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1.
Magnetic resonance imaging (MRI) has been recommended for staging and surgical planning in cats with injection site sarcomas (ISS). The purpose of this retrospective study was to describe low‐field MRI characteristics of confirmed injection site sarcomas in a group of cats. Low‐field MR images, thoracic radiographs, histopathology findings, and medical records of cats that fulfilled histological criteria of injection site sarcoma were retrieved and reviewed retrospectively. Presence or absence of tumor mineralization and pulmonary metastases were recorded from thoracic radiographs. Characteristics recorded from low‐field MRI studies included tumor number, volume (ellipsoid method), intensity relative to surrounding musculature, homogeneity, regions of signal void (mineralization) or cavitation, degree and pattern of contrast enhancement, tumor margination, presence of a peripheral T2W hyperintense zone, and bone contact. A total of 19 cats met inclusion criteria. Cats with multiple tumors were more likely to have had previous excisional biopsy, and were less likely to undergo definitive surgery. All tumors were hyperintense relative to surrounding musculature on T1W and T2W images. Larger tumors were more likely to exhibit mineralization (P < 0.05). Tumor volume could not predict tumor‐free margins at definitive surgery. The majority of tumors showed moderate to marked heterogeneous contrast enhancement. Infiltrative margins and the presence of a peripheral T2W hyperintense zone were more prevalent following excisional biopsy, while cavitation was more prevalent following incisional biopsy. Findings indicated that low‐field MRI characteristics of injection site sarcoma may vary widely and may be affected by prior incisional or excisional biopsy.  相似文献   

2.
The purpose of this retrospective study was to determine the magnetic resonance imaging (MRI) characteristics of feline brain tumors and to determine whether these characteristics can be used to accurately predict the histologic diagnosis. MRI scans of 46 cats with histologically confirmed brain tumors were reviewed, including 33 meningiomas, 6 lymphomas, 4 gliomas, 2 olfactory neuroblastomas, and 1 pituitary tumor. MRI features including axial origin, shape, location, signal intensity, contrast enhancement, peritumoral edema, and mass effect were reviewed and characterized for each tumor type. Tumor shape, axial origin, contrast enhancement, and degree of peritumoral edema aided in the identification of tumor type. Meningiomas were always extra-axial and were most often ovoid with marked contrast enhancement and mild peritumoral edema. Gliomas were always intra-axial with ring enhancement and generally caused more peritumoral edema than other tumors. The brain tumor was detected on MRI in 45 (98%) cats. Two blinded independent reviewers correctly identified 82% of all of the tumor types on the basis of MRI appearance alone. Thus, MRI is an excellent diagnostic tool for the detection of brain tumors in cats, and it provides important information to aid in the diagnosis of tumor type.  相似文献   

3.
Feline injection‐site sarcoma (FISS) is commonly treated with surgery and radiation therapy. Despite aggressive therapy, FISS has a high recurrence rate. The true benefit of adjuvant chemotherapy is not known. DNA damage response mechanisms help protect against genomic instability but can also promote chemoresistance. In order to determine whether DNA damage is a feature of FISS, we evaluated tumour tissues with γH2AX immunohistochemistry. H2AX is phosphorylated to form γH2AX following DNA double strand breaks. Seventeen FISS specimens were evaluated prospectively. DNA damage ranged from 2.18 to33.7%, with a median of 16.2%. Significant differences were noted between cats (P < 0.0001). Mitotic index ranged from 0 to 57 with a median of 13 and did not correlate with γH2AX positivity (P = 0.2). Further studies are needed to determine if γH2AX expression may predict chemosensitivity and have independent value as a prognostic factor.  相似文献   

4.
Little published information is available to guide therapy for canine and feline patients with Coccidioides infections involving the central nervous system (CNS). The purpose of this cross‐sectional retrospective study was to describe magnetic resonance imaging (MRI) features and outcome for a group of dogs and cats with solitary CNS Coccidiodes granulomas. Nine canine and two feline cases met inclusion criteria; four diagnosed and treated with surgery and fluconazole and seven diagnosed by serology or cytology and treated medically. Three cases had left Coccidioides endemic areas long before developing neurological disease. The MRI lesions shared many features with neoplastic masses. The extra‐axial granulomas often had a lack of a distinct border between the mass and neural parenchyma. Four cases were extra‐axial and seven were intra‐axial, but distinguishing between extra‐axial and intra‐axial locations was sometimes challenging. The surgical cases had good outcomes and histology allowed definitive diagnosis. Medically managed patients also had generally good outcomes, with resolution of clinical signs in most cases. Findings indicated that distinction between neoplasia and focal Coccidioides granulomas based on MRI features is likely to be imprecise. Demonstration of the organism by cytology or histology is required for definitive diagnosis. The role of surgery for improving the outcome of brain or spinal coccidioidomycosis granulomas warrants further study.  相似文献   

5.
This study assesses the outcome of two combined treatment strategies for the treatment of feline injection‐site sarcoma (FISS). Twenty‐one cats with primary or recurrent FISS received 3 cycles of neoadjuvant chemotherapy with epirubicin (25 mg m?2), then an anatomical resection of the entire muscle compartment containing the tumour was performed based on the findings of co‐axial imaging. Cats then received a further 3 cycles of adjuvant chemotherapy. Follow‐up was performed by telephone contact with a median follow‐up time of 1072 days. Three cats (14%) developed local tumour recurrence at days 264, 664 and 1573 after surgery. A median survival time could not be calculated as over 80% of the study population remained alive or were censored due to death from other causes. When compared to historical controls, the results of this study demonstrate superior rates of tumour‐free survival and disease‐free interval.  相似文献   

6.
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.  相似文献   

7.
Therapy of cats suffering from feline injection site sarcomas (FISS) is still a challenging problem, as the recurrence rate after surgery is up to 70%. Four FISS-derived primary tumour cell lines and corresponding xenograft tumour mouse models were established to evaluate the efficacy of a concomitant chemo-/radiation therapy with doxorubicin. In vitro, strongly depending upon the timing of administration, pre-treatment with 0.25 µmol doxorubicin resulted in a significant enhancement of radiation-induced (3.5 Gy) tumour cell death. This result was confirmed in vivo, where only the combined chemo-/radiation therapy resulted in a significant reduction in tumour growth compared to the respective mono-therapies with either doxorubicin or radiation. These results support the use of the concomitant chemo-/radiation therapy for adjuvant treatment of FISS, particularly in advanced or recurrent disease where surgery alone is no longer feasible.  相似文献   

8.
The objective of this retrospective study was to estimate using magnetic resonance imaging the size range of the pituitary gland in cats who had no evidence of pituitary disease. The pituitary gland was measured from transverse and sagittal magnetic resonance postgadolinium T1-weighted images in 17 cats. The cats were 0.83 to 15 years of age and weighed between 2.9 and 6.5 kg. Linear pituitary measurements were performed on a dedicated workstation using electronic calipers. Mean (+/- standard deviation) pituitary gland length was 0.54 cm (+/- 0.06 cm) and mean width was 0.50 cm (+/- 0.08 cm). Mean pituitary gland height measured on sagittal images was 0.34 cm (+/- 0.05) and measured on transverse images was 0.32 cm (+/- 0.04 cm). Mean pituitary volume was 0.05 cm3 (+/- 0.01 cm3). There was no significant correlation between cat weight (kg) and pituitary volume or age and pituitary volume. The pituitary gland appearance varied on pre- and postcontrast T1-weighted images. On the precontrast images, the majority of pituitary glands had a mixed signal intensity. On postcontrast images, uniform pituitary gland enhancement was seen commonly.  相似文献   

9.
Evaluation of brain disease in veterinary patients uses a wide variety of MRI sequences. A shortened protocol that maintains consistency of interpretation would reduce radiologist reporting time, patient anesthetic time, and client cost. The aims of this retrospective, methods comparison, observer agreement study were to evaluate whether abbreviated MRI protocols alter differential diagnoses and recommendations compared to our institution's standard protocol; evaluate interobserver agreement on standard brain MRIs; and assess whether differential diagnoses change after postcontrast images. Normal and pathologic canine and feline brain MRIs were retrieved from hospital archives. Three protocols were created from each: a 5-sequence noncontrast enhanced Fast Brain Protocol 1 (FBP1); a 6-sequence contrast-enhanced Fast Brain Protocol 2 (FBP2); and an 11-sequence standard brain protocol (SBP). Three blinded veterinary radiologists interpreted FBP images for 98 cases (1 reader/case) and SBP images for 20 cases (3 readers/case). A fourth observer compared these interpretations to the original MRI reports (OMR). Overall agreement between FBPs and OMR was good (k = 0.75) and comparable to interobserver agreement for multiple reviews of SBP cases. Postcontrast images substantially altered conclusions in 17/97 cases (17.5%), as well as improved interobserver agreement compared to noncontrast studies. The conclusions reached with shortened brain protocols were comparable to those of a full brain study. The findings supported the use of a 6-sequence brain MRI protocol (sagittal T2-weighted [T2w] TSE; transverse T2w turbo spin echo fluid-attenuated inversion recovery, T2*-weighted gradient recalled echo, T1-weighted spin echo, and diffusion weighted imaging/apparent diffusion coefficient; and postcontrast transverse T1-weighted spin echo) for dogs and cats with suspected intracranial disease.  相似文献   

10.
A 6‐year‐old domestic short‐haired cat was presented with an acute onset of right cortical encephalopathy. Magnetic resonance imaging (MRI) performed 4 days after the onset of clinical signs revealed a lesion originating from the right frontal sinus with intracranial extension and compression of the right frontal lobe. The lesion was T1‐weighted hypointense and T2‐weighted and fluid‐attenuated inversion recovery hyperintense. Signal voids within the lesion were observed on T2* images, consistent with hemorrhage. Peripheral ring enhancement was visible on postcontrast sequences. These features were consistent with a giant hemorrhagic mucocele. To the authors’ knowledge, this is the first report of MRI characteristics of this lesion in a cat.  相似文献   

11.
It is not always possible to identify female cats that have undergone previous ovariohysterectomy based on physical examination alone. An easy, cost‐effective method for screening female cats for reproductive status would be helpful for avoiding unnecessary exploratory laparotomies. The purpose of this prospective study was to compare diagnostic sensitivities of digital radiography, ultrasonography, and positive contrast vaginourethrography for determining reproductive status in female cats. Sixty‐seven recently euthanized female cats of unknown medical history and reproductive status were randomly selected and included in the study. Digital abdominal radiography, digital abdominal radiography with compression, abdominal ultrasonography, and positive contrast vaginourethrography were performed in sequence by a board‐certified veterinary radiologist and a second‐year radiology resident. Immediately following diagnostic imaging procedures, necropsy was performed. Ultrasonography of the uterus had the highest sensitivity (86%) for determining reproductive status of all the imaging modalities tested. The specificity was 88%, and the positive predictive value and negative predictive value were 96% and 68%, respectively. The calculated sensitivities and specificities of other modalities were as follows: digital radiographs (28%, 100%), digital compression radiographs (58%, 100%), and vaginourethrography (32%, 100%). Based on McNemar's test statistic, there was a significant difference in the sensitivity of ultrasound compared to digital radiographs (P ≤ 0.05), compression radiographs (P ≤ 0.05), and vaginourethrogram (P ≤ 0.05). Findings from the current study indicated that ultrasonography is a sensitive diagnostic test for determining reproductive status in female cats. Although more readily available in private practice and shelters, digital radiography and vaginourethrography are not reliable predictors of reproductive status.  相似文献   

12.
Local recurrence (LR) is the major concern in the treatment of feline injection‐site sarcoma (FISS). Pretreatment leukocyte counts and ratios have been reported as diagnostic and/or prognostic markers in human and canine oncology. The aim of this retrospective study was to explore the prognostic impact on LR and overall survival time (OST) of pretreatment neutrophil‐to‐lymphocyte ratio (NLR), white blood cell count (WBCC), neutrophil count (NC) and lymphocyte count (LC) in cats with surgically excised FISS. Eighty‐two cats with histologically confirmed FISS at first presentation, without distant metastases, and with available pretreatment haematological analyses were retrospectively enrolled. The correlation of NLR, WBCC, NC, LC with tumour variables and patient variables was explored. NLR was correlated with tumour size (P = .004), histological pattern of tumour growth (P = .024) and histotype (P = .029), while WBCC and NC were associated with ulceration (P = .007, P = .011) and pattern of growth (P = .028, P = .004). No significant relationships emerged between LC and any of the considered variables. The impact of NLR, WBCC, NC, LC on LR and OST was then estimated in univariate and multivariate analysis. In univariate analysis, NLR, WBCC and NC were significant prognostic factors for both LR and OST. NLR, WBCC and NC remained prognostic in multivariate analysis for LR but not for OST. When NLR, WBCC and NC were jointly analysed, WBCC was the marker with the greater impact on LR. Preoperative NLR, WBCC and NC may aid in identifying cats at higher risk of LR.  相似文献   

13.
The aim of this retrospective study was to evaluate the outcome of cats treated with surgical intervention for a discrete intermediate‐/high‐grade gastrointestinal lymphoma prior to CHOP‐based chemotherapy. Variables including sex, breed, haematocrit, white blood cell count, serum albumin concentration, clinical stage of disease, gastrointestinal obstruction and peritonitis were assessed for their effect on survival. Twenty cats met the inclusion criteria with three cats still alive at the time of data analysis. The overall median survival time (MST) was 417 days (range: 12–2962 days). The disease‐free interval (DFI) was 357 days (range: 0–1585 days) with six cats still deemed in remission prior to death. Only clinical stage had a significant effect on both MST and DFI. Cats with discrete intermediate/high‐grade gastrointestinal lymphoma that undergo surgical resection followed by adjuvant CHOP chemotherapy may achieve acceptable overall survival times.  相似文献   

14.
Premortem magnetic resonance imaging (MRI) was performed in two cats with brain stem abscessation confirmed post mortem by histology and recovery of multiple bacterial species. The MRI features of the abscesses were distinctive and included a thick and marked enhancement of the abscess capsule and extension of the lesion from a tympanic bulla in one cat. A focal area of increased signal intensity was present on T2-weighted images. A circumscribed area of decreased signal intensity was surrounded by a ring of increased signal intensity on precontrast T1-weighted images. A center of decreased signal intensity with a thick, markedly enhanced abscess capsule was observed on post contrast T1-weighted images. These findings are compared to the current experimental and clinical literature of brain abscess. The underlying pathogenesis of MRI features is reviewed.  相似文献   

15.
Medical imaging is essential for the diagnostic workup of many soft tissue and bone lesions in dogs and cats, but imaging modalities do not always allow the clinician to differentiate inflammatory or infectious conditions from neoplastic disorders. This review describes interventional procedures in dogs and cats for collection of samples for cytological or histopathological examinations under imaging guidance. It describes the indications and procedures for imaging-guided sampling, including ultrasound (US), computed tomography (CT), magnetic resonance imaging and fluoroscopy. US and CT are currently the modalities of choice in interventional imaging.  相似文献   

16.
The purpose of this study was to describe the ultrasonographic (US) and computed tomographic (CT) appearance of autosomal dominant polycystic kidney disease (ADPKD) in cats; to compare renal volume in cats with ADPKD (n = 5; mean age 59 +/- 10 months)) and normal cats (n = 5; mean age 66 +/- 10 months) using 2 imaging modalities, US and CT; and to calculate cyst volume using CT. Glomerular filtration rate (GFR) was determined by 2 methods: 99mTc-diethylene-triaminepentaacetic acid (99mTc-DPTA) scintigraphic uptake and 99-Tc-DTPA plasma clearance. Sonographically, ADPKD affected kidneys were characterized by multiple anechoic to hypoechoic, round to irregularly shaped structures with variation in size. Affected kidneys had indistinct corticomedullary junctions and foci of mineralization. Intravenous (IV) contrast medium administration allowed more definitive identification of cysts with CT, and identification of distortion of renal pelves by cysts. A significant difference (Welch ANOVA, P = 0.05) was detected between the US-estimated renal volumes of normal and affected cats. No statistically significant differences were detected in CT volume (between the normal and affected cats, or between US and CT volume measurements) or the 2 GFR methods. In this group of clinically normal, middle-aged ADPKD cats, renal function was within normal limits and not significantly different than normal.  相似文献   

17.
High-resolution ultrasonography was evaluated as an alternative to 99mTcO-4 scintigraphy for examining size and appearance of thyroid glands in hyperthyroid cats. Thyroid ultrasound examinations were performed on 6 normal cats and 14 cats with hyperthyroidism. Thyroid lobe volume was estimated from ultrasound images using the equation for a prolate ellipsoid, π/6 (length * height * width). Total thyroid volume was estimated by adding the volume estimations of the left and right lobes. Thyroid lobes of hyperthyroid cats were considered abnormal if estimated volume exceeded the 99% confidence interval for normal thyroid volume determined from the control group. Scintigraphic examinations performed on hyperthyroid cats were evaluated for unilateral versus bilateral disease and for the presence of ectopic activity. Mean thyroid lobe volume and total thyroid volume for normal cats was 85 and 169 mm3, respectively. Mean thyroid lobe volume and total thyroid volume for hyperthyroid cats was 578 and 889 mm3. There was a significant difference in mean estimated total thyroid volume of normal and hyperthyroid cats. Thyroid lobes with greater than normal TcO-4 uptake on scintigraphy were larger and had variable homogeneity, echogenicity, and margination on ultrasound examination. There also was an 85.7% agreement of scintigraphy and ultrasonography in differentiating normal from abnormal thyroid lobes. A fair correlation between estimated total thyroid volume of hyperthyroid cats and most recent pretherapy serum thyroxine values were also found. This preliminary study indicates that thyroid ultrasound examination may provide information that is useful for diagnosis and treatment of feline hyperthyroidism. Although ultrasound provides accurate evaluation of the thyroid glands, it cannot replace 99mTcO-4 scintigraphy for screening of metastatic lesions and ectopic glands.  相似文献   

18.
One recent study indicates a significant association between certain single nucleotide polymorphisms (SNPs) in the genomic sequence of feline p53 and feline injection‐site sarcoma (FISS). The aim of this study was to investigate the correlation between a specific nucleotide insertion in p53 gene and FISS in a German cat population. Blood samples from 150 German cats were allocated to a control group consisting of 100 healthy cats and a FISS‐group consisting of 50 cats with FISS. All blood samples were examined for the presence of the SNP in the p53 gene. Results found the T‐insertion at SNP 3 in 20.0% of the cats in the FISS‐group and 19.2% of cats in the control‐group. No statistically significant difference was observed in allelic distribution between the two groups. Further investigations are necessary to determine the association of SNPs in the feline p53 gene and the occurrence of FISS.  相似文献   

19.
Clinical and imaging diagnosis of canine insulinomas has proven difficult due to nonspecific clinical signs and the small size of these tumors. The aim of this retrospective case series study was to describe MRI findings in a group of dogs with pancreatic insulinomas. Included dogs were presented for suspected pancreatic insulinoma, MRI was used to assist with localization of the primary lesion, and the diagnosis was confirmed with surgical exploratory laparotomy and histopathology. The MRI studies for each dog were retrieved and the following data were recorded: T1‐weighted and T2‐weighted signal intensities, type of contrast enhancement, size and location of the primary lesion, and characteristics of metastatic lesions (if present). A total of four dogs were sampled. In all patients, the insulinoma displayed high‐intensity signal on T2‐weighted fat saturation images, similar to human studies. On postcontrast T1‐weighted fat saturation images, the tumors were primarily isointense to normal pancreatic tissue, in contrast to human studies where a low‐intensity signal is typically identified. Abnormal islet tissue was detected with MRI in all four dogs and metastases were identified in three dogs. Variations in the MRI appearance of primary and metastatic lesions were identified and could have been related to the variation of tissue composition, including the presence of neoplastic cells, hemorrhage, and fibrovascular stroma, and to the transformation of this tissue throughout the disease process.  相似文献   

20.
Intraventricular ependymoma is a rare type of feline intracranial neoplasia and published information on magnetic resonance imaging (MRI) characteristics is currently lacking. The purpose of this retrospective case series study was to describe the clinical and MRI characteristics of histopathologically confirmed intraventricular ependymomas in a group of cats. Five cats met inclusion criteria. In relation to normal gray matter, ependymomas appeared hyperintense on T2W, T2W‐FLAIR, PD, and DW‐EPI images; isointense on ADC images; and had subtle to strong contrast enhancement. Some variability was seen on T2*GRE and on T1W images with masses being isointense to hyperintense. Four ependymomas were small and homogeneous, and one was centrally cavitated. All cats had obstructive hydrocephalus, transtentorial herniation, and foramen magnum herniation. Perilesional edema was identified in most cats but was questionable in one. Intraventricular ependymoma should be considered as a differential diagnosis for cats with this combination of MRI signs.  相似文献   

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