Vascular ultrasonographic findings in canine patients with clinically diagnosed phlebitis

Peripheral vein phlebitis (inflammation) is a relatively frequent complication in dogs, however, published information on the ultrasonographic characteristics is currently lacking. This prospective, observational study describes the ultrasound (US) characteristics of normal canine cephalic veins, and veins with clinical phlebitis. Correlations among US findings and between US findings versus time that the intravenous catheter was in place were investigated. Safety of the US procedure was evaluated. Fifty patients were prospectively recruited for the study and 18 met the final inclusion criteria. Each patient underwent daily US examinations and was assessed for multiple criteria (vascular wall appearance, compressibility, spontaneity of flow, color fill, and presence/absence of filling defects, flow contour, direction, non‐pulsatility). Characteristics of normal canine cephalic veins were as follows: smooth and thin wall, complete compressibility, no flow disturbances, no filling defects, smooth flow contours, and unidirectional, non‐pulsatile flow with no turbulence. Characteristics of cephalic veins with clinical phlebitis were as follows: wall thickening (83%), decreased compressibility (55%), filling defects consistent with intraluminal thrombus (55%), vessel wall hyperechogenicity (44%), and abnormal color Doppler flow (39%). Significant correlations were found between Doppler filling defects and compressibility, Doppler filling defects and presumed thrombosis, and compressibility and presumed thrombosis (P = .001, P = .001, P = .000, respectively). No correlation was found between the US findings and time the intravenous catheter was in place. Findings indicated that duplex and compressibility US are feasible and safe methods for characterizing and monitoring cephalic veins in dogs with clinical phlebitis.     

THE HILAR PERIVENOUS HYPERECHOIC TRIANGLE AS A SIGN OF ACUTE SPLENIC TORSION IN DOGS

Diagnosis of acute primary splenic torsion is challenging. The ultrasonographic appearance of this condition has been described, but other splenic diseases, such as diffuse infarction because of thrombosis, can appear very similar. We describe an additional ultrasonographic sign of acute splenic torsion; a triangular hyperechoic area at the hilus between the veins and the splenic parenchyma that is continuous with the hyperechoic mesentery. In a group of animals where acute splenic torsion was part of the ultrasound report differential diagnosis, we compared findings in dogs with torsion with findings in dogs with other splenic conditions. The presence of a hilar hyperechoic perivenous triangle was significantly associated with splenic torsion (P = 0.005). We speculate that this sign is associated with torsion because of the secondary severe, diffuse splenic enlargement. Although not pathognomonic, this sign could be used to more accurately diagnose splenic torsion in light of other findings consistent with this condition.     

Ultrasonographic features of splenic lymphosarcoma in dogs: 12 cases (1980-1986)

The ultrasonographic appearance of the spleen and adjacent organs in 12 dogs with splenic lymphosarcoma was reviewed. Poorly marginated hypoechoic to anechoic nodules (4 mm to 3 cm in diameter) were found in all dogs. The anechoic nodules did not result in reflective shadowing or acoustic enhancement of the underlying tissues. The remainder of the splenic parenchyma appeared relatively hypoechoic when compared with the liver or renal cortices in 9 dogs. Recognition of this ultrasonographic pattern appears to be a useful diagnostic tool. Needle aspiration guided ultrasonographically will then enable histologic confirmation of lymphosarcoma.     

ULTRASONOGRAPHIC FEATURES OF CANINE ABDOMINAL MALIGNANT HISTIOCYTOSIS

Ultrasonographic features of canine abdominal malignant histiocytosis (MH) of 16 dogs are reported. The most common finding was the presence of hypoechoic nodules in the spleen, some of which caused distortion of the splenic margin. The liver was the second-most commonly affected organ. Hepatic ultrasonographic features were highly variable, including hypoechoic, hyperechoic, or mixed echogenic lesions. Other common ultrasonographic abnormalities included hypoechoic nodules in the kidneys and mesenteric and medial iliac lymphadenopathy. The results of this study suggest that the ultrasonographic appearance of canine abdominal MH is nonspecific, and definitive diagnosis requires cytologic or histologic examination.     

Ultrasonographic evaluation of horses with thrombophlebitis of the jugular vein: 46 cases (1985-1988)

Medical records of 46 horses with jugular vein thrombophlebitis that were evaluated ultrasonographically were reviewed. The ultrasonographic appearance of the thrombus within the jugular vein was classified as noncavitating if it had uniform low to medium amplitude echoes, or as cavitating if it was heterogenous with anechoic to hypoechoic areas representing fluid or necrotic areas within the thrombus, and/or hyperechoic areas representing gas. Signs of pain on palpation of the affected vein (P less than 0.001), heat over the vein (P = 0.001), and swelling of the vein (P less than 0.05) were significantly associated with the ultrasonographic detection of a cavitating lesion. Ultrasonography also was useful for selecting a site for aspiration of a specimen for bacteriologic culturing and susceptibility testing.     

SMOOTH MUSCLE NEOPLASIA OF THE URINARY BLADDER WALL IN THREE DOGS

Smooth muscle origin neoplasia of the urinary bladder wall is rare in dogs. This report describes the ultrasonographic features of two bladder wall leiomyomas and one bladder wall leiomyosarcoma. All three dogs had a single, smoothly marginated, round, hypo to mixed echogenicity intraluminal mass in the urinary bladder. Based on color Doppler examination of the masses, there was no visible blood flow.     

ULTRASONOGRAPHIC APPEARANCE OF JEJUNAL LYMPH NODES IN DOGS WITHOUT CLINICAL SIGNS OF GASTROINTESTINAL DISEASE

The jejunal lymph nodes of 57 dogs without clinical signs of gastrointestinal disease were examined to characterize their ultrasonographic appearance on B-mode and power Doppler examination, and to obtain ultrasonographic measurements. The lymph nodes were mildly hypoechoic to the mesentery in 71% of dogs and isoechoic in 29%. All dogs, 6 years of age or older had jejunal lymph nodes of uniform echogenicity. In dogs less than 6 years of age, nonuniform lymph nodes with different echopatterns were observed. Although most lymph nodes had no blood flow based on power Doppler examination, hilar blood flow was detected in 33% of dogs, which were generally less than 2 years of age. The median maximum thickness of the jejunal lymph nodes was 3.9 mm (range 1.6–8.2 mm), and their median maximum width 7.5 mm (range 2.6–14.7 mm). There was a significant correlation between larger lymph node diameter and younger age and higher body weight. We concluded that patient age should be considered when interpreting the echopattern and vascularity of jejunal lymph nodes in dogs, and that the jejunal lymph nodes of dogs without clinical signs of gastrointestinal disease may exceed the previously stated upper limit of 5–6 mm thickness.     

ULTRASONOGRAPHIC APPEARANCE OF HISTOPLASMOSIS IDENTIFIED IN THE SPLEEN IN 15 CATS

Histoplasmosis is the second most common fungal infection reported in the cat. The disseminated form involving lung, liver, lymph nodes, spleen, and bone marrow is a frequent manifestation of the disease. Limited information is available in the literature regarding the ultrasonographic appearance of the spleen in cats with disseminated or splenic histoplasmosis. A retrospective review of splenic ultrasound images from 15 cats confirmed to have histoplasmosis by splenic aspirates was performed. Size, echotexture, echogenicity, margin appearance, presence of nodules, and the overall shape of the spleen were reported in each case. Splenomegaly was documented in all cases (15/15) and a hypoechoic appearance of the spleen was documented in 14/15 of cases. The spleen was diffusely and uniformly affected in 14/15 (six homogenous and eight with a subtle mottled appearance) and had discrete nodules in 1/15 cats. Histoplasmosis should be included in the differential list for an enlarged and hypoechoic spleen in cats with consistent clinical findings. Additionally, ultrasound guided splenic aspirate may be a useful method to obtain a cytology sample for diagnosis.     

ULTRASONOGRAPHIC EVALUATION OF A TRAUMATIC SPLENIC HEMATOMA AND LITERATURE REVIEW

This report describes a presumed traumatic splenic hematoma in a six-year-old neutered male Greyhound presented for abdominal pain, vomiting, and anorexia. Multiple right-sided rib fractures and minimal pneumothorax were detected on radiographs. Using ultrasonography, an irregular, mixed anechoic and hypoechoic splenic mass was detected. Based on history and ultrasonographic findings, a traumatic splenic hematoma was diagnosed. In follow-up ultrasonographic evaluations there was progressive, and ultimately, complete resolution of this lesion. The animal was clinically normal at ten week follow-up and remains healthy. Clinical, radiographic, and ultrasonographic features of splenic hematomas are discussed, with emphasis on the changing ultrasonographic appearance over time. The different imaging modalities used in people to diagnose traumatic splenic hematoma are reviewed.     

Color and power Doppler ultrasonography for characterization of splenic masses in dogs

Benign and malignant splenic masses can appear similar on B-mode imaging, making ultrasound sensitive but not specific in their diagnosis. Our goal was to characterize color and/or power Doppler characteristics of vasculature within and adjacent to a splenic mass, which would distinguish benign vs. malignant lesions. The hypothesis was that malignant splenic masses will have altered vascular patterns compared with benign masses. Color and power Doppler cineloops evaluating the vasculature within the mass and normal splenic parenchyma were obtained in sagittal and transverse planes using a standardized protocol. Categories of evaluation included presence of peritoneal effusion, a large aberrant or tortuous vessel within the mass, relative blood flow within the mass compared with normal parenchyma, and path of vessels in the adjacent parenchyma entering into the mass. All patients had histopathologic or definitive cytologic diagnosis. Thirty-one dogs were included. There were 13 malignant masses and 18 were benign. Peritoneal effusion was significantly associated with malignancy (P = 0.0007). Presence of an aberrant or tortuous vessel within the mass was nearly significant (P = 0.059). There was no significant difference in any of the color or power Doppler blood flow evaluations. Ultrasonographic findings of a splenic mass and peritoneal effusion may indicate malignancy. The presence of an aberrant vessel within a splenic mass could suggest malignancy; however more data are needed.     

Correlation of ultrasonographic and patho-morphological findings in canine hepatic diseases

Findings of hepatic ultrasonography were analysed in 22 dogs with liver disease and compared with the results of final morphological diagnoses. Ultrasonographic appearance of the liver demonstrated focal alterations in 11 dogs (50 per cent): multifocal lesions in hepatic neoplasia (six), hepatic cirrhosis (one), generalised mycosis (one) and unifocal lesions in haemangiosarcoma (one), nodular hyperplasia (one) and misdiagnosed intestinal invagination (one), Diffuse ultrasonographic alterations were found in 11 dogs (50 per cent): hyperechoic liver of normal/enlarged size in lymphosarcoma (four) and hepatic lipidosis (two); hyperechoic ‘bright’ but small liver in atrophic cirrhosis (two); hypoechoic to normal intensity liver of normal size in liver dystrophy (two) and hepatic venous distension (one). Gallbladder abnormalities were detected in 14 of 20 dogs (70 per cent). Correct ultrasonographic diagnoses were made in 11 dogs (50 per cent). The best results were achieved by combining the clinicolaboratory and ultrasonographic findings, providing a correct diagnosis in 17 dogs (77-3 per cent).     

ULTRASONIC DETECTION OF SPLENIC NECROSIS IN THE DOG

Ultrasonographic findings of splenic infarction and necrosis in three dogs are presented. Two previously unreported ultrasonographic patterns are identified: (1) Focal, hypoechoic or isoechoic, circular, wellmarginated nodular masses with peripheral lesions causing deformation of the splenic margin. (2) Diffuse hypoechoic or heteroechoic coarse/"lacy" parenchymal pattern with no deformation of margin. The presence of gas within the splenic parenchyma of one dog was detected by both radiography and ultrasonography. Ultrasonographic patterns of splenic infarction in both man and the dog are discussed     

SONOGRAPHIC AND RADIOGRAPHIC CHANGES ASSOCIATED WITH SPLENIC TORSION IN THE DOG

The clinical, radiographic, and sonographic signs in three dogs with splenic torsion are presented. AH dogs exhibited weight loss, anorexia, and lethargy. Splenomegaly was consistent radiographic finding in two dogs and large ill-defined midabdominal mass was seen in one dog. The spleen was easily imaged sonographically in all dogs. Splenic sonography in two dogs showed diffuse, hypoechoic pattern consistent with splenic congestion. Hilar splenic vessels were enlarged on the sonograms of two dogs.     

ULTRASONOGRAPHIC ANATOMY OF THE NORMAL CANINE SPINAL CORD AND CORRELATION WITH HISTOPATHOLOGY AFTER INDUCED SPINAL CORD TRAUMA

Prior to trauma, intraoperative ultrasound of the spinal canal in 31 normal dogs was performed through a hemilaminectomy in the left pedicle of L2. A ventral compressive model of spinal cord injury was performed as part of a clinical drug trial. Maximum ultrasonographic spinal cord diameter ranged from 4.9–7.2 mm (5.7 × 0.6). Significant positive correlation (p = 0.023, r = 0.49) was found between age and spinal cord diameter. The dura mater was a separate, well-defined, echogenic horizontal line in 28 (90%) dogs, dorsally, and in 29 (94%) dogs, ventrally. Cerebrospinal fluid was anechoic. Eighteen (58%) dogs had a well-defined anechoic dorsal subarachnoid space, whereas 22 (71%) had a well-defined ventral space. Pia mater was thin but strongly echogenic and covered spinal cord. Central canal was a double hyperechoic line in 17 (55%) dogs and a single-line in 14 (45%) dogs. A difference in the ultrasonographic appearance between gray and white matter was not seen. Epidural fat and connective tissue was a lobular echogenic material in the ventral epidural space. The periosteal-vertebral body interface was seen as a bright curvilinear echo with distal acoustic shadowing. Spinal cord parenchyma could be classified subjectively into four groups based upon ultrasonographic appearance. Spinal cord parenchyma had a uniform hypoechogenicity in 8 (27%) dogs (Group 1), subtle low level echoes in 7 (23%) dogs (Group 2), multiple clusters of defined echogenic foci in 12 (37%) dogs (Group 3), and multiple sharply-defined linear echoes in 4 (13%) dogs (Group 4). There was a significant relationship between pre-trauma ultrasonographic appearance of the spinal cord and histopathology 21 days after trauma. One (13%) dog in Group 1, 4 (57%) dogs in Group 2,10 (91%) dogs in Group 3, and 3 (75%) dogs in Group 4 had malacia on histological evaluation. Therefore, dogs with echogenic spinal cords or linear echoes within cord parenchyma were significantly more likely to develop malacia rather than Wallerian degeneration after induced spinal cord trauma (p = 0.002). Spinal cord echogenicity may indicate vascularity in a segment of spinal cord and might be prognostic following spinal cord trauma. No complications were found related to intraoperative ultrasound. Hematoma or fibrous tissue formation appeared to impede percutaneous ultrasound of the spinal cord in dogs re-evaluated forty-eight hours and one week after surgery.     

ECHO-DOPPLER FINDINGS OF A CAROTID-JUGULAR FISTULA IN A FOAL

A seven-month-old male Standardbred was referred with a 4-month history of left jugular groove distension. On physical examination severely dilated left maxillary, linguofacial and jugular veins were appreciable. Blood gas analysis results indicated higher degree of oxygenation in the left jugular vein. Bi-directional flow signals, with normal systolic and early diastolic flow, and late diastolic retrograde flow, were noted on pulsed-wave Doppler interrogation and color flow mapping of the left jugular blood flow. A systolic-diastolic signal with spectral broadening was detected when positioning the sample gate near the internal jugular wall, in the distal left cervical region. Color Doppler imaging of the same region showed blood flow passage between the left common carotid artery and the left jugular vein through a small carotid-jugular fistula. Markedly increased blood flow velocities and volumetric flow, and decreased resistive index were recorded in the left compared to the right common carotid artery.     

Comparison of B-mode and Doppler ultrasonographic findings with histologic features of benign and malignant superficial lymph nodes in dogs

OBJECTIVE: To compare and correlate B-mode and color Doppler ultrasonographic characteristics with histopathologic findings of benign and malignant superficial lymph nodes in dogs. STUDY POPULATION: 50 superficial lymph nodes that were normal, abnormally large on physical examination, or represented regional lymph nodes draining an area of suspected primary malignancy in 30 dogs. PROCEDURES: Before excision, lymph nodes were evaluated via B-mode and color Doppler ultrasonography to assess size, echogenicity, presence of a hilus, acoustic transmission, and vascular flow. Formalin-fixed, paraffin-embedded tissue sections of excised lymph nodes were stained with H&E and examined for the presence and extent of necrosis, fibrosis, fat, metastases, and tissue heterogeneity. To assess vascularity, the number and distribution of vessels stained by the Verhoeff van Gieson technique were recorded. RESULTS: In superficial lymph nodes, a varied echogenicity corresponded to tissue heterogeneity. The ultrasonographic detection of a hilus was associated with the presence of fibrous tissue, fat, or both in the hilar region. Acoustic enhancement corresponded to presence of areas of intranodal necrosis. There was significant correlation between both the distribution and the number of vessels detected via ultrasonography and that detected by histopathology. The amount of flow estimated via ultrasonography was typically higher than that estimated via histologic examination. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that histopathologic changes in canine lymph nodes have associated ultrasonographic changes and suggest that lymph node ultrasonography has an important role in the evaluation of lymph nodes in dogs in general and in dogs with neoplastic disease in particular.     

Comparative Doppler imaging of the ophthalmic vasculature in normal Beagles and Beagles with inherited primary open-angle glaucoma

The objective of this study was to compare orbital and ocular vasculature velocity, measured by Doppler imaging, in normal Beagles and Beagles with inherited primary open-angle glaucoma. Eight normal Beagles and 13 Beagles with different stages of primary open-angle glaucoma were evaluated twice with a 2–4-week period between measurements. Doppler imaging was performed with the dogs anesthetized, and the Doppler transducer applied directly on the corneal surface. The majority of the orbital vasculature (external ethmoidal artery; internal ophthalmic artery and vein; and external ophthalmic artery and vein) and ocular blood vessels (anterior ciliary artery and veins; long posterior ciliary arteries; short posterior ciliary arteries; primary retinal arteries; and the vortex veins) were identified and Doppler blood velocity parameters were determined. The glaucomatous dogs demonstrated significant differences in the Doppler velocity parameters of several orbital vessels (external ethmoidal, external ophthalmic, and internal ophthalmic arteries), and several ocular vessels (anterior ciliary, short posterior ciliary, and long posterior ciliary arteries). These differences included decreased blood velocities, and increased pulsatility and resistive indexes. The Doppler blood flow velocities of the primary retinal arteries were unchanged between the normal and glaucomatous dogs. In the glaucomatous dogs, the Doppler imaging suggests increased vascular resistance downstream in both the orbital and ocular vasculature. These blood velocity parameter changes may be primary or secondary, and may offer therapeutic opportunities to increase perfusion, prolong the retina and optic nerve head function, and maintain vision in the canine glaucomas.     

COLOR DOPPLER ULTRASONOGRAPHY IN PREDICTION OF THE REDUCIBILITY OF INTUSSUSCEPTED BOWEL IN 15 YOUNG DOGS

Color Doppler ultrasonography was performed in 15 young dogs with intestinal intussusception to test the hypothesis that color Doppler findings can be used as a predictor of the manual reducibility of the intussusception at celiotomy. Color flow Doppler ultrasonography indicated blood flow within mesentery of the intussuscepted bowel in 12 of 15 dogs and reduction was achieved in nine of these 12 dogs (75%). In the remaining three dogs and in three dogs where no color Doppler signal were observed, an irreducible intussusception was confirmed at celiotomy. Color Doppler ultrasonography is a useful method for predicting the reducibility of intussusception in dogs.     

NORMAL DUPLEX DOPPLER WAVEFORMS OF MAJOR ABDOMINAL BLOOD VESSELS IN DOGS: A REVIEW

The normal flow velocity profile and duplex Doppler waveform of the major abdominal blood vessels (aorta, caudal vena cava and the portal vein as well as their major branches) were examined by Doppler ultrasound. The flow velocity profile of an artery is largely determined by its diameter. The pulsatility of the waveform is related to the vascular impedance downstream to the point of measurement. Early systolic peak is present in the Doppler pattern of some vessels in some dogs. The waveform of the veins is mainly affected by the pressure conditions of the right atrium and the intrathoracic and intraabdominal pressure changes due to the respiration. Simultaneous electrocardiogram was used to reveal the effect of the heart beats on the Doppler patterns of the veins.     

DIASTOLIC MITRAL REGURGITATION DETECTED BY PULSED WAVE DOPPLER ECHOCARDIOGRAPHY AND COLOR FLOW DOPPLER MAPPING IN FIVE DOGS AND TWO CATS WITH SECOND- AND THIRD-DEGREE ATRIOVENTRICULAR BLOCK

M-mode echocardiography, color flow Doppler mapping, and pulsed wave Doppler echocardiography were used to characterize diastolic mitral regurgitation in five dogs and two cats with second- and third-degree atrioventricular block. Incomplete closure and partial reopening of the mitral valve following nonconducted P-waves were demonstrated by m-mode echocardiography. Low velocity reflux of blood into the left atrium after nonconducted P-waves was imaged by color-flow Doppler mapping and spectral Doppler echocardiography. Late diastolic mitral regurgitation was not observed in clinically normal control dogs or cats, but a low velocity, mid-diastolic flow reversal was detected in the dogs. This probably represented normal physiologic intravalvular flow. Diastolic mitral regurgitation is a common echocardiographic finding, in dogs and cats with, second- and third-degree atrioventricular block.