B-MODE AND DOPPLER ULTRASOUND IMAGING OF THE SPLEEN WITH CANINE SPLENIC TORSION: A RETROSPECTIVE EVALUATION

The ultrasonographic appearance of splenic torsion has been described; the splenic parenchyma can be normal, hypoechoic or anechoic with interspersed linear echoes (coarse/"lacy" appearance). The ultrasonographic parenchymal appearance of 15 dogs in this report with splenic torsion varied: mottled hypoechoic regions (n=2), diffusely hypoechoic (n=11) and normal (n=2). Because splenic torsion causes vascular congestion due to splenic vein compression and eventual thrombosis, visible splenic vein intraluminal echogenicities compatible with thrombi were seen in 13 dogs using B-mode. Using spectral Doppler and color Doppler imaging of the splenic veins, no measurable flow velocities were detected in any of the 15 dogs. The varied B-mode ultrasonographic appearance of the splenic veins for intraluminal echoes and spectral or color Doppler evaluation for absent velocity flow.     

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 characteristics of splenic and hepatic lymphosarcoma in three horses.

Splenic and hepatic ultrasonography were beneficial for diagnosis of lymphosarcoma in 3 horses with anorexia, weight loss, and lethargy. Ultrasonographic abnormalities of the spleen included a large, complex, hypoechoic mass in 1 horse, multiple well-marginated, hypoechoic nodules in 1 horse, and diffuse hyperechogenicity in another horse. Ultrasonographic abnormalities of the liver included a spherical, hypoechoic nodule in 1 horse and diffuse hyperechogenicity in another. Histologic examination of ultrasound-guided biopsy specimens or aspirates revealed lymphosarcoma. Necropsy findings confirmed diagnosis of lymphosarcoma in all horses. Necropsy findings of the liver and spleen correlated well with antemortem ultrasonographic images.     

Ultrasonographic features of splenic hemangiosarcoma in dogs: 18 cases (1980-1986)

The medical records of 18 dogs in which ultrasonography was useful in making a diagnosis of splenic hemangiosarcoma were reviewed. Splenic ultrasonography revealed masses with echo patterns that ranged from anechoic fluid to hyperechoic tissue. In 7 dogs, metastasis was detected ultrasonographically as anechoic to hypoechoic lesions in the liver.     

Ultrasonographic signs of intestinal intussusception associated with acute enteritis or gastroenteritis in 19 young dogs

The ultrasonographic pattern of intestinal intussusception was studied in 19 young dogs with acute enteritis or gastroenteritis. The intussusception was observed to be a target-like mass consisting of a hyperechoic or anechoic center surrounded by multiple hyperechoic and hypoechoic concentric rings in transverse sections. In longitudinal sections, the intussusception appeared as multiple hyperechoic and hypoechoic parallel lines, as a tumor-like or pseudokidney mass, and as a trident-like configuration. Ultrasonography may provide a sensitive, specific, and accurate method of diagnosing intestinal intussusception in young dogs.     

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.     

Ultrasonographic evaluation of renal parenchymal diseases in dogs: 32 cases (1981-1986)

The medical records of 32 dogs with microscopically proven renal parenchymal disease were evaluated to characterize the associated ultrasonographic patterns and to assess the contribution of ultrasonography to the diagnosis and management in each case. Ultrasonography provided additional information on internal renal architecture in 18 dogs with radiographic evidence of structural abnormality. Ultrasonography determined the renal origin of 2 abdominal masses, defined the extent and distribution of neoplastic disease in 6 dogs, and identified kidneys not seen on survey radiographs or excretory urograms in 5 dogs because of decreased abdominal contrast or poor function. The ultrasonographic patterns were most specific for focal and multifocal or diffuse neoplasia. Ultrasonographic findings were least specific for diffuse parenchymal disease without architectural disruption such as glomerulo/interstitial nephritis, renal tubular necrosis, and nephrocalcinosis. In these cases, biopsy was recommended. Six interpretive errors were made. Four of these errors were related to the overestimation of renal pelvic and diverticular size because of confusion with medullary papilla. Two errors occurred in the diagnosis of renal lymphosarcoma, one of which was interpreted to be pyelonephritis. The other was an interpretive dilemma because of absence of hypoechoic multifocal nodules. Renal tubular necrosis was confirmed in this case.     

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     

ULTRASONIC PATTERNS OF CANINE HEPATIC LYMPHOSARCOMA

Three ultrasonic patterns of canine hepatic lymphosarcoma were found. The first pattern reflected a normal hepatic parenchymal appearance or a slight reduction in echogenicity. The second pattern consisted of anechoic or hypoechoic, poorly marginated lesions. A third pattern was characterized by multiple, round echodensities surrounded by areas of sonolucency. It was concluded that ultrasound is helpful for diagnosis and staging of canine lymphosarcoma with liver involvement and is useful for monitoring the response to chemotherapy.     

ULTRASONOGRAPHIC IMAGING OF THE VAGOSYMPATHETIC TRUNK IN THE DOG

The purpose of this study was to evaluate the applicability of ultrasonographic imaging of the vagosympathetic trunk in the dog. Cervical ultrasound was performed in 30 healthy dogs. In all 30 dogs the vagosympathetic trunk was detected as a hypoechoic structure in the carotid sheath, adhering the dorsomedial surface of the common carotid artery. The echotexture of the nerve was heterogeneous with anechoic areas separated by hypoechoic bands. A scanner equipped with a 5 to 8 MHz linear array probe was used for imaging and measurements. The diameter of the vagosympathetic trunk ranged from 0.59 to 2.48 mm varying in correlation to the body weight. In summary, ultrasonography is a helpful noninvasive method to image and evaluate the cervical vagosympathetic trunk in the dog.     

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).     

Ultrasonographic-anatomic correlation and imaging protocol for the spleen in anesthetized dogs

Sonographic and/or anatomic observations were made of the spleen in 27 dogs. Anatomic studies were used to establish precise correlations between the gross anatomic features of the organ and its ultrasonographic image. In 8 anesthetized dogs, ultrasonographic images of the spleen were made in dorsal, transverse, and sagittal planes. When it was incident to the ultrasonic beam, the splenic capsule was represented by a fine echogenic line that defined the boundaries of the organ. The splenic substance had a uniformly mottled echogenicity apart from the anechoic lumen of the splenic venous rami, which were detected at and near the hilus of the spleen. Less regularly, splenic arterial rami were detected at the hilus, but not within the splenic substance. Dorsal and transverse images were made with the ultrasonic transducer perpendicular to the left thoracic and abdominal wall at the 11th intercostal space and caudoventrad to it. Sagittal images were produced with the transducer's face directed craniad, placed parallel to the left lateral abdominal wall, and pushed under the costal arch. The adoption of such an ultrasonographic imaging protocol ensures that all of the spleen is inspected. A definitive opinion can then be given as to whether the spleen is normal or abnormal. Pathologic changes in the spleen must also be differentiated from changes in adjacent organs or structures.     

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.     

ULTRASONGRAPHIC FINDINGS IN HEPATIC AND SPLENIC LYMPHOSARCOMA IN DOGS AND CATS

In a survey of patients with histologically-confirmed hepatic lymphosarcoma at Tufts University, abnormal ultrasound findings were detected in 3 of 14; two had diffuse hepatic hypoechogenicity, one had a focal hypoechoic lesion. In contrast, 5 of 6 patients with spleic lymphosarcoma had an abnormality on ultrasongraphy; two had diffuse hypoechogenicity, one had multiple hypoechoic foci, one had a large, cavitated-appearing mass, and one had an irregular border. In our experience, ultrasonography is an insensitive means of detecting hepatic lymphosarcoma but appears more sensitive for detection of splenic lymphosarcoma.     

IMAGING DIAGNOSIS—ULTRASONOGRAPHIC APPEARANCE OF SKELETAL MUSCLE METASTASES IN A DOG WITH HEMANGIOSARCOMA

A 13‐year‐old spayed female German shepherd dog was presented for acute onset of lethargy, anorexia, and disseminated erythematous skin lesions. Thoracic radiographs and abdominal ultrasonographic findings were consistent with metastatic hemangiosarcoma. Multiple, ill‐defined, irregularly shaped hypoechoic nodules were also detected within the thoracic and abdominal wall. Hemangiosarcoma metastases to the skeletal muscle were confirmed based on histopathological examination. Multivisceral involvement was also confirmed by necropsy. Metastatic neoplasia should be considered as a differential diagnosis for dogs with ill‐defined, irregular, hypoechoic, intramuscular nodules.     

SONOGRAPHIC FEATURES OF HISTIOCYTIC NEOPLASMS IN THE CANINE ABDOMEN

The purpose of this retrospective study was to describe the ultrasonographic features of malignant histiocytosis (MH), malignant fibrous histiocytoma, and histiocytic sarcoma in abdominal organs of dogs. The medical records of 18 dogs that had undergone abdominal sonography and had a histopathologic diagnosis of abdominal MH, malignant fibrous histiocytoma, and histiocytic sarcoma were reviewed. The organ most commonly affected was the spleen. MH was the most common followed by histiocytic sarcoma and malignant fibrous histiocytoma. In the spleen there were often multiple hypoechoic nodules with well-defined borders. In one dog, without focal lesions, the spleen was enlarged and hypoechoic. The liver was the second most commonly affected organ. MH was most common followed by histiocytic sarcomas and malignant fibrous histiocytoma. The most common sonographic feature in the liver was the presence of multiple hypoechoic nodules with well-defined borders. One dog without hepatic nodules had a liver that was ultrasonographically enlarged and hypoechoic. MH in the abdominal lymph nodes resulted in hypoechoic lymphadenopathy. Malignant fibrous histiocytoma was the only neoplastic type in the kidneys appearing as a single heteroechoic renal mass with well-defined borders. MH was observed in the stomach of one dog. Sonographically there was a single well circumscribed hypoechoic mass with well-defined borders and abnormal stomach layers. In this study it was not possible to differentiate between MH, malignant fibrous histiocytoma, and histiocytic sarcoma using sonography.     

Contrast-enhanced ultrasonography for characterization of focal splenic lesions in dogs

Background: Contrast‐enhanced ultrasonography with perflubutane microbubbles improves the diagnostic accuracy to differentiate benign and malignant focal liver lesions in dogs. Hypothesis: Perflubutane microbubbles‐enhanced ultrasonography is useful for differentiation of benign from malignant focal splenic lesions in dogs. Animals: Twenty‐nine clinical dogs with single or multiple focal splenic lesions detected by conventional ultrasonography. Methods: Prospective clinical observational study. Perflubutane microbubbles‐enhanced ultrasonography was performed in 29 dogs with focal splenic lesions. Qualitative assessment of the enhancement pattern was performed in the early vascular, late vascular, and parenchymal phases. Results: In the early vascular phase, a hypoechoic pattern was significantly associated with malignancy (P= .02) with sensitivity of 38% (95% confidence interval [CI], 25–38%) and specificity of 100% (95% CI, 84–100%). In the late vascular phase, a hypoechoic pattern was significantly associated with malignancy (P= .001) with sensitivity of 81% (95% CI, 66–90%) and specificity of 85% (95% CI, 65–95%). There was no significant difference between malignant and benign lesions during the parenchymal phase. Conclusions and Clinical Importance: Hypoechoic splenic nodules in the early and late vascular phases with perflubutane microbubbles‐enhanced ultrasonography are strongly suggestive of malignancy in dogs.     

IMPROVED DETECTION OF METASTATIC HEPATIC HEMANGIOSARCOMA NODULES WITH CONTRAST ULTRASOUND IN THREE DOGS

Three dogs with a splenic hemangiosarcoma were imaged with conventional gray-scale ultrasound and no lesions were identified in the liver. After administration of intravenous ultrasound contrast medium (Definity) small, poorly enhanced, hypoechoic nodules were identified in the liver in each dog. The spleen and liver lesions were identified at surgery and the dogs underwent splenectomy and nodule biopsy. All lesions were identified histologically as hemangiosarcoma. These preliminary results suggest that contrast ultrasound may result in improved detectability of metastatic hepatic hemangiosarcoma.     

ULTRASONOGRAPHIC FEATURES OF PARAPROSTATIC CYSTS IN NINE DOGS

The ultrasonographic features of paraprostatic cysts in nine dogs are described along with historical, clinical, surgical and pathologic findings. Cysts occurred predominantly in older, large breed dogs (mean age 8 years, range 3–11 years). The most common presenting complaints were depression, inappetance, stranguria, tenesmus and bloody penile discharge. A palpable abdominal mass was the most common physical finding. Ultrasonographically, paraprostatic cysts were usually large anechoic structures; many contained internal septa. Moderately large anechoic cavities or cysts were also detected in the prostatic parenchyma of five dogs, and in two of these communication with the paraprostatic cyst was visualized. There were no clearly distinct ultrasonographic criteria to discriminate septic from nonseptic paraprostatic cysts.