Biomedical Engineering Reference
In-Depth Information
with non-fat suppressed sequence. 3D fat SPGR using an elliptical centric
order and two spec IR reduced the fat signal by 30%. And provided good 3D
MR angiography without substantial prolongation of breath-hold. Two spec
IR can be used for generation of partially fat-suppressed abdominal 3D MRA
without prolongation of the breath-hold when performing 3D fast SPGR using
an elliptical centric view order.
3.4.22 Gadolinium Enhanced MRA with MR
Cholangiography (MRC)
Simultaneously both methods were used in the preoperative evaluation of
gallbladder carcinoma [22]. All MR images were analyzed in order to assess
bile duct invasion, vascular invasion, hepatic invasion or metastasis, lymph
node metastasis, and invasion into adjacent organs. The sensitivity and speci-
ficity of MR examination were distinctive 100% and 89% for bile duct invasion,
100% and 87% for vascular invasion, 67% and 89% for hepatic invasion, and
56% and 89% for lymph node metastasis supported by histopathologic findings.
The “all-in-one” MR protocol, including MR imaging, MRC, and MRA, could be
an effective diagnostic approach in the preoperative work-up for gallbladder
carcinoma.
3.4.23 Ultrashort Contrast-Enhanced (CE) MRA
It was used for the morphologic evaluation of cerebral arteriovenous malfor-
mations (AVMs). The method was compared with conventional X-ray digital
subtraction angiography (DSA) and time-of-flight (TOF) MRA to assess the an-
gioarchitecture of the malformations that is essential for treatment planning
and follow-up. Contrast-enhanced MRA was able to detect all AVMs seen on
DSA, whereas the TOF MRA failed with a very small AVM [23]. However, there
was no difference for the detection and delineation of feeding arteries and the
AVM. The venous drainage patterns could always be clearly delineated in the
CE MRA, whereas TOF MRA could demonstrate the exact venous drainage.
Contrast-enhanced MRA was found to be superior to conventional TOF MRA
in the assessment of the angioarchitecture of cerebral AVMs especially re-
garding the assessment of the venous drainage patterns. The superiority was
