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Gastrointestinal Imaging |
1 From the Departments of Radiology (S.S.L., T.K.K., J.H.B., H.K.H., P.N.K., A.Y.K., M.G.L.) and Surgery (S.G.L), Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul, 138-736, Korea. Received December 12, 2001; revision requested February 25, 2002; revision received July 8; accepted August 15. Address correspondence to T.K.K. (e-mail: tkkim@amc.seoul.kr).
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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MATERIALS AND METHODS: During a 10-month period, 62 potential LRLT donors were evaluated with CT and conventional angiography. Multi–detector row CT was performed after intravenous injection of 150 mL of contrast material at 3 mL/sec. CT angiograms of the hepatic arteries were generated by a radiologist who used volume rendering and maximum intensity projection techniques without knowledge of results of conventional angiography. Two reviewers reviewed CT and conventional angiograms retrospectively in consensus. The results of the two examinations were then compared.
RESULTS: CT examinations were technically adequate in 56 (90%) donors. Respiratory motion artifact compromised detailed hepatic artery analysis in six donors (10%). Second-order branches of right hepatic arteries were visualized in 58 donors (94%), and second-order branches of left hepatic arteries were visualized in 51 (82%). A total of 27 hepatic arterial anatomic variations were detected in 22 donors at conventional angiography. CT angiography accurately depicted 25 (93%) anatomic variations in 20 donors (91%). CT angiography did not depict an accessory right hepatic artery in two donors. The number and origins of dominant arteries supplying segment IV were accurately identified at CT angiography in 51 donors (82%). Hepatic arterial anatomy depicted at CT angiography was identical to that at conventional angiography in 50 donors (81%).
CONCLUSION: Multi–detector row CT angiography is useful but limited in its ability to depict the dominant artery supplying segment IV and small accessory hepatic arteries.
© RSNA, 2003
Index terms: Angiography, comparative studies, 761.1211, 761.12116, 95.1211, 95.12916 • Computed tomography (CT), angiography, 761.12116, 95.12916 • Hepatic arteries, CT, 952.12916 • Liver, transplantation, 761.45
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Because the hepatic artery is subject to many anatomic variations that may necessitate modifications in the surgical approach, the evaluation of hepatic arterial anatomy in an LRLT donor is an important step in preoperative donor evaluation (4,6). Despite its invasive nature, conventional angiography has been considered the method of choice for hepatic artery evaluation (2,7,8). In the past decade, computed tomographic (CT) angiography, a noninvasive method for obtaining angiogram-like images by using the volume acquisition capabilities of spiral CT, has been introduced as an alternative to conventional angiography (9,10). With the introduction of multi–detector row CT scanners, CT angiography can be performed more efficiently than was possible with single–detector row CT scanners. The fast scanning capability of multi–detector row CT enables scanning of the whole liver with thinner collimation, which improves both spatial and temporal resolution (11,12). Therefore, multi–detector row CT angiography is a promising method for evaluation of the hepatic arterial anatomy.
The purpose of this study was to assess the accuracy of multi–detector row CT angiography for evaluation of the hepatic arterial anatomy of potential donors for LRLT.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Informed consent was obtained from all patients before they underwent CT and conventional angiography, according to a protocol approved by the institutional review board. Approval and informed consent were not required for retrospective review of patient images.
There were 44 male patients and 18 female patients (mean age, 31 years; age range, 16–59 years). The mean body weight of these patients was 63.6 kg ± 9.7 (SD) (range, 46–77 kg). Fifty-eight of these patients underwent donor hepatectomy for LRLT, and three types of hepatic resection were performed: right lobectomy in 32 donors, left lobectomy in 24, and left lateral segmentectomy in two. The four remaining patients were excluded as LRLT donors because of severe fatty liver disease confirmed at ultrasonographically guided liver biopsy (n = 2) or inadequate liver volume (n = 2).
Image Acquisition
All CT scans in all 62 patients were obtained with a multi–detector row CT scanner (LightSpeed QX/i; GE Medical Systems, Milwaukee, Wis). A baseline unenhanced scan was obtained by using 5-mm collimation and a pitch of 1:3 (high-quality mode) from the dome of the diaphragm to the lower pole of the right kidney. Then, contrast material–enhanced CT scanning was performed with a biphasic technique after intravenous injection of 150 mL of iopromide (Ultravist 370; Schering, Berlin, Germany) through an 18-gauge angiographic catheter inserted into an antecubital vein by using a power injector at a flow rate of 3 mL/sec. Arterial phase imaging was initiated within 5 seconds after enhancement of the descending aorta to 100 HU, as measured with a bolus-tracking technique (Smart Prep; GE Medical Systems), was achieved.
Images were obtained from a level 1–2 cm below the dome of the diaphragm to the lower pole of the right kidney during a single breath hold. CT parameters for arterial phase scanning included a detector row configuration of 1.25 mm x 4, a pitch of 6:1 (high-speed mode), a gantry rotation speed of 0.8 second, a table speed of 7.5 mm per gantry rotation (1 cm/sec), 120 kVp, and 250 mA. Portal venous phase CT images were obtained 20 seconds after completion of arterial phase scanning through the entire liver (collimation, 2.5 mm; table speed, 15 mm per gantry rotation; pitch, 1:6). The weighted CT dose index for CT scanning was 12.9 mGy for hepatic arterial phase scanning and 10.2 mGy for portal venous phase scanning. The dose-length product for CT scanning was 290.8 mGy x cm ± 14.9 (SD) (range, 267–305 mGy x cm) for hepatic arterial phase scanning and 284.2 mGy x cm ± 15.1 (range, 270–307 mGy x cm) for portal venous phase scanning.
Digital subtraction angiography was performed in all 62 patients. Superior mesenteric angiograms were obtained after catheterization of the superior mesenteric artery with a 5-F angiographic catheter (Rosch Hepatic; Cook, Bloomington, Ind) to evaluate aberrant hepatic arteries that were visualized arising from the superior mesenteric artery and portal vein. Thirty milliliters of iopromide was injected with a power injector at a flow rate of 3 mL/sec. A celiac angiogram was then obtained by using the same catheter after injection of 25–35 mL of the same contrast material at a flow rate of 5–7 mL/sec. A common hepatic angiogram was obtained only when optimal visualization of the hepatic arteries was not achieved with the celiac arteriogram. Eight to 10 images were obtained at celiac arteriography, and 11–14 images were obtained at superior mesenteric arteriography and portal venography.
Image Processing
The 1.25-mm transverse CT sections from arterial phase scanning were reconstructed at 0.62-mm intervals by using a 180° linear interpolation process, and postprocessing was performed at a commercially available workstation (Advantage Windows 3.1; GE Medical Systems). Reformation of the source images of the arterial phase scans was performed by one radiologist (S.S.L.) who was blinded to the conventional angiographic findings. First, a maximum intensity projection (MIP) image was produced in the transverse plane. Then, the radiologist edited bone from the image by using a manual cutting device at the workstation. Three-dimensional models of the hepatic artery were generated by using a volume-rendering technique, and visual enhancement was achieved by means of artificial color assignment to the vascular models.
Volume-rendering parameters were selected subjectively for optimal visualization of the hepatic artery. The ranges of volume-rendering parameters were as follows: threshold, 175–210 HU; window width, 150–170 HU; window level, 240–260 HU; opacity, 60%–90%; and matrix size, 512. MIP images were reconstructed from the same edited data set. The MIP and volume-rendered images were magnified and projected at the appropriate viewing angle. After three-dimensional volume-rendered and MIP images were obtained, transverse source images were reviewed, with special attention given to the origin of the artery supplying segment IV and the presence of aberrant hepatic arteries not visualized on the volume-rendered and MIP images. Targeted MIP images were then generated from the transverse source images in variable slab thicknesses (2–4 cm) and variable projections to enable visualization of the origin of the artery supplying segment IV and the origin of the celiac and superior mesenteric arteries. The total postprocessing time was typically 15–20 minutes. All reconstructed images were sent to a picture archiving and communication system (PACS).
Image Review
Interpretation of all images was performed retrospectively at a PACS monitor by one general radiologist with 5 years of experience (S.S.L., the radiologist who reconstructed the CT angiographic images) and one abdominal radiologist with 7 years of experience (J.H.B.); discrepancies were resolved by consensus (two cases). First, reformatted CT angiography data, including volume-rendered, MIP, and targeted MIP images, were reviewed to evaluate image quality. The adequacy of hepatic artery enhancement was evaluated only by means of visual assessment of the hepatic arterial and venous structures. We considered that optimal enhancement of the hepatic artery was achieved when it was clearly visualized and when no branch of the celiac trunk was obscured by venous structures or the enhancement of solid organs.
Attenuation (in Hounsfield units) was measured on a transverse scan at the origin of the celiac trunk and the main portal vein. Quadrate regions of interest (ROIs) were placed by one reviewer (S.S.L.) to include at least two-thirds of the area of interest. The ROI size range was 25–49 mm2 for the celiac trunk and 49–100 mm2 for the portal vein. We measured the attenuation of liver parenchyma on both nonenhanced scans and hepatic arterial phase scans by calculating the mean of three ROI measurements. A quadrate ROI with an area of 1 cm2 was placed in the liver parenchyma at the level of the celiac trunk, avoiding the vascular structures. Liver parenchymal enhancement values were calculated by subtracting the attenuation values (in Hounsfield units) of the liver parenchyma on nonenhanced CT scans from those of the liver parenchyma on hepatic arterial phase scans. The difference in attenuation between the celiac trunk and the liver parenchyma was also calculated.
Image noise was measured in the liver parenchyma by calculating the SDs of the attenuation values of the liver parenchyma. We also evaluated for the presence or absence of respiratory motion artifact interfering with image interpretation. Respiratory motion artifact was considered to be present when vessels on reformatted CT angiograms were distorted and when respiratory misregistration was detected during review of transverse scans. The image quality of the CT angiograms was classified as technically adequate or inadequate. CT angiograms were considered technically adequate when there was no substantial respiratory motion artifact and when adequate enhancement of the hepatic artery was achieved. Otherwise, CT angiograms were considered technically inadequate.
We noted the visualization of each segmental branch of the bilateral hepatic arteries up to their second-order branches. For evaluation of hepatic arterial anatomy, we completed a study worksheet on which the origin of the segmental hepatic arterial branches, the number and origin of the hepatic arteries supplying segment IV, the presence (and origin) or absence of aberrant hepatic arteries, the branching patterns of the arteries originating from the celiac artery, and the origin of the celiac and superior mesenteric arteries were detailed.
We defined typical hepatic arterial anatomy as (a) the proper hepatic artery dividing into the right and left hepatic arteries, (b) the right hepatic artery further dividing into the right anterior and posterior hepatic arteries, (c) the left hepatic artery dividing into branches supplying segment II and segment III, and (d) one or more branches supplying segment IV arising from the right, left, or proper hepatic artery (13,14) (Fig 1). Hepatic arterial anatomy that differed from the typical anatomy was considered to represent anatomic variation. Variations in the anatomy of the celiac trunk and superior mesenteric artery, such as the existence of a celiacomesenteric or hepaticomesenteric trunk, were also assessed. One reviewer (S.S.L.) measured the diameters of the right and left hepatic arteries, the artery supplying segment IV, and the segmental branches of both hepatic arteries 1 cm distal to their origins at conventional angiography by using the electronic calipers supplied with the PACS system.
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After they reviewed the CT and conventional angiograms, the two reviewers compared the two worksheets. If any discrepancy was present between the results of the two examinations, the CT angiograms and conventional angiograms were then reviewed side by side, and a comparison between the findings was made by the two reviewers. Considering results of conventional angiography as the standard of reference for the evaluation of hepatic arterial anatomy, the reviewers then decided whether a discrepancy was due to a mistake in initial interpretation of the results of one of the two examinations or to a missed vessel at CT angiography. When CT angiograms failed to depict any portion of the hepatic arterial anatomy that was visualized at conventional angiography, the source images were reconstructed again so that the possibility of error in the initial CT angiographic reconstruction could be excluded.
Statistical Analysis
With results of conventional angiography as the standard of reference for the evaluation of hepatic arterial anatomy, sensitivity and specificity of CT angiography in depicting anatomic variation in the hepatic arteries were calculated. Diameters of the segmental branches of both the hepatic arteries and the artery supplying segment IV were compared between the CT angiograms on which these vessels were visualized and those on which the vessels were missed by using the independent sample t test. Potential factors affecting the results of CT angiography, such as size of the hepatic artery, hepatic parenchymal enhancement, difference in attenuation between the celiac trunk and the liver parenchyma, and image noise, were compared between the CT angiographic examinations with results concordant to those of conventional angiography and the CT angiographic examinations with discordant results by using the independent sample t test. A P value of less than .05 was considered to indicate a statistically significant difference.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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The mean attenuation of the celiac artery was 245.7 HU ± 27.2 (SD) (range, 196.0–289.0 HU), and there was a mean difference in attenuation between the celiac artery and the portal vein of 130.0 HU ± 33.2 (range, 67.0–166.0 HU). Mean liver parenchymal enhancement was 11.4 HU ± 4.2 (range, 3.3–18.6 HU), and mean difference in attenuation between the celiac trunk and the liver parenchyma was 208.2 HU ± 28.9 (range, 150.1–240.8 HU). The mean diameter of the left hepatic artery, as measured at conventional angiography, was 2.3 mm ± 0.5 (range, 0.9–3.5 mm), and that of the right hepatic artery was 2.9 mm ± 0.6 (range, 1.6–3.7 mm).
The mean diameters of the segmental hepatic arteries were as follows: artery supplying segment IV, 1.3 mm ± 0.3 (range, 0.7–2.0 mm); right anterior hepatic artery, 2.0 mm ± 0.5 (range, 1.3–3.0 mm); right posterior hepatic artery, 1.7 mm ± 0.4 (range, 1.0–2.7 mm); segment II branch, 1.4 mm ± 0.4 (range, 0.8–2.3 mm); and segment III branch, 1.3 mm ± 0.4 (range, 0.7–2.1 mm). The second-order branches of the right hepatic artery were visualized at 58 CT angiographic examinations (94%); those of the left hepatic artery were visualized at 51 examinations (82%) (Fig 1).
The mean diameters of the right posterior hepatic arteries (1.6 mm ± 0.4 vs 1.2 mm ± 1.35; P = .027), segment II branches (1.5 mm ± 0.3 vs 1.0 mm ± 0.2; P = .003), and segment III branches (1.4 mm ± 0.3 vs 0.9 mm ± 0.2; P = .003) that were visualized at CT angiography were significantly larger than those of the arteries that were missed at CT angiography.
A total of 27 anatomic variations were detected in 22 donors (35%) at conventional angiography. Seventeen donors had only one anatomic variation of the hepatic artery, and five donors had more than one. Table 1 summarizes the anatomic variations detected at conventional angiography and CT angiography. Fifteen aberrant hepatic arteries were present in 13 donors, including a replaced left hepatic artery arising from the left gastric artery (n = 6) (Fig 2), a replaced right hepatic artery arising from the superior mesenteric artery (n = 3) (Fig 3), and the presence of an accessory right hepatic artery (n = 6) (Fig 2). The origins of the accessory right hepatic arteries included the gastroduodenal artery (n = 4) (Fig 2), the dorsal pancreatic artery (n = 1), and the superior mesenteric artery (n = 1). CT angiography accurately depicted 13 (87%) of the 15 aberrant hepatic arteries that were demonstrated at conventional angiography in 11 (85%) of the 13 donors. In the remaining two cases, CT angiography failed to demonstrate an accessory right hepatic artery arising from the gastroduodenal artery. In one of these two cases, interpretation of the CT angiograms was very difficult due to respiratory motion artifact (Fig 3). In the other donor candidate, CT angiography demonstrated normal arterial anatomy, while digital subtraction angiography revealed a small accessory right hepatic artery arising from the gastroduodenal artery (Fig 4). Neither retrospective review of the CT angiograms nor repeated reconstruction of the source images revealed this accessory branch.
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Fifty (81%) of 62 CT angiographic examinations depicted the same hepatic arterial anatomy that was demonstrated at conventional angiography, including the origin and branching pattern of the segmental hepatic branches, the number and origin of the arteries supplying segment IV, and the anatomic variations of the hepatic artery and celiac trunk. Table 3 outlines the possible factors affecting the results of CT angiography in terms of a comparison between the CT angiographic examinations that yielded results concordant with those of conventional angiography and the CT angiographic examinations that yielded discordant results. The mean sizes of the segmental branches of the hepatic artery, including the artery supplying segment IV, were significantly larger at CT angiographic examinations that yielded results concordant with those of conventional angiography than at those that yielded discordant results. There were no significant differences between the CT angiographic examinations with concordant results and those with discordant results in terms of liver parenchymal enhancement, differences in attenuation between the celiac trunk and the liver parenchyma, and image noise.
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Assessment of the hepatic arterial anatomy is one of the most important steps in the preoperative evaluation of potential liver donors because hepatic arterial anatomy is extremely variable and some anatomic variations may necessitate modification of the surgical approach (2–4). The main goal of presurgical evaluation of the hepatic arterial anatomy is to provide a complete arterial "road map" for the transplantation surgeons (4,8).
Therefore, evaluation of hepatic arterial anatomy should focus not only on the detection of variations in hepatic arterial supply but also on the origin and branching pattern of the individual branches of the hepatic artery. Preoperative identification of a situation in which the dominant artery supplying segment IV arises from the right hepatic artery is important in LRLT procedures in which either a left-lobe or right-lobe graft is used. In hepatectomy of the right lobe of the donor, if the main inflow to segment IV has its origin in the right hepatic artery, the right hepatic artery should be clamped distal to the origin of this branch to ensure adequate blood perfusion of the remaining left lobe of the donor (2,7). In hepatectomy of the left lobe of the donor, when the dominant artery supplying segment IV arises from the right hepatic artery or arises separately from the proper hepatic artery, both the left hepatic artery and the artery supplying segment IV are usually prepared for possible anastomosis to the recipient’s artery (15,16). For the same reason, identification of the separate origins of the segment II and III branches from the proper hepatic artery is also important in LRLT procedures in which the left lobe or left lateral segment is used.
For evaluation of hepatic arterial anatomy, conventional angiography has been recognized as the standard of reference (2,7,8). However, with the development of spiral CT, CT angiography has been evaluated for its potential to replace conventional angiography (9,10,17). Recently, multi–detector row CT has improved CT imaging. The advantages of multi–detector row CT over single–detector row spiral CT are mainly faster scanning capability, improved temporal resolution, improved spatial resolution in the z axis, increased effectiveness of the intravascular contrast agent, decreased image noise, and more extensive anatomic coverage (11,12).
A recent study by Kamel et al (17) demonstrated the successful application of multi–detector row CT in donor selection and surgical planning before living adult right lobe liver transplantation. However, to our knowledge, detailed evaluation of the accuracy of CT angiography in the assessment of the hepatic arterial anatomy of potential LRLT donors has not yet been performed.
In the present study, the overall accuracy of CT angiography for assessment of hepatic arterial anatomy was 81%. CT angiography revealed all but two anatomic variations, and its sensitivity in depicting hepatic arterial anatomic variations was 91%. Therefore, we consider CT angiography to be a useful, noninvasive, acceptably accurate method for evaluating hepatic arterial anatomy.
However, we identified a few of the limitations of CT angiography. First, in two donors (3%), an accessory right hepatic artery was not detected at CT angiography. Second, the origins of the arteries supplying segment IV were not demonstrated or were misinterpreted in 11 donors (18%). Third, CT angiography failed to depict the second-order branches of the right hepatic artery in four donors (6%) and the second-order branches of the left hepatic artery in 11 donors (18%).
In six cases (10%) in which the CT angiographic examination was considered technically inadequate, respiratory motion artifact interfered with adequate visualization of the hepatic artery—especially the arterial branches coursing horizontal to the scanning plane. Therefore, respiratory motion artifact is considered to be the main cause of inadequate visualization of the hepatic arterial anatomy at CT angiography. In technically adequate examinations, the cause of failure to visualize the hepatic arterial branches can be explained by limitation in the spatial resolution of CT scanning, interpretation error or possible errors during reconstruction of the CT angiographic data, inadequate enhancement of the hepatic artery, and image noise. Because both retrospective review of the CT angiographic results and repeated reconstruction of the CT angiographic data failed in all cases—yielding persistent discrepancies between the CT angiographic results and the conventional angiographic results—to depict the hepatic arterial anatomy missed during initial interpretation, errors in initial interpretation or reconstruction of CT angiographic data seem to be an unlikely cause of suboptimal results at CT angiography.
Among various factors that may affect the results of CT angiography, only the size of the hepatic arterial segment was significantly different between CT angiographic examinations with results concordant with those of conventional angiography and CT angiographic examinations with discordant results. Therefore, we believe that the cause of failure to produce results concordant with those of conventional angiography is primarily the limited spatial resolution of CT angiography in depicting small hepatic arterial branches; the limit of spatial resolution in CT angiographic examinations in our study was approximately 1 mm.
In contrast to the results of our study, Kamel et al (17) reported that the artery supplying segment IV was identified in 39 of 40 patients at CT angiography. Unlike our study, in which 150 mL of contrast material was used at an infusion rate of 3 mL/sec, their study incorporated the use of 150 mL of contrast material at an infusion rate of 5 mL/sec (17). Because it is difficult to obtain a stable venous route for rapid infusion of contrast material in Asian persons, who generally have a small body habitus, we used a slow contrast material infusion rate. Differences in the volume and injection rate of the contrast agent between our study and the study of Kamel et al (17) may be a potential cause of the poor results of our study. Because the magnitude of peak aortic enhancement increases with increases in the volume and infusion rate of contrast material (18), the use of a large volume of contrast material and a rapid infusion rate in the study of Kamel et al (17) may have led to better enhancement of the hepatic artery than that observed in our study.
However, body weight is another important factor that determines the magnitude of arterial contrast enhancement (19). Therefore, the poor result of our study cannot be explained only by a difference in the injection technique; one must also compare the body weights of the patients included in the two studies. Furthermore, because Kamel et al (17) correlated the results of CT angiography with those of celiac angiography in only 12 donors, their results are less reliable than our results, which are based on correlation of CT angiographic findings with conventional angiographic findings in all 62 patients. Because the time to peak aortic enhancement and the magnitude of peak aortic enhancement increase with reduction of cardiac output (20), the inclusion in our study of mainly young patients, who usually have higher cardiac output than older individuals, may have resulted in lessened enhancement of the hepatic artery. Therefore, the patient population in our study may be another potential cause of the suboptimal results of CT angiography. However, reduced time to peak aortic enhancement prevents the unexpected delay in triggering time during bolus tracking that may occur in patients with severely reduced cardiac output.
We performed CT scanning with a GE LightSpeed system with 4 x 1.25-mm collimation and a pitch of 6:1, which resulted in an effective section thickness of 1.6 mm (21). As demonstrated in our study, the visualization of small vessels below effective section thickness can be limited owing to partial volume effects. Scanning with 4 x 1-mm collimation, which is possible with the so-called matrix detector system used in other vendors’ CT units, may reduce effective section thickness to approximately 1.3 mm (12); this may improve visualization of small vessels.
In this study, we routinely used the bolus tracking method to achieve optimal arterial phase scanning. In all examinations, the timing of arterial phase scanning was considered adequate. Enhancement of the hepatic artery was adequate, enhancement of the venous structures did not interfere with visualization of the hepatic arteries, and liver parenchymal enhancement was lower than 20 HU in all cases. Therefore, we conclude that the bolus tracking technique is useful in achieving adequate arterial phase scanning, as demonstrated in previous studies (22).
On the basis of the results of our study, it does not seem reasonable to replace conventional angiography with CT angiography in the evaluation of all potential LRLT donors. CT angiography may replace conventional angiography only when CT scanning is technically adequate, when all of the second-order hepatic arterial branches are well visualized, and when the artery supplying segment IV is adequately visualized. Otherwise, conventional angiography should be performed for complete evaluation of hepatic arterial anatomy.
Potential limitations of our study included the lack of independent reviewers, the relatively small number of patients included in our series, and the lack of correlation with surgical findings. Despite these limitations, the results of our study demonstrated the accuracy of a commercially available multi–detector row CT angiography system in the evaluation of hepatic arterial anatomy in potential LRLT donors, as compared with conventional angiography. Knowledge of the limitations and accuracy of CT angiography seems to be helpful in the interpretation of CT angiographic results and in planning further work-up.
In conclusion, although multi–detector row CT angiography is useful in evaluating hepatic arterial anatomy in potential LRLT donors, there are limitations in its ability to depict the dominant artery supplying segment IV, as well as the small accessory hepatic artery. Therefore, CT angiography can replace conventional angiography in the evaluation of the hepatic arterial anatomy of potential LRLT donors only in selected cases.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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Author contributions: Guarantor of integrity of entire study, T.K.K.; study concepts, T.K.K.; study design, S.S.L., T.K.K.; literature research, S.S.L.; clinical studies, S.G.L.; data acquisition and analysis/interpretation, S.S.L., J.H.B.; statistical analysis, S.S.L., J.H.B.; manuscript preparation, S.S.L., T.K.K.; manuscript definition of intellectual content, S.S.L., T.K.K., H.K.H., P.N.K.; manuscript editing, S.S.L., T.K.K., A.Y.K., M.G.L.; manuscript revision/review and final version approval, all authors.
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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