Consultant Radiologist Prince Sultan Military Medical City Shiny liver Dr. Ahmed Refaey FRCR Consultant Radiologist Prince Sultan Military Medical City

Format of the lecture Detection of liver masses by CT Hypervascular tumors of the liver Case of the day

Detection of liver masses by CT * Triphasic study * arterial phase * portal venous phase * equilibrium phase ( delayed phase )

When we give IV contrast, it is important to understand that there is a dual blood supply to the liver. Normal parenchyma is supplied for 80% by PV & only for 20% by hepatic artery, so it will enhance in the portal venous phase. All liver tumors however get 100% of their blood supply from hepatic artery , so when they enhance it will be in arterial phase

In the arterial phase hypervascular tumors will enhance via the hepatic artery , when normal liver parenchyma does not yet enhances , because contrast is not yet in the portal venous system. These hypervascular tumors will be visible as hyperdense lesions in a relatively hypodense liver

In the portal venous phase hypovascular tumors are detected when the normal liver parenchyma enhances maximally. These hypovascular tumors will be visible as hypodense lesions in a relatively hyperdense liver.

In the equilibrium phase at about 10 minutes after contrast injection , tumors become visible, that either : - retain their contrast ( become relatively hyperdense to the normal liver ) - wash out their contrast faster than normal liver parenchyma ( become relatively hypodense to the normal liver ).

Hemangioma hcc

Above: arterial phase showing hypervascular FNH Middle: portal venous phase showing hypovascular metastases Down: equilibrium phase showing relatively dense cholangiocarcinoma

Arterial phase imaging

Optimal timing Hypervascular tumors will enhance optimally at 35 seconds after contrast injection (late arterial phase)

A patient who underwent two phases of arterial imaging at 18 and 35 seconds . In the early arterial phase we nicely see the arteries , but we only see some irregular enhancement within the liver . In the late arterial phase, we can clearly identify multiple tumor masses.

Portal venous phase

Portal venous phase imaging work on the opposite idea Portal venous phase imaging work on the opposite idea . We image the liver when it is loaded with contrast through the portal vein to detect hypovascular tumors. The best moment to start scanning is at about 75 sec.

Hypovascular metastases seen as hypodense lesions in late portal venous phase

Liver metastases cancer colon

Equilibrium phase

Starts when contrast is moving away from the liver and the liver starts to decrease in density . This phase begins at about 3-4 minutes after contrast injection and imaging is best done at 10 minutes after contrast injection.

This phase can be valuable if you are looking for: 1- fast tumor washout in hypervascular tumors 2- retention of contrast in blood pool like in hemangioma 3- retention of contrast in fibrous tissue in capsule ( HCC )or scar tissue ( cholangiocarcinoma or FNH )

1- fast tumor washout in hypervascular tumors like HCC

2- retention of contrast in the blood pool as in hemangioma

3- retention of contrast in fibrous tissue in capsule ( HCC ) or scar tissue (cholangiocarcinoma , FNH)

Hypervascular hepatic tumors 1ry Benign Hemangioma Focal nodular hyperplasia adenoma Malignant HCC Fibrolamellar HCC 2ry Hypervascular metastasis Primary hypervasculr tumours Thyroid carcinoma Choriocarcinoma Renal cell carcinoma Iselet cell tumors of pancreas Malignant pheochromocytoma Malignant melanoma Carcinoid tumor 15% of cancer breast

Case of the day

History : A 40 year old male came with abdominal pain

Technique Triphasic contrast enhanced CT was performed for the chest, abdomen and pelvis.

Arterial phase PV phase

Hypervascular hepatic tumors 2ry Hypervascular metastasis 1ry Benign Hemangioma Focal nodular hyperplasia adenoma Malignant HCC Primary hypervasculr tumours Thyroid carcinoma Choriocarcinoma Renal cell carcinoma Iselet cell tumors of pancreas Malignant pheochromocytoma Malignant melanoma Carcinoid tumor 15% of cancer breast

Primary hypervasculr tumours Thyroid carcinoma Choriocarcinoma Renal cell carcinoma Iselet cell tumors of pancreas Malignant pheochromocytoma Malignant melanoma Carcinoid tumor 15% of cancer breast

Primary hypervasculr tumours Thyroid carcinoma Choriocarcinoma Renal cell carcinoma Iselet cell tumors of pancreas Malignant pheochromocytoma Malignant melanoma Carcinoid tumor 15% of cancer breast

Primary hypervasculr tumours Thyroid carcinoma Choriocarcinoma Renal cell carcinoma Iselet cell tumors of pancreas Malignant pheochromocytoma Malignant melanoma Carcinoid tumor 15% of cancer breast

Primary hypervasculr tumours Thyroid carcinoma Choriocarcinoma Renal cell carcinoma Iselet cell tumors of pancreas Malignant pheochromocytoma Malignant melanoma Carcinoid tumor 15% of cancer breast

Location of carcinoid tumor: Appendix …………………………. 45% Small bowel ……………………… 35% - ilium ( 91%) .. Jejenum (7%).. Duodenum ( 2%) Rectum …………………………….. 10% Colon ……………………………….. 5% Stomach ………………………….. < 3%

Diagnosis Carcinoid tumor of the stomach with hypervascular metastasis to the liver

Carcinoid tumor

Carcinoid tumor Low-grade malignancy, resemble adenocarcinoma, but do not have their aggressive behaviour Clinical presentation: Asyptomatic ( 66%) Abdominal pain/intestinal obstruction ( 19%) Nausea, weight loss (16%) Palpable mass ( 14%) Carcinoid syndrome ( 7%)

Carcinoid syndrome: Cause: excess serotonin level when the metabolic pathway to 5-HIAA is bypassed (a) with extensive liver metastasis (b) with 1ry pulmonary/ovarian carcinoids Recurrent diarrhea (70%) Right sided endocardial fibroelastosis (35%), resulting in tricuspid regurgitation and right heart failure Desquamative skin lesions / pellagra /nausea /vomiting /fever/cutaneous flushing ….. (5%) Prognosis: carcinoid syndrome has a higher morbidity and mortality than does the tumor itself

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