Ovarian vein thrombosis

Ovarian vein thrombosis is a well-known but rare entity, which can occur during the post-partum period. This condition has also been associated with inflammatory and malignant processes within the pelvis. Untreated, complications of ovarian vein thrombosis can be significant due to the associated sepsis and risk of pulmonary embolism. Diagnosis can be made with confidence using ultrasound, computed tomography or magnetic resonance imaging. Treatment of ovarian vein thrombosis is particularly important in the post-partum patients, with anticoagulation therapy being the current recommendation.     

Portal vein thrombosis: imaging features and associated etiologies.

Thrombosis of the portal vein and its splanchnic tributaries is often unsuspected clinically and may be recognized only after imaging studies of the abdomen are performed for other reasons. Radiologists should be aware of the clinical situations that predispose a patient to portal or mesenteric vein thrombosis and should also be able to recognize the sequelae of chronic thrombosis. Different modalities can be used to image the patient with portal vein thrombosis; each has its strengths and drawbacks. This paper discusses the conditions that predispose to portal and mesenteric vein thrombosis, differentiating intrahepatic portal vein occlusion secondary to liver disease from extrahepatic portal vein occlusion associated with a normal liver. The imaging features of portal vein thrombosis, its associated causes and sequelae will be reviewed as demonstrated on computed tomography (CT), ultrasound, magnetic resonance imaging (MRI), angiography, and plain film.     

Renal imaging findings in renal vein thrombosis: a note of caution

Renal vein thrombosis is a relatively uncommon disease that is being recognized with increasing frequency owing to both modern angiographic techniques and noninvasive modalities such as magnetic resonance imaging and renal images. It is important to emphasize the various imaging manifestations of renal vein thrombosis, especially if a renal image precedes more invasive testing. The findings of a Tc-99m DTPA renal image with correlative images in a patient with documented renal vein thrombosis are discussed.     

New experimental model of sinus and cortical vein thrombosis in pigs for MR imaging studies

Introduction Diagnosis of cerebral sinus vein thrombosis is still a challenge for imaging. MRI and MRA play a major role in sinus imaging. For further development of MR techniques, MR-compatible animal models are required. The aim of this study was to develop an animal model for sinus thrombosis and additional cortical vein thrombosis with a clot of human blood for MR imaging studies.Methods A combined surgical and interventional approach was carried out in 13 pigs. After minimal invasive surgical access to the anterior superior sagittal sinus and cortical vein, thrombosis with human blood was induced using an interventional catheter approach. MR imaging was performed prior to and after thrombus induction.Results Sinus thrombosis was induced in 12 of 13 animals. Three animals suffered acute subdural haemorrhage; one of these animals died during the intervention, and one died after thrombus induction. MR imaging of the thrombosed sinus could easily be performed without significant artefacts in 11 of 13 animals.Conclusion This new model of sinus and cortical vein thrombosis with a clot of human blood allows artefact-free imaging studies on MR.     

MRI diagnosis of bilateral adrenal vein thrombosis

We report a case of bilateral adrenal vein thrombosis in an adult female who had a history of breast cancer. The patient does not have clinical, serological or imaging evidence of metastatic disease 14 months from the initial diagnosis. Adrenal vein thrombosis is a rare entity. There have been no previous reports specifically stating an association between adrenal vein thrombosis and hypercoaguability, but there are many cases in the literature documenting venous thrombosis elsewhere within the body in patients with hypercoaguable states. Laboratory testing performed to exclude a hypercoaguable state, revealed heterozygosity for the Factor V Leiden mutation/activated protein C resistance and elevated factor VIII levels [3660 IU l(-1) (<1500)]. This is the first reported case of bilateral metachronous adrenal vein thrombosis in which MRI established the diagnosis.     

Diagnosis of portal vein thrombosis: value of color Doppler imaging.

This study was undertaken to determine the accuracy of color Doppler imaging in the diagnosis of portal vein thrombosis. Two hundred fifteen patients were studied with color Doppler imaging to determine patency of the main portal vein. Sonographic findings were confirmed in 75 patients, aged 19 to 66 years. Correlation with angiography was obtained in 13 patients, and surgical correlation was obtained in the remaining 62. Nine patients had portal vein thrombosis on the basis of these gold standards. Sonograms were classified as showing either patency or thrombosis, depending on the ability to show color flow within the main portal vein. Agreement between sonography and angiography or surgery was found in 69 patients (61 patent, eight thrombosed). One patient with a patent portal vein at sonography was found to have a thrombosed vessel at surgery, whereas five patients without portal venous flow at sonography had patent vessels at angiography (one patient) or surgery (four patients). Overall sensitivity and specificity for detection of portal vein thrombosis were 89% and 92%, with an accuracy of 92%, a false-negative rate of 0.11, a negative predictive value of 0.98, and a positive predictive value of 0.62. We postulate that the majority of errors in our study occurred in vessels that, although patent, had only sluggish flow, which could not be resolved because of technical limitations. We conclude that color Doppler imaging is a valuable screening procedure for the assessment of portal vein patency. If the sonogram shows a patent portal vein, no further studies are required. However, a lack of demonstrable flow does not always indicate thrombosis, and other imaging studies should be performed for confirmation.     

Acute portal vein thrombosis

The findings in acute portal vein thrombosis in a patient with chronic calcific pancreatitis and two episodes of pancreatic surgery are described. The diagnosis was made by ultrasound, which showed a dilated portal vein filled with low-level echoes, surrounding hepatic oedema, hypertrophy of the hepatic artery, splenomegaly, collateral vessels and ascites. This was confirmed by computed tomography. The ultrasonic differences in appearance between acute and chronic portal vein thrombosis are discussed, in the context of portal hypertension. The diagnosis of acute portal vein thrombosis should be considered in patients in the appropriate situation who suffer a sudden clinical deterioration with right upper quadrant or abdominal pain. Ultrasound is recommended as the imaging modality of first choice because of the flexibility of its scanning plane and its real time and Doppler capabilities. Computed tomography is valuable in patients with an ileus or heavy pancreatic calcification and for its ability to demonstrate patent vessels on intravenous injection of contrast medium.     

Magnetic resonance portal venography: use of fast-acquisition true FISP imaging in the detection of portal vein thrombosis

AIM: To determine the accuracy of true fast imaging with steady-state precession (true FISP) in the diagnosis of portal vein thrombosis in patients with cirrhosis and compare it to contrast-enhanced three-dimensional (3D) magnetic resonance (MR) angiography, the reference standard. MATERIALS AND METHODS: Twenty-four consecutive patients with suspected portal venous thrombosis underwent contrast-enhanced 3D MR angiography and true FISP imaging of the portal vein. All patients had undergone at least one other imaging study, either computed tomography, (CT) or ultrasound. Both sets of MR images were evaluated for patency of the portal venous system and for image quality. RESULTS: Portal vein thrombosis was diagnosed in six of the 24 patients. Four patients with portal vein thrombosis were accurately diagnosed on the true FISP sequence. This sequence also accurately diagnosed the patency of the portal vein in 17 patients. However, the results were inconclusive in three patients. The image quality of the true FISP sequence of the three inconclusive patients was graded as either poor or fair. Of these three patients, contrast-enhanced 3D MR angiography confirmed portal vein thrombosis in two patients and portal vein stenosis in one patient. True FISP imaging had a sensitivity of 67% and a specificity of 100% for the diagnosis of portal vein thrombosis. CONCLUSION: The results of the present study show that the true FISP sequence is useful in diagnosing portal vein thrombosis. It could be employed as an adjunct to contrast-enhanced MR angiography in the severely debilitated patient where respiratory motion may degrade the images or in patients where the use of intravenous contrast medium is not possible due to poor venous access.     

Portal and hepatic vein thrombosis in liver abscess: CT findings

OBJECTIVE: Our aim is to describe imaging findings of portal and hepatic vein thrombosis in pyogenic liver abscess on contrast-enhanced MDCT and to determine the incidence and evolving patterns on follow-up imaging. METHODS: Over a 5-year period, 67 patients with liver abscess underwent single-phase (n=30) or triphasic (n=37) contrast-enhanced CT. Images were reviewed for the presence of portal vein (PV) or hepatic vein (HV) thrombosis, regional parenchymal attenuation, and changes on follow-up CT. RESULTS: Venous thrombosis was seen in 28/67 patients (42%), involving PV in 16/67 (24%) and HV vein in 15/67 (22%); 3/67 (4%) had both PV and HV thrombosis. Thrombosis was seen as non-enhancing linear structures without expanding the lumen in all cases. Regional parenchymal attenuation during the portal-phase was hyperattenuating (10/16, 63%) or isoattenuating (6/16, 38%) in PV thrombosis, and mostly hypoattenuating (13/15, 87%) in HV thrombosis (P<.001). Of 27 patients with follow-up contrast-enhanced CT, venous thrombosis resolved in 10/27 (37%) within 6 months and persisted in 17/27 (63%) for 3-38 months, including 13 PV thrombosis and 4 HV thrombosis. Interval parenchymal atrophy was seen only in four all with persistent PV thrombosis. CONCLUSIONS: Both PV and HV thrombosis frequently occurs in liver abscess and is seen as non-enhancing linear structures without expanding the lumen on contrast-enhanced CT. Regional attenuation changes in hepatic vein thrombosis were often hypoattenuating whereas none with portal vein thrombosis showed hypoattenuation.     

介入治疗肝移植术后门静脉血栓的护理

目的探讨介入治疗肝移植术后门静脉血栓护理的重要意义。 方法回顾性分析24例肝移植术后门静脉血栓患者的临床资料,所有患者均采用经皮肝穿刺门静脉溶栓,对患者的临床资料、影像资料、介入治疗前、后护理进行总结。 结果所有患者术后临床症状缓解,随访期间超声检查均提示门静脉血流通畅,未见狭窄及血栓形成。其中19例患者病情明显好转,临床症状减轻,彩色多普勒超声提示门静脉血流再通,无感染、管腔阻塞及导管脱落等并发症发生,顺利拔管;5例患者侧枝循环静脉曲张较术前明显减少或消失。 结论加强介入治疗肝移植术后门静脉血栓前后的护理,对溶栓再通成功至关重要。     

Post-traumatic thrombosis of a segmental branch of the inferior mesenteric vein

We report the case of man with post-traumatic thrombosis in a segmental branch of the inferior mesenteric vein with secondary venous congestion and ischemia of the sigmoid colon. We discuss the current imaging modalities for diagnosing venous thrombosis and their relative significance.     

Deep venous thrombosis of the lower extremity: US evaluation

The sensitivity of duplex ultrasonography (US) for detecting deep venous thrombosis of the lower extremity was compared with that of venography in a prospective study of 54 patients. Doppler analysis of the common femoral vein and US imaging of the deep venous system from the common femoral vein to the popliteal vein was performed. Common femoral vein response to the Valsalva maneuver was recorded. Sonographically visible thrombi and abnormal vein compressibility were 91% sensitive for the common femoral vein, and 94% sensitive for the superficial femoral or popliteal veins, with no false-positive examinations. Abnormal Doppler flow and abnormal response of the common femoral vein to the Valsalva maneuver enabled thrombi to be detected only in the common femoral and iliac veins. Combined data allowed accurate diagnoses in all patients with deep venous thrombosis proximal to the deep calf veins. US should be the screening examination of choice for evaluating patients with suspected lower extremity deep venous thrombosis.     

MR, CT, and ultrasonographic demonstration of splenic vein thrombosis

The first case report of magnetic resonance imaging of splenic vein thrombosis is presented together with CT and ultrasound correlation.     

Simultaneous renal vein thrombosis and bilateral adrenal hemorrhage: MR demonstration

A case of simultaneous renal vein thrombosis and bilateral adrenal hemorrhage is presented, demonstrating the ability of magnetic resonance (MR) imaging to identify these abnormalities without the use of intravenous contrast agents or radiopharmaceuticals. Adrenal hemorrhage appeared as markedly enlarged adrenal glands with homogeneous high signal intensity on both T1 and T2 weighted spin echo MR images. The kidney involved with renal vein thrombosis was enlarged and demonstrated increased signal from the renal parenchyma on T2 weighted images.     

Postpartum renal vein thrombosis

Renal vein thrombosis in adults is usually a complication of the nephrotic syndrome. Rarely, it has been reported in nonnephrotic women postpartum. The thrombosis may be a complication of the hypercoagulable state associated with both the nephrotic syndrome and pregnancy. Two postpartum patients with renal vein thrombosis and no prior history of renal disease are reported here. Neither patient had heavy proteinuria. In both cases, pyelonephritis was suspected clinically and the diagnosis of renal vein thrombosis was first suggested and confirmed by radiologic examination. Renal vein thrombosis should be considered in women presenting postpartum with flank pain.     

Postpartum renal vein thrombosis

Renal vein thrombosis in adults is usually a complication of the nephrotic syndrome. Rarely, it has been reported in nonnephrotic women postpartum. The thrombosis may be a complication of the hypercoagulable state associated with both the nephrotic syndrome and pregnancy. Two post-partum patients with renal vein thrombosis and no prior history of renal disease are reported here. Neither patient had heavy proteinuria. In both cases, pyelonephritis was suspected clinically and the diagnosis of renal vein thrombosis was first suggested and confirmed by radiologic examination. Renal vein thrombosis should be considered in women presenting postpartum with flank pain.     

Pathophysiology and diagnosis of deep venous thrombosis

Lower-limb deep venous thrombosis (DVT) affects between 1% to 2% of hospitalized patients. These thrombi disrupt the vascular integrity of the lower limbs and are the source of emboli that kill approximately 200,000 patients each year in the United States. The causes of thrombosis include vessel wall damage, stasis or low flow, and hypercoagulability. These factors favor clot formation by disrupting the balance of the opposing coagulative and fibrinolytic systems. The symptoms and signs of venous thrombosis are caused by obstruction to venous outflow, vascular inflammation, or pulmonary embolization. About 70% of patients referred for clinically suspected venous thrombosis, however, do not have the diagnosis confirmed by objective testing. Among the 30% who have venous thrombosis, about 85% have proximal vein thrombosis, and the remainder have thrombosis confined to the calf. Physicians cannot rely on signs and symptoms to make the diagnosis of DVT and must depend on imaging studies to guide treatment. Patients with proximal vein thrombosis who are inadequately treated have a 47% frequency of recurrent venous thromboembolism over 3 months. In contrast, clinically detectable recurrence occurs in less than 2% of patients with proximal vein thrombosis if an adequate anticoagulant response is achieved. Of the diagnostic procedures for DVT, venography is the only invasive test of proven value, and ultrasonographic (US) studies are the most commonly used noninvasive modaity. Other procedures are occasionally used to diagnose DVT, including impedance plethysmography, computed tomography, and magnetic resonance imaging. US examinations are noninvasive, they are rapidly obtained, and they can be performed serially. In symptomatic patients, venous US is sensitive and specific for proximal DVT; however, US is insensitive to calf vein thrombosis and to asymptomatic DVT occurring after surgery. Patients with symptoms of recurrent DVT also can present a difficult diagnostic problem. Only about 20% to 30% of these individuals actually have the disease; the rest have symptoms arising from chronic venous insufficiency or from any of the causes of lower extremity pain. After an acute episode, up to 50% of patients have compression ultrasound abnormalities for 6 months that are indistinguishable from the original findings of DVT. Hence, there are a significant number of patients and clinical circumstances in which the diagnosis of DVT is difficult. 99mTc-radiolabeled peptides that target the molecular biology of thrombosis should aid in the management of the disease, particularly in asymptomatic patients at high risk, in patients with recurrent symptoms, in patients with active DVT in the calf and/or pelvis, and in patients with intermediate- or low-probability lung scans.     

Jugular venous thrombosis: MR imaging

Magnetic resonance (MR) imaging of jugular venous thrombosis was investigated in three patients who had symptoms suggestive of this condition; the diagnosis was later confirmed by computed tomography, by venography, and clinically. Bright intraluminal signal intensity was seen throughout the course of the affected jugular vein on MR images in all three patients, in sharp contrast to the lack of signal from the corresponding site in the uninvolved venous system. Temporal changes in signal intensity from the acute to subacute stage of thrombosis were evaluated for one patient. A relative increase in signal intensity for the subacute phase was believed to be related to a decrease in the T1 relaxation time. MR may be the imaging modality of choice in the investigation of venous thrombosis.     

Mesenteric vein thrombosis: CT identification

Superior mesenteric vein thrombosis was identified on computed tomographic scans in six patients. In each case, contrast-enhanced scans showed a high-density superior mesenteric vein wall surrounding a central filing defect. Four of the six patients had isolated superior mesenteric vein thrombosis. A fifth patient had associated portal vein and splenic vein thrombosis, and the sixth patient had associated portal vein and inferior vena cava thrombosis. The diagnosis of superior mesenteric vein thrombosis was confirmed by angiography in two patients and by surgery in a third. One of the six patients had acute ischemic bowel disease. The other five patients did not have acute ischemic bowel symptoms associated with their venous occlusion. This study defines the computed tomographic appearance of mesenteric vein thrombosis. A dense venous wall surrounding a central lucency representing blood clot was present in all six cases.     

Venous thrombosis in the neck. The role of real time ultrasound

Real time ultrasound is being increasingly used in the diagnosis of venous thrombosis. We have studied its role in six patients with jugular and/or subclavian vein thrombosis and conclude that ultrasound is a useful, non-invasive first line imaging technique and may negate the need for venography in this small but important group of patients.