• Journal of Veterinary Clinics
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• v.41 no.2
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• pp.117-122
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• 2024

A 3-year-old spayed female Russian blue cat was presented for dyspnea, nasal discharge, and stertorous breathing. Plain thoracic radiography revealed no specific findings. Computed tomography (CT) was performed to differentiate upper airway tract disorders. It revealed the presence of an iso-attenuating mass measuring 10.0 × 7.9 × 15.6 mm, with mild homogeneous contrast enhancement occupying the rostral nasopharynx. The mass was surgically debulked via a longitudinal incision in the soft palate. Histopathological and immunohistochemistry analysis of the surgically excised mass revealed CD3-/CD79a+ B cell lymphoma with an incomplete margin. The patient underwent hypofractionated radiation therapy, receiving a total of 36 Gray (Gy) in 6 Gy fractions over a six-week period. A follow-up CT examination was performed after 27 months of irradiation and the patient was confirmed to have achieved a complete response. There were no complications related to irradiation. The patient was alive for 40 months without recurrence. This study suggests that hypofractionated radiation therapy combined with surgical debulking could be considered as a treatment option for feline nasopharyngeal lymphoma.

• Korean Journal of Radiology
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• v.21 no.1
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• pp.58-67
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• 2020

Objective: Third-generation dual-source computed tomography (3rd-DSCT) allows dynamic myocardial CT perfusion imaging (dynamic CTP) with a 10.5-cm z-axis coverage. Although the increased radiation exposure associated with the 50% wider scan range compared to second-generation DSCT (2nd-DSCT) may be suppressed by using a tube voltage of 70 kV, it remains unclear whether image quality and the ability to quantify myocardial blood flow (MBF) can be maintained under these conditions. This study aimed to compare the image quality, estimated MBF, and radiation dose of dynamic CTP between 2ndDSCT and 3rd-DSCT and to evaluate whether a 10.5-cm coverage is suitable for dynamic CTP. Materials and Methods: We retrospectively analyzed 107 patients who underwent dynamic CTP using 2nd-DSCT at 80 kV (n = 54) or 3rd-DSCT at 70 kV (n = 53). Image quality, estimated MBF, radiation dose, and coverage of left ventricular (LV) myocardium were compared. Results: No significant differences were observed between 3rd-DSCT and 2nd-DSCT in contrast-to-noise ratio (37.4 ± 11.4 vs. 35.5 ± 11.2, p = 0.396). Effective radiation dose was lower with 3rd-DSCT (3.97 ± 0.92 mSv with a conversion factor of 0.017 mSv/mGy∙cm) compared to 2nd-DSCT (5.49 ± 1.36 mSv, p < 0.001). Incomplete coverage was more frequent with 2nd-DSCT than with 3rd-DSCT (1.9% [1/53] vs. 56% [30/54], p < 0.001). In propensity score-matched cohorts, MBF was comparable between 3rd-DSCT and 2nd-DSCT in non-ischemic (146.2 ± 26.5 vs. 157.5 ± 34.9 mL/min/100 g, p = 0.137) as well as ischemic myocardium (92.7 ± 21.1 vs. 90.9 ± 29.7 mL/min/100 g, p = 0.876). Conclusion: The radiation increase inherent to the widened z-axis coverage in 3rd-DSCT can be balanced by using a tube voltage of 70 kV without compromising image quality or MBF quantification. In dynamic CTP, a z-axis coverage of 10.5 cm is sufficient to achieve complete coverage of the LV myocardium in most patients.

• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.74-80
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• 2009

Purpose : To evaluate the characteristic MR imaging findings of Langerhans cell histiocytosis (LCH) in the skull and to compare them with those of plain radiography and computed tomography. Materials and Methods : A total of 10 lesions in 9 patients (Age range; 5-42 years, Mean age; 18, all women) with Langerhans cell histiocytosis in the skull were included in our study. Nine lesions in nine patients were histologically confirmed by surgery or fine needle aspiration biopsy. All patients performed with MRI, and plain radiography and CT scan were done in 7 patients (8 lesions). Two experienced neuroradiologists reviewed the radiological examinations independently with attention to location, size, shape and nature of the lesions in the skull and compared the extent and extension of the lesions to adjacent structures. Results : The lesions were distributed in all of the skulls without predilection site. On MRI, the masses were shown as well-enhancing soft tissue masses (10/10) mainly in diploic spaces (8/10) with extension to scalp (9/10) and dura mater (7/10). Dural enhancement (7/10) and thickening (4/10) were seen. The largest diameter of the soft tissue masses ranged 1.1 cm to 6.8 cm, shaped as round (5/10) or oval (5/10). On CT scans, the lesions were presented as soft tissue masses involving diploic space (6/8) and scalp extension (7/8) were also well visualized. Although bony erosion or destruction was more clearly seen on CT rather than those of MRI, enhancement of soft tissue masses and dura were not well visualized on CT. In contrast, all of the lesions in LCH were seen as punched out (4/8), beveled-edge appearance (4/8) osteolytic masses in plain radiography, but scalp and dural extension could not be seen. Conclusion : Characteristic MR findings in patients with LCH are soft tissue mass in diploic space with extension to dura and scalp, and MRI would be better imaging modality than plain radiography or CT.

• Journal of the Korean Society of Radiology
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• v.81 no.6
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• pp.1436-1447
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• 2020

Purpose To investigate the clinical and CT features at admission to predict the progression to necrotizing pancreatitis (NP) in patients initially diagnosed with interstitial edematous pancreatitis (IEP). Materials and Methods Patients with IEP who underwent contrast-enhanced CT at admission and follow-up CT (< 14 days) were included (n = 178). Two radiologists performed a consensus review of follow-up CT scans and diagnosed the type of acute pancreatitis as IEP or NP. Laboratory findings at admission were recorded. Clinical, CT, and laboratory findings were compared between the IEP-IEP group and IEP-NP group using the chi-square test and the t-test. Multivariate analysis was also performed. Results There were 112 and 66 patients in the IEP-IEP and the IEP-NP groups, respectively. The proportion of patients with alcohol etiology was significantly larger in the IEP-NP group. Among the CT findings, the presence of peripancreatic fluid and heterogeneous parenchymal enhancement were more frequently observed in the IEP-NP group. Among the laboratory variables, serum C-reactive protein levels and white blood cell counts were significantly higher in the IEP-NP group. Multivariate analysis revealed that the presence of peripancreatic fluid and heterogeneous parenchymal enhancement were significant findings distinguishing the two groups. Conclusion CT findings, such as the presence of peripancreatic fluid and heterogeneous pancreatic parenchymal enhancement, may be helpful in predicting the progression to NP in patients initially diagnosed with IEP.

• Journal of Veterinary Clinics
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• v.31 no.4
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• pp.303-306
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• 2014

Three Yorkshire Terriers (12-year-old, 13-year-old, and 15-year-old castrated males) with respiratory distress, coughing and anorexia were the subjects of this report. In laboratory examinations, there were no remarkable findings. However, the thoracic radiographic findings included a large mass of soft tissue density in the cardiac base region, tracheal elevation, and aortic bulging in all three Yorkshire Terriers. There were no remarkable findings in the abdominal radiographs. In echocardiography, a homogeneous hyperechoic mass around the aorta and bicuspid valve regurgitation were found in all three dogs. There were no remarkable findings in abdominal ultrasonography. Computed tomographic findings showed a large well -defined heterogeneous mass in the cranial vena cava, which was dominant in the left side in all three Yorkshire Terriers. The mass sizes were about $3{\times}4cm$. In post-contrast scanning, contrast enhancement was evident. These cases were diagnosed as heart-base tumor. Treatments provided to the three dogs were based on symptomatic medical management of cardiac failure and tracheal collapse. Case 1 (12-year-old) survived for 3 months, case 2 (13-year-old) for 5 months, and case 3 (15-year-old) for 32 months after the diagnosis. Our results show that the clinical findings, thoracic radiography, echocardiography, computed tomography (CT) and symptomatic medical management in dogs suspected to have heart base tumor.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.154-158
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• 2011

A 8-year-old female Shih-tzu dog (weighting 4.5 kg) with history of both hindlimb lameness and cervical mass was presented to Veterinary Teaching Hospital, Gyeongsang National University. In physical examination, ataxia, kyphosis, back pain and cervical mass were identified. Marked periosteal new bone formation of the fourth lumbar vertebra and soft tissue opacity mass of cervical region were observed in survey radiographs. Transverse computed tomography (CT) scan obtained at the lumbar and cervical lesions shown a well defined multilobulated bony mass and partially destructive lytic lesions the fourth lumbar vertebral body and a enlarged retropharyngeal lymph node with heterogeneous contrast enhancement and moderately enhancing left tonsillar mass. Neoplastic squamous epithelium which have developed vessel and lymphocyte infiltration in surrounding tissue were confirmed based on histopathologic examination. Based on the diagnostic findings the dog was diagnosed as a cervical lymph node metastases of tonsillar squamous cell carcinoma.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.502-512
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• 2021

Objective: To objectively and subjectively assess and compare the characteristics of monoenergetic images [MEI (+)] and polyenergetic images (PEI) acquired by dual-energy CT (DECT) of patients with breast cancer. Materials and Methods: This retrospective study evaluated the images and data of 42 patients with breast cancer who had undergone dual-phase contrast-enhanced DECT from June to September 2019. One standard PEI, five MEI (+) in 10-kiloelectron volt (keV) intervals (range, 40-80 keV), iodine density (ID) maps, iodine overlay images, and Z effective (Z_eff) maps were reconstructed. The contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were calculated. Multiple quantitative parameters of the malignant breast lesions were compared between the arterial and the venous phase images. Two readers independently assessed lesion conspicuity and performed a morphology analysis. Results: Low keV MEI (+) at 40-50 keV showed increased CNR and SNR_{breast lesion} compared with PEI, especially in the venous phase ([CNR: 40 keV, 20.10; 50 keV, 14.45; vs. PEI, 7.27; p < 0.001], [SNR_{breast lesion}: 40 keV, 21.01; 50 keV, 16.28; vs. PEI, 10.77; p < 0.001]). Multiple quantitative DECT parameters of malignant breast lesions were higher in the venous phase images than in the arterial phase images (p < 0.001). MEI (+) at 40 keV, ID, and Z_eff reconstructions yielded the highest Likert scores for lesion conspicuity. The conspicuity of the mass margin and the visual enhancement were significantly better in 40-keV MEI (+) than in the PEI (p = 0.022, p = 0.033, respectively). Conclusion: Compared with PEI, MEI (+) reconstructions at low keV in the venous phase acquired by DECT improved the objective and subjective assessment of lesion conspicuity in patients with malignant breast lesions. MEI (+) reconstruction acquired by DECT may be helpful for the preoperative evaluation of breast cancer.

• Investigative Magnetic Resonance Imaging
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• v.11 no.2
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• pp.127-132
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• 2007

Sinonasal neuroendocrine carcinoma is a rare disease, and reports focusing on the MR imaging findings of sinonasal neuroendocrine carcinoma are extremely rare. Threrefore we intend to report 2 cases of histologically confirmed neuroendocrine carcinoma. A 62-year-old man and a 74-year-old man are both presented with nasal bleeding. Computed tomography(CT) images of the 2 patients showed large, ill-defined masses in sinonasal cavities with adjacent bony destructions. MR images showed masses with isosignal intensity on Tl-weighted images and mixed iso- and high signal intensity on T2-weighted images. Post-contrast MR images showed heterogenous enhancement of masses with necrosis. Adjacent bony destructions were also noted on MR images. In both cases, peritumoral cystic lesions or mucoceles with high signal intensity on T1-weighted images were noted in sphenoid sinus. Both of the CT and MR imaging findings of the 2 patients were nonspecific which are usually seen in malignant tumor. But further study is needed for the significance of the peritumoral cystic areas adjacent the tumors.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.593-599
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• 2010

A seven-year-old, castrated male Basset hound weighing 21.1 kg was presented for investigation of anorexia, lethargy, weight loss, melena and vomiting for 4 months. In laboratory findings, microcytic hypochromic anemia was identified, and other results were within a normal reference range. On the plain radiographs, soft tissue opacity was increased in the descending duodenal region; and on the contrast radiographs, ulcerative changes were identified in the entire segment of descending duodenum. Ultrasonographic findings included increased duodenal wall thickness and duodenal wall layering was lost. Endoscopy revealed irregular mucosal surface and luminal narrowing of the descending duodenum. There was concentrically thickened descending duodenum on the computed tomography. And the wall of the descending duodenum showed heterogenous enhancement after contrast agent injection. On histopathological findings, both chronic inflammation with mucosal proliferation and neoplastic changes with multiple small glandslike structures invading into the submucosa were identified. Based on these findings, presented case was diagnosed as an annular form duodenal adenocarcinoma. After 13 months of supportive medical treatment, the patient was expired. The purpose of this case report was to describe the duodenal adenocarcinoma in a dog.