Billary

Evaluation

Obstruction:

with

Three-dimensional

MR Cholanloraphy’ Kouji

useful

Mutsuo

ship

Morimoto, MD Shimoi Toyomi Shirakawa Yoshiko Aoki, MD Soomi

Choi,

Yoshiaki

Miyata, Hara, MD

Kazuo

in establishment between

MD

good

MD

age

with

comparable

correlation

performed

0-21

days

later

terms: stenosis

76.365 mensional

Magnetic

resonance

1992;

183:578-580

Radiology

N

Bile ducts, MR, 76.1214 or obstruction, 76.288,

#{149}

ONINVASIVE

been

(MR),

Bile

#{149}

three-di-

has by the

methods, (endoscopic

resonance

and

bile

ducts

evaluate

such cause

In for obmag-

(MR)

projection

(MR

cholangiograms)

the clinical

images

and

effectiveness

of

Methods

Our technique for 3D MR cholangiography was developed and evaluated by a standard 1.5-T clinical wholeimaging system with a 10-mT/rn

gradient

capability

1.0-

msec minimum rise time (Magnetorn; Siemens, Erlangen, Germany). Signal

reversed with

but or

percutaneous) is often then required to determine the cause and exact site of biliary obstruction prior to surgery. CT and US provide tomographic images; direct cholangiography can demonstrate a whole biliary system as a projection image in different planes, which is

version

of the fast imaging

steady-state

nique.

With

precession

(FISP)

this sequence,

to generate

tech-

it is possible

steady-state

free

precession

(SSFP) signals with certain parameters. The SSFP signal has two contributions: a free induction decay component occurring

at the

interval

and

“SSFP

start

an echo

echo”)

at the

of each

repetition

component end,

just

(the as the

next

radio-frequency (RF) pulse is applied. The CE-FAST sequence is used to detect the SSFP echo signals. This sequence is very sensitive to physiologic factors such

as respiratory

and

cardiac

motion.

To avoid signal loss caused by respiratory motion, breath-hold imaging is used. From

the Department

National Hospital, Osaka 540, Japan

K.H.) and Siemens 1991

of Radiology,

2-1-14 Hoenzaka, (KM., MS., Y.A.,

Asahi,

Tokyo

Osaka

the

RSNA scientific assembly. Received September 9, 1991; revision requested October 9; revision received November 14; accepted November 15. Supported in part by a grant-in-aid for cancer research from the Ministry of Health and Welfare, Japan. Address reprint requests to

KM. c

RSNA,

578

#{149}

1992

Radiology

sequence

cannot

detect

blood

flowing at over 1 mm/sec (2). Under these conditions, it provides a heavily T2-weighted image, and only the fluid

Chuo-Ku, S.C., Y.M.,

(T.S.). From

The

in the played

static state, such as bile, is disas signal of extremely high in-

tensity. The coronal imaging, and technique

was

plane was a 2D and/or used.

selected for 3D imaging

Variables

imaging were as follows: tion time [TR] msec/echo

of 2D

17/7 (repetitime [TE]

signal

aver-

and

with

a 350

256

x

x

field of view. Imaging was performed during a breath hold of 16 seconds. Variables of 3D imaging were as follows: 17/7, 90#{176} flip angle, one signal average, 32-mm slab thickness, 4-mm partition thickness, and 128 x 256 acquisition matrix with 350 x 350-mm field of view. Slabs were acquired dura breath

sides

of

hold

of 20

effect

the

slab

seconds.

was

with

seen

3D

on both

imaging

per-

formed under these conditions. These artifacts were eliminated from the 3D data set, and slabs were overlapped to avoid any resultant data gap. 3 D image reconstruction-The images were processed by using a maximumintensity

projection

(3,4).

and

three

thickness,

matrix

An aliasing

images in determination of the and site of biliary obstruction.

Materials

angle,

section

acquisition

ing

3D fast imaging technique with a flowsensitive gradient-echo pulse sequence (contrast-enhanced Fourier-acquired steady-state technique [CE-FASTJ imaging) (1). This sequence is an exact time-

development of computed tomography (CT) and ultrasound (US). Bile duct dilatation and obstruction sites can be well these

netic of the

perfor-

methods (3D)

6-mm

350-mm

detection was provided by a circularly polarized body coil (Siemens). Data acquisition-The method is based on a two-dimensional (2D) and

76.363,

biliary imaging markedly advanced

demonstrated with direct cholangiography

256

cholangio-

later

90#{176} flip

ages,

im-

cholangiography.

this article, we describe taming three-dimensional

maximum

was

without

of direct

using body

between

observed. Index ducts,

a direct

msec),

and

site. If a projection

be determined

findings at 3D MR cholangiography and percutaneous transhepatic biliary drainage

branches

gram could be obtained noninvasively, the precise location of the obstruction and its relation to the biliary trees could

Three-dimensional (3D) magnetic resonance (MR) projection imaging was evaluated as a noninvasive alternative to direct cholangiography in 12 patients with malignancy-related obstructive jaundice. The 3D images of the bile ducts were formed by subjecting consecutive coronal MR images obtained with a fast imaging method to a maximum-intensity projection algorithm. Dilatation and obstruction of the biliary system were well documented in all and

of the relation-

biliary

the obstruction

mance

cases,

the

With

this

(MIP) method,

algorithm the

images

are

viewed at a user-selected projection angle, and the pixels of highest intensity are identified. These pixels are assumed to represent bile ducts, and their signal intensities are assigned to pixels in the MR cholangiogram.

Two about

recalculated 10#{176} apart

images

for views

could

be observed stereoscopically. The MR cholangiogram was constructed in multiple projections 3#{176}-5#{176} apart and was then displayed in cine mode. These methods allow clear demonstration of the 3D configuration of the bile duct. Clinical application-Twelve patients (10 men, two women) with obstructive jaundice underwent MR cholangiograpity followed by percutaneous transhepatic biliary drainage (PTBD). Dilatation of bile ducts had been previously demonstrated with CT and/or US. Patient age range was 40-85 years (mean, 67.8 years), and patients had pancreatic cancer (i = 3), bile duct cancer (i = 7), or gastric

cancer

(i

benign cluded

causes in the

of obstruction were instudy. The interval be-

tween

=

2).

MR cholangiography

No

patients

and

with

PTBD

(mean, 6 days). At the time of MR cholangiography, the serum bilirubin concentration was 5.3-41.0 mg/dL (91-701 .mol/L), with a mean of was

0-21

15.2

mg/dL

days

(260

p.mol/L).

Results In all cases, dilatation and obstruction of the bile ducts were clearly demonstrated. The hilum of the liver (n = 7) and extrahepatic bile duct (i = 4) or both (n = 1) were the documented sites of obstruction. The findings at MR

May

1992

b.

a. Figure

1.

(a) MIP MR cholangiogram

(full data

C.

set) obtained

in a 70-year-old

man

with

recurrent

gastric

cancer

and

related

obstructive

jaun-

dice shows dilatation of intrahepatic bile ducts and stricture at the hilum of the liver. The extrahepatic duct was also dilated, and obstruction at the end of the conimon bile duct was suspected. (b) MIP image (selected data set) reveals dilated pancreatic duct. (c) PTBD and internal drainage were performed 3 days after MR cholangiography. This direct cholangiogram shows good correlation with the MR cholangiogram (a). Advanced tumor invasion into the hilum of the liver and the duodenum of the peripancreatic area was confirmed at surgery.

cholangiography

were

exactly

corre-

lated with those at PTBD. Dilated creatic ducts also were delineated two cases (pancreatic head cancer recurrence of gastric cancer) (Fig Bile

ducts

strated

or

gallbladder

by means

phy

were

demon-

cholangiogra-

demonstrated in five

cholangiography 2a,

not

of direct

panin and lb).

with

MR

cases

(Figs

la,

3a).

Images

obtained

showed

with

higher

those

obtained

with

With

CE-FAST

data

aging

time

half

the

can

the

2D

data

set. total

shortened

taken

set

im-

to about

with

the

2D

Fourier

a.

method.

With

a stereoscopic

display,

bile

3D data did

than

sampling,

be

time

transform

the

resolution

the

ducts

view

spatial

and

cine

relationship

could

of

be easily

recognized.

technique

is one

b.

Figure

mode

2. (a) MR cholangiogram obtained in a 66-year-old man with bile duct cancer. Dilatation of the intrahepatic bile ducts and gallbladder and obstruction at the common hepatic bile duct are demonstrated. (b) PTBD was performed 3 days after MR cholangiography. The sites of obstruction on the MR cholangiogram are also evident on this direct cholangiogram, but the gallbladder could not be opacified at direct cholangiography.

the

Discussion The

CE-FAST

MR imaging In

the

methods

SSFP

sequence,

RF pulses

of the

plied

with

free

induction

pulse

next

sequence, echo)

With

pulse

the

assumption

acts

second-to-last

RF

would

equal

two

which

is longer

resulting

from

sequence

(5).

existing not

than the To

This

T2-weighted

acquisition

avoid

long

(the

the

true

TE can

creased TE

with

TR

provide

cacy

Se-

a

Number

2

of

suitable bile

respect

longer

the

is displayed signal.

as

These

for

selective

duct

system.

to TR

the

was

contrast

of a 2D

evaluation to the data fast

#{149}

sensi-

inition

of

1 mm/

2D

read

gra-

extremely visualiza-

imaging

fast

associated

PTBD

paramewith

the

imaging

bile

method

showed

duct

tree

method,

and

than

did

the

because

a

in

drainage are

better

treatment

and

(7).

these branch

For

of

must

insertion cially

effective

interventions, be

of the when

the

inter-

patients

with

jaundice an opera-

performance

the

of

optimal

selected

as the

drainage

tube.

obstruction

patic or at the hilum length of the segment

bili-

important

malignancy-related obstructive that cannot be resolved with tion

def-

internal

endoprosthesis

ventions

in

better

ary

de-

of bile ducts (6). With respect sampling method, the 3D method

biliary

imaging

technique.

imaging

between

of the fast

contrast between bile duct and surrounding soft tissue was obtained with the 3D fast imaging method. Also, the total imaging time with the 3D sequence is shorter than that with the 2D sequence. Thus, the 3D fast imaging method appears to be superior for this

characteris-

and surrounding tissues on the constructed MR cholangiogram, although flip angle of greater than 40#{176} did not have much effect in our limited research. Wallner et al reported the effi-

TE,

in a short

direction

state

of the

ters,

TE

>

are With

RF

FISP

TE

image

tics

of the

CE-FAST

static

tion

last

true

the

high-intensity

(1).

confusion the

the

end

indicated

time.

183

at the

In a CE-

time-reversed

with

heavily

each RF RF pulse

the the

order

dient (2). Under such conditions, signal from blood flow is eliminated almost completely. On the other hand, fluid in

TR minus

nomenclature,

adopted

quence.

Volume

pulse,

is very

the

sec)

signal

times

(on

ap-

images

the

along

sequence

flow

The

that

to refocus

slow

are

component

to form

CE-FAST

to

TR.

signal

this echo

The tive

short

interval.

is used

(1).

angle

following the next

by

repetition

SSFP

was

flip and

decay

FAST

the

same

a constant

a spin-echo-like

of the

of the

on SSFP

phase-coherent

is refocused

to form

based

biliary site

for

Espe-

is intrahe-

of the liver, of drainage

Radiology

the tube #{149} 579

inferior to that with direct cholangiography, both maneuvers result in a similar standard of images. The information obtainable with either method is of similar good quality, but the noninvasive procedure is less traumatic for the patient. #{149}

References 1.

2.

Cyngell ML. The application of steadystate free precession in rapid 2DFT NMR imaging: fast and CE-fast sequences. Magn Reson Imaging 1988; 6:415-419. Patz 5, Hawkes RC. The application of steady-state free precession to the study of very slow fluid flow. Magn Reson Med 1986; 3:140-145.

3.

a.

b.

Figure

3.

shows

marked

(a) MR cholangiogram dilatation

(b) PTBD and internal after MR cholangiography. tion

with

MR

obtained

of the

but

bile

ment) branch

is limited, and a longer biliary must be selected for effective

drainage.

(effective

the

in the

view great

drainage

Three-dimensional

cholangiography,

bile

with

left

branches

seg-

MR stereoscopic

and/or cine mode display, is of help in selection of the appropri-

ate approach and effective execution tions.

For patients dice, noninvasive projection image

limited method

insertion of these

with

duct

man

and

with

obstruction

point for interven-

obstructive

jaun-

methods to obtain of bile ducts have

to scintigraphy is not effective

(8,9). This in patients

the

could

#{149} Radiology

liver.

performed 1 day shows exact correla-

be opacified.

of tumor

invasion,

picted clearly. MR cholangiography, method

for constructing

4.

5.

could

6.

7.

8.

be de9.

as a noninvathe

tion image of bile ducts, has great tential in the diagnosis of biliary disease. Although spatial with 3D MR cholangiography

580

cancer

of the

level. In addition, nonopacified areas on the direct cholangiogram, such as sequestrated bile duct or gallbladder as a

sive

with

were

gastric hilum

severe jaundice and does not provide sufficient image quality for planning biliary drainage and surgery. On the other hand, in our preliminary research, MR cholangiography was able to delineate the dilated biliary systern irrespective of the serum bilirubin

result the been

not

advanced at the

drainage of the right branches of the bile duct In the right branches, direct cholangiography

cholangiography,

duct

in a 40-year-old

intrahepatic

projec-

Anderson CM, Saloner D, Tsuruda JS, Shapeero LC, Lee RE. Artifacts in maximumintensity-projection display of MR angiograms. AJR 1990; 154:623-629. Edelman RR, Mattle HP, Atkinson DJ, Hoogewoud HM. MR angiography. AJR 1990; 154:937-946. Lee SY, Cho ZH. Fast SSFP gradient echo sequence for simultaneous acquisitions of FID and echo signals. Magn Reson Med 1988; 8:142-150. Wallner BK, Schumacher KA, Weidenmaier w, Friedrich JM. Dilated biliary tract: evaluation with MR cholangiography with a T2-weighted CE-FAST sequence. Radiology 1991; 181:805-808. Mueller PR. Interventional radiology of the biliary tract: a decade of progress. Radiology 1988; 168:328-330. Lee AW, Ram MD, Shih WJ, Murphy K. Technetium-99m BIDA biliary scintigraphy in the evaluation of the jaundiced patient. Nucl Med 1986; 27:1407-1412. Rosenthall L. Cholescintigraphy in the presence ofjaundice utilizing Tc-IDA. Semin NucI Med 1982; 12:53-63.

po-

resolution is slightly

May 1992

Biliary obstruction: evaluation with three-dimensional MR cholangiography.

Three-dimensional (3D) magnetic resonance (MR) projection imaging was evaluated as a noninvasive alternative to direct cholangiography in 12 patients ...
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