Are Hepatic Portal Venous System Components Distributed Equally in the Liver? A Multidetector Computerized Tomography Study

Abstract

Objective: We aimed to evaluate the relationships between the splenic index, right and left hepatic lobe volumes, diameters of splenic vein (SV), superior mesenteric vein (SMV) and the portal vein (PV) by Multidetector Computerized Tomography (MDCT). We also investigated indirect signs of portal venous flow pattern using these parameters. Material and Methods: Following their contrast thoracoabdominal and abdominal 64-MDCT examinations, the images of 100 cases (61 males and 39 females) were evaluated retrospectively. For each case, the splenic index, total hepatic volume, left and right hepatic volumes were calculated on the post-contrast portal venous phase (50th sec) images. Spearman correlation tests were carried out with the purpose of determining the relationships between the variables. Statistical significance level was set at p<0.005. Results: A statistically significant relation was demonstrated between the diameter of the SMV and right hepatic lobe volume (p<0.0001), and according to Pearson's correlation analysis, a positive correlation of medium strength (r=0.36) was observed. A positive correlation was demonstrated between the diameter of the splenic vein and left hepatic lobe volume (r=0.36). Statistically significant relation between the diameters of the splenic vein and right hepatic lobe was not observed (p=0.62). A strong correlation between the left hepatic lobe volume and the splenic index (r=0.556) was observed. Conclusion: We observed a positive correlation and a significant relation between the diameter of the SMV and the right hepatic lobe, and a relation between the splenic vein and splenic index and both hepatic lobes. We believe that this situation is related to the streamline flow in the portal vein, and as demonstrated in the literature, the flow in the SMV is directed at the right lobe, whereas the splenic vein empties into the liver homogenously. Our study is the first study in the literature performed by multidetector CT, which is a technique that reveals the relations between the streamline flow in the portal vein, the splenic index and the hepatic lobe volumes. Turkish Başlık: Portal Venöz Sistem Bileşenleri Karaciğere Eşit mi Dağılıyor? ÇKBT Çalışması Anahtar Kelimeler: ÇKBT, laminer akım, portal ven, splenik indeks Amaç: Dalak indeksi, karaciğer sol lob volümü, splenik ven (SV), süperior mezenterik ven (SMV) ve portal ven (PV) çapları arasındaki ilişkiyi Çok Kesitli Bilgisayarlı Tomografi (ÇKBT) bulguları ile değerlendirmek ve bu parametreler ile portal vendeki akım paterni hakkında indirekt bulguları araştırmak. Gereç – Yöntem: Kontrastlı torakoabdominal ve abdominal 64-ÇKBT tetkiki yapılan 100 olgunun( 61 erkek, 39 kadın) görüntüleri retrospektif olarak değerlendirildi. Her olgu için postkontrast portal venöz faz görüntüler üzerinden dalak indeksi, karaciğer total ve sol lob volümü hesaplandı. SV, SMV ve PV çapları ölçüldü. Splenik indeks ile karaciğer sağ-sol lob volümleri ve ölçülen ven çapları spearman korelasyon testi ile karşılaştırıldı. Bulgular: Splenik indeks ile karaciğer sol lob volümü arasında güçlü korelasyon sağlandı (r=0.556). SMV çapı ile karaciğer sağ lob volümü arasında istatistiksel olarak anlamlı bir ilişki mevcutken (p<0.0001), Pearson korelasyon testine göre de pozitif korelasyon sağlandı. Splenik ven çapı ile karaciğer sol lob volümü arasında pozitif korelasyon mevcutken (r=0.36), sağ lob ile istatistiksel olarak anlamlı ilişki saptanmadı (p:0.62). Sonuç: Portal venöz sistem akım hemodinamiği ile ilgili literatürlere göre portal sistemdeki SV akımı büyük oranda karaciğer sol lobuna doğru yönelmektedir. Çalışmamızda da ÇKBT bulgularına göre splenik indeks ile sol lob volümü arasında SMV çapı ile sağ lob volümü arasında istatistiksel olarak anlamlı ilişki saptanmış olup bu bulgular gastrointestinal sistem tümör metastazlarının karaciğerdeki sağ lob dominansını açıklayabilir.

Keywords

• MDCT, laminar flow, portal vein, splenic index

Are Hepatic Portal Venous System Components Distributed Equally in the Liver? A Multidetector Computerized Tomography Study

Öz

Kaynakça

1. Gates GF, Dore EK. Streamline flow in the human portal vein. J Nucl Med 1973;14:79-83.
2. Thrush A, Hartshorne T. Peripheral vascular ultrasound how, why and when. 2nd ed. London: Elsevier, 2005.p.53.
3. Konopke R, Distler M, Ludwig S, Kersting S. Location of liver metastases reflects the site of the primary colorectal carcinoma. Scand J Gastroenterol 2008;43:192-5. [CrossRef]
4. Shirai Y, Wakai T, Ohtani T. Colorectal carcinoma metastases to the liver. Does primary tumor location affect its lobar distribution? Cancer 1996;77:2213-6. [CrossRef]
5. Shiomi S, Kuroki T, Miyazawa Y, Ueda T, Takeda T, Nishiguchi S, et al. Hepatic distribution of blood flow from the superior or inferior mesenteric vein mapped by portal scintigraphy with iodine123-iodoamphetamine. J Nucl Med 1996;37:51-4.
6. Kashiwagi T, Kamada T, Abe H. Dynamic studies on the portal hemodynamics of scintiphotosplenoportography. Streamline flow in the human portal vein. Gastroenterology 1975;69:1292-6.
7. Fenchel S, Boll DT, Fleiter TR, Brambs HJ, Merkle EM. Multislice helical CT of the pancreas and spleen. Eur J Radiol 2003;45:59-72. [CrossRef]
8. Barbaro B, Manfredi R, Bombardieri G, Vecchio FM, Palazzoni G, Mancini AP, et al. Correlation of MRI liver volume and doppler sonographic portal hemodynamics with histologic findings in patients with chronic hepatitis C. J Clin Ultrasound 2000;28:461-8. [CrossRef]

9. Torres WE, Whitmire LF, Gedgaudas-McClees K, Bernardino ME. Computed tomography of hepatic morphologic chang es in cirrhosis of the liver. J Comput Assist Tomogr 1986;10: 47-50. [CrossRef]
10. Bezerra AS, D’Ippolito G, Faintuch S, Szejnfeld J, Ahmed M. Determination of splenomegaly by CT: is there a place for a single measurement? AJR Am J Roentgenol 2005;184:1510-3.
11. Standring S. Gray’s anatomy. 39th ed. Elsevier Churchill Livingstone, 2005;1219.
12. Nomura F, Ohnishi K, Ochiai T, Okuda K. Obesity-related nonalcoholic fatty liver: CT features and follow-up studies after lowcalorie diet. Radiology 1987;162:845-7.