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503
Pictorial
Essay
I
I. Endorectal Sonography Perirectal Disease Edward Barbara
W. St. Ville,1 S. Zafan H. Jafri,1 F. Rosenberg3
in the Evaluation
Beatrice
L. Madrazo,1
Endorectal sonography initially was developed for evaluation of the prostate and now has been adapted for evaluation of rectal and perirectal disease. We used endorectal sonography to evaluate a spectrum of diseases, including primary and recurrent rectal carcinoma, metastases, villous adenoma, leiomyosarcoma, endometnosis, sacrococcygeal teratoma, chordoma, retroperitoneal cystic hamartoma, pelvic lipomatosis, diverticulitis, and perirectal abscess. The technique has been useful in localization of penrectal
abscesses
and in sonographically
guided
biopsy of
perirectal masses. Knowledge of normal sonographic anatomy of the rectum is essential in the evaluation of rectal and perirectal disease. In this essay, we describe the technique of endorectal
Duane
of Rectal
G. Mezwa,1
sonography diseases.
and illustrate
Robert
and
L. Bree,2
the sonographic
and
findings
in a variety
of
The rectum and peninectal space are the sites of numerous diseases, both benign and malignant. Because of the anatomic detail provided by endonectal sonography, it is useful for the evaluation of the direction of spread of rectal disease, depth of tumor penetration, and assessment of invasion of adjacent viscera [1, 2]. The technique provides accurate definition of the layers of the rectal wall and peninectal soft
Fig. 1.-Sonogram
and drawing
show five lay-
ers of normal rectum: (1) interface between balloon and mucosa, (2) deep mucosa and muscularis mucosa, (3) interface between submucosa and musculans propria, (4) musculans propria, and (5) interface between musculans propna and penrectal fat.
Received January 24, 1991; accepted after revision April 17, 1991. Presented at the annual meeting of the American Roentgen Ray Society, Washington, DC, May 1990. ‘Department of Diagnostic Radiology, William Beaumont Hospital, 3601 W. Thirteen Mile Rd., Royal Oak, Ml 48073. Address reprint requests to S. Z. H. Jafri. 2 of Diagnostic Radiology, Veterans Administration Hospital, 2215 Fuller Rd., Ann Arbor, Ml 48105. of Surgical Pathology, William Beaumont Hospital, Royal Oak, MI 48073. AJR
157:503-508, september
1991 0361 -803X/91/1
573-0503
© American
Roentgen
Ray Society
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
504
Fig. 2.-Primary tal wall. Endorectal hypoechoic lesion (arrows).
ST.
rectal carcinoma confined to recsonogram shows a well-defined confined to muscularis propria
VILLE
ET AL.
AJR:157,
September
1991
Fig. 3.-Primary rectal carcinoma with local invasion. A, Sonogram shows soft-tissue mass with muscularis propria in left anterolateral wall of rectum (arrows). B, Sonogram obtained at a higher level reveals mass, which appears to disrupt muscularis propria (arrows) and invade penrectal fat planes.
Fig. 4.-Primary vasion. A, Endorectal
rectal sonogram
carcinoma shows
with
local
in-
a well-defined
mass of mixed echogenicity in posterior wall of rectum that disrupts muscularis layer and invades perlrectal fat (arrows). A well-defined hypoechoic area (arrowhead) represents extension of tumor to a perirectal lymph node. B, CT scan at same level shows a soft-tissue mass in posterior rectal wall with extension into perirectal fat (arrow). Microscopic section revealed invasive mucin-producing adenocarcinoma of rectum with extension into perirectal fat.
Fig. 5.-Recurrent
rectal carcinoma.
Sonogram
obtained after abdominoperineal resection shows diffuse thickening of rectal wall and disruption of muscularis propria (arrowheads). Enlarged perirectal lymph nodes also were identified (open arrow). Surgical suture is present in anterior rectal wall (solid arrow). Biopsy revealed recurrent rectal carcinoma.
Fig. 6.-Villous
adenoma. sonogram shows a well-defined area of mixed echogenicity contained within muscularis propria layer in anterior rectal wall (arrows). B, Air-contrast barium enema shows marked mucosal irregularity in anterior rectal wall (arrow). Microscopic section of resected specimen showed characteristic frondlike appearance of villous A, Endorectal
adenoma.
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
Fig. 7.-Leiomyosarcoma.
Endorectal
sonogram
Fig. 8.-carcinoma of prostate. A, Sonogram shows large, pooriy defined hypoechoic mass disrupting perirectal soft-tissue planes anteriorly between prostate (P) and rectum (arrows). B, CT scan at same level shows a soft-tissue mass posteriorly between prostate and perirectal soft-tissue planes with extension into anterior rectal wall (arrowheads). Diagnosis of carcinoma was confirmed by results of transrectal biopsy.
obtained at level of palpable rectal mass in a patient with chronic active ulcerative colitis shows a uniform hypoechoic lesion limited by muscularis propria layer (arrows). Microscopic section revealed a discrete area of malignant spindle cell proliferation
corresponding to a 1.5-cm Ieiomyosarcoma found in gross pathologic specimen. This neoplasm was confined to muscularis propna. Overlying submucosa and mucosa are obliterated as a result of chronic active
ulcerative
colitis.
Fig. 9.-Malignant
melanoma.
Fig. 10.-Endometriosis.
A, Endorectal sonogram shows a hypoechoic mass in left seminal vesicle (arrow) in a patient with malignant melanoma. B, Sonogram obtained at a lower level shows a well-defined hypoechoic metastasis in left lobe of prostate that disrupts and Invades anterior rectal wall (arrow).
showed a focus of endometriosis, muscularis
propria.
Fig. 11.-Lipomatosis. shows pelvic lipomatosis with perlrectal deposition of fat causing anterior displacement of left seminal vesicle (small arrow). Note asymmetry of echo texture of perirectal tissue between seminal vesicle and rectum, with decreased echogenicity on left (larg. arrow) simulating a mass. B, Ti-weighted MR image of pelvis shows a A, Sonogram
uniform Intensity
circumferential In perirectal
lipomatosis.
ring
of increased
signal
soft tissues consistent with
Note more anterior
location
seminal vesicle relative to right masses were Identified.
(arrow).
of left No
A
Sonogram
shows
a well-de-
marcated area (arrows) interposed between muscularis propria and mucosa. Lesion is confined by and does not extend beyond muscularis propria. Histologic examination
B
which was delimited by
506
ST.
VILLE
ET AL.
AJR:157, September
Fig. 12.-Chordoma. A, Endorectal sonogram
shows
a complex
1991
mass
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
posteriorly that lies outside rectal wall. Mass is mostiy hypoechoic and poorly defined and contains several bright reflectors (arrow) caused by tiny calcifications. B, CT scan at same level shows soft-tissue mass posterior to rectum that contains tiny calcifications and appears to extend into coccyx (ar. row).
Fig. 13.-Diverticulitis. A, Sonogram shows hypoechoic area in anterior rectal wall outside muscularis propria. Fluid extends into penrectal soft tissues (arrows). B, CT scan of pelvis confirms edema and thickening of wall of rectosigmoid colon (arrows).
A
B
Fig. 14.-Perirectal
abscess.
A, CT scan in a patient with inflammatory bowel disease shows perirectal abscess anterior to rectum (arrow) that could not be found during surgery. B, Endorectal sonogram obtained after surgery shows a poorly defined hypoechoic area anterior to rectum (arrows). C, Under sonographic guidance, a guidewire (arrows) was inserted and secured to skin. Surgery was repeated, and guidewire was used successfully
to locate abscess
cavity.
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
AJR:157,
September
SONOGRAPHY
1991
Fig. 15.-Sacrococcygeal teratoma. Endorectal sonogram shows a well-defined hypoechoic mass, with acoustic
enhancement
outside
posterior
Fig. 16.-Retroperitoneal
DISEASE
cystic hamartoma
507
(tailgut
cyst).
A, Sonogram shows a homogeneous well-circumscribed hypoechoic mass (M) rectum (arrow). B, CT scan at level of tailgut cyst (arrow) correlates with endorectal sonogram, perirectal soft-tissue mass (M) in presacral space that narrows rectal lumen.
rectal
wall.
tissues (Fig. 1). Anatomic changes caused by masses, cysts, calcification, and fluid collections tected. In this essay, we describe the technique of sonognaphy and illustrate the sonognaphic findings of diseases. Pathologic verification of sonognaphic
was available
IN RECTAL
soft-tissue can be deendonectal in a variety findings
in all cases.
compressing revealing
a
most hypoechoic line represents the deep mucosa and musculanis mucosa. The third and most echogenic line is produced by the submucosa. The outer, widen hypoechoic line deline-
ates only the musculans
propna.
This is of clinical importance
because it defines a sonognaphic criterion for determining intramural or extramural invasion. The most peripheral line, the fifth echogenic line, corresponds to the interface between the musculanis propria and peninectal fat.
Technique An axial,
transversely
oriented
BnUel & Kjaen, Copenhagen,
radial
scanner
Denmark)
(model
is used most
1850,
com-
monly. The total length of the rigid probe with the transducer is 24 cm. The transducer rotates at a rate of two to three
cycles
pen second.
rectal
probe
Scanning
provides
of the
rectum
a scanning
with
A minimum the probe.
by a disposable
luminal diameter is filled
to provide an acoustic
window.
at 1 -cm
intervals
from
latex sheath
gel, is introduced
The sheath
in Rectal
Endorectal sonognaphy initially was developed tion of carcinoma of the prostate and recently
and
adapted
into the rectum.
of 25 mm is necessary with
to insert
60 ml of degassed
Images routinely
approximately
water
are obtained
2-1 5 cm
above
the
anus, which is the usual maximal depth of insertion. The transducer also can be inserted via a nectoscope to evaluate the rectum. During simultaneous withdrawal of the probe and the rectoscope, the region of interest is scanned in a stepwise fashion. Depending on the extent tion takes 10-15 mm.
of the lesion,
the examina-
for staging
of rectal
of the Normal
Rectum
When a 7-MHz transducer is used, sonograms show five layers in the rectal wall; three are hyperechoic and two are hypoechoic. The first echogenic line corresponds to the interface between the water balloon and the mucosa. The inner-
carcinoma
for evaluahas been
and evaluating
a
of benign and malignant rectal and penirectal conditions [3]. Rectal carcinoma appears on endonectal sonograms as a low-echogenicity lesion that abruptly interrupts the normal sequence of layers (Figs. 2 and 3). In order to
stage
the tumor precisely, it is necessary to determine the between the neoplasm and the outer hypoechoic layer (musculanis propnia). When no infiltration has taken place, this layer has a smooth regular course and is separated by the thin echogenic line of submucosa. Disappearance of submucosa may indicate infiltration of the musculanis propnia. This pattern is most difficult to determine. Tumor with minimal relationship
spread
could
tension into the pennectalfat Anatomy
Disease
spectrum
extrarectal Sonographic
and Penrectal
and
surrounding lubricated
Findings
radial to the long axis of the
a 360#{176} display
tissues. The transducer, covered
Sonographic
therefore
be understaged
is represented
also.
Ex-
by the interruption
of the musculanis propnia by the neoplasm (Fig. 4). In addition, infiltration into the adjoining pelvic organs and penmrectal lymph nodes should be sought. Lymphadenopathy caused by metastases or lymph-node hyperplasia resulting from local sepsis commonly is seen with endorectal sonography. When no lymph nodes are visible in
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508
ST. VILLE
ET AL.
metastases is low [4]. The enlarged nodes may be hyperechoic and hypoechoic. Hypenechoic lymph nodes are enlarged because of nonspecific inflammatory change. When enlarged lymph nodes are hypoechoic, metastases are most likely, although nonspecific inflammation cannot be excluded. Preoperative assessment of the depth of tumor invasion is important
in the
treatment
of rectal
carcinoma,
diverticulitis
(Figs.
circumscribed
494 498 516 520 526 532 544 584
602 608
peninectal
abscess
cystic
hamartoma
masses
outside
and needle
be demonstrated
tenatoma (Fig.
of the
(Fig. 15) and
1 6) are seen rectal
1991
wall.
for localization
as well-
Endonectal
of peninectal
particularly
OF
REFERENCES 1. Orrom WJ, Wong WD, Rothenberger DA, Jensen LL, Goldberg SM. Endorectal ultrasound in the preoperative staging of rectal tumors: a leaming experience. Dis Colon Rectum 1990;33:654-659 2. Konishi F, Ugajin H, Kanazawa K. Endorectal ultrasonography with a 7.5 MHz linear array scanner for the assessment of invasion of rectal carcinoma. Int J Colorectal Dis 1990;5: 15-20 3. Beynon J, Foy DM, Temple LN, Channer JL, Virgee J, Mortenson NJ. The endosonic appearances of normal colon and rectum. Dis Colon Rectum
BOOK
AND
1986;29:810-813 4. Glaser F, Schlag P, Herfarth C. Endorectal ultrasonography for the assessments of invasion of rectal tumors and lymph node involvement. Br J Surg 1990;77:883-887
VIDEOTAPE
REVIEWS
Resonance
Imaging of Carcinoma
of the Urinary Bladder.
JO, Debruyne FMJ, Ruijs SHJ Textbook of Uroradiology. Dunnick NR, McCailum RW, SandIer MRI of the Musculoskeletal System, 2nd ed. Berquist TH, ed. The Language of Fractures, 2nd ed. Schultz RJ Obstetrics and Gynecology. Berman MC, ed. Neuroradiology Test and Syllabus. Weinberg PE, section ed. Gamuts and Pearls in MRI. Pomeranz SJ
A Short Textbook
can
September
biopsy of peninectal masses.
Detection and Treatment of Early Breast Cancer. Fentiman! The Radiologic Clinics of North America. Interventional Radiology Biliary Tract. Burhenne HJ, ed. RSNA Today, Vol. 4, No, 5. Casareila WJ, moderator Atlas of Roentgenographic Measurement, 6th ed. Keats TE
Magnetic
abscess
also has been useful
sonognaphy
with endorectal sonography than with CT (Fig. 5). The high spatial resolution of endonectal sonography also has proved useful in characterizing the nature and extent of numerous rectal and penirectal disease entities. Endonectal sonognaphy shows villous adenoma (Fig. 6), leiomyosancoma (Fig. 7), metastases (Figs. 8 and 9), endometniosis (Fig. 10), and pelvic lipomatosis (Fig. 11) as nonspecific, solid masses within the rectal wall and perirectal soft tissues. Calcification within a chordoma (Fig. 12) and pennectal fluid collections seen in
480 490
and
13 and 14). Sacnococcygeal
netnopenitoneal
when local excision is being considered. A major value of endonectal sonognaphy is to determine the depth of tumor invasion. The procedure can be used to detect local recurrence after low anterior resection or local excision. Extent of primary on recurrent tumor infiltration is defined more exactly
LIST
AJR:157,
of Clinical Imaging.
Sutton
D, Young
JWR,
CM
eds.
of the
Barentsz
503
Pictorial
Essay
I
I. Endorectal Sonography Perirectal Disease Edward Barbara
W. St. Ville,1 S. Zafan H. Jafri,1 F. Rosenberg3
in the Evaluation
Beatrice
L. Madrazo,1
Endorectal sonography initially was developed for evaluation of the prostate and now has been adapted for evaluation of rectal and perirectal disease. We used endorectal sonography to evaluate a spectrum of diseases, including primary and recurrent rectal carcinoma, metastases, villous adenoma, leiomyosarcoma, endometnosis, sacrococcygeal teratoma, chordoma, retroperitoneal cystic hamartoma, pelvic lipomatosis, diverticulitis, and perirectal abscess. The technique has been useful in localization of penrectal
abscesses
and in sonographically
guided
biopsy of
perirectal masses. Knowledge of normal sonographic anatomy of the rectum is essential in the evaluation of rectal and perirectal disease. In this essay, we describe the technique of endorectal
Duane
of Rectal
G. Mezwa,1
sonography diseases.
and illustrate
Robert
and
L. Bree,2
the sonographic
and
findings
in a variety
of
The rectum and peninectal space are the sites of numerous diseases, both benign and malignant. Because of the anatomic detail provided by endonectal sonography, it is useful for the evaluation of the direction of spread of rectal disease, depth of tumor penetration, and assessment of invasion of adjacent viscera [1, 2]. The technique provides accurate definition of the layers of the rectal wall and peninectal soft
Fig. 1.-Sonogram
and drawing
show five lay-
ers of normal rectum: (1) interface between balloon and mucosa, (2) deep mucosa and muscularis mucosa, (3) interface between submucosa and musculans propria, (4) musculans propria, and (5) interface between musculans propna and penrectal fat.
Received January 24, 1991; accepted after revision April 17, 1991. Presented at the annual meeting of the American Roentgen Ray Society, Washington, DC, May 1990. ‘Department of Diagnostic Radiology, William Beaumont Hospital, 3601 W. Thirteen Mile Rd., Royal Oak, Ml 48073. Address reprint requests to S. Z. H. Jafri. 2 of Diagnostic Radiology, Veterans Administration Hospital, 2215 Fuller Rd., Ann Arbor, Ml 48105. of Surgical Pathology, William Beaumont Hospital, Royal Oak, MI 48073. AJR
157:503-508, september
1991 0361 -803X/91/1
573-0503
© American
Roentgen
Ray Society
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
504
Fig. 2.-Primary tal wall. Endorectal hypoechoic lesion (arrows).
ST.
rectal carcinoma confined to recsonogram shows a well-defined confined to muscularis propria
VILLE
ET AL.
AJR:157,
September
1991
Fig. 3.-Primary rectal carcinoma with local invasion. A, Sonogram shows soft-tissue mass with muscularis propria in left anterolateral wall of rectum (arrows). B, Sonogram obtained at a higher level reveals mass, which appears to disrupt muscularis propria (arrows) and invade penrectal fat planes.
Fig. 4.-Primary vasion. A, Endorectal
rectal sonogram
carcinoma shows
with
local
in-
a well-defined
mass of mixed echogenicity in posterior wall of rectum that disrupts muscularis layer and invades perlrectal fat (arrows). A well-defined hypoechoic area (arrowhead) represents extension of tumor to a perirectal lymph node. B, CT scan at same level shows a soft-tissue mass in posterior rectal wall with extension into perirectal fat (arrow). Microscopic section revealed invasive mucin-producing adenocarcinoma of rectum with extension into perirectal fat.
Fig. 5.-Recurrent
rectal carcinoma.
Sonogram
obtained after abdominoperineal resection shows diffuse thickening of rectal wall and disruption of muscularis propria (arrowheads). Enlarged perirectal lymph nodes also were identified (open arrow). Surgical suture is present in anterior rectal wall (solid arrow). Biopsy revealed recurrent rectal carcinoma.
Fig. 6.-Villous
adenoma. sonogram shows a well-defined area of mixed echogenicity contained within muscularis propria layer in anterior rectal wall (arrows). B, Air-contrast barium enema shows marked mucosal irregularity in anterior rectal wall (arrow). Microscopic section of resected specimen showed characteristic frondlike appearance of villous A, Endorectal
adenoma.
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
Fig. 7.-Leiomyosarcoma.
Endorectal
sonogram
Fig. 8.-carcinoma of prostate. A, Sonogram shows large, pooriy defined hypoechoic mass disrupting perirectal soft-tissue planes anteriorly between prostate (P) and rectum (arrows). B, CT scan at same level shows a soft-tissue mass posteriorly between prostate and perirectal soft-tissue planes with extension into anterior rectal wall (arrowheads). Diagnosis of carcinoma was confirmed by results of transrectal biopsy.
obtained at level of palpable rectal mass in a patient with chronic active ulcerative colitis shows a uniform hypoechoic lesion limited by muscularis propria layer (arrows). Microscopic section revealed a discrete area of malignant spindle cell proliferation
corresponding to a 1.5-cm Ieiomyosarcoma found in gross pathologic specimen. This neoplasm was confined to muscularis propna. Overlying submucosa and mucosa are obliterated as a result of chronic active
ulcerative
colitis.
Fig. 9.-Malignant
melanoma.
Fig. 10.-Endometriosis.
A, Endorectal sonogram shows a hypoechoic mass in left seminal vesicle (arrow) in a patient with malignant melanoma. B, Sonogram obtained at a lower level shows a well-defined hypoechoic metastasis in left lobe of prostate that disrupts and Invades anterior rectal wall (arrow).
showed a focus of endometriosis, muscularis
propria.
Fig. 11.-Lipomatosis. shows pelvic lipomatosis with perlrectal deposition of fat causing anterior displacement of left seminal vesicle (small arrow). Note asymmetry of echo texture of perirectal tissue between seminal vesicle and rectum, with decreased echogenicity on left (larg. arrow) simulating a mass. B, Ti-weighted MR image of pelvis shows a A, Sonogram
uniform Intensity
circumferential In perirectal
lipomatosis.
ring
of increased
signal
soft tissues consistent with
Note more anterior
location
seminal vesicle relative to right masses were Identified.
(arrow).
of left No
A
Sonogram
shows
a well-de-
marcated area (arrows) interposed between muscularis propria and mucosa. Lesion is confined by and does not extend beyond muscularis propria. Histologic examination
B
which was delimited by
506
ST.
VILLE
ET AL.
AJR:157, September
Fig. 12.-Chordoma. A, Endorectal sonogram
shows
a complex
1991
mass
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
posteriorly that lies outside rectal wall. Mass is mostiy hypoechoic and poorly defined and contains several bright reflectors (arrow) caused by tiny calcifications. B, CT scan at same level shows soft-tissue mass posterior to rectum that contains tiny calcifications and appears to extend into coccyx (ar. row).
Fig. 13.-Diverticulitis. A, Sonogram shows hypoechoic area in anterior rectal wall outside muscularis propria. Fluid extends into penrectal soft tissues (arrows). B, CT scan of pelvis confirms edema and thickening of wall of rectosigmoid colon (arrows).
A
B
Fig. 14.-Perirectal
abscess.
A, CT scan in a patient with inflammatory bowel disease shows perirectal abscess anterior to rectum (arrow) that could not be found during surgery. B, Endorectal sonogram obtained after surgery shows a poorly defined hypoechoic area anterior to rectum (arrows). C, Under sonographic guidance, a guidewire (arrows) was inserted and secured to skin. Surgery was repeated, and guidewire was used successfully
to locate abscess
cavity.
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
AJR:157,
September
SONOGRAPHY
1991
Fig. 15.-Sacrococcygeal teratoma. Endorectal sonogram shows a well-defined hypoechoic mass, with acoustic
enhancement
outside
posterior
Fig. 16.-Retroperitoneal
DISEASE
cystic hamartoma
507
(tailgut
cyst).
A, Sonogram shows a homogeneous well-circumscribed hypoechoic mass (M) rectum (arrow). B, CT scan at level of tailgut cyst (arrow) correlates with endorectal sonogram, perirectal soft-tissue mass (M) in presacral space that narrows rectal lumen.
rectal
wall.
tissues (Fig. 1). Anatomic changes caused by masses, cysts, calcification, and fluid collections tected. In this essay, we describe the technique of sonognaphy and illustrate the sonognaphic findings of diseases. Pathologic verification of sonognaphic
was available
IN RECTAL
soft-tissue can be deendonectal in a variety findings
in all cases.
compressing revealing
a
most hypoechoic line represents the deep mucosa and musculanis mucosa. The third and most echogenic line is produced by the submucosa. The outer, widen hypoechoic line deline-
ates only the musculans
propna.
This is of clinical importance
because it defines a sonognaphic criterion for determining intramural or extramural invasion. The most peripheral line, the fifth echogenic line, corresponds to the interface between the musculanis propria and peninectal fat.
Technique An axial,
transversely
oriented
BnUel & Kjaen, Copenhagen,
radial
scanner
Denmark)
(model
is used most
1850,
com-
monly. The total length of the rigid probe with the transducer is 24 cm. The transducer rotates at a rate of two to three
cycles
pen second.
rectal
probe
Scanning
provides
of the
rectum
a scanning
with
A minimum the probe.
by a disposable
luminal diameter is filled
to provide an acoustic
window.
at 1 -cm
intervals
from
latex sheath
gel, is introduced
The sheath
in Rectal
Endorectal sonognaphy initially was developed tion of carcinoma of the prostate and recently
and
adapted
into the rectum.
of 25 mm is necessary with
to insert
60 ml of degassed
Images routinely
approximately
water
are obtained
2-1 5 cm
above
the
anus, which is the usual maximal depth of insertion. The transducer also can be inserted via a nectoscope to evaluate the rectum. During simultaneous withdrawal of the probe and the rectoscope, the region of interest is scanned in a stepwise fashion. Depending on the extent tion takes 10-15 mm.
of the lesion,
the examina-
for staging
of rectal
of the Normal
Rectum
When a 7-MHz transducer is used, sonograms show five layers in the rectal wall; three are hyperechoic and two are hypoechoic. The first echogenic line corresponds to the interface between the water balloon and the mucosa. The inner-
carcinoma
for evaluahas been
and evaluating
a
of benign and malignant rectal and penirectal conditions [3]. Rectal carcinoma appears on endonectal sonograms as a low-echogenicity lesion that abruptly interrupts the normal sequence of layers (Figs. 2 and 3). In order to
stage
the tumor precisely, it is necessary to determine the between the neoplasm and the outer hypoechoic layer (musculanis propnia). When no infiltration has taken place, this layer has a smooth regular course and is separated by the thin echogenic line of submucosa. Disappearance of submucosa may indicate infiltration of the musculanis propnia. This pattern is most difficult to determine. Tumor with minimal relationship
spread
could
tension into the pennectalfat Anatomy
Disease
spectrum
extrarectal Sonographic
and Penrectal
and
surrounding lubricated
Findings
radial to the long axis of the
a 360#{176} display
tissues. The transducer, covered
Sonographic
therefore
be understaged
is represented
also.
Ex-
by the interruption
of the musculanis propnia by the neoplasm (Fig. 4). In addition, infiltration into the adjoining pelvic organs and penmrectal lymph nodes should be sought. Lymphadenopathy caused by metastases or lymph-node hyperplasia resulting from local sepsis commonly is seen with endorectal sonography. When no lymph nodes are visible in
Downloaded from www.ajronline.org by 117.244.26.80 on 10/17/15 from IP address 117.244.26.80. Copyright ARRS. For personal use only; all rights reserved
508
ST. VILLE
ET AL.
metastases is low [4]. The enlarged nodes may be hyperechoic and hypoechoic. Hypenechoic lymph nodes are enlarged because of nonspecific inflammatory change. When enlarged lymph nodes are hypoechoic, metastases are most likely, although nonspecific inflammation cannot be excluded. Preoperative assessment of the depth of tumor invasion is important
in the
treatment
of rectal
carcinoma,
diverticulitis
(Figs.
circumscribed
494 498 516 520 526 532 544 584
602 608
peninectal
abscess
cystic
hamartoma
masses
outside
and needle
be demonstrated
tenatoma (Fig.
of the
(Fig. 15) and
1 6) are seen rectal
1991
wall.
for localization
as well-
Endonectal
of peninectal
particularly
OF
REFERENCES 1. Orrom WJ, Wong WD, Rothenberger DA, Jensen LL, Goldberg SM. Endorectal ultrasound in the preoperative staging of rectal tumors: a leaming experience. Dis Colon Rectum 1990;33:654-659 2. Konishi F, Ugajin H, Kanazawa K. Endorectal ultrasonography with a 7.5 MHz linear array scanner for the assessment of invasion of rectal carcinoma. Int J Colorectal Dis 1990;5: 15-20 3. Beynon J, Foy DM, Temple LN, Channer JL, Virgee J, Mortenson NJ. The endosonic appearances of normal colon and rectum. Dis Colon Rectum
BOOK
AND
1986;29:810-813 4. Glaser F, Schlag P, Herfarth C. Endorectal ultrasonography for the assessments of invasion of rectal tumors and lymph node involvement. Br J Surg 1990;77:883-887
VIDEOTAPE
REVIEWS
Resonance
Imaging of Carcinoma
of the Urinary Bladder.
JO, Debruyne FMJ, Ruijs SHJ Textbook of Uroradiology. Dunnick NR, McCailum RW, SandIer MRI of the Musculoskeletal System, 2nd ed. Berquist TH, ed. The Language of Fractures, 2nd ed. Schultz RJ Obstetrics and Gynecology. Berman MC, ed. Neuroradiology Test and Syllabus. Weinberg PE, section ed. Gamuts and Pearls in MRI. Pomeranz SJ
A Short Textbook
can
September
biopsy of peninectal masses.
Detection and Treatment of Early Breast Cancer. Fentiman! The Radiologic Clinics of North America. Interventional Radiology Biliary Tract. Burhenne HJ, ed. RSNA Today, Vol. 4, No, 5. Casareila WJ, moderator Atlas of Roentgenographic Measurement, 6th ed. Keats TE
Magnetic
abscess
also has been useful
sonognaphy
with endorectal sonography than with CT (Fig. 5). The high spatial resolution of endonectal sonography also has proved useful in characterizing the nature and extent of numerous rectal and penirectal disease entities. Endonectal sonognaphy shows villous adenoma (Fig. 6), leiomyosancoma (Fig. 7), metastases (Figs. 8 and 9), endometniosis (Fig. 10), and pelvic lipomatosis (Fig. 11) as nonspecific, solid masses within the rectal wall and perirectal soft tissues. Calcification within a chordoma (Fig. 12) and pennectal fluid collections seen in
480 490
and
13 and 14). Sacnococcygeal
netnopenitoneal
when local excision is being considered. A major value of endonectal sonognaphy is to determine the depth of tumor invasion. The procedure can be used to detect local recurrence after low anterior resection or local excision. Extent of primary on recurrent tumor infiltration is defined more exactly
LIST
AJR:157,
of Clinical Imaging.
Sutton
D, Young
JWR,
CM
eds.
of the
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