Contrast-Enhanced Ultrasonography for Characterization of Focal Splenic Lesions in Dogs

Nakamura, Kensuke; Sasaki, Noboru; Murakami, Masahiro; Kumara, Wickramasekara Rajapakshage Bandula; Ohta, Hiroshi; Yamasaki, Masahiro; Takagi, Satoshi; Osaki, Tomohiro; Takiguchi, Mitsuyoshi

doi:10.1111/j.1939-1676.2010.0609.x

Cited by 33 publications

(39 citation statements)

References 20 publications

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“…Splenic malignant neoplasms, most of which are hemangiosarcomas, frequently contain extensive hemorrhage or necrosis and so may be difficult to distinguish from hematoma on the basis of either gross or histologic examination . As noted above with respect to hepatic masses, other imaging techniques that depict vascularity of tissues also have limited potential to distinguish the histologic types of splenic mass …”

Section: Discussionmentioning

confidence: 99%

Associations Between Dual‐phase Computed Tomography Features and Histopathologic Diagnoses in 52 Dogs With Hepatic or Splenic Masses

Jones

Lamb

Drees

et al. 2016

Vet Radiology Ultrasound

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Ability to noninvasively differentiate malignant from nonmalignant abdominal masses would aid clinical decision making. The aim of this retrospective, cross‐sectional study was to identify features in dual‐phase computed tomographic (CT) studies that could be used to distinguish malignant from nonmalignant hepatic and splenic masses in dogs. Medical records were searched for dogs that had an abdominal dual‐phase CT examination, a hepatic or splenic mass, and subsequent histopathologic diagnosis. Computed tomographic images for all included dogs were acquired prior to and <30 s (early phase) and >60 s (delayed phase) after intravenous contrast administration. Fifty‐two dogs with 55 masses were studied: 24 hepatic, including 14 (58%) malignant and 10 (42%) non‐malignant; 31 splenic, including 18 (58%) malignant and 13 (42%) nonmalignant. There was substantial overlap in the pre‐ and postcontrast CT features of malignant and nonmalignant hepatic and splenic masses. Regardless of histologic diagnosis, hepatic masses most frequently showed marked, generalized enhancement in early phase images that persisted in the delayed phase. Splenic hemangiosarcoma and nodular hyperplastic lesions most frequently showed marked, generalized enhancement in early phase images that persisted in delayed images whereas most splenic hematomas had slight enhancement in early phase images. All splenic hematomas and 77% of the hemangiosarcomas had contrast accumulation compatible with active hemorrhage. There were no other significant differences in quantitative or categorical CT data between malignant and nonmalignant hepatic or splenic masses. Dual‐phase CT of dogs with hepatic or splenic masses provides limited specific diagnostic information.

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Section: Discussionmentioning

confidence: 99%

Associations Between Dual‐phase Computed Tomography Features and Histopathologic Diagnoses in 52 Dogs With Hepatic or Splenic Masses

Jones

Lamb

Drees

et al. 2016

Vet Radiology Ultrasound

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“…The obvious advantage of bolus injection is that it is easy to administer, less cumbersome, more repeatable [30], gives good tissue to tumor contrast and is the conventional method employed in characterizing nodular lesions [9, 12, 16, 20, 21, 27, 29]. However, contrast enhancement is too rapid and brief in the pancreas [6].…”

Section: Discussionmentioning

confidence: 99%

“…For bolus injection, we estimated that a microbubble contrast agent dose of 0.01 m l /kg would be suitable based on manufacturer’s recommendation (0.015 m l /kg) and clinical experiences with canine liver and spleen imaging in our facility [19,20,21]. For continuous infusion of microbubble contrast agent, based on preliminary studies (unpublished data), a dose 5 times of the bolus injection dose that was reported to be safe [17] was used.…”

Section: Methodsmentioning

confidence: 99%

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Qualitative and Quantitative Contrast Enhanced Ultrasonography of the Pancreas Using Bolus Injection and Continuous Infusion Methods in Normal Dogs

Lim

Nakamura

Morishita

et al. 2013

The Journal of Veterinary Medical Science

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Quantitative contrast enhanced ultrasound is a major breakthrough for ultrasound imaging in recent years. However, contrast enhancement of the pancreas is brief with bolus injection. To assess if continuous infusion of Sonazoid® can prolong the duration of pancreatic enhancement over bolus injections, eight adult dogs received bolus injection and continuous infusion of Sonazoid® on separate days. Contrast enhanced ultrasound of the pancreatic parenchyma and proximal descending duodenum was performed, and time intensity curves reflecting tissue perfusions were generated. Perfusion parameters- time to initial upslope, peak time, time to wash-out and peak intensity were calculated and evaluated. Fast wash-in to intense peak, followed by rapid wash-out was observed for time intensity curves of bolus injection. With continuous infusion, contrast wash-in to peak intensity was gradual, followed by long plateau and slow wash-out. Median contrast enhancement durations of the pancreas and duodenum were significantly prolonged by continuous infusion from 11 sec (range, 10 to 23 sec) and 16 sec (range, 3 to 43 sec) at bolus injection to 205 sec (range, 170 to 264 sec, P<0.01) and 193 sec (range, 169 to 216 sec, P<0.05), respectively. Median peak intensity of the pancreas was 100.9 MPV (range, 80.2 to 124.3 MPV) at bolus injection and 77.6 MPV (range, 58.2 to 99.5 MPV, P<0.05) at continuous infusion. Prolonged continuous imaging is afforded by continuous infusion of contrast agent. Peak intensity of the pancreas was slightly diminished in continuous infusion, but offered adequate imaging subjectively.

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“…The study population was recruited from canines with single or multiple focal splenic lesions detected by conventional ultrasonography in the Veterinary Teaching Hospital of the Graduate School of Veterinary Medicine, Hokkaido University [20]. Sonazoid (Daiichi-Sankyo, Tokyo, Japan) was used as the contrast agent.…”

Section: Experimental Datamentioning

confidence: 99%

Lesion Type Classification by Applying Machine-Learning Technique to Contrast-Enhanced Ultrasound Images

Takagi

Kondo

Nakamura

et al. 2014

IEICE Trans. Inf. & Syst.

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SUMMARYOne of the major applications of contrast-enhanced ultrasound (CEUS) is lesion classification. After contrast agents are administered, it is possible to identify a lesion type from its enhancement pattern. However, CEUS image reading is not easy because there are various types of enhancement patterns even for the same type of lesion, and clear classification criteria have not yet been defined. Some studies have used conventional time intensity curves (TICs), which show the vessel dynamics of a lesion. It is possible to predict lesion type from the TIC parameters, such as the coefficients obtained by curve fitting, peak intensity, flow rate and time to peak. However, these parameters are not always provide sufficient accuracy. In this paper, we prepare 1D Haar-like features which describe intensity changes in a TIC and adopt the Adaboost machine learning technique, which eases understanding of which features are useful. Hyperparameters of weak classifiers, e.g., the step size of a Haar-like filter length and threshold for output of the filter, are optimized by searching for those parameters that give the best accuracy. We evaluate the proposed method using 36 focal splenic lesions in canines 16 of which were benign and 20 malignant. The accuracies were 91.7% (33/36) when inspected by an experienced veterinarian, 75.0% (27/36) by linear discriminant analysis (LDA) using conventional three TIC parameters: time to peak, area under curve and peak intensity, and 91.7% (33/36) using our proposed method. McNemar testing shows the p-value to be less than 0.05 between the proposed method and LDA. This result shows the statistical significance of differences between the proposed method and the conventional TIC analysis method using LDA.

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Contrast-Enhanced Ultrasonography for Characterization of Focal Splenic Lesions in Dogs

Cited by 33 publications

References 20 publications

Associations Between Dual‐phase Computed Tomography Features and Histopathologic Diagnoses in 52 Dogs With Hepatic or Splenic Masses

Associations Between Dual‐phase Computed Tomography Features and Histopathologic Diagnoses in 52 Dogs With Hepatic or Splenic Masses

Qualitative and Quantitative Contrast Enhanced Ultrasonography of the Pancreas Using Bolus Injection and Continuous Infusion Methods in Normal Dogs

Lesion Type Classification by Applying Machine-Learning Technique to Contrast-Enhanced Ultrasound Images

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