Navigator‐triggered isotropic three‐dimensional magnetic resonance cholangiopancreatography in the diagnosis of malignant biliary obstructions: Comparison with direct cholangiography

Choi, Jin-Young; Lee, Jeong Min; Lee, Jae Young; Kim, Se Hyung; Lee, Min Woo; Han, Joon Koo; Choi, Byung Ihn

doi:10.1002/jmri.21038

Cited by 41 publications

(24 citation statements)

References 30 publications

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“…Respiratory triggering is another method that can be proposed to improve image quality of DWI. Respiratory triggering is a technique that attempts to avoid motion artifacts prospectively by using respiratory signals to synchronize the image acquisition with the patient's breathing cycle and by acquiring the imaging data during the relative quite end expiration phase (28,29,38,(55)(56)(57)(58)(59).…”

Section: Discussionmentioning

confidence: 99%

Diffusion‐weighted imaging of the liver: Comparison of navigator triggered and breathhold acquisitions

Taouli

Sandberg

Stemmer

et al. 2009

Magnetic Resonance Imaging

150

122

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Purpose: To compare a free breathing navigator triggered single shot echoplanar imaging (SS EPI) diffusion-weighted imaging (DWI) sequence with prospective acquisition correction (PACE) with a breathhold (BH) DWI sequence for liver imaging. Materials and Methods:Thirty-four patients were evaluated with PACE-DWI and BH DWI of the liver using bvalues of 0, 50, and 500 s/mm 2 . There were 29 focal liver lesions in 18 patients. Qualitative evaluation was performed on a 3-point scale (1-3) by two independent observers (maximum score 9). Quantitative evaluation included estimated SNR (signal to noise ratio), lesion-to-liver contrast ratio, liver and lesion apparent diffusion coefficients (ADCs), and coefficient of variation (CV) of ADC in liver parenchyma and focal liver lesions (estimate of noise contamination in ADC).Results: PACE-DWI showed significantly better image quality, higher SNR and lesion-to-liver contrast ratio when compared with BH DWI. ADCs of liver and focal lesions with both sequences were significantly correlated (r ϭ 0.838 for liver parenchyma, and 0.904 for lesions, P Ͻ 0.0001), but lower with the BH sequence (P Ͻ 0.02). There was higher noise contamination in ADC measurement obtained with BH DWI (with a significantly higher SD and CV of ADC). Conclusion:The use of a navigator echo to trigger SS EPI DWI improves image quality and liver to lesion contrast, and enables a more precise ADC quantification compared with BH DWI acquisition. THERE IS A GROWING interest in using liver diffusionweighted imaging (DWI) for lesion detection and characterization, prediction of treatment response and assessment of chronic liver disease, by means of apparent diffusion coefficient (ADC) measurement (1-20). The interest in DWI is motivated by the recently described risk of nephrogenic systemic fibrosis (21-24), which makes DWI an attractive alternate method to Gadolinium-enhanced sequences. Most prior studies have used breathhold (BH) single shot echoplanar imaging (SS EPI) to acquire diffusion-weighted images, using various sets of b-values. SS EPI sequences are very fast, however, suffer from limited image quality, mostly related to limited signal to noise ratio (SNR) especially at higher b-values, and limited spatial resolution, which constitute an obstacle for its widespread use in clinical practice. Techniques such as parallel imaging (25,26) and pulse triggering (27) have been proposed to improve SS EPI image quality and precision of ADC measurement.There are several recent reports on the use of respiratory triggered acquisitions for liver DWI (15,16,[28][29][30][31]. However, only two studies have specifically compared different diffusion acquisition schemes for liver imaging (28,30). The first study (28) included a population of patients with liver lesions, and compared image quality and ADC of free breathing versus BH DWI. The second study included healthy volunteers, and compared BH, free breathing and respiratory triggered DWI (without navigator echoes) (30). There are, however, no reports on the use of a...

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Section: Discussionmentioning

confidence: 99%

Diffusion‐weighted imaging of the liver: Comparison of navigator triggered and breathhold acquisitions

Taouli

Sandberg

Stemmer

et al. 2009

Magnetic Resonance Imaging

150

122

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“…A comparison of 3D respiratorytriggered sequences with 3D breath-hold sequences showed no substantial difference in image quality, although the former may be favored in patients who cannot hold their breath (25). The primary disadvantage of 3D sequences is the long acquisition time, which has been decreased through the use of parallel imaging techniques but remains longer than with standard 2D MR cholangiopancreatographic techniques based on single-shot RARE sequences (24). However, ghosting and blurring artifacts are more conspicuous on source images from 3D acquisitions than on standard 2D MR cholangiopancreatograms due to longer acquisition times and variability in the depth of respiration (26).…”

Section: Three-dimensional Isotropic Mr Cholangiopancreatographymentioning

confidence: 96%

“…The imaging obstacles of long acquisition times and respiratory motion artifact have largely been overcome with technical innovations such as short-breathhold T2-weighted acquisitions, parallel imaging, and sophisticated respiratory triggering mechanisms (13,24,25). The use of modern high-fieldstrength magnets (1.5 T or greater) and state-ofthe-art multichannel surface coil technology are required for even shorter imaging times.…”

Section: Standard Mr Cholangiopancreatographymentioning

confidence: 99%

“…T1-weighted images obtained with and without gadolinium-based contrast material are also helpful in characterizing biliary stones and local inflammation and in the staging of biliary malignancies. State-of-the-art MR cholangiopancreatography can now be performed with both two-dimensional (2D) and 3D heavily T2-weighted sequences, usually RARE (fast spin-echo or turbo spin-echo) or a variant thereof (24). These variants include singleshot fast spin-echo (also referred to as half-Fourier acquisition single-shot turbo spin-echo [HASTE; Siemens Medical Solutions, Malvern, Pa]) and fast-recovery fast spin-echo (26).…”

Section: Standard Mr Cholangiopancreatographymentioning

confidence: 99%

“…Each of these images is acquired during a 0.3-7-second breath hold with a long effective echo time, a technique that minimizes background tissue signal, thereby providing water-only images similar to those obtained at ERCP (Fig 16). Because the Current standard MR cholangiopancreatographic protocols generally consist of two techniques that provide complementary information, including a thick-slab single-section sequence and a thin-section multisection sequence (24). Both components are generally now derived from single-shot RARE techniques (single-shot fast spin-echo, HASTE [Siemens]), which allow very short acquisition times, usually during a single breath hold, and even permit free-breathing imaging in uncooperative patients because individual sections can be acquired in less than 500 msec (27).…”

Section: Standard Mr Cholangiopancreatographymentioning

confidence: 99%

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MR Imaging and CT of the Biliary Tract

Liu²,

et al. 2009

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Magnetic resonance (MR) imaging and computed tomography (CT) can be useful in the diagnosis of biliary disease, with both modalities allowing detailed evaluation of the biliary tract. Careful interrogation of the images is critical, regardless of modality. The identification of dilated bile ducts necessitates evaluation for strictures or filling defects, which is best performed with thin-section imaging. Smooth, concentric short-segment strictures favor a benign cause, whereas abrupt, eccentric long-segment strictures favor a malignancy. At MR imaging, extrabiliary entities such as crossing vessels or metallic clip artifact may mimic strictures and should not be mistaken for disease. A stone is the most common biliary filling defect and may occur in the absence of dilated ducts. Stones commonly have a lamellated, geometric shape and are found in a dependent portion of the duct. Identification of bile duct wall thickening raises concern for cholangitis or malignancy. Improved diagnosis of biliary disease can be achieved with a knowledge of the benefits and limitations of modern MR and CT cholangiographic techniques, including the use of biliary-excreted contrast material and of various postprocessing techniques. Familiarity with the radiologic appearances of the duct lumen, wall, and surrounding structures is also important for accurate image interpretation. The rapidly evolving technology for both MR imaging and CT of the biliary tract will continue to present radiologists with opportunities as well as challenges.

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Gallbladder and Biliary Tree Imaging Techniques

Soto

Castrillón

2013

Abdominal Imaging

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Navigator‐triggered isotropic three‐dimensional magnetic resonance cholangiopancreatography in the diagnosis of malignant biliary obstructions: Comparison with direct cholangiography

Cited by 41 publications

References 30 publications

Diffusion‐weighted imaging of the liver: Comparison of navigator triggered and breathhold acquisitions

Diffusion‐weighted imaging of the liver: Comparison of navigator triggered and breathhold acquisitions

MR Imaging and CT of the Biliary Tract

Gallbladder and Biliary Tree Imaging Techniques

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