MR venography of the inferior mesentery vein

OBJECTIVE: To evaluate on three-dimensional (3D) dynamic contrast-enhanced (DCE) MR venography (MRV), the visibility of the inferior mesenteric vein (IMV), its insertion pattern into the portal system, and the difference of IMV diameters between healthy subjects and patients with cirrhosis. MATERIALS AND METHODS: Two hundred and seventeen consecutive patients who had abdominal 3D DCE MRI was included in this study. The original image data of 3D DCE MRI was used to generate multiple planar volume reconstruction (MPVR) images, which were evaluated for visualization of the IMV and its pattern of insertion into the portal system. The diameter of IMV was measured and compared in 24 patients with cirrhosis (Cirrhosis Group) and in 30 patients without hepatic lesions or liver disease (Healthy Group). RESULTS: In the 217 patients, the frequencies of visualization of IMV, grade 1 order branches and grade 2 order branches were, respectively, 88%, 24% and 9%. The IMV inserted into the splenic vein (SV), the portal confluence and the superior mesenteric vein (SMV) in 45%, 18% and 37%, respectively. Among patients with cirrhosis, 12.5% had IMV diameter larger than 5.1mm, although there was no significant difference between cirrhosis and healthy groups (P>0.05). However, the diameters of the main portal vein (MPV), SV and SMV were significantly larger in the Cirrhosis Group (P<0.05). CONCLUSION: The IMV and its branches can be depicted well by 3D DCE MRV. The most common insertion of the IMV is into the splenic vein. A minority of patients with cirrhosis had dilatation of the IMV.     

Giant varicose inferior mesenteric vein

In portal hypertension, a variety of portocaval collateral pathways develops in attempt to decompress the portal circulation. The most common collateral pathway is the coronary-gastroesophageal route. Here we report a case of portocaval anastomosis of inferior mesenteric vein (IMV) reaching to iliac veins via hemoroidal veins with the findings on ultrasonography, computed tomography (CT) and splenoportography. The route of this portocaval anastomoses is not frequent and the huge caliber of IMV is unusual in our case.     

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.     

Magnetic resonance venography in consecutive patients with suspected deep vein thrombosis of the upper extremity: initial experience

Purpose: To assess the feasibility and accuracy of two magnetic resonance (MR) venography methods in a consecutive series of patients with suspected deep vein thrombosis of the upper extremity (DVTUE).

Material and Methods: Consecutive in- and outpatients who were referred for imaging of suspected DVTUE in a large teaching hospital during the period April 2001 to October 2002 were eligible for inclusion. All patients were scheduled to undergo contrast venography with the intention to perform additional MR venography. Both time-of-flight and gadolinium-enhanced 3D MR venography were scheduled. All MR imaging were interpreted independently by consensus of two experienced radiologists, who were blinded for contrast venography outcome. Patients were managed based on contrast venography only.

Results: A total of 44 patients were eligible for inclusion. Thirteen patients were excluded (5 refused consent, 2 inability to gain venous access, 2 renal failure, 4 logistic reasons). Contrast venography was performed in 31 patients, and demonstrated DVTUE in 11 patients. MR imaging was not feasible in 10 patients (4 unable to lie flat, 3 claustrophobia, 1 too large for MR scanner, 1 osteosynthesis of shoulder, 1 pacemaker). The sensitivity and specificity of TOF MRV versus Gadolinium 3D MRV was 71% and 89% versus 50% and 80%, respectively.

Conclusion: A high number of patients were unable to undergo MR venography in this setting. Contrast-enhanced MRV did not improve diagnostic accuracy. The clinical utility of MR venography in the setting of suspected DVTUE seems disappointing.     

Anomalous inferior vena cava demonstrated by contrast-enhanced magnetic resonance venography

We discuss the technique of contrast-enhanced magnetic resonance venography and its advantages over other methods of imaging the veins of the chest. An example is presented of the results of this technique in a patient with agenesis of the hepatic segment of the inferior vena cava and azygos continuation.     

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.     

MDCT of inferior mesenteric vein: normal anatomy and pathology

Multidetector computed tomography (MDCT) is a useful technique for imaging the inferior mesenteric vein. The aim of the present review was to discuss the normal anatomy and the pathologies of the inferior mesenteric vein, including partial or total thrombosis secondary to inflammation (pyophlebitis) and malignancy, occlusion, dilatation and reversed flow, which are rarely encountered. Optimal reconstruction techniques are also discussed. The pathologies of the inferior mesenteric vein can be clearly demonstrated using MDCT using curved-planar reformatted multiplanar reconstruction (MPR) and minimum intensity projection (MIP) images.     

Magnetic resonance imaging of bowel ischemia induced by ligation of superior mesenteric artery and vein in a cat model

OBJECTIVE: To assess the usefulness of magnetic resonance (MR) imaging for detecting bowel ischemia with strangulation compared with histopathologic findings in an experimental cat model. MATERIALS AND METHODS: Fourteen cats were assigned to the normal control group (n = 3), acute ischemic group (induced by ligation of superior mesenteric vessels for 3 hours, n = 7), and subacute ischemic group (induced by ligation of superior mesenteric vessels for 10 hours, n = 4). Using a 4.7-T MR scanner, contrast-enhanced T1-weighted images were obtained at 0, 10, 20, 30, and 60 minutes after bolus injection of contrast media. T1- and T2-weighted images were obtained from the extracted bowel wall and compared with histopathologic findings. RESULTS: On contrast-enhanced MR images, the target-like bowel wall layers were clearly demonstrated and the submucosal layer showed the most prominent enhancement. At 10 minutes after administration of contrast media, the subacute ischemic group showed significantly lower enhancement of the submucosal layer than the normal or acute ischemic group (P <0.05). On T1-weighted images, there were not significant differences between the normal and ischemic bowel groups (P >0.05). On T2-weighted images, the signal intensity of all layers of acute ischemic bowel wall was significantly higher than that of the normal control or subacute ischemic group (P <0.05). CONCLUSION: Delayed contrast-enhanced MR images and T2-weighted images were helpful for detecting subacute and acute bowel ischemia with strangulation, respectively.     

May-Thurner syndrome with inferior mesenteric vein drainage and porta system - Case report

We present the case of a 12-year-old girl with a history of vascular anomalies in the lower pelvic limbs and back, who developed unilateral deep vein thrombosis of the left lower limb after her pubertal development, she was diagnosed with May-Thurner syndrome with an abnormal venous drainage of the pelvic structures through the superior hemorrhoidal veins to the inferior mesenteric vein towards the porta system, this being a chronic manifestation. This kind of behavior has not been documented in the reviewed medical literature. Secondarily, balloon angioplasty was performed without breaking the stenotic ring. As a second attempt, it was decided to place the venous stent, with satisfactory resolution of the symptoms. There are controversies about the indications for the use of anticoagulants and antiplatelet agents, or the indications to place a venous stent in children. We must consider an approach to for effective therapeutic treatment in these cases is to control bleeding, the main goal being trying to avoid ulcerations in the lower limb due to venous insufficiency with irreversible affectation of the valvular system.     

Aneurysm of the extrahepatic portal vein associated with segmental portal hypertension and spontaneous porto-caval shunting through the inferior mesenteric vein.

A case of a congenital aneurysm of the extrahepatic portal vein is reported. It was complicated by segmental portal hypertension of the territory of the inferior mesenteric vein, which was a pathway for spontaneous porto-caval shunting.     

Magnetic resonance imaging of renal vein and inferior vena cava thrombosis in a patient with glomerulonephritis: a case report

We report a case of bilateral renal vein and inferior vena cava thrombosis in a patient with membranous glomerulonephritis. To the best of our knowledge, this is the first case demonstrated by magnetic resonance imaging.     

Magnetic resonance VIBE venography using the blood pool contrast agent gadofosveset trisodium--an interrater reliability study

Purpose

In this study, image quality of leg veins and vena cava inferior was scored by independent raters using the new intravascular magnetic resonance imaging (MRI) contrast agent gadofosveset trisodium using fat-suppressed 3D gradient echo Volume Interpolated Breath-hold Examination.

Material and methods

The leg venous system without clinical signs of deep venous thrombosis (DVT) and sonography-ruled out DVT were imaged using a fat-suppressed 3D gradient echo Volume Interpolated Breath-hold Examination (VIBE FS). Image interpretation was done independently by two experienced radiologists (raters) using a 5-point scoring system.

Results

High diagnostic image quality with an overall mean visibility score of 4.8 ± 0.1 was acquired in patients enrolled in the study using gadofosveset trisodium-enhanced MRI for the venous system of the leg. There were no cases with moderate, poor or nondiagnostic image quality. Additionally, an excellent interrater reliability was observed.

Conclusions

This study shows the feasibility of acquiring high resolution images with excellent image quality of the venous system of the leg using gadofosveset trisodium.     

Magnetic resonance venography of achondroplasia: correlation of venous narrowing at the jugular foramen with hydrocephalus

In achondroplasia, venous narrowing associated with a small skull base leads to elevated venous pressure which impairs cerebrospinal fluid (CSF) absorption, resulting in communicating hydrocephalus. We correlated venous narrowing at the jugular foramina and collateral circulation on magnetic resonance venography (MRV) with ventricular size in 17 patients. Patients were divided into three groups: Group I: progressive hydrocephalus; Group II: nonprogressive hydrocephalus; and Group III: normal ventricular size. The grades of venous narrowing and types of collaterals were well correlated with hydrocephalus groups.     

Flow-independent magnetic resonance venography of the calf

PURPOSE: To show that flow-independent venography that exploit the intrinsic MR properties of blood to isolate vessels from surrounding structures can be used for depiction of peripheral veins and for detection of deep venous thrombosis (DVT). MATERIALS AND METHODS: Sequence and parameters were first determined on a theoretical basis. The sequence was then optimized in volunteers (N = 4) for the depiction of the peripheral venous vessels. Qualitative evaluation of the normal venous anatomy was performed in five volunteers. The feasibility of diagnosing DVT of the calf with this method was evaluated with preliminary clinical studies. RESULTS: Excellent depiction of the venous anatomy was achieved in all volunteers with the optimized technique. Very small venous structures, such as superficial, muscular, and perforator veins, were clearly depicted because of the high spatial and contrast resolution capacities of the sequences. In all six patients, DVT findings diagnosed by duplex sonography were also seen on MR venography. CONCLUSION: Venous anatomy mapping and detection of lower-limb DVT appear feasible using flow-independent MR venograms.