Barton
N. Milestone,
Herbert
Y. Kressel,
MD
#{149} Mitchell
D. Schnall,
Cervical Carcinoma: with an Endorectal Ten
consecutive
patients
opsy-proved
noma (MR) body face
invasive
with
and The
carci-
with an endorectal endorectal coil pro-
sur-
vided a markedly improved signalto-noise ratio, enabling the use of small
had
fields
of view;
significantly
resolution.
images
an MR imaging clinical staging
invasion coil
images
detail planes
When
provided
endorectal technique
side-
were
all well
compared
with
increased
coil
anatomic
the accuracy carcinoma.
genital tract. the potential to
of staging
nosed during ing of cervical
noise
the the
the past carcinoma
primarily
patient clinical
for
with
anesthesia, classifications
gynecologists
use
of the
carcinoma
cervical
its resectability. unresectable dengo
radiation
therapy,
the
stage
Those cancers
by
using of
and
size
to determine patients with will initially un-
therapy
sometimes
on chemo-
followed
this
resonance
been
very
female contrast,
due
for
the
leiomyomas,
in imaging
FOV
images stage
endometriosis,
and
(2-8). Recently, onstrated the
ing.
of cervical
carcinoma
MR imaging has demability to enable staging
carcinoma
better
than
ex-
amination under anesthesia, with the overall staging accuracy of MR imagbeing
especially
Radiology
sults
and
proximal
sion,
but
MR
lem
areas
ing
are
76%-83%
for staging the
evaluation
imaging
(9-12).
ultrasound
prob-
MR imag-
of parametrial
false-positive vaginal
re-
wall
inva-
is excellent
for
the evaluation of tumor However, standard body aging of the female pelvis plane resolution than do imaging modalities, such lution
The
with
volume. coil MR imhas less inother pelvic as high-reso-
or computed
to-
mography. To achieve increased resolution, the number of frequency and phase-encoding steps could be increased or the field of view (FOV) could be decreased, but these modifications to-noise
would ratio
therefore
of the prostate
Herein,
nience female noma.
to decrease
high-resolution
prostate gland
gland carcinoma
we
report
with endonectal patients with
Ten
cone
carcinoma,
cervical
and
to obtain
and
to (13).
We studied the feasibility of the use of an endonectal coil in female patients with lower genital tract disease to obtam higher-resolution images than can be obtained with body coil imag-
of the
tissue uterine
emdom.etniab
ratio
the
PATIENTS
of uterine
adenomyosis,
anomalies,
to augment
Excellent results have been obtamed with use of an endorectal sunface coil to increase the signal-to-
imaging
to its high
diagnosis
measures
our
early
expe-
coil imaging cervical carci-
in
by sun-
(MR)
useful
pelvis,
other
ratio.
geny.
invasion,
From the Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St. Philadelphia, PA 19104. Received November 14, 1990; revision requested January 14, 1991; revision received February 14; accepted March 8. Address reprint requests to B.N.M. e RSNA, 1991
(1). Stagis still per-
the International Federation of Gynecology and Obstetrics (FIGO). Most
ing
180:91-95
year
at examination
under staging
Index terms: Magnetic resonance (MR), intracavitary coils #{149}Magnetic resonance (MR), surface coils #{149}Uterine neoplasms, MR studies, 854.1214 1991;
PhD
require
has
surface coil is a promising to obtain high-resolution female has
E. Lenkinski,
the availability of Papanicolaou smears, cervical carcimoma remains a major health problem, with approximately 13,000 new cases of invasive cervical cancer diag-
Magnetic
tissue and normal
that were not seen on the images. This preliminary indicates that use of an
images of the This technique
improve cervical
and
the endorectal
and demonstrated between tumor
structures body coil investigation
assigned
of Gynecology wall, vaginal and pelvic
images,
Robert
ESPITE
formed
images
in-plane
were
by tumor
demonstrated.
body
the
stage based on the system of the Interna-
tional Federation Obstetrics. Vaginal fornix, parametrium,
wall
thus,
improved
The
PhD
MR Imaging Surface Coil’
D
bi-
cervical
underwent magnetic resonance imaging with both a standard coil coil.
MD,
MD
cause decreased signaland would therefore
AND
patients
with
biopsy-proved
METHODS
needle
biopsy-
invasive
or
cervical
car-
cinoma were imaged between November i989 and June i990, before treatment. One healthy volunteer underwent endorectal coil imaging only. All images were obtamed with a i.5-T system (Signa Advantage; GE Medical Systems, Milwaukee) that employs 4.0 software. Imaging was conducted in two parts. The first part consisted of body coil imaging. Each patient was prepared with insufflation of air into the rectum, i mg of intramuscular gluca-
gon, and, in the early studies, a vaginal tampon. Use of the vaginal tampon was abandoned in later studies because the vaginal walls and fornices were imaged better without it. Coronal Ti-weighted spin-echo (SE) (repetition time = 600 msec, echo time = i2 msec [600/12]) MR images
tion i2)
were
thickness. MR
renal
images
obtained
Axial were
hila through
with
a iO-mm
Ti-weighted
sec-
SE (600/
obtained
from
the pubic
the
symphysis,
with a 10-mm section thickness, a 2.5-mm section gap, and a 30-32-cm FOV. Axial and sagittal T2-weighted SE (2,500/40, 80) images
were
Abbreviations:
also
obtained
FIGO
=
through
the
International
tion of Gynecology and Obstetrics, of view, SE = spin echo.
Federa-
FOV
=
field
91
Table 1 Comparison of Image Resolution between Body Coil and Endoiectal Coil Images Imaging
Endorectal
Parameter
Coil
30-32
FOV (cm) Section (mm)
Coil
Body
10-14
thickness
128 x 256
4 128 x 256
2.74-3.13
0.30-0.61
5
Matrix size Pixel size (2) Voxel size (mm3)
13.7-15.7
1.2-2.4
cervix, and vagina, with a 5-mm thickness, a i-mm section gap, a 30-32-cm FOV, gradient moment nulbing, and a 32-kHz bandwidth. After this, with the patient in the left lateral decubitus pouterus,
section
sition,
an endorectal
burgh)
was placed
(13),
and
coil (Medrad;
Pitts-
as previously
an additional
described
1 mg of glucagon
was administered intramuscularly. The patient was placed in the supine position, and sagittal Ti-weighted SE images were obtained for localization. Initially, depending on the orientation of the cervix after placement of the coil, axial or coronal SE images were obtained to achieve an imaging plane that was more perpendicular to the cervix to evaluate better any parametrial spread of tumor. Oblique planes directly perpendicular to the cervix were not used because the chosen parameters required an increase in the FOV. Ti-weighted (600/12) and T2weighted (2,500/40, 80) MR images were obtained, with a 10-14-cm FOV, a 4-mm section thickness, and a i-mm section gap. In the last six cases, transverse imaging was
performed
because
the balloon
of gradient
motion 32-kHz trates
moment
nulbing
the improved
1.
Images
demonstrate
improved
resolution SE (2,500/80)
signal-to-noise
Table
of MR Imaging
Stage
Imaging
Stage
FIGO Stage
Tumor
1/43
0/lA
1A
None
put
through
a
The endorectal coil images were compared retrospectively with the body coil images in each case. Those patients (n = 6) with large or advanced-stage tumors were treated with radiation therapy; (n = 3) with stage lB or lower derwent radical hysterectomy.
those tumors
un-
One patient with a bulky low-stage tumor underwent imaging followed by radiation therapy and then radical hysterectomy. Three surgical specimens were imaged in 92
#{149} Radiology
Size*
fluid
detail due to tumor. in
the
to
vagina.
Treatment Radical hysterectomy, carcinoma
2/47
lB
iB
Large
(58)
Radiation
therapy
6
3B
3B
Large
(86)
therapy
4/61
lB
lB
Large
(34)
Radiation Radiation
no invasive
therapy,
radical
hysterec-
tomy’ /46
2B
lB
Large (28)
W30
0/lA
1A
None
7/46
0/lA
IA
None
2B
2B
Large (48)
Radical hysterectomy, carcinoma situ possible, microinvasion’ Radiation therapy
3B
2B
Large
(38)
Radiation
therapy
3B
3B
Large
(224)
Radiation
therapy
8/71 9/39 10/58 *
Approximate
tumor
volume
calculation:
the tumor. Numbers in parentheses t Specimen images were obtained.
(length
Radiation therapy Radical hysterectomy, carcinomat
x width
x height,2,
no residual
at maximum
in
dimensions
of
are cubic centimeters.
the axial plane with Ti- and T2-weighted SE sequences. Pathologic findings in those cases were compared with the images.
signed
were
greater posterior
MR
tion (14).
images
with use of the enwhich cervical carci(2,500/80) endorectal
and FIGO Stage
Patient’ Age (y)
surface coil correction program (spatial filter) that was developed at our institu-
endorectal
carcinoma
2
Comparison
We employed the criteria of Togashi et at (10) for staging of cervical carcinoma with MR imaging. These criteria were established on the basis of the FIGO staging criteria. The MR imaging stage was as-
ratio from the endorectal coil allowed for markedly improved in-plane resolution. All
of cervical
dorectal coil versus body coil. (a) Sagittal body coil image in noma (arrow) can be seen posterior to endocervical canal. (b) Sagittal SE coil image at same level demonstrates cervix and tumor (open arrows) in increased in-plane resolution. Endorectal coil (ERC) is inflated in rectum Very thin high-signal-intensity line inferiorly (solid arrows) represents B = bladder, EC = endometrial canal.
to reduce
effects from rectal spasm and a sampling bandwidth. Table 1 illusthat
b.
Figure
from
the coil tended to orient the cervix into a vertical position. In addition, sagittal T2weighted SE images were also obtained with the same parameters. In three cases, a chemical-shift-selection, fat-saturation imaging technique was used to test whether this would improve tissue contrast between high-signal-intensity tumor and low-signal-intensity parametrial fat. All T2-weighted series were performed with use
a.
before
the FIGO
stage
was
known.
RESULTS Higher-resolution images of the lower female genital tract were obtamed with the endonectal coil (Fig 1). The coil was tolerated well by the patients during the study. Table 2 lists the patients, tumor sizes, and treatments and compares the MR imaging
stage
with
the
FIGO
stage.
imaging stage both the body
was and
ages. quality
of 10 patients,
In seven images
determined endorectal
The
MR
with coil imgood-
were obtained, although in four of these the balloon displaced the cervix laterally, causing some loss of signal intensity where the tumor was farthest from the coil. In three of 10 patients, suboptimal images were obtained due to difficulty in advancing the endorectal
coil
posterior to the cervix. In these patients, the endorectal coil actually displaced the cervix superiorly and thus most
of the
the sensitivity one patient
cervix
was
lying
beyond
profile of the coil. In (patient 10), the tumor July 1991
b. Figure 2. (a) Endorectat with no residual tumor. surrounded correlation bladder,
coil image and (b) axial SE (2,500/80) image Note fimbriated appearance of endocervicat
by whirled tow-signal-intensity between the endorectal coil = endorectat coil.
*
cervical image and
of a cervix
of specimen canal (arrow
in a and b)
stroma. No tumor is seen. There image of the pathologic specimen.
is good
Figure
B
(arrows) are a transverse cx = cervix,
=
Figure large placed
Figure
4. Vaginal wall invasion by cervical carcinoma is demonstrated on sagittat SE (2,500/ 80) images of a large infiltrating tumor. (a) Near midline, tumor is shown to be enlarging and involving the anterior and posterior cervical lips (open arrows). Normal low-signal-intensity vaginal wall (solid arrows) is demonstrated. (b) To the right of a, the tumor (arrows) is shown
inferiorly
compared soft tissue
with a, normal representing
and
invading thin, tumor
the normal
anterior
dark vaginal walls invasion (arrowheads).
that it extended the sensitivity
anteriprofile of
and
have
posterior
been
vaginal
replaced
appearance
on
the
T2-weighted
dorectal coil images mal cervical stroma signal
intensity
pearance and the that
within which ear
with
body
en-
a whirled
coil
ap-
sequences, was similar images.
to
Fluid
the normal vaginal fornices, appeared as triangular or bin-
high
signal
intensity
on
the
T2-
walls.
ate
than
180
on
the
body
ligaments, #{149} Number
1
coil
images.
which
on
the body depicted
endorectal
coil
and
are
coil on the
images
as
structures then posteri-
muscle (*) also aptumor, indicating
T2-weighted
Cervical signal
weighted
the
intensity
images
on
and
the
was
hypeninas The
fat-saturation pulse on the T2weighted images was used in only a few cases and did not significantly improve tissue or tumor contrast, but further evaluation with more cases is necessary.
Vaginal
wall,
vaginal
phytic
isointemse
gina
coil
had
were
Ti-
canal
endorectal
carcinoma
carcinomas
but did not appear relatively as on the body coil images.
intenmedi-
structures
endocenvicab
cervical
tense bright
fornix, parametrial, and pelvic sidewall invasion by cervical carcinoma were all readily demonstrated on the endorectal coil images (Figs 4, 5) according to the criteria established with body coil imaging (10,11). In three cases, on the T2-weighted endorectal coil images, the intact dark vaginal wall was identified better when it stretched around a large exo-
5 mm in diameter) as small, round,
high-signal-intensity
images
Volume
to identify are routinely
ian cysts (less than were often identified joining
sacrouterine
with
When
only from the cervix (Fig 3). On the transverse T2-weighted endorectal coil images, the normal urethra was a small horizontal line with high signal intensity surrounded by three concentric rings of low-, high-, and bowsignal-intensity tissue. Small naboth-
weighted images, was better identifled around the cervix as it protruded into the vagina on the endorectal coil The
image of a is disendorectal
by high-signal-intensity
thin, low-signal-intensity that extend laterally
(Fig 2). The nonhad decreased
on T2-weighted signal intensity
of the
difficult images,
canal had a fimbriated
5. Transverse SE (600/12) cervical carcinoma (T), which to the right by the inflated
with the cervix and uterus. On the T2-weighted emdorectal coil images,
transverse
The normal endocenvical high signal intensity and
sacrouterine ligaments demonstrated in a volunteer on SE (600/12) image. B = bladder, * = endorectal coil.
right obturator internus pears to be infiltrated sidewall involvement.
the was so lange only beyond the coil.
Normal
coil in the rectum. Tendrils of tumor (arrows) extend from the surface of the tumor into the paracervical fat on the right. Fat adjacent to
b.
extending
3.
ad-
on the images.
tumor
but
did
that
not
grew
invade
into
the
the walls Radiology
va-
(Fig #{149} 93
Figure
6.
cervical
Transverse carcinoma
SE (2,500/80) (TI) growing into
nat vault and left vaginal nal fornix (straight solid
image of the vagi-
fornix. Right vagiarrow) is shown
with low-signal-intensity vaginal rounding an intermediate-signal-intensity line. Low-signal-intensity vaginal (curved arrows) can be followed
walls
sur-
a.
b.
Figure
7.
volving walls from right
and
(a) Transverse SE (2,500/80) the posterior lip of the cervix.
the posterior
paracervical
level
fornix around tumor, indicating that there is no vaginal wall invasion. Focal area (straight open arrow) of high signal intensity on the right side of the tumor is due to hemorrhage
from
the posterior
secondary
men mor
images in demonstrating mass and small nabothian
biopsy.
6). The panacervical tissues in one case were separated from tumor by a very narrow band of low-signal-intensity cervical stroma that was not apparent on the body coil images (Fig 7). In two cases,
on
the
body
coil
images,
a plane
could not be defined between a large exophytic cervical carcinoma and the bladder wall (n = 1) or the anterior rectal images
wall (ii clearly
separating
=
1). The endorectal coil demonstrated a plane
the bladder
walls from the (Fig 8). Neither anesthesia nor copy demonstrated
and
rectal
tumor in these cases examination under proctoscopy or cystosrectal on bladder
No
coil image
cervical
fat. (b) Transverse
same
to needle
body
as in a demonstrates
a thin
paracervical
rim
These
first
early
strate
that
resolution dorectal
no tucysts.
of the
of women
cal
the
cialby large images
vaginal
espe-
when it was stretched around a exophytic tumor. Endorectal coil can also demonstrate a thin
wall invasion. In one case of a large cervical carcinoma, thickening and shortening of the left sacrouterine ligament that
rim of cervical been interrupted
was
aging. There was 80% agreement between the findings at MR imaging and at FIGO staging, but FIGO stag-
contiguous
to the
tumor
was
identified and appeared to indicate tumor invasion of the ligament (Fig 9). Specimen images of the cervices with no residual tumor or carcinoma in situ demonstrated am almost featheny or fimbriated high-signal-intensity appearance of the endocervical epithelium on T2-weighted images, as was
demonstrated
dorectal sity
coil images.
of the
normal
on
the
The surrounding
in vivo
signal
en-
intemstroma
remained decreased, although, as has been described in younger patients, an outer rim of intermediate-signalintensity stroma was seen cases (4,15). The endorectal ages correlated webb with 94
#{149} Radiology
in two coil imthe speci-
the
stroma that by tumor,
has not as was
valuable
tumor
transverse
through
the
for evaluation
vaginal
a better
vagina,
tissues
wall,
were
carcinoma
of cervical
its surrounding
the
intumor
at the
the
transaxially
posterior
vided
high-
can be obtained. In our study the endorectal coil images were useful in clarifying equivocal findings of bladden or rectal invasion in two cases and
in delineating
separating
so that
imaged
plane
lower
demon-
to obtain
images
and
the
coil image
(arrows),
position
plane
images with use of an ensurface coil; in addition,
higher-resolution
endorectal
stroma
(arrow)
between
cervix, which allowed for better evabuation of the parametnial and panacenvical tissues. Images of the sagittal
it is possible
carcinoma
carcinoma
fat.
images
tract
cervical
is demonstrated
SE (2,500/80)
of cervical
DISCUSSION genitourinany
shows
stroma
fornix
overall
and uterus,
view
pro-
of cervical
its relationship
bladder,
of
and
to the
and
rectum.
Certain problems specific to the female anatomy were encountered with use of the endorectal coil as designed for evaluation of the prostate gland, resulting in some suboptimal images.
The
mobility
caused away
of the
cervix
it to be displaced from the endorectal
inflation
of the balloon.
mobility
also
being
sometimes
pushed
therefore,
superiorly
it was
difficult
sometimes laterally, coil after
This
cervical
resulted by
in its
the
coil;
to place
the
known to be imperfect compared with pathologic or surgical staging
coil beyond the stretched vagina. Alterations in balloon design, probe stiffness, and shaft angulation may resolve these problems of coil placement. The problem of imaging large tumors that lie beyond the sensitivity profile of the endorectal coil may be eliminated by use of an anterior ab-
(16-18).
dominal
shown in one not seen with
ing
case; this standard
by examination
thin body
under
rim was coil im-
anesthesia
is
The most useful with the endorectab transverse
and
sagittal.
plane often imaged liquely, as did the but the difficult
The
coronal images were more to interpret at the junction
full
an inflated This
coronal
the cervix obtransverse plane,
the cervix and the vagina. were imaged when they tially
the
imaging planes coil were the
placed
urinary
bladder,
endorectal the
cervix
of
Patients had a parwith
use
coil balloon. in a more
verti-
of
surface
endorectal
coil combined coil
with
in a multiarray
coil
system. Because a small FOV is used with the emdorectal coil, the entire pelvis is not visualized, so the evaluation of pelvic lymphademopathy with this coil is incomplete. Use of the endorectab coil often results in good visualization of the obturator and internal iliac regions, but for complete evaluation of bymphadenopathy, body coil imaging of the lower abdomen and pelvis July
1991
b. Figure
8.
posterior
(a) Transverse aspect
SE (2,500/80)
of the
cervix
and
body
abuts
against
coil image the
shows
anterior
a tumor rectal
plane
is demonstrated between the rectal wall and the cervical (2,500/80) endorectal coil image at the same level as in a shows that separates the tumor from the anterior rectal wall.
is necessary, as is dome gland examinations.
Therefore, high-resolution
in prostate
whether use of these images will improve
the ability (specifically, and rectal
to stage cervical carcinoma panametrial, vaginal wall, or bladder wall invasion)
compared with use of images obtamed at standard MR imaging will require further study, with pathologic correlation. This technique might also prove useful when questionable abnonmabities
of the
lower
female
geni-
tourinany tract are identified with standard MR imaging and when betten characterization is required. U
2.
Cancer statistics, ACS, from Journalfor Clinicians. Cancer
Hricak
H, Tscholakoff
D, Heinrichs
Uterine leiomyomas: correlation histopathologic findings, and Radiology 1986; 158:385-391.
Volume
180
#{149} Number
Ca-A Cancer 1989; 39:3-39.
1
from No
(b) Transverse SE tissue plane (arrows)
4.
Togashi K, Ozasa H, Konishi larged uterus: differentiation nomyosis
5.
and
ing. Radiology WorthingtonJ,
leiomyoma
with
7.
H. 8. 9.
10.
11.
Enade-
MR imag-
M, Thickman
MR evaluation
D, Gussman
of uterine
are
infiltrated ligament
by tumor. is markedly
The left thickened
proximally, indicating direct tumor extension from the cervix. The parametriat fat surrounding the right sacrouterine ligament is infiltrated by tumor that extends into the hgament, indicating tumor infiltration.
12.
13.
Uter-
Radiology
Zawin M, McCarthy 5, Scoutt L, Comite F. Endometriosis: appearance and detection at MR imaging. Radiology 1989; 171:693696. Mintz
picted and sacrouterine
Ad-
I, et al. between
1989; 171:531-534. Balfe D, LeeJ, et al.
me neoplasms: MR imaging. 1986; 159:725-730.
6.
the
tissue
Togashi K, Nishimura K, Itoh K, et al. enomyosis: diagnosis with MR imaging. Radiology 1988; 166:111-114.
L, et al.
of MR. symptoms.
carcinoma. a definite
extends
(arrows).
3.
References 1.
that
wall
coil image of a huge cervical carcinoma (7) demonstrates tumor invasion of the pelvic sidewalls (open arrow). In addition, both sacrouterine ligaments (solid arrows) are de-
14.
15.
MM. J Digital Imaging 1989; 2:2-8. Heiken J, Lee J. MR imaging of the pelvis. Radiology
16.
D, Kressel
anomalies.
AJR 1987; 148:287-290. Hricak H. MM of the female pelvis: a review. AIR 1986; 146:1115-1122. Rubens D, ThornburyJ, Angel C, et al. Stage lB cervical carcinoma: comparison of clinical, MR. and pathologic staging. AIR 1988; 150:135-138. Togashi K, Nishimura K, Sagoh T, et al. Carcinoma of the cervix: staging with MR imaging. Radiology 1989; 171:245-251. Hricak H, Lacey C, Sandtes L, et al. Invasive cervical carcinoma: comparison of MR imaging and surgical findings. Radiology 1988; 166:623-631.
Kim 5, Choi B, Lee H, et al. Uterine cervical carcinoma: comparison of CT and MR findings. Radiology 1990; 175:45-51. Schnall M, Lenkinski R, Pollack H, et al. Prostate: MR imaging with an endorectal surface coil. Radiology 1989; 172:570-574. Listerud J, Axel L, Lenkinski RE. The correction of non-uniform signal intensities in
17.
1988; 166:11-16. J, RoddickJ, Lowin D. The staging of cervical cancer: inevitable discrepancies between clinical staging and pathologic findings. Am J Obstet Gynecol 1971; 110:973-978. Averette H, Dudan R, Ford J. Exploratory celiotomy for surgical staging of cervical cancer. AmJ Obstet Gynecol 1972; 113:
Van Nagell
1090-1096. 18.
Lagasse
al.
L, Creasman
Results
W, Shingleton
and complications
H, et
of operative
staging in cervical cancer: experience of the Gynecologic Oncology Group. Gynecol Oncol 1980; 9:90-98.
Radiology
#{149} 95
N. Milestone,
Herbert
Y. Kressel,
MD
#{149} Mitchell
D. Schnall,
Cervical Carcinoma: with an Endorectal Ten
consecutive
patients
opsy-proved
noma (MR) body face
invasive
with
and The
carci-
with an endorectal endorectal coil pro-
sur-
vided a markedly improved signalto-noise ratio, enabling the use of small
had
fields
of view;
significantly
resolution.
images
an MR imaging clinical staging
invasion coil
images
detail planes
When
provided
endorectal technique
side-
were
all well
compared
with
increased
coil
anatomic
the accuracy carcinoma.
genital tract. the potential to
of staging
nosed during ing of cervical
noise
the the
the past carcinoma
primarily
patient clinical
for
with
anesthesia, classifications
gynecologists
use
of the
carcinoma
cervical
its resectability. unresectable dengo
radiation
therapy,
the
stage
Those cancers
by
using of
and
size
to determine patients with will initially un-
therapy
sometimes
on chemo-
followed
this
resonance
been
very
female contrast,
due
for
the
leiomyomas,
in imaging
FOV
images stage
endometriosis,
and
(2-8). Recently, onstrated the
ing.
of cervical
carcinoma
MR imaging has demability to enable staging
carcinoma
better
than
ex-
amination under anesthesia, with the overall staging accuracy of MR imagbeing
especially
Radiology
sults
and
proximal
sion,
but
MR
lem
areas
ing
are
76%-83%
for staging the
evaluation
imaging
(9-12).
ultrasound
prob-
MR imag-
of parametrial
false-positive vaginal
re-
wall
inva-
is excellent
for
the evaluation of tumor However, standard body aging of the female pelvis plane resolution than do imaging modalities, such lution
The
with
volume. coil MR imhas less inother pelvic as high-reso-
or computed
to-
mography. To achieve increased resolution, the number of frequency and phase-encoding steps could be increased or the field of view (FOV) could be decreased, but these modifications to-noise
would ratio
therefore
of the prostate
Herein,
nience female noma.
to decrease
high-resolution
prostate gland
gland carcinoma
we
report
with endonectal patients with
Ten
cone
carcinoma,
cervical
and
to obtain
and
to (13).
We studied the feasibility of the use of an endonectal coil in female patients with lower genital tract disease to obtam higher-resolution images than can be obtained with body coil imag-
of the
tissue uterine
emdom.etniab
ratio
the
PATIENTS
of uterine
adenomyosis,
anomalies,
to augment
Excellent results have been obtamed with use of an endorectal sunface coil to increase the signal-to-
imaging
to its high
diagnosis
measures
our
early
expe-
coil imaging cervical carci-
in
by sun-
(MR)
useful
pelvis,
other
ratio.
geny.
invasion,
From the Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce St. Philadelphia, PA 19104. Received November 14, 1990; revision requested January 14, 1991; revision received February 14; accepted March 8. Address reprint requests to B.N.M. e RSNA, 1991
(1). Stagis still per-
the International Federation of Gynecology and Obstetrics (FIGO). Most
ing
180:91-95
year
at examination
under staging
Index terms: Magnetic resonance (MR), intracavitary coils #{149}Magnetic resonance (MR), surface coils #{149}Uterine neoplasms, MR studies, 854.1214 1991;
PhD
require
has
surface coil is a promising to obtain high-resolution female has
E. Lenkinski,
the availability of Papanicolaou smears, cervical carcimoma remains a major health problem, with approximately 13,000 new cases of invasive cervical cancer diag-
Magnetic
tissue and normal
that were not seen on the images. This preliminary indicates that use of an
images of the This technique
improve cervical
and
the endorectal
and demonstrated between tumor
structures body coil investigation
assigned
of Gynecology wall, vaginal and pelvic
images,
Robert
ESPITE
formed
images
in-plane
were
by tumor
demonstrated.
body
the
stage based on the system of the Interna-
tional Federation Obstetrics. Vaginal fornix, parametrium,
wall
thus,
improved
The
PhD
MR Imaging Surface Coil’
D
bi-
cervical
underwent magnetic resonance imaging with both a standard coil coil.
MD,
MD
cause decreased signaland would therefore
AND
patients
with
biopsy-proved
METHODS
needle
biopsy-
invasive
or
cervical
car-
cinoma were imaged between November i989 and June i990, before treatment. One healthy volunteer underwent endorectal coil imaging only. All images were obtamed with a i.5-T system (Signa Advantage; GE Medical Systems, Milwaukee) that employs 4.0 software. Imaging was conducted in two parts. The first part consisted of body coil imaging. Each patient was prepared with insufflation of air into the rectum, i mg of intramuscular gluca-
gon, and, in the early studies, a vaginal tampon. Use of the vaginal tampon was abandoned in later studies because the vaginal walls and fornices were imaged better without it. Coronal Ti-weighted spin-echo (SE) (repetition time = 600 msec, echo time = i2 msec [600/12]) MR images
tion i2)
were
thickness. MR
renal
images
obtained
Axial were
hila through
with
a iO-mm
Ti-weighted
sec-
SE (600/
obtained
from
the pubic
the
symphysis,
with a 10-mm section thickness, a 2.5-mm section gap, and a 30-32-cm FOV. Axial and sagittal T2-weighted SE (2,500/40, 80) images
were
Abbreviations:
also
obtained
FIGO
=
through
the
International
tion of Gynecology and Obstetrics, of view, SE = spin echo.
Federa-
FOV
=
field
91
Table 1 Comparison of Image Resolution between Body Coil and Endoiectal Coil Images Imaging
Endorectal
Parameter
Coil
30-32
FOV (cm) Section (mm)
Coil
Body
10-14
thickness
128 x 256
4 128 x 256
2.74-3.13
0.30-0.61
5
Matrix size Pixel size (2) Voxel size (mm3)
13.7-15.7
1.2-2.4
cervix, and vagina, with a 5-mm thickness, a i-mm section gap, a 30-32-cm FOV, gradient moment nulbing, and a 32-kHz bandwidth. After this, with the patient in the left lateral decubitus pouterus,
section
sition,
an endorectal
burgh)
was placed
(13),
and
coil (Medrad;
Pitts-
as previously
an additional
described
1 mg of glucagon
was administered intramuscularly. The patient was placed in the supine position, and sagittal Ti-weighted SE images were obtained for localization. Initially, depending on the orientation of the cervix after placement of the coil, axial or coronal SE images were obtained to achieve an imaging plane that was more perpendicular to the cervix to evaluate better any parametrial spread of tumor. Oblique planes directly perpendicular to the cervix were not used because the chosen parameters required an increase in the FOV. Ti-weighted (600/12) and T2weighted (2,500/40, 80) MR images were obtained, with a 10-14-cm FOV, a 4-mm section thickness, and a i-mm section gap. In the last six cases, transverse imaging was
performed
because
the balloon
of gradient
motion 32-kHz trates
moment
nulbing
the improved
1.
Images
demonstrate
improved
resolution SE (2,500/80)
signal-to-noise
Table
of MR Imaging
Stage
Imaging
Stage
FIGO Stage
Tumor
1/43
0/lA
1A
None
put
through
a
The endorectal coil images were compared retrospectively with the body coil images in each case. Those patients (n = 6) with large or advanced-stage tumors were treated with radiation therapy; (n = 3) with stage lB or lower derwent radical hysterectomy.
those tumors
un-
One patient with a bulky low-stage tumor underwent imaging followed by radiation therapy and then radical hysterectomy. Three surgical specimens were imaged in 92
#{149} Radiology
Size*
fluid
detail due to tumor. in
the
to
vagina.
Treatment Radical hysterectomy, carcinoma
2/47
lB
iB
Large
(58)
Radiation
therapy
6
3B
3B
Large
(86)
therapy
4/61
lB
lB
Large
(34)
Radiation Radiation
no invasive
therapy,
radical
hysterec-
tomy’ /46
2B
lB
Large (28)
W30
0/lA
1A
None
7/46
0/lA
IA
None
2B
2B
Large (48)
Radical hysterectomy, carcinoma situ possible, microinvasion’ Radiation therapy
3B
2B
Large
(38)
Radiation
therapy
3B
3B
Large
(224)
Radiation
therapy
8/71 9/39 10/58 *
Approximate
tumor
volume
calculation:
the tumor. Numbers in parentheses t Specimen images were obtained.
(length
Radiation therapy Radical hysterectomy, carcinomat
x width
x height,2,
no residual
at maximum
in
dimensions
of
are cubic centimeters.
the axial plane with Ti- and T2-weighted SE sequences. Pathologic findings in those cases were compared with the images.
signed
were
greater posterior
MR
tion (14).
images
with use of the enwhich cervical carci(2,500/80) endorectal
and FIGO Stage
Patient’ Age (y)
surface coil correction program (spatial filter) that was developed at our institu-
endorectal
carcinoma
2
Comparison
We employed the criteria of Togashi et at (10) for staging of cervical carcinoma with MR imaging. These criteria were established on the basis of the FIGO staging criteria. The MR imaging stage was as-
ratio from the endorectal coil allowed for markedly improved in-plane resolution. All
of cervical
dorectal coil versus body coil. (a) Sagittal body coil image in noma (arrow) can be seen posterior to endocervical canal. (b) Sagittal SE coil image at same level demonstrates cervix and tumor (open arrows) in increased in-plane resolution. Endorectal coil (ERC) is inflated in rectum Very thin high-signal-intensity line inferiorly (solid arrows) represents B = bladder, EC = endometrial canal.
to reduce
effects from rectal spasm and a sampling bandwidth. Table 1 illusthat
b.
Figure
from
the coil tended to orient the cervix into a vertical position. In addition, sagittal T2weighted SE images were also obtained with the same parameters. In three cases, a chemical-shift-selection, fat-saturation imaging technique was used to test whether this would improve tissue contrast between high-signal-intensity tumor and low-signal-intensity parametrial fat. All T2-weighted series were performed with use
a.
before
the FIGO
stage
was
known.
RESULTS Higher-resolution images of the lower female genital tract were obtamed with the endonectal coil (Fig 1). The coil was tolerated well by the patients during the study. Table 2 lists the patients, tumor sizes, and treatments and compares the MR imaging
stage
with
the
FIGO
stage.
imaging stage both the body
was and
ages. quality
of 10 patients,
In seven images
determined endorectal
The
MR
with coil imgood-
were obtained, although in four of these the balloon displaced the cervix laterally, causing some loss of signal intensity where the tumor was farthest from the coil. In three of 10 patients, suboptimal images were obtained due to difficulty in advancing the endorectal
coil
posterior to the cervix. In these patients, the endorectal coil actually displaced the cervix superiorly and thus most
of the
the sensitivity one patient
cervix
was
lying
beyond
profile of the coil. In (patient 10), the tumor July 1991
b. Figure 2. (a) Endorectat with no residual tumor. surrounded correlation bladder,
coil image and (b) axial SE (2,500/80) image Note fimbriated appearance of endocervicat
by whirled tow-signal-intensity between the endorectal coil = endorectat coil.
*
cervical image and
of a cervix
of specimen canal (arrow
in a and b)
stroma. No tumor is seen. There image of the pathologic specimen.
is good
Figure
B
(arrows) are a transverse cx = cervix,
=
Figure large placed
Figure
4. Vaginal wall invasion by cervical carcinoma is demonstrated on sagittat SE (2,500/ 80) images of a large infiltrating tumor. (a) Near midline, tumor is shown to be enlarging and involving the anterior and posterior cervical lips (open arrows). Normal low-signal-intensity vaginal wall (solid arrows) is demonstrated. (b) To the right of a, the tumor (arrows) is shown
inferiorly
compared soft tissue
with a, normal representing
and
invading thin, tumor
the normal
anterior
dark vaginal walls invasion (arrowheads).
that it extended the sensitivity
anteriprofile of
and
have
posterior
been
vaginal
replaced
appearance
on
the
T2-weighted
dorectal coil images mal cervical stroma signal
intensity
pearance and the that
within which ear
with
body
en-
a whirled
coil
ap-
sequences, was similar images.
to
Fluid
the normal vaginal fornices, appeared as triangular or bin-
high
signal
intensity
on
the
T2-
walls.
ate
than
180
on
the
body
ligaments, #{149} Number
1
coil
images.
which
on
the body depicted
endorectal
coil
and
are
coil on the
images
as
structures then posteri-
muscle (*) also aptumor, indicating
T2-weighted
Cervical signal
weighted
the
intensity
images
on
and
the
was
hypeninas The
fat-saturation pulse on the T2weighted images was used in only a few cases and did not significantly improve tissue or tumor contrast, but further evaluation with more cases is necessary.
Vaginal
wall,
vaginal
phytic
isointemse
gina
coil
had
were
Ti-
canal
endorectal
carcinoma
carcinomas
but did not appear relatively as on the body coil images.
intenmedi-
structures
endocenvicab
cervical
tense bright
fornix, parametrial, and pelvic sidewall invasion by cervical carcinoma were all readily demonstrated on the endorectal coil images (Figs 4, 5) according to the criteria established with body coil imaging (10,11). In three cases, on the T2-weighted endorectal coil images, the intact dark vaginal wall was identified better when it stretched around a large exo-
5 mm in diameter) as small, round,
high-signal-intensity
images
Volume
to identify are routinely
ian cysts (less than were often identified joining
sacrouterine
with
When
only from the cervix (Fig 3). On the transverse T2-weighted endorectal coil images, the normal urethra was a small horizontal line with high signal intensity surrounded by three concentric rings of low-, high-, and bowsignal-intensity tissue. Small naboth-
weighted images, was better identifled around the cervix as it protruded into the vagina on the endorectal coil The
image of a is disendorectal
by high-signal-intensity
thin, low-signal-intensity that extend laterally
(Fig 2). The nonhad decreased
on T2-weighted signal intensity
of the
difficult images,
canal had a fimbriated
5. Transverse SE (600/12) cervical carcinoma (T), which to the right by the inflated
with the cervix and uterus. On the T2-weighted emdorectal coil images,
transverse
The normal endocenvical high signal intensity and
sacrouterine ligaments demonstrated in a volunteer on SE (600/12) image. B = bladder, * = endorectal coil.
right obturator internus pears to be infiltrated sidewall involvement.
the was so lange only beyond the coil.
Normal
coil in the rectum. Tendrils of tumor (arrows) extend from the surface of the tumor into the paracervical fat on the right. Fat adjacent to
b.
extending
3.
ad-
on the images.
tumor
but
did
that
not
grew
invade
into
the
the walls Radiology
va-
(Fig #{149} 93
Figure
6.
cervical
Transverse carcinoma
SE (2,500/80) (TI) growing into
nat vault and left vaginal nal fornix (straight solid
image of the vagi-
fornix. Right vagiarrow) is shown
with low-signal-intensity vaginal rounding an intermediate-signal-intensity line. Low-signal-intensity vaginal (curved arrows) can be followed
walls
sur-
a.
b.
Figure
7.
volving walls from right
and
(a) Transverse SE (2,500/80) the posterior lip of the cervix.
the posterior
paracervical
level
fornix around tumor, indicating that there is no vaginal wall invasion. Focal area (straight open arrow) of high signal intensity on the right side of the tumor is due to hemorrhage
from
the posterior
secondary
men mor
images in demonstrating mass and small nabothian
biopsy.
6). The panacervical tissues in one case were separated from tumor by a very narrow band of low-signal-intensity cervical stroma that was not apparent on the body coil images (Fig 7). In two cases,
on
the
body
coil
images,
a plane
could not be defined between a large exophytic cervical carcinoma and the bladder wall (n = 1) or the anterior rectal images
wall (ii clearly
separating
=
1). The endorectal coil demonstrated a plane
the bladder
walls from the (Fig 8). Neither anesthesia nor copy demonstrated
and
rectal
tumor in these cases examination under proctoscopy or cystosrectal on bladder
No
coil image
cervical
fat. (b) Transverse
same
to needle
body
as in a demonstrates
a thin
paracervical
rim
These
first
early
strate
that
resolution dorectal
no tucysts.
of the
of women
cal
the
cialby large images
vaginal
espe-
when it was stretched around a exophytic tumor. Endorectal coil can also demonstrate a thin
wall invasion. In one case of a large cervical carcinoma, thickening and shortening of the left sacrouterine ligament that
rim of cervical been interrupted
was
aging. There was 80% agreement between the findings at MR imaging and at FIGO staging, but FIGO stag-
contiguous
to the
tumor
was
identified and appeared to indicate tumor invasion of the ligament (Fig 9). Specimen images of the cervices with no residual tumor or carcinoma in situ demonstrated am almost featheny or fimbriated high-signal-intensity appearance of the endocervical epithelium on T2-weighted images, as was
demonstrated
dorectal sity
coil images.
of the
normal
on
the
The surrounding
in vivo
signal
en-
intemstroma
remained decreased, although, as has been described in younger patients, an outer rim of intermediate-signalintensity stroma was seen cases (4,15). The endorectal ages correlated webb with 94
#{149} Radiology
in two coil imthe speci-
the
stroma that by tumor,
has not as was
valuable
tumor
transverse
through
the
for evaluation
vaginal
a better
vagina,
tissues
wall,
were
carcinoma
of cervical
its surrounding
the
intumor
at the
the
transaxially
posterior
vided
high-
can be obtained. In our study the endorectal coil images were useful in clarifying equivocal findings of bladden or rectal invasion in two cases and
in delineating
separating
so that
imaged
plane
lower
demon-
to obtain
images
and
the
coil image
(arrows),
position
plane
images with use of an ensurface coil; in addition,
higher-resolution
endorectal
stroma
(arrow)
between
cervix, which allowed for better evabuation of the parametnial and panacenvical tissues. Images of the sagittal
it is possible
carcinoma
carcinoma
fat.
images
tract
cervical
is demonstrated
SE (2,500/80)
of cervical
DISCUSSION genitourinany
shows
stroma
fornix
overall
and uterus,
view
pro-
of cervical
its relationship
bladder,
of
and
to the
and
rectum.
Certain problems specific to the female anatomy were encountered with use of the endorectal coil as designed for evaluation of the prostate gland, resulting in some suboptimal images.
The
mobility
caused away
of the
cervix
it to be displaced from the endorectal
inflation
of the balloon.
mobility
also
being
sometimes
pushed
therefore,
superiorly
it was
difficult
sometimes laterally, coil after
This
cervical
resulted by
in its
the
coil;
to place
the
known to be imperfect compared with pathologic or surgical staging
coil beyond the stretched vagina. Alterations in balloon design, probe stiffness, and shaft angulation may resolve these problems of coil placement. The problem of imaging large tumors that lie beyond the sensitivity profile of the endorectal coil may be eliminated by use of an anterior ab-
(16-18).
dominal
shown in one not seen with
ing
case; this standard
by examination
thin body
under
rim was coil im-
anesthesia
is
The most useful with the endorectab transverse
and
sagittal.
plane often imaged liquely, as did the but the difficult
The
coronal images were more to interpret at the junction
full
an inflated This
coronal
the cervix obtransverse plane,
the cervix and the vagina. were imaged when they tially
the
imaging planes coil were the
placed
urinary
bladder,
endorectal the
cervix
of
Patients had a parwith
use
coil balloon. in a more
verti-
of
surface
endorectal
coil combined coil
with
in a multiarray
coil
system. Because a small FOV is used with the emdorectal coil, the entire pelvis is not visualized, so the evaluation of pelvic lymphademopathy with this coil is incomplete. Use of the endorectab coil often results in good visualization of the obturator and internal iliac regions, but for complete evaluation of bymphadenopathy, body coil imaging of the lower abdomen and pelvis July
1991
b. Figure
8.
posterior
(a) Transverse aspect
SE (2,500/80)
of the
cervix
and
body
abuts
against
coil image the
shows
anterior
a tumor rectal
plane
is demonstrated between the rectal wall and the cervical (2,500/80) endorectal coil image at the same level as in a shows that separates the tumor from the anterior rectal wall.
is necessary, as is dome gland examinations.
Therefore, high-resolution
in prostate
whether use of these images will improve
the ability (specifically, and rectal
to stage cervical carcinoma panametrial, vaginal wall, or bladder wall invasion)
compared with use of images obtamed at standard MR imaging will require further study, with pathologic correlation. This technique might also prove useful when questionable abnonmabities
of the
lower
female
geni-
tourinany tract are identified with standard MR imaging and when betten characterization is required. U
2.
Cancer statistics, ACS, from Journalfor Clinicians. Cancer
Hricak
H, Tscholakoff
D, Heinrichs
Uterine leiomyomas: correlation histopathologic findings, and Radiology 1986; 158:385-391.
Volume
180
#{149} Number
Ca-A Cancer 1989; 39:3-39.
1
from No
(b) Transverse SE tissue plane (arrows)
4.
Togashi K, Ozasa H, Konishi larged uterus: differentiation nomyosis
5.
and
ing. Radiology WorthingtonJ,
leiomyoma
with
7.
H. 8. 9.
10.
11.
Enade-
MR imag-
M, Thickman
MR evaluation
D, Gussman
of uterine
are
infiltrated ligament
by tumor. is markedly
The left thickened
proximally, indicating direct tumor extension from the cervix. The parametriat fat surrounding the right sacrouterine ligament is infiltrated by tumor that extends into the hgament, indicating tumor infiltration.
12.
13.
Uter-
Radiology
Zawin M, McCarthy 5, Scoutt L, Comite F. Endometriosis: appearance and detection at MR imaging. Radiology 1989; 171:693696. Mintz
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I, et al. between
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the
tissue
Togashi K, Nishimura K, Itoh K, et al. enomyosis: diagnosis with MR imaging. Radiology 1988; 166:111-114.
L, et al.
of MR. symptoms.
carcinoma. a definite
extends
(arrows).
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14.
15.
MM. J Digital Imaging 1989; 2:2-8. Heiken J, Lee J. MR imaging of the pelvis. Radiology
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#{149} 95
