Left Gastric Vein Visualization with Hepatopetal Flow Information in Healthy Subjects Using Non-Contrast-Enhanced Magnetic Resonance Angiography with Balanced Steady-State Free-Precession Sequence and Time-Spatial Labeling Inversion Pulse

OBJECTIVE: To selectively visualize the left gastric vein (LGV) with hepatopetal flow information by non-contrast-enhanced magnetic resonance angiography under a hypothesis that change in the LGV flow direction can predict the development of esophageal varices; and to optimize the acquisition protocol in healthy subjects. MATERIALS AND METHODS: Respiratory-gated three-dimensional balanced steady-state free-precession scans were conducted on 31 healthy subjects using two methods (A and B) for visualizing the LGV with hepatopetal flow. In method A, two time-spatial labeling inversion pulses (Time-SLIP) were placed on the whole abdomen and the area from the gastric fornix to the upper body, excluding the LGV area. In method B, nonselective inversion recovery pulse was used and one Time-SLIP was placed on the esophagogastric junction. The detectability and consistency of LGV were evaluated using the two methods and ultrasonography (US). RESULTS: Left gastric veins by method A, B, and US were detected in 30 (97%), 24 (77%), and 23 (74%) subjects, respectively. LGV flow by US was hepatopetal in 22 subjects and stagnant in one subject. All hepatopetal LGVs by US coincided with the visualized vessels in both methods. One subject with non-visualized LGV in method A showed stagnant LGV by US. CONCLUSION: Hepatopetal LGV could be selectively visualized by method A in healthy subjects.

Pseudostenosis at the Origin of the Vertebral Artery on Contrast-enhanced MRA: Correlation with Aortic Motion on Dynamic 3D Time-Resolved Contrast-Enhanced MRA

PURPOSE: The origin of the vertebral artery (VA) is a frequent site of pseudostenosis on contrast-enhanced MRA (CE-MRA). The purpose of this study is to evaluate the relationship between the motion of the aortic arch and pseudostenosis at the origin of the VA. MATERIALS AND METHODS: Our study had approval of our institutional review board. 47 patients underwent CT angiography (CTA), CE-MRA, and 3D time-resolved contrast-enhanced MRA (TR-CEMRA) within 6.87+/-9.89 days (mean+/-SD). Percent stenosis using the NASCET criteria was measured on CTA and CE-MRA. CTA was used as a reference standard to classify the CE-MRA into pseudostenosis and control group. Pseudostenosis was determined as 50%-99% stenosis observed on CE-MRA but normal to less than 50% stenosis on CTA. Aortic motion (distance between the highest position and lowest position of aortic arch) was measured on TR-CEMRA. Age, route of intravenous contrast media, motion of aortic arch, and normal distal diameter of VA were compared between the two groups. RESULTS: There were 17 patients and 23 vertebral arteries of pseudostenosis. Patients with pseudostenosis showed more aortic motion (3.61+/-1.88 vs. 2.05+/-1.97 mm) and older age (71.29+/-8.88 vs. 62.32+/-13.19 year-old). Route of intravenous contrast media and normal distal diameter of VA were not associated with pseudostenosis. CONCLUSION: VA origin is a frequent site of pseudostenosis. Older age and more motion of aortic arch are associated with pseudostenosis on CE-MRA.

Diagnosis of Vertebral Artery Ostial Stenosis on Contrast-Enhanced MR Angiography: Usefulness of a Thin-Slab MIP Technique

It is a well-known clinical fact that contrast-enhanced magnetic resonance angiography exaggerates vertebral arterial ostial stenosis and sometimes shows pseudostenosis. Considering the clinical significance of a lesion in the posterior circulation ischemia, the importance of an accurate imaging diagnosis of ostial stenosis should not be underestimated. We were able to differentiate pseudostenosis of the ostium from true stenosis using thin-slab maximum-intensity-projection(MIP) images which are thought to be helpful for minimizing standard full thickness MIP images.

Non-Invasive Follow-up Evaluation of Post-Embolized AVM with Time-Resolved MRA: A Case Report

We report the hemodynamic assessment in a patient with cerebral arteriovenous malformation using time-resolved magnetic resonance angiography (TRMRA), a non-invasive modality, and catheter-based digital subtraction angiography (DSA), before and after embolization. Comparison of the results showed that TR-MRA produced very fast dynamic images and the findings closely matched those obtained at DSA. For initial work-up and follow-up studies in patients with vascular lesions, TR-MRA and DSA are therefore comparable.

Relationship between the posterior circulation ischemia and vertebrobasilar artery lesion / 临床神经病学杂志

Objective To explore the relationship between the posterior circulation ischemia(PCI) and vertebrobasilar artery lesion.Methods 57 patients with PCI(PCI group) were examined by DCE-MRA for their craniocervical artery,and the results were compared with the stroke inpatients but non-PCI during the same period(non-PCI group).Results The abnormal rate of vertebrobasilar artery in PCI group(70.2%)was significantly higher than that in non-PCI group(50.7%)(P