Maurizio Longo

Clinical and computed tomography tumour dimension assessments for planning wide excision of injection site sarcomas in cats: how strong is the agreement?

In injection site sarcoma (ISS) in cats lateral as well as deep margins should be correctly planned for a successful surgical outcome. The discrepancy between clinical and computed tomography (CT) measurements of dimension in resectable tumour has led to possible bias that affects the subsequent surgical dose. The aim of this study was to prospectively investigate the agreement between clinical and CT measurements of dimension in newly diagnosed ISS in cats. Fifty-three client-owned cats that underwent both clinical and CT measurements of the length and width of ISS were included. CT measurements showed a tendency towards being larger than clinical dimensions, and this difference increased with increasing tumour size. Based on our results, in further studies focusing on ISS in cats, the kind of assessment used to define tumour dimensions (CT versus clinic) should be declared and specified to properly consider surgical results and prognostic impact of this variable.

Advances in the anatomic study of the interscapular region of the cat

BackgroundNew clinical oriented approaches are supported by the integration of advanced imaging techniques, e.g. computed tomography and magnetic resonance, with gross anatomy imaging. The interscapular region of the cat is a typical site of a highly invasive infiltrative pathology, i.e. Feline Injection-Site Sarcoma. Even if chemotherapy and radiotherapy have been considered as pre-surgical therapies, extensive surgery is still the recommended treatment. Evidence suggested that the relationships between muscles, infiltrative mass and adjacent musculoskeletal structures could change according to the forelimb positions: a fact to be duly considered while planning the surgical approach.Anatomic and tomographic atlases provide only images of the interscapular region from cats positioned with their forelimbs extended cranially, which means that, they do not record musculoskeletal modifications due to the forelimb movements.Aim of this study was to provide detailed images of the changes occurring in the musculoskeletal structures of the interscapular region of cats according to their forelimb position by comparing cross-sectional gross anatomy, computed tomography and magnetic resonance imaging.ResultsWe provide an atlas of normal cross-sectional anatomy, computed tomography and magnetic resonance imaging of the interscapular region of the cat, from the fifth cervical vertebra to the fifth thoracic vertebra. We compare and couple the slices obtained both in flexed and extended forelimb positioning with the animal maintained in sternal recumbency.ConclusionThis study shows a new and dynamic way to investigate the interscapular region of the cat and provides anatomical references for in vivo computed tomography and magnetic resonance imaging, considering changes in the muscular form according to the forelimb positioning. We believe that an in-depth anatomical knowledge of the interscapular region may be helpful to approach the study of any pathology located there and, in particular, to set up an appropriate therapy for the feline injection-site sarcoma.

A rare case of pituitary chromophobe carcinoma in a dog: Clinical, tomographic and histopathological findings

A 9 year old male mixed-breed dog was presented for progressive aggressiveness towards the owner. The neurological evaluation was consistent with a forebrain syndrome. Magnetic Resonance Imaging (MRI) of the brain revealed enlargement of the third ventricle and presence of a large spheroidal neoplasm in the sellar/parasellar region suggestive of a pituitary macroadenoma. On the owner request, the dog was euthanized. Histopathological examination revealed the presence of a pituitary chromophobe carcinoma. To the author’s knowledge, pituitary carcinomas have been rarely described in dogs, especially the chromophobe subtype.

Ultrasound and computed tomography of sacculitis and appendicitis in a rabbit

A 9-month-old neutered male rabbit was referred for lethargy, anorexia, and gastrointestinal stasis. Routine hematology, serum biochemistry, and diagnostic imaging were performed. Computed tomography revealed a wall thickening of the sacculus rotundus and appendix, which was further confirmed on abdominal ultrasound. Full thickness biopsies were collected with histopathology diagnosing a chronic multifocal heterophilic granulomatous sacculitis and appendicitis. The patient was treated medically and at 6 weeks follow-up, clinical signs and intestinal changes had completely regressed. Inflammation of the sacculus rotundus and appendix should be considered as a cause of gastrointestinal stasis in rabbits.

Real‐time elastosonography of lipomatous vs. malignant subcutaneous neoplasms in dogs: Preliminary results

Real-time elastography is a recently introduced ultrasound technique allowing the investigation of elastic properties of tissues. A diagnostic accuracy study was conducted to test the performance of this technique in the assessment of subcutaneous lesions in dogs. Fifty-two dogs were prospectively included in the preliminary study (34 malignant and 18 benign lesions). B-mode ultrasound was performed assessing the shape, margins, heterogeneity, and echotexture of the lesions. On elastosonography, assessment of the percentage of softness/hardness was recorded. A qualitative assessment was performed according to the Tsukuba elasticity score with a 1-5 score, representing the increased percentage of high stiffness areas. Results were compared with cytology/histopathology of the lesions. Receiver Operating Curves of the overall diagnostic sensitivity and specificity were obtained. Fishers exact test and Pearsonss Chi-squared test estimated the relationship between the B-mode appearance of the lesions and final diagnosis. A hardness cutoff of 50.25% was identified between lesions, with malignant neoplasms having higher percentages. A 100% specificity and 89% sensitivity for correctly detecting the nature of the lesion on elastosonography was established. Qualitative assessment of the Tsukuba elasticity score established 1.5 as the cutoff between elastograms of lipomatous and malignant lesions, with 100% sensitivity and 61% specificity in differentiating them. Real-time elastosonography is a novel, noninvasive, and accurate technique for differentiating malignant from benign lipomatous lesions in dogs. This method could be considered as a complementary tool with additional diagnostic value for routine invasive procedures, such as fine needle aspirates.

Vascular conspicuity differs among injection protocols and scanner types for canine multiphasic abdominal computed tomographic angiography

Multiphasic multidetector computed tomographic angiography is a standard diagnostic test for canine abdominal vascular disorders. Three imaging protocols have been previously described. The test-bolus protocol allows precise timing but can be time consuming to perform. Bolus-tracking software is fast and easy to use but can be problematic for exact timing of vascular phases. A recently described fixed-injection-duration protocol is not influenced by body weight and provides a wider temporal window for arterial acquisitions. Objectives of this retrospective and prospective, multicentric, method comparison study were to determine which of the three multidetector computed tomographic angiography protocols allows best vascular conspicuity of the canine abdomen and to assess the influence of different multidetector computed tomography (CT) scanners on study quality. Triple-phase multidetector computed tomographic angiography canine abdominal studies from 30 dogs were retrospectively retrieved from three different institutions. Each institution performed one of the three computed tomographic angiography protocols (4-row and 16-row multidetector CT). Prospectively, the three protocols were also acquired with similar conditions on a 64-row MDCT in 21 dogs. Main abdominal vessels were scored by blinded readers for each phase. The fixed-injection-duration protocol had the best combined arterial and portal vascular conspicuity on scanners of limited speed, while the test-bolus protocol provided the best overall vascular conspicuity on 64-row multidetector CT scanner. The quality of arterial studies performed on 64-row MDCT scanner was improved compared to the ones performed on four- to 16-row multidetector CT scanners. Findings supported the fixed-injection-duration protocol as the best compromise between an ideal portal vascular enhancement and an easily reproducible protocol on scanners with low and high number of detector rows.

Dynamic tomographic studies of interscapular feline injection-site sarcoma: essential or useless practice?

Objectives Feline injection-site sarcomas (FISSs) are soft tissue tumours typically characterised by an interscapular location and highly infiltrative behaviour. CT is considered the modality of choice for FISS staging and double positioning (dynamic approach) was reported to successfully detect the exact extent of infiltration into the muscles. The aim of the present study was to investigate the utility of the dynamic approach in feline patients referred for preoperative staging of interscapular FISS. Methods Tumour volume estimates were compared between the ellipsoid and the semi-automated segmentation methods. Two radiologists blinded to the patient coding used images from each position to assess the extent of muscular infiltration. The distance between the neoplasm and the adjacent skeletal structures (scapulae, spinous processes) was recorded in both positions by a single radiologist. Results Fifty-nine of 84 neoplasms invaded the adjacent muscular structures, with up to 15 muscles infiltrated. Between the extended and flexed position the average estimated numbers of muscles infiltrated were 1.9 (extended) and 1.84 (flexed) for observer A and 1.89 (extended) and 1.85 (flexed) for observer B. Good agreement between observers was established, with higher tumour volumes detected via the ellipsoid method. Moreover, tumours with smaller volumes showed slightly decreased muscular infiltration. Marked difference in the recorded distance between the skeletal structures and the neoplasm in the two different positions was established (mean ± SD difference spinous processes: 9.74 ± 9.57 mm; mean ± SD difference scapulae: 15.15 ± 11.76 mm). Conclusions and relevance A dynamic approach should be used for a complete evaluation of the invasiveness of FISS along with appropriate methodology for tumour volume measurement, which could potentially alter the tomographic estimation of the real dimension of the neoplasms.

A First Case Description of Adrenal Gland Tumour in a Lion (Panthera Leo): Tomographic and Clinico-Pathological Findings

The lion was sedated by tele-anaesthesia with dexmedetomidine (5 mcg/kg) and ketamine (2 mg/kg) combination. A complete clinical evaluation and subsequent abdominal ultrasound examination were performed by the referring veterinarian with no significant abnormalities reported. Blood was collected to perform a complete blood count, a basic serum chemistry panel (AST, ALT, Albumin, ALKP, GGT, Total Bilirubin, Cholesterol, Total Protein, Triglycerides, Glucose, Urea, Creatinine, Albumin, Globulin and A/G ratio, Ca++, P, Na+, K+, Cl-), and the measurement of serum concentrations of thyroxine (T4), cortisol and testosterone. Serum protein electrophoresis and Feline Immunodeficiency Virus (FIV)/Feline Leukemia Virus (FeLV) tests were also performed. Nevertheless, laboratory results were unremarkable. The patient was discharged in order to collect data from the examinations performed. Over the next three months, the patient did not show any significant improvement of the clinical condition with a severe anorexia, progressive weight loss and lethargy. Therefore, the patient was immobilised again with the same anaesthetic protocol and after the placement of a 18G catheter into the right cephalic vein, the patient was maintained deeply sedated until reaching the University Hospital – Azienda Polo Veterinario di Lodi. A constant rate infusion (CRI) was administered by infusion pumps at 6 mcg/kg/h of dexmedetomidine, to achieve an adequate continuous sedation (approximately for 3 hours). At the arrival the CRI was stopped and an intravenous bolus of propofol (~0, 5 mg/kg) was administered in order to obtain orotracheal intubation; general anaesthesia was maintained by isoflurane in 100% oxygen to effect, on mechanical ventilation. The patient was placed in dorsal recumbency on the computed tomography (CT) table with the hindlimbs extended caudally. A complete CT examination of the abdomen was Abstract

Therapeutic chemonucleolysis of the lumbosacral disk in a cadaveric model: lateral vs sternal technique.

The widespread use of advanced Imaging techniques has dramatically improved the diagnosis of cauda equina syndrome in geriatric small animal patients. Two different techniques (sternal vs lateral recumbency) were tested in twelve cadavers for the L7-S1 disk injection under fluoroscopic guidance. Twelve dogs were enrolled in the study: eight intervertebral lumbosacral disks were injected with a gelatinous radiopaque compound and the remnants four disks with an alcoholic radiopaque solution. The dogs were randomly positioned either in lateral recumbency with the lumbo-sacral joint in neutral position (six dogs), or in sternal recumbency with the hind limbs extended cranially along the body and the lumbosacral joint flexed (six dogs). The correct injection of the compounds within the lumbosacral disk was checked both by computed tomography (CT) and gross anatomic examination. The lateral technique required less time of execution and minor attempts for the correct positioning of the needle. All the injected disks were visible on CT, while necroscopy resulted satisfactory only in five patients. Leakage of the compounds outside the disk was observed in two cases. The percutaneous injection in lateral recumbency under fluoroscopic guidance resulted rapid and feasible in a cadaveric model. Future clinical trials are required to assess the safety of chemonucleolysis in diseased patients.

Presumptive cystic haemorrhages in a cat with polycystic kidney and hepatic disease

An adult Persian cat was referred after an abdominal ultrasound revealed a polycystic renal and hepatic disease along with a suspected renal mass on the left kidney. Two non-enhancing, hyperattenuating cysts were detected on CT on the left and on the right kidney, respectively. A presumptive diagnosis of intracystic bleeding was made, and the subsequently performed aspiration biopsies confirmed a chronic haemorrhage. At 12 months, the CT showed that the same renal lesions appeared similar. The present findings suggest that bleeding from cystic lesions should be considered in case of non-enhancing, heterogeneous and hyperattenuating renal lesions in cats.