ABSTRACT
Recent improvements in MR technology have enabled the development of volumetric three-dimensional (3D) imaging methods for fat-suppressed T1-weighted images of the entire upper abdomen with pixel sizes of approximately 2 mm in all dimensions and with acquisition times of less than 25 seconds for breath-hold imaging. When performed with a timing scheme, dynamic contrast-enhanced volumetric imaging of the liver can be performed with selective imaging during the arterial phase and portal venous phase of enhancement. The volumetric data sets can be reconstructed in any oblique plane, enabling improved detection, localization, and characterization of small liver lesions. The combination of high-resolution isotropic pixels and accurate timing also permits angiographic reconstructions of the 3D images, producing MR angiography and venography that can be useful in therapeutic planning, such as for catheter-based interventions or surgical resections or transplantation. Additionally, with use of a hepatobiliary contrast agent such as mangafodipir, T1-weighted volumetric MR cholangiography can be performed in patients with nonobstructed systems for depiction of intrahepatic biliary anatomy.
Subject(s)
Liver/pathology , Magnetic Resonance Imaging/methods , Bile Ducts/anatomy & histology , Bile Ducts/pathology , Contrast Media , Humans , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Liver/anatomy & histology , Liver/blood supply , Magnetic Resonance Angiography , Magnetic Resonance Imaging/instrumentation , Portal Vein/anatomy & histology , Portal Vein/pathologyABSTRACT
In this article, the author reviews the effect of contemporary imaging techniques on the diagnosis of various pancreatic neoplasms. Histologic detail and the relationship to other means of diagnosis are included.
Subject(s)
Cholangiopancreatography, Endoscopic Retrograde , Pancreatic Cyst/diagnostic imaging , Pancreatic Neoplasms/diagnostic imaging , Tomography, X-Ray Computed , Adenocarcinoma, Mucinous/diagnostic imaging , Adenoma/diagnostic imaging , Cystadenoma, Papillary/diagnostic imaging , HumansABSTRACT
Current MR imaging technology offers the surgeon diagnostic information about pancreatic diseases. This article reviews the basics of MR imaging formation and the rationale for the different types of imaging sequences that comprise a comprehensive pancreaticobiliary examination. Clinical examples include evaluation of pancreatic neoplasms, acute and chronic pancreatitis, and congenital abnormalities.
Subject(s)
Magnetic Resonance Imaging , Pancreas/anatomy & histology , Pancreatic Neoplasms/pathology , Pancreatitis/pathology , Acute Disease , Chronic Disease , HumansABSTRACT
OBJECTIVE: Our aim was to investigate the feasibility of MR imaging as a comprehensive preoperative imaging test for examination of liver donor candidates for adult-to-adult right lobe transplantation. SUBJECTS AND METHODS: Twenty-five consecutive donor candidates were examined at 1.5 T using a torso phased array coil with breath-hold T1- and T2-weighted imaging of the abdomen, MR cholangiography using T2-weighted turbo spin-echo imaging, and MR angiography and venography of the liver using two interpolated three-dimensional spoiled gradient-echo sequences (average dose of gadolinium contrast material, 0.17 mmol/kg). Images were interpreted for liver parenchymal and extrahepatic abnormalities; measurements of right and left lobe liver volumes; definition of hepatic arterial, portal venous, and hepatic venous anatomy; and definition of the biliary branching pattern. Findings were compared with those of conventional angiography in 13 patients, 11 of whom also had surgical findings for comparison. RESULTS: Nine patients were excluded as candidates for donation on the basis of MR imaging findings that included parenchymal or extrahepatic abnormalities in five patients, vascular anomalies in two, and biliary anomalies in three. Two patients who did not undergo surgery underwent conventional angiography that confirmed MR angiographic findings except for a small (<2 mm) accessory left hepatic artery missed on MR imaging. Of the nine patients who underwent successful right hepatectomy, all MR imaging findings were corroborated intraoperatively. In two patients, right hepatectomy was aborted at laparotomy because of intraoperative cholangiography findings; in one of them, the biliary finding was unsuspected on MR imaging. CONCLUSION: A comprehensive MR imaging examination has the potential to serve as the sole preoperative imaging modality for living adult-to-adult liver donor candidates provided improvements in definition of intrahepatic biliary anatomy can be achieved.
Subject(s)
Hepatectomy , Liver Transplantation , Living Donors , Magnetic Resonance Imaging , Adult , Angiography , Bile Ducts/anatomy & histology , Contrast Media , Feasibility Studies , Female , Hepatic Artery/anatomy & histology , Hepatic Veins/anatomy & histology , Humans , Liver/blood supply , Magnetic Resonance Angiography , Male , Portal Vein/anatomy & histology , Prospective StudiesABSTRACT
PURPOSE: To assess the accuracy of an interpolated breath-hold T1-weighted three-dimensional (3D) gradient-echo (GRE) magnetic resonance (MR) imaging sequence with near-isotropic pixel size (
Subject(s)
Hepatic Artery/anatomy & histology , Imaging, Three-Dimensional , Liver/anatomy & histology , Magnetic Resonance Imaging/methods , Angiography, Digital Subtraction , Case-Control Studies , Contrast Media , Female , Gadolinium DTPA , Humans , Image Processing, Computer-Assisted , Liver Cirrhosis/pathology , Male , Middle AgedABSTRACT
PURPOSE: To evaluate the feasibility, reproducibility, and technical quality of a dynamic contrast material-enhanced isotropic three-dimensional (3D) volumetric interpolated breath-hold hepatic magnetic resonance (MR) imaging examination. MATERIALS AND METHODS: Fifty patients underwent 3D spoiled gradient-echo imaging (4.2/1.8 [repetition time msec/echo time msec]; flip angle, 12 degrees; interpolation in three directions; intermittent fat saturation; pixel size
