estudio dinamico con tem de las masas hepaticas

8/3/2019 Estudio Dinamico Con Tem de Las Masas Hepaticas

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AJR:180, May 2003


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OBJECTIVE.

Our aim was to determine which of three contrast-enhanced phases (early arterial, late arterial, or portal

venous) was optimal for achieving maximalenhancement of the celiac artery, portal vein, andhepatic parenchyma.

We also wanted to learn which phase provided themaximal tumor-to-parenchyma difference when usingmultidetector CT (MDCT) with fixed timing delays.


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Tcnica

In all patients, CT was performed using an MDCTscanner (Lightspeed QX/i; General Electric).

One hour before scanning, patients received 320 mL of dilute

barium orally(Scan C: 2.1% weight by weight bariumsulfate) for gastrointestinal tract opacification.

Via a power injector, 150 mL of Omnipaque 300 mg I/mL (iohexol300 mg I/mL) was injected IV at a rate of 4 mL/sec.


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Tcnica

The entire liver was scanned in a cephalad-to-caudad direction using a detector collimation of5 mm with a table speed per rotation of 15

mm/0.8 sec, a pitch of 3 in the scanners HQmode, and an image thickness of 5 mm.


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Material y mtodos

52 patients with suspected or known hepatic tumorsunderwent multiphasic contrast-enhanced MDCTI

Images were acquired at 20 sec for the early arterial phase, 35 sec for the late arterial phase, and

60 sec for the portal venous phase.

Attenuation measurements of the celiac artery, portalvein, normal hepatic parenchyma, and the hepatic

tumor were compared. Three reviewers independently and subjectively rated

tumor conspicuity for each of the three phases.


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Introduccin

The arterial phase in these studies, defined as occurring 18-35 secafter

initiation of IV contrast media administration, has beenfound to be most useful for maximizing enhancement

ofhypervascular tumors. In comparison, portal venous phase imaging, defined as occurring

50-70 sec after the initiation of IV contrast media

administration, has been found to be most useful for

obtaining maximal hepatic parenchymal enhancementand thus maximizing tumor-to-parenchyma differencesfor hypovascular tumors


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Hypovascular tumors: metastases from colon and pancreatic adenocarcinoma

Hypervascular tumors: hepatocellular carcinoma,

hepatic adenomas,

Focal nodular hyperplasia

hypervascular metastases choriocarcinoma,

renal cell carcinoma,

thyroid carcinoma, carcinoid tumor,

islet cell tumor

neuroendocrine tumors


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Resultados:

Celiac Axis Enhancement

The greatest average celiac axis attenuation wasobserved in the late arterial phase and wassignificantly superior (p


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Resultados:

Portal Vein Enhancement

The greatest average attenuation of the portalvein was observed on the portal venous phase


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Resultados:

Normal Hepatic ParenchymalEnhancement

Hepatic parenchymal attenuation was greatest in

the portal venous phase and was significantlyhigher (p < 0.0001) than that of each of theother phases. Although the hepatic attenuation

in the late arterial phase was significantly greaterthan that in the early arterial phase, thedifference was not as great.


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Resultados:

Quantitative Analysis: Tumor-to-Parenchyma

Differences

For the subgroup of hypervascular tumors, althoughmaximal tumor-to-parenchyma differences were greaterduring the late arterial and portal venous phases thanduring the early arterial phase, the differences were notstatistically significant.

In the subgroup of hypovascular tumors, maximaltumor-to-parenchyma differences were significantlygreater during the late arterial and portal venous phasesthan during the early arterial phase. However, nosignificant difference was found between the latearterial and portal venous phases.


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52-year-old man with metastases from

colon carcinoma. Metastases

hypovascular best seen in late arterial

and portal venous phase.


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57-year-old man with

hepatocellular carcinoma,best seen in late arterial

phase.


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76-year-old woman with hypervascular metastases

from primary extrahepatic neuroendocrine tumor.

Metastases hypervascular best seen in late arterial

phase.


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76-year-old woman with metastases

from colon carcinoma. Metastases

hypovascular best seen in portal venous

phase.
http://www.ajronline.org/cgi/content/full/183/2/443/FIG16http://www.ajronline.org/cgi/content/full/183/2/443/FIG13


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Utilidad de la fase arterial temprana en el carcinoma hepatocelular, permite estudiar sus arterias nutricias.
http://www.ajronline.org/cgi/content/full/183/2/443/FIG16http://www.ajronline.org/cgi/content/full/183/2/443/FIG13http://www.ajronline.org/content/vol183/issue2/images/large/AD1260_04B.jpeg


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Focal nodular hyperplasia in

28-year-old woman, best seen

in early arterial phase.
http://www.ajronline.org/content/vol183/issue2/images/large/AD1260_05B.jpeghttp://www.ajronline.org/content/vol183/issue2/images/large/AD1260_05A.jpeghttp://www.ajronline.org/content/vol183/issue2/images/large/AD1260_04B.jpeghttp://www.ajronline.org/cgi/content/full/183/2/443/FIG2http://www.ajronline.org/cgi/content/full/183/2/443/FIG1


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Typical hemangioma in 72-year-old woman. Conventional axial CT image obtained in arterial phase

reveals lesion in right lobe of liver (arrow), with peripheral nodular enhancement. In portal venous phase

reveals gradual contrast filling of tumor.
http://www.ajronline.org/cgi/content/full/183/2/443/FIG2http://www.ajronline.org/cgi/content/full/183/2/443/FIG1


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Conclusiones

Although we found that late arterial and portal venousphase images had better MDCT results than earlyarterial phase images for hypervascular liver tumors,

this finding was not statistically significant. For hypovascular liver tumors, late arterial and portal

venous phase images had statistically significantsuperior maximal tumor-to-parenchyma differences

compared with early arterial phase images.


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Conclusiones

Because use of early arterial phase images doesnot contribute to tumor detection in mostpatients, we no longer routinely perform early

arterial phase imaging in patients with known orsuspected hepatic neoplasms.

At our institution, patients referred for CT withpossible or known hepatic tumors undergoMDCT using only late arterial and portal venousphase imaging.


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Conclusiones

The early arterial phase images are acquired onlyif CT angiography is required to depict hepaticarterial anatomy before surgery.

Although the arterial enhancement is superior inthe late arterial phase, some venouscontamination occurs, which makes the early

arterial phase more suitable for CT angiography.

estudio dinamico con tem de las masas hepaticas

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