1
|
Lux CN, Sula MJM, Sun X, Hecht S. Gadoxetate disodium (Gd-EOB-DTPA) contrast-enhanced magnetic resonance imaging for differentiation between benign and malignant splenic lesions in dogs. Vet Radiol Ultrasound 2024; 65:556-566. [PMID: 38899373 DOI: 10.1111/vru.13397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 04/21/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024] Open
Abstract
Malignant splenic lesions in dogs are common, with hemangiosarcoma diagnosed most frequently, and there have been no consistent clinicopathologic, gross, or imaging characteristics identified that differentiate malignant from benign splenic lesions. Histopathology is required for definitive diagnosis, and given the poor long-term prognosis of malignant splenic lesions, a noninvasive tool to aid in diagnosis would be valuable. This prospective cohort study utilized gadoxetate disodium, a liver-specific contrast agent (Gd-EOB-DPTA; Eovist), to identify the general lesion and pre- and postcontrast signal characteristics of benign and malignant splenic and hepatic lesions in dogs with naturally occurring disease. Twenty-five dogs were enrolled, Eovist-enhanced MRI was performed, and dogs were taken to surgery for splenectomy and other organ biopsy. All histopathology and MRI studies were evaluated by a single pathologist and a single radiologist, respectively. The associations between the tumor type and numerous variables defined on MRI were evaluated using Fisher's exact tests, and the significance was identified at a P-value of .05. Malignant splenic masses were identified in 11/25 (44%) dogs, and 5/11 malignancies represented hemangiosarcoma. The presence of abdominal effusion (P = .017) and the presence of hepatic nodules on MRI (P = .009) were associated with splenic malignancy. There were no benign T2 hyperintense and no malignant T2 hypointense lesions (P = .021). Utilization of the T2 W MRI sequence may aid in the identification of malignant splenic lesions, particularly when accompanied by abdominal effusion and hepatic lesions.
Collapse
Affiliation(s)
- Cassie N Lux
- Department of Small Animal Clinical Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, Tennessee, USA
| | - Mee-Ja M Sula
- Department of Biomedical and Diagnostic Services, University of Tennessee College of Veterinary Medicine, Knoxville, Tennessee, USA
- Charles River Laboratories, Mattawan, Michigan, USA
| | - Xiaocun Sun
- Office of Innovative Technologies, Research Computing Support, University of Tennessee Knoxville, Knoxville, Tennessee, USA
| | - Silke Hecht
- Department of Small Animal Clinical Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, Tennessee, USA
| |
Collapse
|
2
|
Kurokawa S, Tanaka T, Yamazaki H, Noguchi S, Wada Y, Nishida H, Akiyoshi H. Comparing the CT and MRI findings for canine primary hepatocellular lesions. Vet Rec 2021; 190:e1083. [PMID: 34751436 DOI: 10.1002/vetr.1083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 08/24/2021] [Accepted: 10/17/2021] [Indexed: 11/11/2022]
Abstract
BACKGROUND Triple-phase CT and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) MRI have been used to differentiate hepatocellular carcinomas (HCCs) in dogs. METHODS This retrospective case series aimed to compare the CT findings with MRI findings of 20 canine hepatocellular lesions, including eight poorly/moderately-differentiated HCCs, eight well-differentiated HCCs and four hyperplasias. CT data were analysed, and the following parameters were noted: vessel enhancement, enhancement pattern in the equilibrium phase, maximal transverse diameter, the lowest enhancement, and the attenuation values of each hepatocellular lesion in the precontrast and triple-phase series, including the arterial phase, portal phase and equilibrium phase. MRI data were analysed, and the following parameters were noted: signal intensities of each hepatocellular lesion on T2-weighted images and T1-weighted images, and signal intensity ratio of the hepatocellular lesions in the hepatobiliary phase. RESULTS In 62.5% of poorly/moderately-differentiated HCC and 75% of well-differentiated HCC, presumptive necrosis was detected on CT and MRI. In the hepatobiliary phase on MRI, the median signal intensity ratio of poorly/moderately-differentiated HCC (0.54 [range: 0.3-0.71]) was significantly lower than that of well-differentiated HCC (0.75 [range: 0.6-0.96]) and hyperplasia (0.79 [range: 071-0.98]; p = 0.02 and p = 0.02, respectively). CONCLUSION Gd-EOB-DTPA-enhanced MRI may be a superior modality for differentiating hepatocellular origin lesions.
Collapse
Affiliation(s)
- Shohei Kurokawa
- Department of Graduate School of Life and Environmental Sciences, Laboratory of Veterinary Surgery, Osaka Prefecture University, Izumisano, Japan
| | - Toshiyuki Tanaka
- Department of Graduate School of Life and Environmental Sciences, Laboratory of Veterinary Surgery, Osaka Prefecture University, Izumisano, Japan.,Kinki Animal Medical Training Institute & Veterinary Clinic, Higashiosaka, Japan
| | - Hiroki Yamazaki
- Department of Graduate School of Life and Environmental Sciences, Laboratory of Veterinary Surgery, Osaka Prefecture University, Izumisano, Japan
| | - Shunsuke Noguchi
- Department of Graduate School of Life and Environmental Sciences, Laboratory of Veterinary Radiology, Osaka Prefecture University, Izumisano, Japan
| | - Yusuke Wada
- Veterinary Medical Centre, College of Life, Environmental and Advanced Sciences, Osaka Prefecture University, Izumisano, Japan
| | - Hidetaka Nishida
- Department of Graduate School of Life and Environmental Sciences, Laboratory of Veterinary Surgery, Osaka Prefecture University, Izumisano, Japan
| | - Hideo Akiyoshi
- Department of Graduate School of Life and Environmental Sciences, Laboratory of Veterinary Surgery, Osaka Prefecture University, Izumisano, Japan
| |
Collapse
|
3
|
Burti S, Zotti A, Contiero B, Banzato T. Computed tomography features for differentiating malignant and benign focal liver lesions in dogs: A meta-analysis. Vet J 2021; 278:105773. [PMID: 34742915 DOI: 10.1016/j.tvjl.2021.105773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 10/19/2022]
Abstract
Computed tomography (CT) is often performed to complement ultrasound following detection of focal liver lesions (FLL). There is no consensus in the literature regarding the CT features that might be helpful in the distinction between benign and malignant FLL. The aim of this meta-analysis was to identify, based on the available literature, the qualitative and quantitative CT features able to distinguish between benign and malignant FLL. Studies on the diagnostic accuracy of CT in characterising FLL were searched in MEDLINE, Web of Science, and Scopus databases. Pooled sensitivity, pooled specificity, diagnostic odds ratio (DOR), receiver operator curve (ROC) area, were calculated for qualitative features. DOR were used to determine which qualitative features were most informative to detect malignancy; quantitative features were selected/identified based on standardised mean difference (SMD). Well-defined margins, presence of a capsule, abnormal lymph nodes, and heterogeneity in the arterial, portal and delayed phase were classified as informative qualitative CT features. The pooled sensitivity ranged from 0.630 (abnormal lymph nodes) to 0.786 (well-defined margins), while pooled specificity ranged from 0.643 (well-defined margins) to 0.816 (heterogeneous in delayed phase). Maximum dimensions, ellipsoid volume, attenuation of the liver in the pre-contrast phase, and attenuation of the liver in the arterial, portal, and delayed phase were found to be informative quantitative CT features. Larger maximum dimensions and volume (positive SMD), and lower attenuation values (negative SMD) were more associated with malignancy. This meta-analysis provides the evidence base for the interpreting CT imaging in the characterization of FLL.
Collapse
Affiliation(s)
- S Burti
- Department of Animal Medicine, Production and Health, University of Padua, Viale dell'Università 16, 35020 Legnaro, Padua, Italy
| | - A Zotti
- Department of Animal Medicine, Production and Health, University of Padua, Viale dell'Università 16, 35020 Legnaro, Padua, Italy
| | - B Contiero
- Department of Animal Medicine, Production and Health, University of Padua, Viale dell'Università 16, 35020 Legnaro, Padua, Italy
| | - T Banzato
- Department of Animal Medicine, Production and Health, University of Padua, Viale dell'Università 16, 35020 Legnaro, Padua, Italy.
| |
Collapse
|
4
|
Tanaka T, Nishida H, Mie K, Yamazaki H, Lin LS, Akiyoshi H. Assessment of hepatitis and fibrosis using Gd-EOB-DTPA MRI in dogs. Vet Rec Open 2020; 7:e000371. [PMID: 32818058 PMCID: PMC7401995 DOI: 10.1136/vetreco-2019-000371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 01/27/2023] Open
Abstract
Background Gadoxetate sodium (Gd-EOB-DTPA) is taken into hepatocytes and excreted into the bile. Hepatocytes with reduced function or dysfunction due to hepatocellular carcinoma (HCC), hepatitis or hepatic fibrosis show impaired Gd-EOB-DTPA uptake. The purpose of the present retrospective case series was to assess the relationship between liver function and contrast enhancement using Gd-EOB-DTPA MRI. Methods Sixteen dogs with a histopathological diagnosis of liver disease, including six with HCC, three with nodular hyperplasia, two with hepatocellular adenoma, two with liver fibrosis and three with hepatitis were included in the study along with three dogs with suspected liver disease but no histopathological diagnosis of liver disease. Relative signal intensities (RSI) of the common bile duct and gall bladder were calculated, and their relationship with the following serum biochemical parameters was assessed: total bilirubin, alanine transaminase, alkaline phosphatase and albumin (Alb). To assess anatomical liver function, relative contrast enhancement indices (RCEI) of the liver were calculated, and differences were assessed between normal and diseased liver. Results RSI showed no significant differences between dogs without and with a histopathological diagnosis of liver disease (P=0.88) although they were significantly correlated with Alb (ρ=0.57, P=0.02) in dogs with a histopathological diagnosis of liver disease. RCEI was significantly higher in normal liver tissue than that in livers with hepatitis/fibrosis (P=0.048) and HCC (P=0.03) but not nodular hyperplasia/hepatocellular adenoma (P=0.51). Conclusions Gd-EOB-DTPA MRI may be potentially useful in the assessment of anatomical liver function in dogs with liver disease.
Collapse
Affiliation(s)
- Toshiyuki Tanaka
- Laboratory of Veterinary Surgery, Department of Veterinary Clinical Medicine, Graduate School of Life and Environmental Sciences, Osaka Prefecture University - Rinku Campus, Izumisano, Osaka, Japan.,Kinki Animal Medical Training Institute & Veterinary Clinic, Higashiosaka, Osaka, Japan
| | - Hidetaka Nishida
- Laboratory of Veterinary Surgery, Department of Veterinary Clinical Medicine, Graduate School of Life and Environmental Sciences, Osaka Prefecture University - Rinku Campus, Izumisano, Osaka, Japan
| | - Keiichiro Mie
- Laboratory of Veterinary Surgery, Department of Veterinary Clinical Medicine, Graduate School of Life and Environmental Sciences, Osaka Prefecture University - Rinku Campus, Izumisano, Osaka, Japan
| | - Hiroki Yamazaki
- Laboratory of Veterinary Surgery, Department of Veterinary Clinical Medicine, Graduate School of Life and Environmental Sciences, Osaka Prefecture University - Rinku Campus, Izumisano, Osaka, Japan
| | - Lee-Shuan Lin
- Laboratory of Veterinary Diagnostic Imaging, Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Hideo Akiyoshi
- Laboratory of Veterinary Surgery, Department of Veterinary Clinical Medicine, Graduate School of Life and Environmental Sciences, Osaka Prefecture University - Rinku Campus, Izumisano, Osaka, Japan
| |
Collapse
|
5
|
Vatnikov Y, Vilkovysky I, Kulikov E, Popova I, Khairova N, Gazin A, Zharov A, Lukina D. Size of canine hepatocellular carcinoma as an adverse prognostic factor for surgery. J Adv Vet Anim Res 2020; 7:127-132. [PMID: 32219118 PMCID: PMC7096117 DOI: 10.5455/javar.2020.g401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/10/2019] [Accepted: 10/12/2019] [Indexed: 01/04/2023] Open
Abstract
Objective Liver neoplasms are problematic among small domestic animals. The etiological cause of hepatocellular carcinomas in domestic animals is still unknown although it is believed that chronic infections and toxic substances can affect the development of this type of tumor. This study aimed to analyze the clinical and morphological characteristics of canine hepatocellular carcinoma. Materials and methods In total, 6,958 cancer operations were performed in the clinic. Liver tumors were detected in 123 dogs in vivo and 375 dogs postmortem. All animals with suspected liver neoplasm were assessed, including history, clinical examination, complete blood count, biochemical blood tests, radiographic examination, and ultrasound with a biopsy for performing cytological and histological analyses. Results Hepatocellular carcinomas have nonspecific clinical manifestations, also a characteristic aspect of other tumors of the hepatobiliary system. The hematological changes have an impact on the prognosis, and biochemical abnormalities reflect the changes in liver activity. The cytological diagnosis of hepatocellular tumors is difficult because of hepatocyte atypia in highly differentiated carcinomas. Finally, a histological examination was performed in all the dogs diagnosed with hepatocellular carcinoma. Conclusion Hematological changes in dogs with hepatocellular carcinoma affect their prognosis. Biochemical abnormalities of this pathology reflect the changes in liver activity, not indicating a specific pathology. However, an increase in the activity of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase is an unfavorable prognostic sign. In this study, five of seven dogs with a tumor size of more than 5.0 cm had a life expectancy of 30, 51, and 91 days, suggesting that the size of the tumor is an adverse prognostic factor.
Collapse
Affiliation(s)
- Yury Vatnikov
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| | - Ilya Vilkovysky
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| | - Evgeny Kulikov
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| | - Irina Popova
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| | - Nadia Khairova
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| | - Aleksey Gazin
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| | - Andrey Zharov
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| | - Darya Lukina
- Department of Veterinary Medicine, Agrarian and Technological Institute, Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya street, 6, Moscow 117198, Russia
| |
Collapse
|
6
|
Borusewicz P, Stańczyk E, Kubiak K, Spużak J, Glińska-Suchocka K, Jankowski M, Sławuta P, Kubiak-Nowak D, Podgórski P. Magnetic resonance imaging of liver tumors using gadoxetic acid (Gd-EOB-DTPA) - pilot study. BMC Vet Res 2019; 15:293. [PMID: 31412920 PMCID: PMC6694506 DOI: 10.1186/s12917-019-2038-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 08/02/2019] [Indexed: 01/05/2023] Open
Abstract
Background Magnetic resonance imaging using gadoxetic acid, a hepatocyte-specific contrast agent, is one of the most useful MRI techniques used to diagnose liver tumours in humans. During the hepato-biliary phase, there is uptake of gadoxetic acid by normal hepatocytes, leading to hepatic parenchymal enhancement. This feature is used in human medicine to diagnose hepatic parenchymal metastatic disease, to differentiate primary liver tumours, to diagnose liver cirrhosis and focal nodular hyperplasia. This study presents the preliminary results of magnetic resonance imaging of focal lesions localised in the liver parenchyma in dogs following the administration of gadoxetic acid. Results The lesion enhancement ratio (ERlesion) in the tumour metastasis was 0.05; the liver enhancement ratio (ERliver) – 0.49 and the post-contrast lesion-to-liver contrast ratio (CR) was 0.17. In dogs with hepatocellular hyperplasia, these values were 0.54; 0.51; and 1.18, respectively. In two dogs with a hepatic adenoma, the ERlesion was 0.26 and 0.17, respectively; the ERliver was 0.47 and 0.47, respectively and the CR was 0.33 and 0.31, respectively. In the dog with a neuroendocrine tumour, the ERlesion was 0.03; the ERliver amounted to 0.58 and the CR was 0.35. In the case of a hepatocellular carcinoma, these coefficients were 0.2, 0.6 and 0.3, respectively. Conclusion Based on the results, it may be assumed that the MR images of the proliferative hepatic parenchymal lesions in dogs using gadoxetic acid are similar to those obtained in humans. This suggests that the contrast enhancement patterns used in human medicine may be useful in differentiating hepatic parenchymal lesions in dogs.
Collapse
Affiliation(s)
- Pola Borusewicz
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Faculty of Veterinary Medicine Wroclaw, University of Environmental and Life Sciences, Wroclaw, Poland.
| | - Ewa Stańczyk
- Center of Experimental Diagnostics and Innovative Biomedical Technology, Faculty of Veterinary Medicine, University of Environmental and Life Sciences, Wroclaw, Poland.,Clinic of Diagnostic Imaging, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Krzysztof Kubiak
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Faculty of Veterinary Medicine Wroclaw, University of Environmental and Life Sciences, Wroclaw, Poland
| | - Jolanta Spużak
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Faculty of Veterinary Medicine Wroclaw, University of Environmental and Life Sciences, Wroclaw, Poland
| | - Kamila Glińska-Suchocka
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Faculty of Veterinary Medicine Wroclaw, University of Environmental and Life Sciences, Wroclaw, Poland
| | - Marcin Jankowski
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Faculty of Veterinary Medicine Wroclaw, University of Environmental and Life Sciences, Wroclaw, Poland
| | - Piotr Sławuta
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Faculty of Veterinary Medicine Wroclaw, University of Environmental and Life Sciences, Wroclaw, Poland
| | - Dominika Kubiak-Nowak
- Department and Clinic of Surgery, Faculty of Veterinary Medicine, University of Environmental and Life Sciences, Wroclaw, Poland
| | - Przemysław Podgórski
- Department of General and Interventional Radiology and Neuroradiology, Wroclaw Medical University, Wroclaw, Poland
| |
Collapse
|
7
|
Pilton JL, Chau J, Foo TS, Hall EJ, Martinez-Taboada F, Podadera JM, Makara MA. Hepatic computed tomography and cholangiography by use of gadoxetic acid in healthy cats. Am J Vet Res 2019; 80:385-395. [PMID: 30919679 DOI: 10.2460/ajvr.80.4.385] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate 3 doses of gadoxetic acid (Gd-EOB-DPTA) for hepatic CT and cholangiography in cats and to determine optimal timing for hepatobiliary image acquisition and evaluation of the contrast-enhanced hepatobiliary anatomy. ANIMALS 6 healthy cats. PROCEDURES Cats were anesthetized; sequential CT scans were performed 0, 5, 25, 45, 65, and 85 minutes after IV administration of Gd-EOB-DTPA at low (0.0125 mmol/kg), medium (0.1 mmol/kg), and high (0.3 mmol/kg) doses. Hepatobiliary enhancement for each dose was objectively assessed over time and by use of a subjective semiquantitative visual assessment score. RESULTS No contrast-related adverse effects were detected. Each increase in dose of contrast medium resulted in a significant increase in HU across the hepatobiliary system. The liver had a significantly higher number of HU at 45 minutes, with homogenous enhancement at all doses of contrast medium. Contrast-enhanced cystic and bile duct HU were significantly higher and maximal at 65 minutes. Contrast-enhanced gallbladder HU did not plateau by 85 minutes. At a high dose of contrast medium, 12 of 60 (20%) biliary tract scores indicated no enhancement, 34 (57%) indicated poor enhancement, and 14 (23%) indicated moderate enhancement. No cat had excellent enhancement of the biliary tract at any dose. CONCLUSIONS AND CLINICAL RELEVANCE Gd-EOB-DTPA-enhanced hepatic CT and cholangiography in cats were safely performed and provided good hepatic enhancement but poor to moderate enhancement of the biliary tract. This technique may be useful for assessing the liver parenchyma in cats, but its value for assessing the biliary tract is questionable.
Collapse
|
8
|
Influence of Indocyanine Green on Hepatic Gd-EOB-DTPA Uptake: A Proof-of-Concept Study in Mice. Invest Radiol 2017; 52:441-445. [PMID: 28195848 DOI: 10.1097/rli.0000000000000359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The aim of this study was to explore the influence of indocyanine green (ICG) on hepatic uptake of gadolinium ethoxybenzyldiethylenetriaminepenta-acetic acid (Gd-EOB-DTPA). MATERIALS AND METHODS Groups of 6 female C57BL6 mice were injected with 5 mg/kg ICG, 20 mg/kg ICG, or phosphate-buffered saline (control group) 10 minutes before the injection of Gd-EOB-DTPA; identical 3-dimensional gradient echo T1-weighted images were subsequently obtained to create time-intensity curves and to measure the peak contrast ratios (CRs) of liver parenchyma. We studied both hypothermic and normothermic mice. Peak CRs for all experimental conditions were evaluated, and among-group differences were assessed using 2-way factorial analysis of variance with Bonferroni post hoc testing. RESULTS In hypothermic mice, the time-intensity curves of the 3 groups gradually increased from 5 to 30 minutes and almost plateaued after 30 minutes. The peak CR decreased as the amount of injected ICG increased (control group, 5 mg/kg ICG, 20 mg/kg ICG: 1.66 ± 0.09, 1.37 ± 0.18, 1.25 ± 0.24, respectively). In normothermic animals, the time-intensity curves of the control and ICG 5 mg/kg groups peaked 10 to 15 minutes after injection, the peak CRs were very similar (control group, 5 mg/kg ICG: 2.01 ± 0.16, 1.95 ± 0.14, respectively), and the intensities thereof then gradually fell until 60 minutes. Compared with these groups, the ICG 20 mg/kg group exhibited lower peak CR (1.48 ± 0.14) and a weaker decrease in intensity to 60 minutes. Both the amount of ICG injected (P < 0.001) and the experimental temperature (P < 0.001) significantly affected the measurements. CONCLUSIONS Indocyanine green inhibits the hepatic uptake of Gd-EOB-DTPA and affects the signal intensity upon Gd-EOB-DTPA-enhanced magnetic resonance imaging. Such inhibition was more obvious in hypothermic mice.
Collapse
|