Combined hepatocellular carcinoma-cholangiocarcinoma: report of MR appearance in eleven patients.

PURPOSE: To describe the magnetic resonance imaging (MRI) appearance of hepatic combined hepatocellular-cholangiocarcinoma (cHCC-CC) in 11 patients. MATERIALS AND METHODS: The database of the Department of Pathology was cross-referenced with the MRI database to identify patients with confirmed cHCC-CC who had undergone MRI. Eleven consecutive patients were included (seven female, mean age 57.6 years). All patients were Caucasian. Five of 11 had a clinical history of chronic liver disease. Two radiologists retrospectively analyzed the images in consensus. RESULTS: cHCC-CC was a single mass in 10/11 patients. Margins were well-defined in 6/11. All tumors showed heterogeneous hyperintensity on T2. On postcontrast imaging, 6/11 showed early ring-enhancement (four noncirrhotic), with progressive enhancement in central portions, and 5/11 patients showed a diffuse heterogeneous early enhancement. Three of these five were cirrhotic and displayed partial washout with portions of contrast retention on later phases. Other findings included: late capsule enhancement (two patients), biliary dilatation (one), venous invasion (three), lymphadenopathy (six), and findings of cirrhosis (five). CONCLUSION: cHCC-CC presents most commonly as a single mass. Five of 11 had MR findings of cirrhosis. Clues to the diagnosis were moderately high signal on T2, portions of tumor that show progressive enhancement/contrast retention, and frequent lack of capsule. Early enhancement patterns included early ring-enhancement and diffuse heterogeneous enhancement.

In-phase and out-of-phase gradient-echo imaging in abdominal studies: intra-individual comparison of three different techniques.

BACKGROUND: T1-weighted gradient-echo in-phase and out-of-phase imaging is an essential component of comprehensive abdominal MR exams. It is useful for the study of fat-containing lesions and to identify various disease states related to the presence of fat in the liver. PURPOSE: To compare three T1-weighted in-phase and out-of-phase (IP/OP) gradient-echo imaging sequences in an intra-individual fashion, and to determine whether advantages exist for each of these sequences for various patient types. MATERIAL AND METHODS: One hundred and eighteen consecutive subjects (74 men, 44 women; mean age 53.9 ± 13.8 years) who had MRI examinations containing all three different IP/OP sequences (two-dimensional spoiled gradient-echo [2D-GRE], three-dimensional gradient-echo [3D-GRE], and magnetization-prepared gradient-recall echo [MP-GRE]) were included. Two different reviewers independently and blindly qualitatively evaluated IP/OP sequences to determine image quality, extent of artifacts, lesion detectability and conspicuity, and subjective grading of liver steatosis for the various sequences. Quantitative analysis was also performed. Qualitative and quantitative data were subjected to statistical analysis. RESULTS: Respiratory ghosting, parallel imaging, and truncation artifacts as well as shading and blurring were more pronounced with 3D-GRE IP/OP imaging. Overall image quality was higher with 2D-GRE (P < 0.05). Detectability of low-fluid content lesions was lower with IP/OP MP-GRE sequences. MP-GRE sequences had the lowest SNRs (P < 0.001). Liver-to-spleen and liver-to-lesion CNRs were significantly lower with 3D-GRE and MP-GR, respectively (P < 0.001). Fat liver indexes showed strongly positive correlation between all sequences. CONCLUSION: Currently, 2D-GRE remains the best approach for clinical IP/OP imaging. The good image quality of MP-GRE sequences acquired in a free-breathing manner should recommend its use in patients unable to suspend breathing.

Comparison of T1-weighted in- and out-of-phase single shot magnetization-prepared gradient-recalled-echo with three-dimensional gradient-recalled-echo at 3.0 Tesla: preliminary observations in abdominal studies.

PURPOSE: To describe in-phase (IP)/out-of-phase (OP) imaging with single shot magnetization-prepared gradient-recalled-echo (MP-GRE) and to compare intra-individually IP/OP MP-GRE with IP/OP three-dimensional gradient-recalled-echo (3D-GRE) at 3.0 Tesla (T). MATERIALS AND METHODS: Thirty-six subjects (15 males, 21 females; mean age 46.97 ± 14.97) who had abdominal MRI examinations including precontrast T1-weighted IP/OP MP-GRE, IP/OP 3D-GRE were included in the study. Two radiologists independently evaluated the sequences qualitatively for extent of artifacts, lesion detectability, and conspicuity and subjective grading of liver steatosis. Quantitative evaluation was performed by one radiologist and included liver fat index, liver and spleen SNR, and liver-lesion and liver-spleen CNR. RESULTS: Respiratory ghosting was more pronounced on 3D-GRE (P < 0.0008). The degrees of parallel imaging residual artifacts, shading and blurring were significantly higher on the 3D-GRE sequences (P < 0.0008). Spatial misregistration and bounce point artifacts were only observed with MP-GRE images. Pixel graininess was more apparent on MP-GRE (P < 0.0008). Lesion detectability, confidence, and conspicuity were considerably higher on MP-GRE. Visual appreciation of steatosis was superior on 3D-GRE. Overall image quality was superior on MP-GRE (P < 0.0008). CONCLUSION: Higher image quality and improved lesion detectability were present with IP/OP MP-GRE technique. Inversion-recovery prepared techniques may represent an important evolution for precontrast T1-weighted image at 3.0T. The good image quality of MP-GRE sequences acquired in a free breathing manner should recommend its use in patients unable to suspend breathing.

Free-breathing 3D T1-weighted gradient-echo sequence with radial data sampling in abdominal MRI: preliminary observations.

OBJECTIVE: The purposes of this study were to evaluate the feasibility of a free-breathing 3D gradient-recalled echo sequence with radial data sampling (radial 3D GRE) in abdominal MRI compared with a standard 3D GRE volumetric interpolated breath-hold examination (VIBE) sequence for imaging of cooperative patients and to perform a preliminary assessment in imaging of noncooperative patients. MATERIALS AND METHODS: Fifty-five consecutively registered patients who underwent unenhanced and contrast-enhanced abdominal MRI with the free-breathing radial 3D GRE technique constituted the study population. Two readers independently and blindly evaluated the images. RESULTS: Overall image quality with the contrast-enhanced radial 3D GRE sequence was lower than but rated at least nearly as good as that with the 3D GRE VIBE sequence (p < 0.0001). Higher scores were recorded for 3D GRE VIBE images with respect to pixel graininess, streaking artifact, and sharpness (p = 0.0009 to p < 0.0001). Except for sharpness of vessels on unenhanced images, results for the radial 3D GRE sequence did not differ significantly in the comparison of cooperative and noncooperative patients (p = 0.004). For imaging of noncooperative patients, radial 3D GRE images of children had higher ratings for shading (unenhanced, p = 0.0004; contrast-enhanced, p < 0.0001) and streaking artifacts on contrast-enhanced images (p = 0.0017) than did those of adults. Overall image quality was higher for pediatric patients. In lesion analysis, use of the 3D GRE VIBE sequence was associated with significantly greater detectability, confidence, and conspicuity than was use of the radial 3D GRE sequence (p = 0.00026-0.011). CONCLUSION: A free-breathing radial 3D GRE sequence is feasible for abdominal MRI and may find application in imaging of patients who are unable to suspend respiration, especially children.

Characterization of adrenal lesions with 1.5-T MRI: preliminary observations on comparison of three in-phase and out-of-phase gradient-echo techniques.

OBJECTIVE: The purpose of this study was to use previously described quantitative evaluation methods to compare the performance of 3D gradient-recalled echo (GRE) and magnetization-prepared (MP) GRE in-phase and out-of phase sequences with standard 2D GRE technique in the characterization of adrenal lesions. MATERIALS AND METHODS: The study sample consisted of 44 consecutively registered patients (22 men, 22 women; mean age, 59.1 ± 11.6 years) with 50 adrenal lesions who underwent standard abdominal MRI that included in-phase and out-of-phase 2D GRE (n = 41), 3D GRE (n = 35), MP GRE (n = 36), or a combination of these techniques. The adrenal signal intensity (SI) index and adrenal-to-spleen, adrenal-to-liver, and adrenal-to-muscle SI ratios of each lesion were calculated and compared for the three techniques by independent samples Student t test. The area under the receiver operating characteristic (ROC) curve (AUC) for each evaluation method was determined, and comparisons of independent ROC curves were performed for all sequences. RESULTS: For all sequences, the mean adrenal SI index and SI ratios of adenomas and nonadenomas differed significantly (p < 0.001). For the 3D GRE and MP GRE techniques, adrenal SI index and modified adrenal-to-spleen ratio, respectively, had the larger AUCs, but the difference was not statistically significant. Different thresholds for the three techniques were recommended for discriminating adenoma from nonadenoma. CONCLUSION: The results of characterization of adrenal lesions with MP GRE and 3D GRE in-phase and out-of-phase MRI techniques are comparable to those obtained with the reference standard 2D GRE technique. Different thresholds should be selected according to the in-phase and out-of-phase techniques used and for the various evaluation methods.

Bone metastases: evaluation of acuity of lesions using dynamic gadolinium-chelate enhancement, preliminary results.

PURPOSE: To evaluate whether enhancement on serial dynamic gadolinium-enhanced abdominal-pelvic MR imaging (DCE-MRI) can determine the acuity of bone metastases. MATERIALS AND METHODS: Twenty consecutive patients who underwent abdominal-pelvic DCE-MRI for evaluation/staging of a proven cancer and had bone metastases were included. Two radiologists analyzed in consensus 59 DCE-MRIs of these patients. Region of interest measurements were performed in up to three lesions on noncontrast T1-weighted, serial hepatic arterial dominant phase (HADP), early hepatic venous phase (EHVF), and interstitial phase (IP) postgadolinium images, and the percentage enhancement of 134 lesions was calculated. The coordinator separately and retrospectively sorted the lesions into three groups based on the imaging and clinical information: acute/active, subacute, and chronic metastases. RESULTS: The mean percentage enhancement of the bone metastases classified as acute/active, subacute, and chronic in the HADP, EHVP and IP were respectively (%): 134, 107, 99; 87, 86, 87; and 39, 65, 73. In the HADP, acute/active lesions enhanced significantly more than both subacute (1.53-fold) and chronic (3.4-fold) lesions (P < 0.01). Time intensity curves were significantly different between these three entities as well. CONCLUSION: The enhancement on arterial phase images and the time-intensity curves were different for acute/active, subacute, and chronic bone metastases.