http://www.radnet.ucla.edu/radweb/research/faculty/Ruehm.jsp
http://www.americanimaging.net/index
https://provider2.anthem.com/wps/portal/ebpmybcc/
1: Ajaj W, Rühm SG, Papanikolaou N, Lauenstein TC, Gerken G, Goyen M. Dark lumen
MR colonography: can high spatial resolution VIBE imaging improve the detection
of colorectal masses? Rofo. 2006 Nov;178(11):1073-8. PubMed PMID: 17128377.
2: Ajaj W, Goyen M, Langhorst J, Ruehm SG, Gerken G, Lauenstein TC. MR
colonography for the assessment of colonic anastomoses. J Magn Reson Imaging.
2006 Jul;24(1):101-7. PubMed PMID: 16736477.
3: Ajaj W, Ruehm SG, Lauenstein T, Goehde S, Kuehle C, Herborn CU, Langhorst J,
Zoepf T, Gerken G, Goyen M. Dark-lumen magnetic resonance colonography in
patients with suspected sigmoid diverticulitis: a feasibility study. Eur Radiol.
2005 Nov;15(11):2316-22. Epub 2005 Aug 13. PubMed PMID: 16132933.
4: Ajaj W, Lauenstein TC, Schneemann H, Kuehle C, Herborn CU, Goehde SC, Ruehm
SG, Goyen M. Magnetic resonance colonography without bowel cleansing using oral
and rectal stool softeners (fecal cracking)--a feasibility study. Eur Radiol.
2005 Oct;15(10):2079-87. Epub 2005 Jul 14. PubMed PMID: 16021453.
5: Goehde SC, Descher E, Boekstegers A, Lauenstein T, Kühle C, Ruehm SG, Ajaj W.
Dark lumen MR colonography based on fecal tagging for detection of colorectal
masses: accuracy and patient acceptance. Abdom Imaging. 2005
Sep-Oct;30(5):576-83. Epub 2005 Mar 4. PubMed PMID: 15759203.
6: Lauenstein TC, Ajaj W, Kuehle CA, Goehde SC, Schlosser TW, Ruehm SG. Magnetic
resonance colonography: comparison of contrast-enhanced three-dimensional vibe
with two-dimensional FISP sequences: preliminary experience. Invest Radiol. 2005
Feb;40(2):89-96. PubMed PMID: 15654253.
7: Ajaj W, Lauenstein TC, Pelster G, Holtmann G, Ruehm SG, Debatin JF, Goehde SC.
MR colonography in patients with incomplete conventional colonoscopy. Radiology.
2005 Feb;234(2):452-9. Epub 2004 Dec 10. PubMed PMID: 15591429.
8: Herborn CU, Yang F, Robert P, Laclédère C, Violas X, Bara J, Corot C, Debatin
JF, Ruehm SG. Dark lumen magnetic resonance colonography in a rodent polyp model:
initial experience and demonstration of feasibility. Invest Radiol. 2004
Dec;39(12):723-7. PubMed PMID: 15550833.
9: Ajaj W, Lauenstein TC, Pelster G, Goehde SC, Debatin JF, Ruehm SG. MR
colonography: how does air compare to water for colonic distention? J Magn Reson
Imaging. 2004 Feb;19(2):216-21. PubMed PMID: 14745756.
10: Lauenstein TC, Goehde SC, Ruehm SG, Holtmann G, Debatin JF. MR colonography
with barium-based fecal tagging: initial clinical experience. Radiology. 2002
Apr;223(1):248-54. PubMed PMID: 11930074.
11: Lauenstein T, Holtmann G, Schoenfelder D, Bosk S, Ruehm SG, Debatin JF. MR
colonography without colonic cleansing: a new strategy to improve patient
acceptance. AJR Am J Roentgenol. 2001 Oct;177(4):823-7. PubMed PMID: 11566681.
12: Lauenstein TC, Herborn CU, Vogt FM, Göhde SC, Debatin JF, Ruehm SG. Dark
lumen MR-colonography: initial experience. Rofo. 2001 Sep;173(9):785-9. PubMed
PMID: 11582556.
13: Weishaupt D, Patak MA, Froehlich J, Ruehm SG, Debatin JF. Faecal tagging to
avoid colonic cleansing before MRI colonography. Lancet. 1999 Sep
4;354(9181):835-6. PubMed PMID: 10485732.
1. Rofo. 2006 Nov;178(11):1073-8.
Dark lumen MR colonography: can high spatial resolution VIBE imaging improve the
detection of colorectal masses?
Ajaj W, Rühm SG, Papanikolaou N, Lauenstein TC, Gerken G, Goyen M.
Medical Center, University Hospital Hamburg-Eppendorf. ajaj@uke.uni-hamburg.de
PURPOSE: To assess whether the detection of colorectal lesions can be improved
using high spatial resolution VIBE imaging.
MATERIALS AND METHODS: 48 patients underwent same-day dark lumen MR colonography
(MRC) and conventional colonoscopy (CC) as the standard for the detection of
colorectal masses. MRC was performed using contrast-enhanced standard and high
spatial resolution T1-weighted 3D VIBE sequences. The findings and the image
quality of the standard and high spatial resolution VIBE sequences were compared
qualitatively and quantitatively. The findings of both sequences regarding
colorectal lesions were compared to those of a subsequently performed
colonoscopy.
RESULTS: The high spatial resolution VIBE sequence significantly improved the
quantitative image quality (CNR 54.0 vs. 36.8). However, high spatial resolution
VIBE imaging did not detect more colorectal lesions than the standard VIBE
sequence. In addition, none of the sequences employed was able to detect lesions
with a diameter of less than 5 mm (CC 40 lesions). However, 13 colorectal lesions
with a diameter of greater than 5 mm were detected by both sequences (CC 15).
CONCLUSION: High spatial resolution VIBE imaging did not improve the detection of
colorectal masses and MRC fails to detect colorectal lesions with a diameter of
less than 5 mm.
PMID: 17128377 [PubMed - indexed for MEDLINE]
2. J Magn Reson Imaging. 2006 Jul;24(1):101-7.
MR colonography for the assessment of colonic anastomoses.
Ajaj W, Goyen M, Langhorst J, Ruehm SG, Gerken G, Lauenstein TC.
Medical Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
ajaj@uke-hamburg.de
PURPOSE: To assess colonic anastomoses in patients after surgical treatment by
means of MR colonography (MRC) in comparison with conventional colonoscopy (CC).
MATERIALS AND METHODS: A total of 39 patients who had previously undergone
colonic resection and end-to-end-anastomosis were included in the study. MRI was
based on a dark-lumen approach. Contrast-enhanced T1-weighted (T1w)
three-dimensional (3D) images were collected following the rectal administration
of water for colonic distension. The MRC data were evaluated by two radiologists.
The criteria employed to evaluate the anastomoses included bowel wall thickening
and increased contrast uptake in this region. Furthermore, all other colonic
segments were assessed for the presence of pathologies.
RESULTS: In 23 and 20 patients the anastomosis was rated to be normal by MRC and
CC, respectively. In three patients CC revealed a slight inflammation of the
anastomosis that was missed by MRI. A moderate stenosis of the anastomosis
without inflammation was detected by MRC in five patients, which was confirmed by
CC. In the remaining 11 patients a relevant pathology of the anastomosis was
diagnosed by both MRC and CC. Recurrent tumor was diagnosed in two patients with
a history of colorectal carcinoma. In the other nine patients inflammation of the
anastomosis was seen in seven with Crohn's disease (CD) and two with ulcerative
colitis. MRC did not yield any false-positive findings, resulting in an overall
sensitivity/specificity for the assessment of the anastomosis of 84%/100%.
CONCLUSION: MRC represents a promising alternative to CC for the assessment of
colonic anastomoses in patients with previous colonic resection.
PMID: 16736477 [PubMed - indexed for MEDLINE]
3. Eur Radiol. 2005 Nov;15(11):2316-22. Epub 2005 Aug 13.
Dark-lumen magnetic resonance colonography in patients with suspected sigmoid
diverticulitis: a feasibility study.
Ajaj W, Ruehm SG, Lauenstein T, Goehde S, Kuehle C, Herborn CU, Langhorst J,
Zoepf T, Gerken G, Goyen M.
Department of Diagnostic and Interventional Radiology and Neuroradiology,
University Hospital, Hufelandstrasse 55, 45122, Essen, Germany.
Waleed.ajaj@uni-essen.de
To assess dark-lumen magnetic resonance colonography (MRC) for the evaluation of
patients with suspected sigmoid diverticulitis. Forty patients with suspected
sigmoid diverticulitis underwent MRC within 72 h prior to conventional
colonoscopy (CC). A three-dimensional T1-weighted volumetric interpolated
breath-hold examination sequence was acquired after an aqueous enema and
intravenous administration of gadolinium-based contrast agents. All MRC data were
evaluated by two radiologists. Based on wall thickness and focal uptake of
contrast material and pericolic reaction including mesenteric infiltration on
T1-weighted sequence the sigmoid colon was assessed for the presence of
diverticulitis. MRC classified 17 of the 40 patients as normal with regard to
sigmoid diverticulitis. However, CC confirmed the presence of light inflammatory
signs in four patients which were missed in MRC. MRC correctly identified wall
thickness and contrast uptake of the sigmoid colon in the other 23 patients. In
three of these patients false-positive findings were observed, and MRC classified
the inflammation of the sigmoid colon as diverticulitis whereas CC and
histopathology confirmed invasive carcinoma. MRC detected additionally relevant
pathologies of the entire colon and could be performed in cases where CC was
incomplete. MRC may be considered a promising alternative to CC for the detection
of sigmoid diverticulitis.
PMID: 16132933 [PubMed - indexed for MEDLINE]
4. Eur Radiol. 2005 Oct;15(10):2079-87. Epub 2005 Jul 14.
Magnetic resonance colonography without bowel cleansing using oral and rectal
stool softeners (fecal cracking)--a feasibility study.
Ajaj W, Lauenstein TC, Schneemann H, Kuehle C, Herborn CU, Goehde SC, Ruehm SG,
Goyen M.
Department of Diagnostic and Interventional Radiology and Neuroradiology,
University Hospital of Essen, Hufelandstrasse 55, 45122, Essen, Germany.
Waleed.ajaj@uni-essen.de
The aim of our study was to assess the effect of oral and rectal stool softeners
on dark-lumen magnetic resonance (MR) colonography without bowel cleansing. Ten
volunteers underwent MR colonography without colonic cleansing. A baseline
examination was performed without oral or rectal administration of stool
softeners. In a second set, volunteers ingested 60 ml of lactulose 24 h prior to
MR examination. In a third examination, water as a rectal enema was replaced by a
solution of 0.5%-docusate sodium (DS). A fourth MR examination was performed, in
conjunction with both oral administration of lactulose and rectal application of
DS. A T1-weighted data set was acquired at scanning times of 0, 5 and 10 min
after colonic filling. A fourth data set was acquired 75 s after i.v. injection
of contrast agent. Signal intensity of stool was calculated for all colonic
segments. Without oral ingestion of lactulose or rectal enema with DS stool
signal intensity was high and did not decrease over time. However, lactulose and
DS caused a decrease in stool signal intensity. Both substances together led to a
decreasing signal intensity of feces. Combination of lactulose and DS provided
the lowest signal intensity of stool. Thus, feces could hardly be distinguished
from dark rectal enema allowing for the assessment of the colonic wall.
PMID: 16021453 [PubMed - indexed for MEDLINE]
5. Abdom Imaging. 2005 Sep-Oct;30(5):576-83. Epub 2005 Mar 4.
Dark lumen MR colonography based on fecal tagging for detection of colorectal
masses: accuracy and patient acceptance.
Goehde SC, Descher E, Boekstegers A, Lauenstein T, Kühle C, Ruehm SG, Ajaj W.
Department of Diagnostic and Interventional Radiology, University Hospital Essen,
Hufelandstrasse 55, Essen 45122, Germany. susanne.goehde@uni-essen.de
BACKGROUND: Magnetic resonance colonography (MRC) with fecal tagging has recently
been investigated in clinical studies for the detection of polyps. We assessed
fecal tagging MRC in a field trial.
METHODS: Forty-two patients in a private gastroenterologic practice underwent MRC
with barium-based fecal tagging (150 mL of 100% barium at each of 6 main meals
before MRC) and conventional colonoscopy. Diagnostic accuracy of MRC and patient
acceptance were assessed and compared with the respective results of conventional
colonoscopy.
RESULTS: Eighteen percent of all MRC examinations showed a remaining high stool
signal in the colon that impeded a reliable inclusion or exclusion of polyps. On
a lesion-by-lesion basis, sensitivities for polyp detection were 100% for polyps
larger than 2 cm (n = 1), 40% for polyps between 10 and 19 mm, 16.7% for polyps
between 6 and 9 mm, and 9.1% for polyps smaller than 6 mm. The main reason for
the low acceptance of MRC was the barium preparation, which was rated worse than
the bowel cleaning procedure with conventional colonoscopy.
CONCLUSION: MRC with fecal tagging must be further optimized. The large amount of
barium resulted in poor patient acceptance, and barium according to this protocol
did not provide sufficient stool darkening. Other strategies, such as increasing
the hydration of stool, must be developed.
PMID: 15759203 [PubMed - indexed for MEDLINE]
6. Invest Radiol. 2005 Feb;40(2):89-96.
Magnetic resonance colonography: comparison of contrast-enhanced
three-dimensional vibe with two-dimensional FISP sequences: preliminary
experience.
Lauenstein TC, Ajaj W, Kuehle CA, Goehde SC, Schlosser TW, Ruehm SG.
Department of Diagnostic and Interventional Radiology, University Hospital Essen,
Germany. thomas.lauenstein@uni-essen.de
PURPOSE: The purpose of this study was to compare a dark-lumen magnetic resonance
colonography (MRC) approach with a True FISP-based bright-lumen technique
concerning presence of artifacts and the detection rate of colorectal
pathologies.
MATERIALS AND METHODS: Thirty-seven patients with suspected colorectal lesions
were included in this trial. The colon was filled with 2500 mL of tap water.
Two-dimensional True FISP datasets as well as T1-weighted GRE sequences (pre- and
post intravenous contrast) were acquired. The detection rate of colorectal masses
and inflammatory lesions was determined for both techniques separately. Besides,
image quality was assessed. All patients underwent conventional colonoscopy as
the standard of reference.
RESULTS: By means of dark-lumen MRC datasets, all polyps >5 mm were correctly
diagnosed, whereas 4 polyps <5 mm were missed. Sensitivity of dark-lumen MRC
amounted to 78.9%. There were no false-positive results: residual stool could
correctly be differentiated from colorectal masses. The True FISP-based
bright-lumen MRC, however, failed to detect 2 additional polyps resulting in a
sensitivity of 68.4%. Furthermore, bright-lumen MRC led to false-positive results
in 5 patients. Both techniques visualized inflammatory bowel disease in 5
patients. However, image quality of True FISP was rated superior to that of
dark-lumen MRC.
CONCLUSION: Dark-lumen MRC proved to be superior over bright-lumen MRC regarding
the detection of colorectal masses. However, True FISP imaging can turn out to be
helpful as a result of high image quality and motion insensitivity.
PMID: 15654253 [PubMed - indexed for MEDLINE]
7. Radiology. 2005 Feb;234(2):452-9. Epub 2004 Dec 10.
MR colonography in patients with incomplete conventional colonoscopy.
Ajaj W, Lauenstein TC, Pelster G, Holtmann G, Ruehm SG, Debatin JF, Goehde SC.
Department of Diagnostic and Interventional Radiology, University Hospital Essen,
Hufelandstrasse 55, 45122 Essen, Germany. waleed.ajaj@uni-essen.de
PURPOSE: To assess dark-lumen magnetic resonance (MR) colonography for the
evaluation of colonic segments in patients in whom conventional colonoscopy could
not be completed.
MATERIALS AND METHODS: Institutional review board approval and written informed
consent were obtained. Within 24 hours of incomplete conventional colonoscopy, 37
patients (22 women, 15 men; age range, 25-63 years) underwent MR colonography.
Contrast material-enhanced T1-weighted three-dimensional images were collected
after rectal administration of water for colonic distention. Data from MR
colonography were evaluated by two radiologists. With a three-point scale, image
quality was characterized in terms of colonic distention (1 = good; 2 = moderate,
diagnostic; and 3 = poor, nondiagnostic) and presence of artifacts (1 = none; 2 =
moderate, diagnostic; and 3 = extensive, nondiagnostic). Depiction of colorectal
disease was assessed according to the following colonic segments: cecum,
ascending colon, transverse colon, descending colon, sigmoid colon, and rectum.
RESULTS: Four patients had history of colorectal cancer, and each had undergone
partial colonic resection of two segments. Hence, 214 segments were evaluated.
Conventional colonoscopy failed in assessment of 127 of 214 potentially visible
colonic segments in the 37 patients. MR image quality was rated diagnostic in 35
patients and permitted assessment of 206 of 214 potentially visible segments.
Nondiagnostic image quality in two patients was attributed to inadequate
distention of prestenotic colonic segments owing to high-grade tumor stenosis.
All inflammation- and tumor-induced stenoses and all five polyps identified at
conventional colonoscopy in poststenotic segments were correctly detected at MR
colonography. However, MR-based assessment of prestenotic segments revealed two
lesions suspected of being carcinoma, five polyps, and four segments affected by
colitis.
CONCLUSION: MR colonography proved reliable in evaluating the majority of colonic
segments inaccessible with conventional colonoscopy. The identification of
additional disease at MR colonography underscores the need for a second
diagnostic step in the setting of incomplete conventional colonoscopy.
PMID: 15591429 [PubMed - indexed for MEDLINE]
8. Invest Radiol. 2004 Dec;39(12):723-7.
Dark lumen magnetic resonance colonography in a rodent polyp model: initial
experience and demonstration of feasibility.
Herborn CU, Yang F, Robert P, Laclédère C, Violas X, Bara J, Corot C, Debatin JF,
Ruehm SG.
Department of Diagnostic and Interventional Radiology, University Hospital Essen,
Germany. christoph.herborn@uni-essen.de
PURPOSE: We sought to assess dark lumen magnetic resonance (MR) colonography for
the detection of colon polyps in a rodent model with histology as the gold
standard.
MATERIAL AND METHODS: Fourteen male Wistar rats were subjected to carcinogenic
N-methyl-N'-nitro-N-nitrosoguanidine at the age of 4 months to induce colon
neoplasms. MR imaging was performed after a time interval of 1 year. Preparation
and data acquisition was performed with the animals under full anesthesia. After
a body-warm saline enema images were acquired on a clinical 1.5-T whole-body MR
system using a standard extremity coil. Plain and contrast-enhanced (0.3 mmol/kg;
Gd-DOTA; Dotarem, Guerbet, France) 3-dimensional T1-weighted gradient recall echo
images were acquired. Two radiologists analyzed the MR data sets in consensus for
lesion depiction. Contrast uptake in colonic wall and polyps was quantitatively
assessed by signal-to-noise ratio and contrast-to-noise ratio measurements and
compared using a Wilcoxon-Mann-Whitney U test with statistical significance at a
P value < 0.05. Finally, all animals were killed, and the MR imaging results were
compared with pathologic findings. Sensitivity and specificity were calculated.
RESULTS: By pathology, a total of 15 polyps were found in 9 of 14 rats. MR
colonography detected 13 of 15 polyps measuring between 4 and 11 mm (mean 7 +/-
0.6 mm) in 8 of 9 animals, resulting in a sensitivity and specificity of 0.87 and
1.0, respectively. Compared with the precontrast data, all polyps showed a
statistically significant increase in signal-to-noise ratio (78.2 +/- 6.3 to
167.4 +/- 17.7) and contrast-to-noise ratio (45.4 +/- 5.2 to 124.6 +/- 11.2).
CONCLUSION: MR colonography with a dark colon lumen and a bright,
contrast-enhanced colon wall appears well suited for the detection of colonic
lesions in a rodent model.
PMID: 15550833 [PubMed - indexed for MEDLINE]
9. J Magn Reson Imaging. 2004 Feb;19(2):216-21.
MR colonography: how does air compare to water for colonic distention?
Ajaj W, Lauenstein TC, Pelster G, Goehde SC, Debatin JF, Ruehm SG.
Department of Diagnostic and Interventional Radiology, University Hospital,
Essen, Germany. Waleed.ajaj@uni-essen.de
PURPOSE: To prove the feasibility of air-distended magnetic resonance
colonography (MRC) and compare it with water-based distention.
MATERIALS AND METHODS: In five volunteers, the colon was imaged twice: once after
distending the colon with air and a second time after distending the colon with
water. A total of 50 patients, who had been referred to colonoscopy for a
suspected colorectal pathology were randomized into water-distention (N = 25) and
air-distention (N = 25) groups. A contrast-enhanced T1-weighted three-dimensional
volume interpolated breath-hold (VIBE) sequence was collected. Comparative
analysis was based on qualitative ratings of image quality and bowel distention,
as well as contrast-to-noise ratio (CNR) measurements for the colonic wall with
respect to the colonic lumen. In addition, patient acceptance was evaluated.
RESULTS: Inflammatory changes and colorectal masses were correctly identified on
MRC in eight patients each. One 4-mm polyp identified at colonoscopy was missed
on water-distended MRC. There were no false positive findings. No significant
differences were found between air- and water-distention regarding discomfort
levels and image quality. The presence of air in the colonic lumen was not
associated with susceptibility artifacts. CNR of the contrast-enhanced colonic
wall, as well as bowel distention, were superior on air-distended
three-dimensional data sets.
CONCLUSION: MRC can be performed using either water or air for colonic
distention. Both techniques permit assessment of the colonic wall and
identification of colorectal masses. While discomfort levels are similar for both
agents, MRC with air provides higher CNR and better colonic distention.
PMID: 14745756 [PubMed - indexed for MEDLINE]
10. Radiology. 2002 Apr;223(1):248-54.
MR colonography with barium-based fecal tagging: initial clinical experience.
Lauenstein TC, Goehde SC, Ruehm SG, Holtmann G, Debatin JF.
Department of Diagnostic Radiology, University Hospital Essen, Hufelandstrasse
55, D-45122 Essen, Germany.
Comment in
Z Gastroenterol. 2003 Jun;41(6):625-6.
PURPOSE: To assess a strategy for fecal tagging with barium sulfate as an
inexpensive tagging agent in conjunction with magnetic resonance (MR)
colonography in patients suspected of having colorectal lesions.
MATERIALS AND METHODS: Twenty-four patients suspected of having colonic lesions
because of rectal bleeding, positive fecal occult blood test results, or altered
bowel habits underwent MR colonography and subsequent conventional colonoscopy. A
200-mL dose of a barium sulfate-containing contrast agent was ingested with each
of four low-fiber meals, beginning 36 hours before the examination. For MR
colonography, the colon was filled with tap water. Gadobenate dimeglumine was
injected intravenously. Images were acquired 75 seconds after gadobenate
dimeglumine administration by using only a T1-weighted three-dimensional
gradient-echo sequence. Images were reviewed by two radiologists blinded to
conventional colonoscopic data. By using colonoscopy as the reference standard,
sensitivity and specificity of MR colonography were determined for detecting
colorectal masses.
RESULTS: On the basis of MR colonography, 15 polyps of 5-20 mm and 10 carcinomas
were detected and later confirmed with conventional colonoscopy. Conventional
colonoscopy depicted three additional lesions less than 8 mm in diameter. Thus,
sensitivity of MR colonography was 89.3% (25 of 28) for lesions and 91.7% (22 of
24) for patients.
CONCLUSION: Barium-tagged MR colonography obviates bowel cleansing and depicts
all lesions exceeding 8 mm in diameter.
PMID: 11930074 [PubMed - indexed for MEDLINE]
11. AJR Am J Roentgenol. 2001 Oct;177(4):823-7.
MR colonography without colonic cleansing: a new strategy to improve patient
acceptance.
Lauenstein T, Holtmann G, Schoenfelder D, Bosk S, Ruehm SG, Debatin JF.
Department of Diagnostic Radiology, University Hospital Essen, Hufelandstr. 55,
D-45122 Essen, Germany.
OBJECTIVE: MR colonography permits accurate detection of colonic polyps larger
than 8 mm. Patient acceptance remains limited because of the need for bowel
cleansing. The aim of this study was to develop and assess a strategy obviating
colonic cleansing by performing MR colonography in conjunction with fecal tagging
based on the oral administration of barium.
SUBJECTS AND METHODS: Six healthy volunteers and six patients with suspected
colorectal tumors, undergoing conventional colonoscopy within 1 week of MR
imaging, were included in this study. For fecal tagging, 200 mL of a
barium-containing contrast agent was ingested with each of four principal meals
preceding the examination. For MR colonography, the colon was filled with a
barium and water mixture while gadobenate dimeglumine (0.2 mmol/kg) was injected
IV.
RESULTS: The combination of fecal tagging and colonic filling with barium
resulted in a homogeneously low signal throughout the colonic lumen in all 12
subjects. IV injection of gadolinium caused avid enhancement of the colonic wall.
Similarly, lesions arising from the colonic wall enhanced avidly. In the six
evaluated patients, MR colonography correctly identified two colonic carcinomas
in two patients and one polyp in each of another two patients.
CONCLUSION: Fecal tagging obviates bowel cleansing and should, therefore, enhance
patient acceptance for MR colonoscopy. Barium used as the tagging agent is
promising because it is inexpensive, commercially available, and characterized by
an excellent safety profile.
PMID: 11566681 [PubMed - indexed for MEDLINE]
12. Rofo. 2001 Sep;173(9):785-9.
Dark lumen MR-colonography: initial experience.
Lauenstein TC, Herborn CU, Vogt FM, Göhde SC, Debatin JF, Ruehm SG.
Zentralinstitut für Röntgendiagnostik Universitätsklinikum Essen.
thomas.lauenstein@uni-essen.de
PURPOSE: The aim of this study was to assess a new strategy of MR colonography
for the detection of colonic polyps/malignancy. The technique is based on a
rectal enema with water in combination with the intravenous application of a
paramagnetic contrast agent.
METHODS: Twelve subjects were included in this study either due to suspected
colorectal tumors or for screening purposes. For MR colonography the colon was
filled with approximately 3000 ml of tap water while Gadobenate dimeglumine (0.2
mmol/kg) was injected intravenously. A T1w GRE sequence was acquired before and
75 sec after the contrast administration only in prone position. Three patient
underwent the "bright lumen" MRC as well. All MR examinations were performed at
least five days prior to conventional colonoscopy and the results of both
modalities were compared.
RESULTS: The colonic filling with water resulted in a homogeneously low signal
throughout the colonic lumen in all twelve subjects. Intravenous injection of
gadolinium caused avid enhancement of the colonic wall. Similarly lesions arising
from the colonic wall enhanced avidly. Dark lumen MR colonography correctly
identified five polyps in four patients. Bright lumen MRC showed in one patient
false positive results.
CONCLUSION: The new MR colonography concept based on a dark colonic lumen and a
bright, contrast enhanced colonic wall turned out to be a promising alternative
to the traditional MRC based on a bright lumen concept. The new technique
suggests a higher accuracy in detecting polyps, a better evaluation of other
parenchymal organs as well as a reduced time needed for data acquisition and
analysis.
PMID: 11582556 [PubMed - indexed for MEDLINE]
13. Lancet. 1999 Sep 4;354(9181):835-6.
Faecal tagging to avoid colonic cleansing before MRI colonography.
Weishaupt D, Patak MA, Froehlich J, Ruehm SG, Debatin JF.
Colonic cleansing is unpleasant and has low acceptance by patients. We show the
feasibility of faecal tagging, which obviates the need for colonic cleansing, in
conjunction with internal magnetic resonance imaging colonography.
PMID: 10485732 [PubMed - indexed for MEDLINE]