certain markers of renal blood flow between dogs treated orally with and without hydrocortisone. Additional studies are needed to investigate the usefulness of quantitative CEUS in the diagnosis of diffuse renal lesions.
Objective—To assess vascular changes induced by hyperadrenocorticism of hyperplastic adrenal glands in dogs via contrast-enhanced ultrasonography.
Animals—12 dogs with pituitary-dependent hyperadrenocorticism (PDH) and 7 healthy control dogs ≥ 7 years old.
Procedures—Dogs were assigned to the PDH and control groups and to small-breed (n = 6), medium-breed (4), and large-breed (9) subgroups. Contrast-enhanced ultrasonography of both adrenal glands in each dog was performed with IV injections of contrast agent. Time-intensity curves for the adrenal cortex, adrenal medulla, and ipsilateral renal artery of both adrenal glands were generated. Perfusion variables (time to peak [TTP], upslope of wash-in phase, and downslope of washout phase) were calculated.
Results—Contrast-enhanced ultrasonography revealed no qualitative difference between PDH and control groups. Quantitatively, TTPs were longer in the adrenal cortex and adrenal medulla of the PDH group, compared with values for the control group, particularly in the adrenal cortex and adrenal medulla of the small-breed subgroup. Washout downslopes were lower for the renal artery, adrenal cortex, and adrenal medulla of the small-breed subgroup between the PDH and control groups. No other perfusion variables differed between groups.
Conclusions and Clinical Relevance—Contrast-enhanced ultrasonography of the adrenal glands in dogs with PDH revealed a delayed TTP in the adrenal cortex and adrenal medulla, compared with values for control dogs. Contrast-enhanced ultrasonography was able to detect vascular changes induced by hyperadrenocorticism. Further studies are needed to evaluate whether reference ranges for clinically normal dogs and dogs with PDH can be determined and applied in clinical settings.
To describe articular process joints (APJs) of the cervical spine in horses on the basis of CT and to determine whether abnormalities were associated with clinical signs.
86 client-owned warmblood horses.
Horses that underwent CT of the cervical spine between January 2015 and January 2017 were eligible for study inclusion. Medical records were reviewed for age, body weight, breed, sex, history, clinical signs, and CT findings. Horses were divided into 3 case groups and 1 control group on the basis of clinical signs.
70 warmblood horses were cases, and 16 were controls. Abnormalities were more frequent from C5 through T1 and were severe in only horses from the case group. Narrowing of the intervertebral foramen was common in horses in the case group (85.7%), often owing to enlarged, misshaped articular processes, followed by degenerative changes, periarticular osteolysis, cyst-like lesions, and fragmentation. High articular process-to-vertebral body (C6) ratio (APBR) and high-grade narrowing of the intervertebral foramen and periarticular osteolysis were noted for horses with forelimb lameness or signs of cervical pain or stiffness. No association was identified between APBR and age or sex. An APBR > 1.5 was found in only horses in the case group, and 32.3% of APJs with APBRs > 1.5 did not have any degenerative changes and periarticular osteolysis.
CONCLUSIONS AND CLINICAL RELEVANCE
CT was useful to identify abnormalities of the APJs of the cervical spine. An association existed between CT findings and clinical signs. The APJs can be enlarged without concurrent degenerative changes.