AJR 2004; 183:1071-1074
© American Roentgen Ray Society
Hilar Cholangiocarcinoma: Staging with Intrabiliary MRI
Aravind Arepally1,
Christos Georgiades1,
Lawrence V. Hofmann1,
Michael Choti2,
Paul Thuluvath3 and
David A. Bluemke1
1 The Russell H. Morgan Department of Radiology and Radiological Science,
Division of Cardiovascular and Interventional Radiology, Johns Hopkins Medical
Institutes, Blalock 544, 600 N Wolfe St., Baltimore, MD 21287.
2 Department of Surgery, Division of Surgical Oncology, Johns Hopkins Medical
Institutes, Baltimore, MD.
3 Department of Medicine, Division of Gastroenterology and Hepatology, Johns
Hopkins Medical Institutes, Baltimore, MD.
Received December 28, 2004;
accepted after revision March 8, 2004.
A. Arepally is a 2003–2004 American Roentgen Ray Society Scholar.
Address correspondence to A. Arepally
(aarepall{at}rad.jhu.edu).
Introduction
Cholangiocarcinoma is the second most common primary malignant liver tumor.
Globally, the hepatocellular–cholangiocellular carcinoma ratio is 3:1
and varies from 1:1 in some Northern European countries to greater than 10:1
in Southeast Asia [1]. Despite
improvements in surgical technique and advances in chemotherapy, the prognosis
remains dismal. In patients with potentially resectable disease, the 1-, 3-,
and 5-year survival rates are 68%, 30%, and 11%, respectively
[2].
Resectability of the biliary malignancies is dependent on the local extent
of tumor in the adjacent liver parenchyma, vascular and lymphatic invasion,
and lymph node involvement. Despite advances in imaging technology, the
overall accuracy for assessing resectability is 60% for both multiphasic
helical imaging and MRI [3].
Even after optimum planning before surgery, 25–40% of patients who were
deemed to have resectable tumors were found to have unresectable tumors at
surgery [4]. Therefore,
accurate planning before surgery and assessment of resectability are essential
in the evaluation of patients with cholangiocarcinoma.
Recent advances in miniature coil designs have allowed placement of MRI
receiver coils directly in both arteries and veins for MRI. Intravascular
coils allow superior spatial resolution and increased signal-to-noise ratio in
the tissue immediately adjacent to the coil. By decreasing the field of view,
we can achieve 100- to 200-µm resolution of arterial wall disease
[5]. For similar reasons, we
hypothesized that coil technology may be adapted to the assessment of other
deep structures in the body, such as the biliary tree, where external coils
may have limitations. We describe the technique and imaging features for two
patients who successfully underwent intrabiliary MRI through indwelling
biliary access.
Percutaneous Transhepatic Cholangiography–Biliary Drainage
Access to the biliary tree was required in both patients to provide
decompression and cholangiography to fully delineate the biliary tree. Biliary
access was achieved in a standard fashion under fluoroscopic visualization
using a two-step technique of opacifying the biliary tree with a 22-gauge
needle (Chiba, Cook Inc.) and puncturing a peripheral right posterior duct
with a 21-gauge trocar needle. After placement of a dilator-sheath assembly
set (Neff Percutaneous Access Set, Cook Inc.), the occluded biliary duct was
traversed with a hydrophilic guidewire and a 10-French biliary drainage
catheter (Boston Scientific) was inserted in a standard fashion over a stiff
guidewire.
Intrabiliary MRI
Intrabiliary MRI was performed along with conventional MRI for tumor
staging after biliary decompression for 1–2 weeks. Because some of the
biliary tubes have metallic braiding, they were removed over a standard
guidewire and replaced with an 8-French vascular sheath with the tip placed in
the duodenum under fluoroscopic guidance. The Intercept Esophageal Internal
MRI Coil (Surgivision) (Fig.
1B) was inserted through the sheath into the area of interest.
The Intercept coil (Figs.
1B,
2A, and
2B) is an 8-French, 75-cm-long
catheter that can be readily inserted into a standard biliary tube 10-French
or larger without the use of guidewires. The current imaging length is 5 cm
with a field of view of 8–24 cm with high spatial resolution. These
receiver coils are Food and Drug Administration (FDA)–approved devices
designed for internal imaging of the esophagus, aorta, and surrounding area.
The MRI coil was placed in the vascular sheath with the 5-cm imaging length of
the wire placed in the area of interest.
After placement of the receiver coils (Figs.
1A,
1B,
2A, and
2B), both patients were
transferred to the MRI suite for further imaging. The receiver coils were
secured to the sheath using sterile tape to prevent movement during the
transfer to the MRI unit. Breath-hold coronal and axial oblique MR images were
obtained on a 1.5-T MRI system (CV/i, GE Healthcare). MRI sequences were
obtained with an intrabiliary MRI coil as one channel of a phased array, with
two additional anterior and one posterior surface coils forming the
phased-array coil. T1-weighted images (2D spoiled gradient-recalled echo
[TR/TE, 100/2.8; flip angle, 70°] and 3D fast spoiled gradient-recalled
echo breath-hold [4.1/1.6; flip angle, 15°]), T2-weighted fast spin-echo
images (3,000/105; echo-train length, 16), and single-shot fast spin-echo
images (infinite/90) were acquired. T1-weighted images were obtained before
and at 20 sec and 70 sec after 0.1 mmol/kg of IV gadodiamide (Omniscan,
Amersham Health) was administered. Sequences were prescribed so that the
in-plane resolution was approximately 150–200 µm (field of view,
8–12 cm; frequency imaging matrix, 512; 256 phase encodes interpolated
to 512 pixels).
Case 1
The patient was a 62-year-old woman who initially presented 4 years earlier
with relatively acute onset of abdominal pain, fever, chills, nausea or
vomiting, and a 5-cm obstructing mass at the ampulla. After staging with
cross-sectional imaging, she underwent a radical Whipple procedure. She was
discharged after an uneventful recovery, and biliary drains were removed after
1 month. Four years later she presented with complaints of abdominal pain,
fever, chills, and elevated level of alkaline phosphatase. Percutaneous
transhepatic cholangiography or percutaneous biliary drainage showed complete
occlusion of the common bile duct at the hepaticojejunostomy. Because of her
history, the differential diagnosis was either benign biliary stricture or
recurrent tumor.
Intrabiliary MRI was performed through the existing biliary access. Figures
1C and
1D were obtained after
gadolinium-enhanced MRI without (Fig.
1C) and with (Fig.
1D) the intrabiliary coil. As shown in the figures, placement of
the intrabiliary coil increased the signal-to-noise ratio and enhanced the
visualization of the adjacent liver parenchyma. The biliary lumen had
increased signal with better delineation of the biliary wall from the adjacent
structures. Intrabiliary MRI showed no discernible masses. Biliary biopsies
showed reactive, inflammatory tissue and fibrosis and no evidence of neoplasm.
Because of these findings, the patient was percutaneously treated under the
diagnosis of postoperative biliary stricture.
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Fig. 1C. —62-year-old woman with history of Whipple surgery.
Gadolinium-enhanced MR image (3D fast spoiled gradient-recalled echo; TR/TE,
5.8/2.1; flip angle, 12°) obtained 4 months before patient presented with
biliary obstruction shows liver without receiver coil. Circle surrounds common
bile duct.
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Fig. 1D. —62-year-old woman with history of Whipple surgery.
Gadolinium-enhanced MR image (3D fast spoiled gradient-recalled echo; 4.1/1.6;
flip angle, 15°) of liver shows intrabiliary receiver coil in place. Note
increased signal from common bile duct in comparison with B. No tumor
was identified.
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Case 2
The patient was a 48-year-old man who presented to the emergency department
with painless jaundice and elevated level of bilirubin. CT revealed a hilar
mass and dilated intrahepatic biliary system. After decompression with
bilateral percutaneous biliary drains, he underwent biopsy, which confirmed
hilar cholangiocarcinoma or Klatskin's tumor. On the basis of CT and standard
MRI evaluation, the patient was found to be a candidate for surgical
evaluation; however, he opted for alternative therapies and declined surgery.
The patient returned 4 months later for surgical evaluation. At that time, he
was still considered a surgical candidate on the basis of cholangiography.
Intrabiliary MRI was performed to better delineate liver involvement.
Intrabiliary MR images (Figs.
3A and
3B) showed local liver invasion
and the extension into the bifurcation of the right anteroposterior ductal
system. Images obtained lower in the common bile duct also showed invasion of
the tumor into the adjacent liver. On standard cholangiograms, this degree of
involvement was not visible.
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Fig. 3A. —48-year-old man with painless jaundice. Intrabiliary MR image
(axial fast spin-echo; TR/TE, 7,000/100; echo-train length, 22; thickness, 4
mm; matrix, 512 x 512; field of view, 17.9 x 17.9) shows abnormal
soft-tissue mass extending from common bile duct to adjacent liver parenchyma
(short arrow). Normal common bile duct (long solid arrow)
and intrabiliary coil (dashed arrow) are also seen.
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Fig. 3B. —48-year-old man with painless jaundice. Intrabiliary MR image
(axial fast spoiled gradient-recalled echo; 125/1.7; thickness, 4 mm; matrix,
512 x 512; field of view, 17.9 x 17.9) shows extension of tumor to
bifurcation of right anterior and right posterior ductal system. RT =
right.
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Discussion
Cholangiocarcinoma is a neoplasm with usually late presentation. It can be
multifocal and exhibit periductal invasion, thus making delineation on regular
cross-sectional imaging difficult. Hepatectomy for cholangiocarcinoma can be a
challenging procedure and has a long convalescence period. Morbidity rates are
rather high, with 44% of patients suffering a major postoperative complication
and a nearly 10% overall mortality rate
[6].
In patients with malignant obstruction, staging and evaluation before
operation are critical in identifying candidates for surgical resection.
Despite advances in CT and MRI, these imaging techniques can be insufficient
in identifying the presence or the extent of tumor involvement with regard to
biliary malignancy. Because of the difficulty in identifying subtle biliary
malignancies, many patients often undergo repeated imaging before an accurate
diagnosis can be made. Also, additional invasive studies such as ERCP or
percutaneous transhepatic cholangiography are also used for proper diagnosis
and staging before surgery. The use of intrabiliary MRI in our two patients
expedited the imaging process and allowed rapid diagnosis and staging at the
same setting. In the first patient, the absence of a soft-tissue mass in an
area that is notoriously difficult to visualize on routine axial imaging
allowed the proper diagnosis of biliary stricture, which was also confirmed
with biopsies. In the second patient, the improvement in visualization of the
adjacent liver made it possible to identify tumor infiltration into the right
posterior ducts that was not identified on cholangiography.
Advances in MRI coil designs have allowed placement of MRI receiver coils
in various lumens to enhance clinical MRI. First described by Kantor et al.
[6] for spectroscopic imaging
of the canine heart, the coils have seen gradual improvement in design and
size over the past decade. Initial catheters were fairly bulky and relatively
inflexible, requiring long imaging times. Kandarpa et al.
[7] constructed a single-loop
multiturn coil and were able to acquire ex vivo images of human arterial
specimens. Designed on an 8-French polytetrafluoroethylene catheter, this
device was fairly large but was not tested on in vivo studies. A more recent
design by Ocali and Atalar [8]
involves a loopless dipole catheter that directly interfaces with the MRI
scanner and optimizes the match of frequency of the radiofrequency coil to the
scanner for improved signal reception. In addition, this catheter is smaller
in size, has improved longitudinal coverage, and is more flexible. The
catheter we currently use is the Intercept, a modification of the catheter
designed by Ocali and Atalar.
The relatively small size and flexibility of the Intercept coil allow easy
delivery into an 8-French vascular sheath. Through the use of this catheter,
it is anticipated that improved imaging of multiple organ systems will be
possible, including transesophageal aortic plaque imaging, esophageal cancer
staging, and, potentially, prostate and urethra imaging.
The placement of intrabiliary MRI receiver coils directly in the biliary
system served to improve the imaging resolution of the biliary tract by
increasing the signal-to-noise ratio. The intrabiliary MRI technique provides
two advantages. When the receiver coil is placed directly in the biliary
system, the field of view is decreased without significant phase-wrap artifact
and allows high in-plane resolution. The coil also produces increased signal
in the biliary lumen alone, which provides contrast between the biliary lumen,
biliary wall, and adjacent structures. With these two advantages, improved
imaging of the biliary tree is possible with superior signa-to-noise and
contrast-to-noise ratios.
In conclusion, these two cases show the potential impact of intrabiliary
MRI. This technique provides near microscopic resolution of the biliary tree
compared with conventional MRI. Not only was the presence of a tumor mass
identified, but tumor margins were better delineated and the level of invasion
was discernible. Intrabiliary MRI allowed us to improve the accuracy of
staging before surgery for cholangiocarcinoma. This technique can potentially
minimize needless surgery and its associated morbidity, mortality, and
cost.
References
- Okuda K, Nakanuma Y, Miyazaki M. Cholangiocarcinoma: recent
progress. 1. Epidemiology and etiology. J Gastroenterol
Hepatol 2002;17:1049
-1055[Medline]
- Lillemoe KD, Cameron JL. Surgery for hilar cholangiocarcinoma: the
Johns Hopkins approach. J Hepatobiliary Pancreat Surg2000; 7:115
-121[Medline]
- Choi BI, Han JK, Shin YM, Baek SY, Han MC. Peripheral
cholangiocarcinoma: comparison of MRI with CT. Abdom
Imaging 1995;20:357
-360[Medline]
- Jarnagin WR, Fong Y, DeMatteo RP, et al. Staging, resectability,
and outcome in 225 patients with hilar cholangiocarcinoma. Ann
Surg 2001;234:507
-517[Medline]
- Atalar E, Bottomley PA, Ocali O, et al. High resolution
intravascular MRI and MRS by using a catheter receiver coil. Magn
Reson Med 1996;36:596
-605[Medline]
- Kantor HL, Briggs RW, Balaban RS. In vivo 31P nuclear magnetic
resonance measurements in canine heart using a catheter-coil. Circ
Res 1984;55:261
-266[Abstract/Free Full Text]
- Kandarpa K, Jakab P, Patz S, Schoen FJ, Jolesz FA. Prototype
miniature endoluminal MR imaging catheter. J Vasc Interv
Radiol 1993;4:419
-427[Medline]
- Ocali O, Atalar E. Intravascular magnetic resonance imaging using a
loopless catheter antenna. Magn Reson Med1997; 37:112
-118[Medline]
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