Liver Specific MRI using Gd-EOB-DTPA Disodium (Primovist) Effects Change in Management of Indeterminate Liver Lesions.

Transcription

1 Liver Specific MRI using Gd-EOB-DTPA Disodium (Primovist) Effects Change in Management of Indeterminate Liver Lesions. Poster No.: C-1751 Congress: ECR 2012 Type: Authors: Keywords: DOI: Educational Exhibit N. Rao, D. Assaf, K. Burney, S. Zar, N. Khosla, A. Mahmood; Carshalton/ Metastases, Haemangioma, Contrast agent-intravenous, MR, CT, Management,, Liver /ecr2012/C-1751 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 20

2 Learning objectives To illustrate that liver specific MRI using Gd-EOB-DTPA (Primovist) contrast agent not only assists in detecting and characterising liver lesions but can also influence management. We also hope to demonstrate that a locally lead service can be benefical in terms of effectiveness of resources. Page 2 of 20

3 Background Focal liver lesions can range from benign to malignant primary or secondary lesions, hence it is important to characterise such lesions accurately, allowing appropriate and prompt management. Potential causes for benign lesions commonly include; cysts, haemangiomas, Focal Nodular Hyperplasia (FNH) and adenomas, while the main malignant threats remain hepatocellular carcinoma and secondary metastases. Various modalities allow visualization of the liver parenchyma including; Ultrasound, Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) but more often than not, the latter is advantageous with respects to soft tissue contrast as well as detection and characterisation of lesions. Liver specific contrast agents have gained favour for detecting and characterising indeterminate lesions found on computed tomography (CT). One such agent is Primovist [Gd-EOB-DTPA]. It is initially transported into hepatocytes by the organic anion transporting polypeptide 1 (OATP1) and is eventually excreted via the same transport system as bile. This demonstrates enhancement within normal liver cells during the late (hepatocyte) phase on MRI. This predictably occurs within 20 minutes after administration of the agent (table 1). Page 3 of 20

4 Table 1: Typical Imaging Appearance of Focal Liver Lesions Before and After Injection of Gadoxetate Disodium References: Ringe KI, Husarik DB, Sirlin, Merkle EM. Gadoxetate Disodium- Enhanced MRI of the Liver: Part 1, Protocol Optimization and Lesion Appearance in the Noncirrhotic Liver. AJR 2010; 195:13-28 We commenced a Gd-EOB-DTPA MRI service within our district hospital from April Prior to this, indeterminate lesions on CT or ultrasound were all sent for liver specific MRI to a tertiary liver centre (University Hospital Southampton). This required an additional referral to a gastroenterologist and then radiologist for the scan. The patient would then be sent in the reverse direction for benign Page 4 of 20

5 or normal scans for further management. This was a poor use of resources but more importantly a cause of prolonged time and concern for the patient. Our new service would effectively lead to direct requests from gastroenterologists for liver specific MRIs within our own setting and thus reduce multiple referrals and appointment slots across hospital trusts. Page 5 of 20

6 Imaging findings OR Procedure details We collated data from the hospital Radiology Information Systems (RIS) and Patient Archiving & Communication System (PACS). We performed 28 Primovist MRIs on patients with indeterminate liver lesions on CT (26 cases) and ultrasound (2 cases), over a 21 month period. The average age of patients was 58 years (range years) with a male to female ratio of 13:15. The reports for the initial modality and subsequent MRI were compared in terms of; number of lesions detected, change in diagnosis and whether a second opinion was required from a tertiary liver imaging unit. Twenty eight patients were assessed, one CT scan had no written report but images were reviewed at a local meeting. The MRI revealed no definite lesions on early or late phase. Of the 27 with a written report, CT and MRI concurred in 48% (13 patients), with 48% (13 patients) having differing numbers of lesions reported. 33% (9) of the patients had additonal lesions detected. Furthermore, Primovist MRI lead to changes in the diagnoses of 44% of those imaged. Only three MRI results needed review by a tertiary centre with their reports concurring with our own. Three patients were referred to tertiary centres in view of the MRI findings for further management. The results are shown graphically in figure; Page 6 of 20

7 Fig. 4: Graphical representation of the outcomes following liver specific MRI using Gd- EOB-DTPA. Percentages indicated are cases from the cohort number of 27. The majority of cases were found to be haemangiomas (13); Page 7 of 20

8 Fig. 5: A 27yr old female. History of recurrent pneumothoraces on the right but more recently on the left. Sensations of 'popping' in chest at time of menstrual periods hence underwent a CT (above) which reveals three small nodules which appear intimately related to the liver rather than pleural in nature and have similar characteristics to the liver in enhancement. An MRI of the liver was organised to determine whether these represent small humps on the surface of the liver or are due to pleural endometriotic lesions. Page 8 of 20

9 Fig. 6: MRI with Primovist - showing a 33mm lesion is visible at the junction of segment 4A and 8 of the liver, lying predominantly within segment 8. Dynamic imaging shows intense uptake in the arterial phase with the lesion becoming isointense on the portal venous phase images (2). On the 20 minute scan (image 4), there is marked enhancement around the edges with central wash-out. The appearances are most likely to represent a haemangioma. Malignant lesions confirmed or discovered included; metastases... Page 9 of 20

10 Fig. 7: A 44yr old female, underwent ERCP for obstructive jaundice and mild pancreatitis. She was found to have a tight stricture - biliary stent inserted. CT Abdomen - portal venous phase. Fatty change throughout liver with evidence of perfusion change in multiple sites. No discrete lesion is identified. Biliary stent is in situ (arrow) with inflammatory change in pancreatic head. Page 10 of 20

11 Fig. 8: MRI with Primovist contrast - 1. arterial, 2. Portal venous and 3. Hepatic phases showing multiple liver lesions none of which show any Primovist uptake and are highly suspicious of multiple liver metastases. 4. showing axial FLAIR images - multiple lesions are seen which correspond to non enhancing Primovist lesions (arrows). These were biopsied and confirmed to be malignant histologically(of pancreatic origin) Page 11 of 20

12 Fig. 9: Coronal MRI - showing abnormal soft tissue at the level of the pancreatic head (arrow) which appears to be abutting the SMA. There was a history of previous pancreatitis....and hepatocellular carcinomas Page 12 of 20

13 Fig. 10: The liver appears somewhat irregular in outline suggesting a degree of underlying chronic liver disease. There is however a 4.4cm lesion visible within segment 4 of the liver (circled). Following Primovist there appears to be some enhancement along its edges but on the biliary excretory phase this lesion can be appreciated separately from the background of the parenchyma and probably does not have significant Primovist uptake and is therefore suspicious of an underlying liver primary (HCC). Hepatic cysts were diagnosed in 2 cases; Page 13 of 20

14 Fig. 11: A 37yr old male presented with abnormal liver functions. He was found to have gastric varices on gastroscopy. A CT was performed which showed splenomegaly, varicies and occlusion of the splenic vein. Image 1 shows the CT of the liver with a tiny low-density focus in the liver in the superior aspect of the right lobe measuring 1cm in diameter. The differential was either a cyst or a haemangioma. MRI with TEs of 90 (image 2), 180 (image 3) and 200 (image 4) showing persisting high signal of the 2cm cyst. Page 14 of 20

15 Fig. 12: MRI of cyst (arrow) showing non enhancement during all phases of Primovist contrast inkeeping with a simple cyst. An interesting case revealed 67yr old female, investigated for abnormal liver functions, found to have large cystic lesions on ultrasound, further imaging on CT revealed a large pelvic tumour, presumed to be a ovarian malignancy with two, large lesions in the liver thought to be metastases. The images and findings are presented below; Page 15 of 20

16 Fig. 13: 67yr old female, investigated for abnormal liver functions, found to have large cystic lesions on ultrasound. She went on to have the following - CT Abdomen during arterial (A) and portal venous phase (PV) showing two significant large hypodense liver masses with wall thickening in the right liver lobe causing significant mass effect. There is mild segmental dilatation of the intrahepatic biliary tree in the left liver lobe. Page 16 of 20

17 Fig. 14: MRI Liver (Axial Post Primovist Hepatocyte phase (A) & coronal FIESTA (C) ) - showing two large cysts present within the right lobe of the liver (thin arrows). The signal characteristics of these cysts are very similar with slight heterogeneity present within the cyst fluid signal. Some degree of oedema/compressive effect is seen around the cysts. On the delayed phase oedematous changes seen around both the cyst with an altered area of perfusion seen anteriorly between the cyst. The diagnosis of organising liver abscesses was thought most probable. An ultrasound guided aspiration confirmed pus within the cavity. A large heterogeneous pelvic tumour is also noted on some of the sequences (Broad arrow - Under investigation). Page 17 of 20

18 Conclusion The introduction of Primovist MRI at Epsom and St Helier NHS Trust has offered a local service that is more sensitive and lead to changes in diagnosis and management. This study has demonstrated that the new protocol has enabled management to be tailored locally with referral to tertiary care centres only made when required. Page 18 of 20

19 Personal Information N. Rao 1, D. Assaf 2, K. Burney 3, S. Zar 4, N. Khosla 3, A. Mahmood 4 Epsom & St Helier University Hospitals NHS Trust, Carshalton, Surrey SM5 1AA, 1 Undergraduate Department 2 Department of Paediatrics 3 Department of Interventional Radiology 4 Department of Gastroenterology Page 19 of 20

20 References Purysko AS, Remer EM, Veniero JC. Focal liver lesion detection and characterization with GD-EOB-DTPA. Clinical Radiology 66 (2011) 673 e684. Ringe KI, Husarik DB, Sirlin, Merkle EM. Gadoxetate Disodium-Enhanced MRI of the Liver: Part 1, Protocol Optimization and Lesion Appearance in the Noncirrhotic Liver. AJR 2010; 195:13-28 Page 20 of 20