Doppler of the portal system discusses Doppler ultrasound findings related to portal hypertension. It describes various portosystemic collaterals that can develop as compensatory pathways in portal hypertension, such as the coronary vein, umbilical vein, splenorenal collateral, and gastrorenal collateral. It also discusses Doppler ultrasound signs of portal hypertension seen in cirrhosis, including dilatation of the portal vein, decreased mean blood flow velocity, and hepatofugal or to-and-fro flow patterns. Additional findings discussed include enlargement and tortuosity of the hepatic artery and changes in hepatic vein blood flow patterns.

1. Doppler of the portal system
Pathological findings
Dr. Muhammad Bin Zulfiqar
PGR-II FCPS-II SIMS/SHL

2. Doppler of the portal system
 Portal hypertension
 Portal vein thrombosis

3. Causes of portal hypertension
Pre-sinusoidal Congenital hepatic fibrosis
Sarcoidosis
Schistosomiasis
Lymphoma
Hyperdynamic Arterio-portal fistula or malformation
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Intra-hepatic
Post-sinusoidal Cirrhosis
Causes Disease
Extra-hepatic Portal vein thrombosis or compression
most common cause
Supra-hepatic Budd-Chiari syndrome
Right heart insufficiency

4. Doppler US signs of PHT in cirrhosis
• P-S collaterals Highly sensitive & specific
• Portal vein Dilated PV
Decreased mean velocity (< 15 cm/sec)
To-and-fro flow /Hepatofugal flow
Increased pulsatility (VPI) >0.48+/-0.31
Arterio-portal fistula
• Hepatic vein Compression (Pseudo-portal flow)
• Hepatic artery Enlargement & tortuosity
Increased RI & PI
Harkanyi Z. Ultrasound Clin 2006 ; 1 : 443 – 455.
P-V: portovenous, VPI: Venous pulsatility index

5. Porto-systemic collaterals
High sensitivity & specificity for PHT
• Tributary collaterals
“Drain normally into PS”
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Coronary vein (left gastric)
Short gastric veins
Branches of SMV & IMV
• Developed collaterals
“Developed or recanalized”
Recanalized umbilical vein
Spleno-renal collateral
Gastro-renal collateral
Spleno-retroperitoneal collateral

6. Common spontaneous porto-systemic collaterals
More than 20 P-S collaterals described
Patnquin1 H et al. Am J Roentgenol 1987 ; 149 : 71 – 76.
Most common: LGV – PUV – Spleno-renal – Gastro-renal

7. P-S collaterals / Coronary vein
Most prevalent (80-90%) – Most clinically important
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Sagittal view slightly superior
Tortuosity of CV as it extends
superiorly toward GE junction
Sagittal paramedial view
Flow in CV directed superiorly
& away from splenic vein

8. P-S collaterals / Gastroesophageal collateral
Gastroesophageal collateral veins close to diaphragm
McGahan J et al. Diagnostic ultrasound, Informa Healthcare, 2nd edition, 2008.
Longitudinal view of left liver lobe

9. Normal umbilical vein anatomy
UV communicates with umbilical segment of LPV
Travels down anterior abdominal wall toward umbilicus
Eventually drains into systemic system via inferior epigastric vein
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

10. Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Hepatofugal flow within UV
Similar color Doppler viewLongitudinal US of LLL
Dilated umbilical vein (10 mm)
P-S collaterals / Recanalized umbilical vein
PUV observed only in hepatic or suprahepatic blockage
LLL: Left lobe of Liver

11. Sagittal panoramic view
PUV traveling to periumbilical region where it becomes tortuous.
UV ramifies into smaller PU collaterals when it proceeds inferiorly
P-S collaterals / Recanalized umbilical vein
Caput medusae

12. Porto-systemic collaterals
• Coronary vein & umbilical vein are the easiest
& most productive to analyze
• Other collaterals detected sonographically
albeit with more difficulty in some cases
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

13. P-S collaterals / Spleno-renal collateral
Yamada M et al. Abdom Imaging 2006 ; 31:701 – 705.
Mansour MA et al. Vascular Diagnosis. Elsevier-Saunders, Philadelphia, 1st edition, 2005.
Transverse color Doppler US
Splenic vein feeding large
splenorenal collaterals
Flow direction from SV to LRV
Reversed or to-and-fro flow in SV
Schematic drawing

14. P-S collaterals / Spleno-renal collateral
Flow inversion in splenic vein
Flow inversion in SV increases dg of spleno-renal shunt
Mansour MA et al. Vascular Diagnosis. Elsevier-Saunders, Philadelphia, 1st edition, 2005

15. P-S collaterals / Short gastric veins
Sato T et al. J Gastroenterol 2002 ; 37 : 604 – 610.
Short gastric vein as inflowing vessel to gastric varices

16. P-S collaterals / Gastro-renal collateral
Yamada M et al. Abdom Imaging 2006 ; 31 : 701 – 705.
Maruyama H et al. Acad Radiol 2008 ; 15 : 1148 – 1154.
From cranial & dorsal side to
caudal & ventral side into LRV
Long-axis view of GRS
GRS LRV
From SV at confluence
coursing backward to join LRV
Schematic drawing

17. P-S collaterals / Superior mesenteric vein
Flow toward SMV in sup branch
Flow away from SMV in inf branch
Color Doppler view
2 mesenteric branches
of superior mesenteric vein
Semicoronal view of SMV
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

18. P-S collaterals / Inferior mesenteric vein
Mansour MA et al. Vascular Diagnosis. Elsevier-Saunders, Philadelphia, 1st edition, 2005.
Hepatofugal flow in IMV originating from PV confluence

19. P-S collaterals / IMV & rectal venous drainage
Wachsberg RH. Am J Roentgenol 2005 ; 184 : 481 – 486.
Peri-rectal varices
Transverse US posterior to bladderLeft parasagittal CDUS
Hepatofugal flow in dilated IMV

20. P-S collaterals / Gallbladder varices
Harkanyi Z. Ultrasound Clin 2006 ; 1 : 443 – 455.
Serpentine area in wall of GB
Cystic vein to anterior abdominal wall or patent PV branches
Most commonly observed in PV thrombosis (30%) 80% association
(Dahnert)

21. P-S collaterals / Spleno-retroperitoneal
collateral
Prominent varices surrounding posterior aspect of spleen
Owen C et al. J Diag Med Sonography 2006 ; 22 : 317 – 328.

22. Cirrhosis & PHT / Diameter of portal vein
1 Weinreb J et al. Am J Roentgenol 1982 ; 139 : 497 – 499.
2 Goyal AK et al. J Ultrasound Med 1990 ; 9 : 45 – 48.
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Diameter: 16.9 mm
Sign of portal hypertension
Longitudinal view of MPV
Contoversy on normal PV diameter
Up to 13 mm in one study1
Up to 16 mm in another study2
Unusual large PV: sign of PHT
Normal PV size: do not exclude PHT

23. Cirrhosis & PHT / Portal vein velocity
Low velocity: good indicator of PHT
Normal velocity: do not exclude PHT
Controversy on normal PV velocity
Difficult to rely on velocity for dg
Normal mean velocity: 15 – 18 cm/sec
Swart J et al. Ultrasound Clin 2007 ; 2 : 355 – 375.
Shrunken liver & irregular margin
Vmax: 10 cm/s
Diagnosis of PHT
Triplex image of PV

24. Portal vein pseudoclot – Incorrect velocity
Cirrhotic patient with portal hypertension
Slower flow in portal vein
demonstrated
Velocity scale: 7 cm/s
Rubens DJ et al. Ultrasound Clin 2006 ; 1 : 79 – 109.
Velocity scale: 20 cm/s
Good flow in HA anteriorly
No flow in adjacent PV

25. Cirrhosis & PHT / Portal vein flow
Normal flow
Kok Th et al. Scand J Gastroenterol 1999 ; 34 (Suppl 230) : 82 – 88.
Reversed flow
Advanced PHT
SOS
Porto-systemic shunt
To and fro flow
Advanced PHT
Heart failure
Arterio-portal fistula
SOS: Sinusoidal obstruction syndrome

26. Cirrhosis & PHT / To-and-fro flow in PV
Cardiac cycle
Hepatopetal & hepatofugal with each heart beat
Seen before frank hepatofugal flow
Wachsberg RH et al. RadioGraphics 2002 ; 22 : 123 – 140.
Duplex US of LPV during suspended respiration

27. Cirrhosis & PHT / To-and-fro flow in PV
Respiratory cycle
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
On real-time US, these alterations corresponded to respiratory cycle
Transverse color Doppler US of left portal vein
Hepatopetal flow Hepatofugal flow

28. Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Transverse CDUS of left portal vein
Hepatopetal flow Hepatofugal flow
Cirrhosis & PHT / To-and-fro flow in PV
Compression

29. Causes of to-and-fro flow
Exaggerated pulsatility
Minimum velocity below baseline
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
- Portal hypertension
- Tricuspid regurgitation
- Right heart failure
- Aerterio-portal vein fistula

30. Cirrhosis & PHT / Reversed flow of PV
Hepatopetal flow in HA & hepatofugal flow in PV
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Not pathognomonic feature of cirrhosis
Severe PHT – Rare

31. Hepatopetal flow in HA
Hepatofugal flow in PV
Color Doppler of peripheral liver
Arterial flow above baseline
Portal venous below
baseline
Duplex Doppler of same area
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Cirrhosis & PHT / Reversed flow in PV branches

32. Cirrhosis & PHT / Reversed flow in PV branches
Mansour MA et al. Vascular Diagnosis. Elsevier-Saunders, Philadelphia, 1st edition, 2005.
Right anterior PV branch
Hepatofugal flow
Right posterior PV branch
Hepatopetal flow

33. Hepatofugal flow in portal vein
Portal vein flow away from liver
• Cirrhosis
• Budd-Chiari syndrome & SOS
• TIPS
• Arterio-portal fistula Tumor: HCC – Hemangioma
Percutaneous liver biopsy
Percutaneous biliary drainage
Rupture vein aneurysm
Rendu-Osler-Weber disease
Hwang HJ et al. J Clin Ultrasound 2009 ; 37 : 511 – 524.

34. Hepatofugal portal / TIPS
Right portal vein to right hepatic vein
Hwang HJ et al. J Clin Ultrasound 2009 ; 37 : 511 – 524.
Reversion of hepatofugal flow
Stent devoid of color signals
Malfunction of TIPS
1 week after TIPS
Hepatofugal flow in RPV
Vigorous color flow in stent
Immediately after TIPS

35. Arterio-portal fistula / High-flow hemangioma
Hwang HJ et al. J Clin Ultrasound 2009 ; 37 : 511 – 524.
65-year-old man with high-flow hemangioma in LLL
Hypoechoic nodule with intratumoral flow
Peritumoral hepatofugal flow in segmental PV
Hepatopetal flow in proximal PV

36. Arterio-portal fistula / Post-liver biopsy
Bertolotto M et al. J Clin Ultrasound 2008 ; 36 : 527 – 538.
Vascular lesion between
HA & PV branches
Inverted flow in PV
Oblique CDUSOblique gray-scale US
Focal echogenic area
in region of biopsy
Spectral Doppler US
High-velocity flow
Low-resistance flow
Turbulent flow

37. Arterio-portal fistula / Rendu-Osler-Weber
Bertolotto M et al. J Clin Ultrasound 2008 ; 36 : 527 – 538.
Low-resistance arterial flow Arterialized & inverted PV flow
Dilated tortuous structures Dilated vascular structures with aliasing

38. Helical portal vein flow
Near bifurcation
• Normal subjects 2%
• Severe liver disease 20%
• TIPS
• Post-liver transplantation Donor PV > recipient PV
• Portal vein stenosis
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

39. Helical portal vein flow
If not properly recognized, it can produce
the mistaken impression of PV flow reversal
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.

40. Helical portal vein flow
Mimic of hepatofugal flow
Wachsberg RH et al. RadioGraphics 2002 ; 22 : 123 – 140.
Hepatopetal flow within liver confirms that net flow is hepatopetal

41. Cirrhosis & PHT / Prominent hepatic artery
Enlarged HA with tortuous or ‘‘corkscrew’’ appearance
Increased flow in HA to compensate decreased flow in PV
Swart J et al. Ultrasound Clin 2007 ; 2 : 355 – 375.

42. Causes of enlargement of hepatic artery
• Cirrhosis
• Hepatic diseases associated with alcoholism
• Congenital hepatic fibrosis
• Vascular tumors
• Hereditary hemorrhagic telangiectasia
Buscarini E et al. Ultraschall Med 2004 ; 25 : 348 – 55.

43. Parallel channel sign
von Herbay A et al. J Clin Ultrasound 1999 ; 27 : 426 – 432.
Gray-scale US
IH parallel channel sign
Suspicious of dilated IHBD
Color & pulsed Doppler US
Flow in both intra-hepatic lumina
Portal vein & hepatic artery
Absence of dilated intra-hepatic bile duct

44. Parallel channel sign
von Herbay A et al. J Clin Ultrasound 1999 ; 27 : 426 – 432.
Gray-scale US
IH parallel channel sign
Suspicious of dilated IHBD
Color & pulsed Doppler US
Blood flow in anterior structure
No flow in posterior structure
Confirmation of dilated intra-hepatic bile duct

45. Cirrhosis & PHT / Changes of hepatic artery flow
Kok Th et al. Scand J Gastroenterol 1999 ; 34 (Suppl 230) : 82 – 88.
Decreased diastolic flow
ESLD
Reversed diastolic flow
ESLD
Normal flow
Normal in most
patients

46. Cirrhosis & PHT / Pulsatility index of HA
Cirrhotic patients vs controls – Correlation with HVPG
Schneider AW et al. J Hepatol 1999 ; 30 : 876 – 881.
PI: 0.85
20 controls
0.92 ± 0.1
PI: 1.22
50 cirrhotic patients
1.14 ± 0.18
Directly correlated with HVPG (Hepatic venous pressure gradient)

47. Cirrhosis & PHT / Changes of hepatic vein flow
Kok Th et al. Scand J Gastroenterol 1999 ; 34 (Suppl 230) : 82 – 88.
Triphasic Biphasic
Cirrhosis
Budd-Chiari syndrome
Metastases
Ascites
Healthy subjects
Monophasic
Cirrhosis
Budd-Chiari syndrome
Metastases
Ascites
Healthy subjects

48. Damping index of HV waveform
Severe portal hypertension : HVPG > 12 mmHg
Kim MY et al. Liver International 2007 ; 27 : 1103 – 1110.
Minimum velocity of downward HV
Maximum velocity of downward HV
Damping index =
Normal value: < 0.6
Severe portal hypertension: ≥ 0.6

49. Damping index of HV waveform in cirrhosis
DI: 0.26
HVPG: 7 mmHg
DI: 0.72
HVPG: 15 mmHg
Kim MY et al. Liver International 2007 ; 27 : 1103 – 1110.
DI of 0.6: Sen 76%, Sp 82, & AUC 0.86 for severe PHT
HVPG :Hepatic venous pressure gradient

50. Doppler in cirrhosis / PHT
Prognostic implications
• Collaterals PUV High bleeding risk in surgery
Reversed LGV High bleeding risk of EV
S-R shunt Low bleeding risk of EV
• Portal vein Low flow High risk of HE
Inversed flow CI for TIPS & porto-caval
shunt
Congestion index High bleeding risk of EV
• Hepatic artery Increased PI ESLD
• Hepatic vein Monophasic ESLD
Increased DI Severe PHT (> 12 mmHg)

51. Portal Vein Thrombosis

52. Classification of portal vein thrombosis
• Duration Acute
Chronic
• Severity Complete
Partial
• Causes Malignant
Non-malignant

53. Portal vein thrombosis
• Etiology Extra-hepatic: multiple causes
Cirrhosis ± HCC: complete – partial
Budd-Chiary syndrome: 15% – poor prognosis
• Sensitivity Equal to CT – Power Doppler increase Sen
• False positive Very low portal flow
• Partial Gray scale better than color Doppler
• Indications Before hepatic surgery
Before porto-caval shunt
Before hepatic transplantation

54. Splenic vein thrombosis
Gastric cancer

55. Superior mesenteric vein thrombosis
Pancreatic cancer
Sagittal view of pancreas & SMV
Thrombosed
SMV
Mass in
Pancreatic neck
Shunt between SMV
& systemic venous return
http://www.sonographers.ca

56. Superior mesenteric vein thrombosis
Transverse image of SMA & SMV
http://www.ultrasoundcases.info
SMA
SMV

57. Acute thrombosis of portal vein
Complete thrombosis
http://www.sites.tufts.edu
Echogenic material visualized within portal vein.
Increased diameter of portal vein.

58. Partial thrombosis of portal vein
Echogenic material occluding lumen of PV by ≈ 50%
Sacerdoti D et al. J Ultrasound 2007 ; 10 : 12 – 21.

59. Partial thrombosis of portal vein
Swart J et al. Ultrasound Clin 2007 ; 2 : 355 – 375.
Gray scale ultrasound
Partial echogenic thrombus
Color & pulsed Doppler
Complete filling of main PV
obscuring the clot

60. Non-malignant PV thrombosis in cirrhosis
Systematic review – Many unresolved issue
• Incidence 10 – 25%
• Pathophysiology Cirrhosis no longer hypocoagulable state
• Clinical findings Asymptomatic disease
Life-threatening condition
• Management Not addressed in any consensus publication
1st line treatment: warfarin or LMWH
2nd line treatment: thrombectomy, TIPS
Tsochatzis EA et al. Aliment Pharmacol Ther 2010; 31 : 366 – 374.

61. Diagnosis of malignant PV thrombosis
• Color Doppler US* PV > 23 mm in diameter
“AASLD” Arterial-like flow on Doppler
Increased serum α-FP
• FNA CT- or US-guided
• CEUS Contrast-Enhanced Ultrasound
* DeLeve L et al. AASLD practice guidelines: Vascular disorders of the liver.
Hepatology 2009 ; 49 : 1729 – 1764.
AASLD: American association of study of liver disease.

62. Portal vein thrombus in HCC
Swart J et al. Ultrasound Clin 2007 ; 2 : 355 – 375.
FNA of portal vein thrombus confirmed HCC
Gray-scale US image
Thrombus in PV & its branches
Color Doppler image
Vascularity within thrombus
Low-resistance arterial waveform

63. Malignant PV thrombosis / CEUS
38 pts (15 benigns - 23 malignants) – Conclusive (37/38)
Dănilă M et al. Medical Ultrasonography 2011 ; 13 : 102 – 107.
Gray-scale US
Malignant PVT Arterial phase
Enhancement
Portal phase
Wash-out
Late phase
Wash-out
Contrast-Enhanced US

64. Portal vein pseudoclot – Augmentation
Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Color Doppler US of main portal vein
At rest
No detectable flow
Compression of lower abdomen
Augmented portal venous flow

65. Chronic portal vein thrombosis
Portal cavernoma
Parikh et al. Am J Med 2010 ; 123 : 111 – 119.
Hepatopetal collaterals around thrombosed portal vein

66. Portal cavernoma
Gray-scale ultrasound Color & pulsed Doppler

67. Tchelepi H et al. Ultrasound Clin 2007 ; 2 : 415 – 422.
Transverse color US of stomach
Multiple dilated gastric varices
P-S collaterals / Isolated gastric varices
Collaterals via short gastric veins
Isolated gastric varices
Hepatopetal flow in LGV
Splenic vein thrombosis

68. P-S collaterals / Transcapsular collaterals
Chronic PVT due to necrotizing pancreatitis or surgery
Seeger M et al. Radiology 2010 ; 257 : 568 – 578.
Transcapuslar collateral
from SB varices to PVs
Color Doppler image
Submucosal varices
in small-bowel loop
US image
Ectopic intestinal varices
& transcapsular collaterals
Schematic diagram
SB: small bowel

69. THANK YOU

70. Transjugular Intrahepatic Portosystemic Shunt
TIPS
Highly effective for
– Reducing ascites
– Recurrent variceal hemorrhage
– Improving quality of life
High rate of stenosis or thrombosis
High rate of hepatic encephalopathy

71. Normal Doppler parameters for TIPS
• Portal vein Hepatopedal flow – Velocity > 30 cm/sec
• IHPV Hepatofugal flow
• Hepatic artery Increased PSV
• Stent Flow completely filling the stent
Monophasic pulsatile flow
Vmin: 90 cm/sec – Vmax: 190 cm/sec
Vmax – Vmin: 50 – 100 cm/sec
Temporal changes: ↑ or ↓ less 50 cm/sec
Middleton WD et al. Ultrasound Quarterly 2003 ; 19 : 56 – 70.

72. Follow-up of TIPS by Doppler US
• 24 to 48 hours (baseline)
• 3 months
• 6 months
• 12 months
• Annually thereafter
Middleton WD et al. Ultrasound Quarterly 2003 ; 19 : 56 – 70.
Real goal of surveillance
Detect stenosis before complete thrombosis

73. TIPS / Normal
Middleton WD et al. Ultrasound Quarterly 2003 ; 19 : 56 – 70.
Stent within liver parenchyma
Hepatopetal flow in MPV
Hepatofugal flow in RPV
Color Doppler of TIPS Color & pulsed Doppler of TIPS
Monophasic pulsatile flow
Velocity: 106 cm/sec

74. TIPS / Mirror image artifact
If not recognized: migration into heart (emergency intervention)
If uncertainty persists: chest radiograph
Wachsberg RH. Ultrasound Quarterly 2003 ; 19 : 139 – 148.
Stent on either side of
diaphragm
Mirror image artifact Variant of mirror image artifact
Stent above diaphragm
True TIPS visible by rotating probe

75. TIPS / migration
Middleton WD et al. Ultrasound Quarterly 2003 ; 19 : 56 – 70.
Proximal portion migrated out of PV into parenchymal tract
This resulted in complete thrombosis of stent
Longitudinal view of TIPS

76. TIPS – Stenosis
Middleton WD et al. Ultrasound Quarterly 2003 ; 19 : 56 – 70.
Mid TIPS
Mean portal vein Right portal vein
Mid TIPS Distal TIPS
Vel 26 cm/sec
Aliasing 371 cm/sec 98 cm/sec
Hepatopetal flow

77. TIPS / occlusion
Ricci P et al. J Ultrasound 2007 ; 10 : 22 – 27.
Homogeneous hyperechoic intraluminal material
without any color flow within TIPS

78. Robinson KA et al. Ultrasound Quarterly 2009 ; 25 : 3 – 13.
Detectable flow within UV
Flow directed away from LPV
Indicating recanalization & PHT
Similar color Doppler viewLongitudinal US of LLL
UV extending from LPV
Diameter: 1.8 mm
P-S collaterals / Recanalized umbilical vein

79. Mansour MA et al. Vascular Diagnosis. Elsevier-Saunders, Philadelphia, 1st edition, 2005
P-S collaterals / Omental varices
Transverse view with linear transducer (7-MHz)
Omental varices just beneath abdominal wall

80. P-S collaterals / Lumbar & epigastric collaterals
Mansour MA et al. Vascular Diagnosis. Elsevier-Saunders, Philadelphia, 1st edition, 2005
Large collateral vein between LK & lower pole of spleen
shunting blood from splenic hilum to lumbar & epigastric veins

82. Intestinal infarction
Considered from presentation until resolution of pain
• Ascites
• Thinning of intestinal wall
• Lack of mucosal enhancement of thickened wall
• Development of multi-organ failure
Intestinal infarction is likely
Surgical exploration should be considered

83. Ultrasound in ischemic bowel
Thickening of small bowel wall
Loss of layering structure of wall
Chen MJ et al. J Med Ultrasound 2006 ; 14 : 79 – 85.
Thickening of small bowel wall
Bright flecks within the wall

84. Portal vein gas
Acute transmural mesenteric infarction
Tritou I et al. J Clin Ultrasound 2011 (in press).
Wiesner W et al. Radiology 2003 ; 226 : 635 – 650.
Intrahepatic PV gas in
periphery of both
lobes
CECT scan
Tiny echogenic foci
in liver parenchyma
Gray-scale US
Vertical bidirectional
spikes on PV waveform
Duplex of MPV