Comparison of nonenhanced computed tomography and ultrasonography for detection of ureteral calculi in cats: A prospective study.

BACKGROUND: Radiographs and ultrasound (US) are the primary imaging modalities used to assess ureteral calculi in cats. Reports describing the use of nonenhanced computed tomography (CT) are scarce. HYPOTHESIS/OBJECTIVES: To compare US and nonenhanced CT for detection, number and localization of ureteral calculi in cats. ANIMALS: Fifty-one cats with at least 1 ureteral calculus, and 101 ureters. METHODS: Prospective case series. All cats underwent an US followed by a nonenhanced CT. Cats were included in the study if at least 1 ureteral calculus was diagnosed on either modality. Number of calculi and their localization (proximal, middle, and distal) were recorded on both modalities. Pelvic dilatation and maximal ureteral diameter were recorded with US. RESULTS: More calculi were detected by nonenhanced CT (126) compared to US (90), regardless of localization (P < .001). More ureters were affected on nonenhanced CT (70) compared to US (57; P < .001). The number of calculi detected was significantly different between US and nonenhanced CT in the proximal (P = .02) and distal ureteral region (P < .001). Bilateral calculi were more frequent with nonenhanced CT (19 cats) compared to US (9 cats; P < .001). A pelvic size superior to 5 mm and a maximal ureteral diameter value superior to 3 mm were always associated with ureteral calculi. CONCLUSIONS AND CLINICAL IMPORTANCE: Computed tomography is an emerging imaging modality in cats with a suspected ureteral obstruction. Combination of CT and US can be beneficial for case management.

Brain Ependymoma in an African Grey Parrot (Psittacus erithacus erithacus).

A 14-year-old unsexed African grey parrot (Psittacus erithacus erithacus) was presented with a 12-hour history of neurological signs and vomiting. The external physical examination of the patient revealed lethargy, moderate hypothermia, a head tilt, and horizontal nystagmus. Whole-body radiographic imaging and blood biochemistry parameters were unremarkable, and a serological test to detect bornavirus was negative. A computed tomography scan of the bird revealed a large cystic lesion located on the fourth ventricle of the brain. In spite of treatment (nonsteroidal anti-inflammatory drugs and antibiotic and antiparasitic therapy), the parrot's health continued to decline, and it was euthanatized 12 days after presentation. A complete postmortem examination was performed on the patient's brain. Histopathological interpretation of tissues submitted described a large neoformation composed of cells arranged in perivascular pseudorosettes. Hyperchromatic nuclei and marked anisokaryosis were suggestive of a malignant tumor. The tissue mass was associated with significant dilation of the fourth ventricle and a severe peripheral gliosis. The histopathological diagnosis of the neoformation was an ependymoma. Ependymomas are glial tumors of the ependymal cells that line the central canal and the ventricles of the brain and are rarely described in mammals. In birds, ependymomas were only described in budgerigars (Melopsittacus undulatus). In human medicine, the recommended treatment is surgical removal of the tumor when possible, followed by radiotherapy.

Rectal duplication in an adult cat: a novel transanal surgical approach.

CASE SUMMARY: A 3-year and 8-month-old male entire European domestic shorthair cat was presented with a history of recurrent rectal prolapse, straining and pain when defaecating. Previous non-surgical and surgical treatments had not provided a satisfactory result. Rectal prolapse had recurred within 2 weeks of treatment. Upon clinical examination, an intraluminal mass could be palpated rectally. A CT scan examination revealed the mass was of a cystic nature and the cyst was surgically excised via a transanal approach. On histological evaluation, the cyst walls consisted of three of the layers of normal rectum: mucosa, muscularis of the mucosa and submucosa. These findings led to the definite diagnosis of rectal duplication. RELEVANCE AND NOVEL INFORMATION: Enteric duplication is among the differential diagnoses for straining and rectal prolapse in cats. This condition has previously been discussed in the veterinary literature, with a single case report describing a rectal duplication in a cat. In that particular case, the authors described a perineal surgical approach. Here we present a novel approach whereby the duplicated material was excised transanally in order to limit intra- and postoperative morbidity. The clinical outcome was excellent in our case, with complete resolution of clinical signs and no recurrence 18 months after surgery.

Imaging of primary bone tumors in veterinary medicine: which differences?

Veterinary medicine is most often a mysterious world for the human doctors. However, animals are important for human medicine thanks to the numerous biological similarities. Primary bone tumors are not uncommon in veterinary medicine and especially in small domestic animals as dogs and cats. As in human medicine, osteosarcoma is the most common one and especially in the long bones extremities. In the malignant bone tumor family, chondrosarcoma, fibrosarcoma and hemangiosarcoma are following. Benign bone tumors as osteoma, osteochondroma and bone cysts do exist but are rare and of little clinical significance. Diagnostic modalities used depend widely on the owner willing to treat his animal. Radiographs and bone biopsy are the standard to make a diagnosis but CT, nuclear medicine and MRI are more an more used. As amputation is treatment number one in appendicular bone tumor in veterinary medicine, this explains on the one hand why more recent imaging modalities are not always necessary and on the other hand, that prognostic on large animals is so poor that it is not much studied. Chemotherapy is sometimes associated with the surgery procedure, depending on the aggressivity of the tumor. Although, the strakes differs a lot between veterinary and human medicine, biological behavior are almost the same and should led to a beneficial team work between all.

Solitary bone lesions: which ones to worry about?

The question is not classic: which signs suggest a possible malignancy when faced with a solitary bone lesion? Usually radiologists try to identify the leave me alone lesions, for which nothing is needed. Here we consider the suspicious lesions. Clinical and radiological indicators are proposed, leading to a probability. Nowadays, a biopsy is nevertheless always requested before treating a malignant lesion, even if suspicion is very high. But histology should integrate with the radiological signs.

Clinical significance and prognosis of deep digital flexor tendinopathy assessed over time using MRI.

Deep digital flexor (DDF) tendinopathy is one of the most frequent causes of foot lameness and the prognosis is guarded. The progress of lesion healing may be followed by magnetic resonance (MR) imaging to formulate a prognosis and to adapt the rehabilitation program. We assessed the correlation of outcome with total tendon damage and temporal resolution of MR abnormalities. Images from 34 horses with DDF tendinopathy that had undergone at least two low-field standing MR examinations of the foot (mean 2.5 ± 1.3 times) were reviewed. No horse having a T1-GRE hyperintense lesion over 30 mm in length or over 10% tendon cross-sectional area returned to its previous activity level. Horses with concomitant lesions had worse outcome than horses with DDF tendinopathy only (P = 0.005). In all horses including those with excellent outcome, the lesion persisted, even mildly, in T1-GRE and PD images. Horses with tendon lesion resolution on STIR-FSE and T2-FSE images on recheck examination had a better outcome (P = 0.0004 and P = 0.002, respectively), and all horses that returned to their previous level of performance had complete resolution of signal hyperintensity on the STIR-FSE sequence. Although rehabilitation remains multifactorial, characteristics of DDF tendinopathy and concomitant lesions on first and recheck MR examinations allow refining the prognosis.