Hepatocellular carcinoma: correlation between gadobenate dimeglumine-enhanced MRI and pathologic findings

RATIONALE AND OBJECTIVES: To correlate the appearance of hepatocellular carcinoma on delayed (60 minutes) postcontrast T1-weighted gradient echo images with the mode of action of gadobenate dimeglumine (Gd-BOPTA) and the anatomic and pathologic characteristics of the lesions. METHODS: A total of 34 patients with hepatocellular carcinoma and varying degrees of diffuse liver disease were studied. T2-weighted spin echo and T1-weighted spin echo and gradient echo images were acquired before and 60 minutes after the intravenous administration of 0.1 mmol/kg Gd-BOPTA. Qualitative and quantitative evaluations of the images were performed and correlated with histologic findings. The quantitative evaluation, performed on T1-weighted gradient echo images, looked at the percentage increase of liver enhancement after Gd-BOPTA administration, the lesion-to-liver contrast/noise (C/N) ratio before and after Gd-BOPTA administration, and the C/N variation after Gd-BOPTA administration. Qualitative assessment considered the morphologic features of the lesions as well as the visual variation of contrast before and after Gd-BOPTA administration. Finally, a histologic evaluation was made of the degree of differentiation of the lesions and of the presence of fatty metaplasia, necrosis, bile, or intratumoral peliosis. RESULTS: Among the parameters affecting lesion identification were the extent of liver function, degree of vascularization, residual functionality of the tumor cells, and characteristics of the neoplastic tissue. Positive correlations (Spearman coefficients = 0.359 and 0.393, respectively) were observed precontrast between the degree of liver failure and the amount of contrast noise, and postcontrast between the amount of intralesional fatty metaplasia and the extent to which lesion conspicuity worsened after Gd-BOPTA administration. An inverse correlation (Spearman coefficient = -0.330) was observed between the degree of lesion differentiation and the visible appearance after Gd-BOPTA administration, with well-differentiated lesions tending toward worsened conspicuity postcontrast. A statistically significant difference (P = 0.001) was observed in the mean precontrast C/N ratio for lesions later showing unchanged conspicuity and worse conspicuity on postcontrast images, respectively. Marked variation (P = 0.019) was also observed between Child A and B cirrhotic patients for the degree of hepatic enhancement on postcontrast images. CONCLUSIONS: The results suggest that liver parenchyma signal intensity is influenced by the extent to which liver function is compromised, that residual hepatocytic functionality permits Gd-BOPTA uptake by certain lesions and that this uptake might subsequently impair the observed C/N ratio on delayed images, and that the worsening of lesion conspicuity on postcontrast images is influenced also by high quantities of intralesional fatty metaplasia.     

Hepatocellular carcinoma: correlation of MR imaging and histopathologic findings.

Seventy-two histologically proved nodular hepatocellular carcinomas (HCCs) were studied with magnetic resonance (MR) imaging at 1.5 T. Capsules were present in 56 of the 72 tumors. Thirty-seven capsules were depicted on T1-weighted spin-echo MR images, and 16 were depicted on T2-weighted MR images. Visualization was dependent on thickness and structure of the capsules. Of the 72 tumors, 36 had a mosaic pattern. A mosaic pattern was visualized in 12 of the 36 tumors on T1-weighted images and in 27 of the 36 tumors on T2-weighted images. Six tumors were determined to be histologic grade 1, and all were hyperintense on T1-weighted images, regardless of whether intracellular fat deposits were present. Four of the six grade 1 tumors were isointense on T2-weighted images. In contrast, grades 2 and 3 tumors had various signal intensities on T1-weighted images and most were hyperintense on T2-weighted images. Twenty-one of 32 tumors (66%) with focal areas of increased signal intensity on T2-weighted images had intratumoral dilated sinusoids at histologic examination.     

Detection of liver metastases: gadobenate dimeglumine-enhanced three-dimensional dynamic phases and one-hour delayed phase MR imaging versus superparamagnetic iron oxide-enhanced MR imaging

The aim of this study was to compare the diagnostic performance of gadobenate dimeglumine (Gd-BOPTA)-enhanced MR imaging, including dynamic phases and one-hour delayed phase, versus superparamagnetic iron oxide (SPIO)-enhanced imaging for detection of liver metastases. Twenty-three patients with 59 liver metastases underwent Gd-BOPTA-enhanced MR imaging (unenhanced, arterial, portal, equilibrium and one-hour delayed phase) using three-dimensional volumetric interpolated imaging and SPIO-enhanced T2-weighted turbo spin–echo and T2*-weighted gradient-echo sequences on a 1.5-T unit. Three observers independently interpreted the three sets of images, i.e. Gd-BOPTA-enhanced dynamic MRI (set 1), delayed phase imaging (set 2) and SPIO-enhanced MRI (set 3). Diagnostic accuracy was evaluated using the alternative-free response receiver operating chracteristic (ROC) analysis. Sensitivity and positive predictive value were also evaluated. The mean accuracy (Az values) and sensitivity of Gd-BOPTA-enhanced delayed phase imaging (0.982, 95.5%) were comparable to those of SPIO-enhanced imaging (0.984, 97.2%). In addition, Az values and sensitivities of both imaging sets were significantly higher than those of Gd-BOPTA-enhanced dynamic images (0.826, 77.4%: p<0.05). There was no significant difference in the positive predictive value among the three image sets. Gd-BOPTA-enhanced delayed phase imaging showed comparable diagnostic performance to SPIO-enhanced imaging for the detection of liver metastases, and had a better diagnostic performance than Gd-BOPTA-enhanced dynamic images.     

Prostatic carcinoma and benign prostatic hyperplasia: MR imaging with histopathologic correlation

Twenty-eight patients with prostatic carcinoma who underwent magnetic resonance (MR) imaging and subsequent radical prostatectomy were studied. The resected prostates were sectioned axially, and the whole-mount prostatic specimen was compared with the corresponding MR images. The carcinoma could be identified in 20 cases (71%), but the tumor volume was underestimated in 12 patients (43%). In 19 of 20 visualized cases (95%), the carcinoma was seen as an area of low signal intensity within the peripheral zone on T2-weighted images. However, in one case the signal intensity of the carcinoma was higher than that of the remainder of the peripheral zone. All carcinomas were located within the peripheral zone. The accuracy of MR imaging in the prediction of extraglandular tumor spread was 82%, with a sensitivity of 37.5% and a specificity of 100%. Nineteen patients (67%) exhibited histologically benign hyperplasia, which could be identified on MR images in 10 cases (53%). The signal intensities of the nodules varied. All areas of benign hyperplasia were located within the central zone. The location of the pathologic changes must therefore be considered in differential diagnosis.     

前列腺癌和增生的MRI与病理对照研究

目的 研究前列腺癌不同ＭＲＩ表现的病理基础,以提高ＭＲＩ对前列腺癌和增生诊断的准确性。方法 观察经病理证实的４３例前列腺癌和４０例增生患者的前列腺形态及信号改变,并加以比较,前列腺癌组中１７例取前列腺左右两侧外周区上中下、左右移行区上下共１０点进行穿刺,对穿刺组织分别进行病理检查,同时计算癌变组织占总穿刺体积的百分比,并与其ＭＲＩ进行对比。结果 前列腺癌形态规则３１例,不规则１２例,增生组分别为３     

Detection of liver metastases: comparison of gadobenate dimeglumine-enhanced and ferumoxides-enhanced MR imaging examinations

PURPOSE: To compare gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance (MR) imaging with ferumoxides-enhanced MR imaging for detection of liver metastases. MATERIALS AND METHODS: Twenty consecutive patients known to have malignancy and suspected of having focal liver lesions at ultrasonography (US) underwent 1.0-T MR imaging with gradient-recalled-echo T1-weighted breath-hold sequences before, immediately after, and 60 minutes after Gd-BOPTA injection. Subsequently, MR imaging was performed with turbo spin-echo short inversion time inversion-recovery T2-weighted sequences before and 60 minutes after ferumoxides administration. All patients subsequently underwent intraoperative US within 15 days, and histopathologic analysis of their resected lesion-containing specimens was performed. Separate qualitative analyses were performed to assess lesion detection with each contrast agent. Quantitative analyses were performed by measuring signal-to-noise and contrast-to-noise ratios (CNRs) on pre- and postcontrast Gd-BOPTA and ferumoxides MR images. Statistical analyses were performed with Wilcoxon signed rank and Monte Carlo tests. RESULTS: Sensitivity of ferumoxides-enhanced MR imaging was superior to that of Gd-BOPTA-enhanced MR imaging for liver metastasis detection (P <.05). Ferumoxides MR images depicted 36 (97%) of 37 metastases detected at intraoperative US, whereas Gd-BOPTA MR images depicted 30 (81%) metastases during delayed phase and 20 (54%) during dynamic phase. All six metastases identified only at ferumoxides-enhanced MR imaging were 5-10 mm in diameter. There was a significant increase in CNR between the lesion and liver before and after ferumoxides administration (from 3.8 to 6.8, P <.001) but not before or after Gd-BOPTA injection (from -4.8 to -5.5, P >.05). CONCLUSION: Ferumoxides-enhanced MR imaging seems to be superior to Gd-BOPTA-enhanced MR imaging for liver metastasis detection. Copyright RSNA, 2002     

Preoperative staging of rectal carcinoma with MR imaging: surgical and histopathologic correlation

Twenty-nine patients with rectal carcinoma were examined with magnetic resonance (MR) imaging at 1.0 T. In most patients a Helmholtz coil was used and a bowel distention obtained with a barium enema balloon tip. The MR findings were graded according to the modified Astler-Coller staging classification and correlated with the surgical or histopathologic results. Correct diagnosis was made in nine of the 12 patients with stage A and B1 tumors. Overestimation occurred in the other three patients, who had previously undergone radiation therapy or surgery. Local stage was correctly assessed in 11 patients with stage B2 carcinoma and in six patients with stage B3 tumors. Enlarged lymph nodes were detected in four of seven patients with nodes containing carcinoma. In two other patients with enlarged nodes, no carcinoma was identified at histologic examination. MR imaging may enable correct staging of local extent of rectal carcinoma, particularly in patients who have not previously undergone radiation therapy or surgery. However, evaluation of lymph nodes is less accurate.     

Soft-tissue tumors: value of static and dynamic gadopentetate dimeglumine-enhanced MR imaging in prediction of malignancy

PURPOSE: To prospectively evaluate static and dynamic gadopentetate dimeglumine-enhanced magnetic resonance (MR) imaging relative to nonenhanced MR imaging in differentiation of benign from malignant soft-tissue lesions and to evaluate which MR imaging parameters are most predictive of malignancy, with associated interobserver variability. MATERIALS AND METHODS: One hundred forty consecutive patients (78 male patients [median age, 51 years], 62 female patients [median age, 53 years]) with a soft-tissue mass underwent nonenhanced static and dynamic contrast material-enhanced MR imaging. Diagnosis was based on histologic findings in surgical specimens (86 of 140), findings at core-needle biopsy (43 of 140), or results of all imaging procedures with clinical follow-up (11 of 140). Multivariate logistic regression analysis was used to identify the best combination of MR imaging parameters that might be predictive of malignancy. Subjective overall performance of two observers was evaluated with receiver operating characteristic analysis. RESULTS: For subjective overall diagnosis, area under the receiver operating characteristic curve, a measure for diagnostic accuracy, was significantly larger for combined nonenhanced and contrast-enhanced MR imaging than it was for nonenhanced MR imaging alone, with no significant difference between observers. Multivariate analysis of all lesions revealed that combined nonenhanced static and dynamic contrast-enhanced MR imaging parameters were significantly superior to nonenhanced MR imaging parameters alone and to nonenhanced MR imaging parameters combined with static contrast-enhanced MR imaging parameters in prediction of malignancy. The most discriminating parameters were presence of liquefaction, start of dynamic enhancement (time interval between start of arterial and tumor enhancement), and lesion size (diameter). Results for extremity lesions were the same, with one exception: With dynamic contrast-enhanced MR imaging parameters, diagnostic performance of one observer did not improve. CONCLUSION: Static and dynamic contrast-enhanced MR imaging, when added to nonenhanced MR imaging, improved differentiation between benign and malignant soft-tissue lesions.     

Hepatocellular carcinoma: MR imaging

Sixty patients with hepatocellular carcinoma (HCC) were studied with computed tomography (CT) and magnetic resonance (MR) imaging at 1.5 T. MR imaging was equivalent to CT in detection of HCC. MR imaging was superior to CT in demonstrating the details of tumors, especially pseudocapsules. In 58 cases, main tumors were detected with MR imaging. On spin-echo (SE) 600/25 (repetition time msec/echo time msec) sequences, tumors were hyperintense in 18 cases, isointense in ten, and hypointense in 30. On SE 2,000/60 sequences, all but two tumors had high signal intensity. Pseudocapsules, intratumoral septa, daughter nodules, and tumor thrombi, which are important characteristics of HCC, were demonstrated in 22, three, six, and six cases, respectively, on MR imaging. MR imaging is useful for characterizing the internal architecture of HCC.     

Salivary gland tumors: diagnostic value of gadolinium-enhanced dynamic MR imaging with histopathologic correlation

PURPOSE: To evaluate the diagnostic value of gadolinium-enhanced dynamic magnetic resonance (MR) imaging of salivary gland tumors and correlate the MR imaging and histopathologic findings. MATERIALS AND METHODS: Thirty-three salivary gland tumors in 29 patients were examined preoperatively at gadolinium-enhanced dynamic MR imaging. There were 22 benign and 11 malignant tumors. Dynamic contrast material-enhanced MR images were obtained for 5 minutes. Time of peak enhancement (T(peak)) and washout ratio (WR) were determined from time-signal intensity curves (TICs). Microvessel count and cellularity-stromal grade were evaluated histopathologically. The strengths of correlations between T(peak) and microvessel count and between WR and cellularity-stromal grade were statistically analyzed. Statistical analysis was also performed to determine whether any differences among the various histopathologic tumor types existed [corrected]. In a validation study, 13 salivary gland tumors in 13 patients were examined consecutively. RESULTS: At a T(peak) of 120 seconds, malignant tumors could be differentiated from pleomorphic adenomas but not from Warthin tumors. A WR of 30%, however, enabled differentiation between malignant and Warthin tumors. Classification of TICs on the basis of a T(peak) of 120 seconds and a WR of 30% had high sensitivity (91%) and specificity (91%) in the differentiation of benign and malignant tumors. Correlations between T(peak) and microvessel count (P <.0001, rho = -0.800) and between WR and cellularity-stromal grade (P =.0105, rho = 0.572) were significant. The validation study also yielded high sensitivity (100%) and specificity (80%) in the differentiation between benign and malignant tumors. CONCLUSION: Gadolinium-enhanced dynamic MR imaging is useful for differentiating benign from malignant salivary gland tumors.     

Hepatocellular carcinoma: evaluation with color Doppler US and MR imaging.

Fifteen patients with hepatocellular carcinoma underwent examination with color Doppler ultrasound (US), magnetic resonance (MR) imaging, dynamic computed tomography (CT), and angiography. Doppler signals ranging from 0.22 to 3.48 kHz could be obtained from within the tumor in 14 of 15 patients. The resistive index was 0.38-0.77. Color Doppler signals were visualized in nine of 15 lesions with a Doppler shift greater than 0.7 kHz. The Doppler signals and the resistive index of the tumor vessels became lower as the vessels progressed into the center of the lesion. The appearance of tumor vessels recognized on MR images obtained with gradient-recalled acquisition in the steady state (GRASS) in 11 of 15 lesions was compared with that on CT scans and angiograms. Tumors that were hyperintense on GRASS images obtained with a flip angle of 15 degrees transmitted Doppler signals of considerably higher amplitude compared with the isointense lesions. Both color Doppler US and MR imaging provided useful information for characterizing intratumoral blood flow.     

肝细胞癌在MR扩散加权成像与动态增强成像中的影像表现

信号;2个T1WI平扫等信号的病变,各期增强仍然呈等信号,DWI表现为高信号,其中1个病理证实为再生结节.1个肝硬化再生结节T1WI平扫及DWI均为高信号,动脉期明显强化,门静脉及平衡期为等信号.结论 多数HCC在MR动态增强图像上表现为动脉期明显强化,部分小HCC可表现为等信号.Gd-DTPA动态增强与DWI结合可能有助提高HCC的诊断准确性.     

Contrast-enhanced sonography with SonoVue: enhancement patterns of benign focal liver lesions and correlation with dynamic gadobenate dimeglumine-enhanced MRI

OBJECTIVE: Contrast-enhanced real-time low-mechanical-index sonography is a new diagnostic technique for the assessment of macro- and microcirculation. The purpose of our article is to describe contrast-enhancement patterns of different benign focal liver lesions using the second-generation contrast agent SonoVue and to compare these findings with those of gadobenate dimeglumine-enhanced MRI. CONCLUSION: SonoVue-enhanced real-time low-mechanical-index sonography provides specific contrast-enhancement patterns of different benign focal liver lesions, allowing accurate characterization. Findings on SonoVue-enhanced sonography correlate well with those obtained on gadobenate dimeglumine-enhanced MRI.     

Dynamic gadopentetate dimeglumine-enhanced MR imaging of hepatocellular carcinoma

Nineteen patients with 28 histologically proven hepatocellular carcinomas (HCCs) were examined using T1- and T2-weighted spin-echo sequences and dynamic gadopentetate dimeglumine-enhanced magnetic resonance imaging (MRI) performed by fast T1-weighted gradient-echo sequence (100/5/80°) which was performed before and repeatedly (12 sets of images) after intravenous bolus injection of gadopentetate dimeglumine (Gd-DTPA) over a period of 10 min. Enhancement of HCC was heterogeneous in 24 lesions (85.7%). Intra-lesional non-enhancing areas were seen in 18 cases (64%). A late-enhancing pseudocapsule was seen in 12 lesions (42.9%). In addition, two groups were distinguished in the examined HCCs: 16 lesions (57.1%) showed stronger enhancement compared to liver parenchyma with maximum positive lesion-to-liver contrast on the 15-s images, while 12 lesions (42.9%) had an enhancement less than normal liver with a maximum negative contrast on the 15-s images. We conclude that the morphologic features most frequently encountered in HCC on dynamic Gd-DTPA-enhanced MRI are inhomogeneity of enhancement, intra-lesional non-enhancing areas, and relatively late enhancement of a pseudocapsule. Taking the degree of enhancement to be representative of the degree of vascularity, we also conclude that HCC can appear either hypervascular or hypovascular in the early phase of the dynamic study. Correspondence to: B. Hamm     

Rectal carcinoma treated by preoperative irradiation: MR imaging and histopathologic correlation.

We evaluated the role of MR imaging in assessing the effect of preoperative irradiation in 11 patients with primary rectal carcinoma. Findings on MR images obtained before radiotherapy and 5-6 weeks afterward were analyzed and correlated with the histopathological findings (nine patients) or the findings at laparotomy (two patients). Before irradiation, the tumor volumes on MR images were between 3.3 and 51.7 cm3 (mean 19.7 cm3). After irradiation, the volumes were from 0.8 to 33.2 cm3 (mean, 10.4 cm3), representing a decrease in volume of 11% to 88% (mean, 55%). On the MR images obtained before irradiation, the tumors were confined to the bowel wall in four cases (stage A-B1), penetrated the perirectal fat in six cases (stage B2), and involved an adjacent organ in one case (stage B3). After irradiation, no apparent changes were seen in the MR appearance of the local tumor stage in nine of the 11 patients. In one patient, progression of stage was suspected on the postirradiation MR images, but this was not confirmed at histologic examination. In one patient, possible downstaging occurred after irradiation, although this could not be proved. Our findings suggest that MR imaging may be useful for determining the effect of preoperative radiotherapy on rectal carcinomas.     

Detection and characterization of focal hepatic lesions: comparative study of MDCT and gadobenate dimeglumine-enhanced MR imaging

The aim of this study was to compare the diagnostic performance of multidetector row helical CT (MDCT) and gadobenate dimeglumine-enhanced magnetic resonance (MR) imaging (in the detection and characterization of focal liver lesions. Two blind reviewers analyzed the MDCT and MR images of a total of 44 malignant and 85 benign lesions in 46 patients independently. Receiver operating characteristic curves were established to analyze the results for each reviewer and modality.     

Spin-echo and dynamic gadoliniumenhanced flash MR imaging of hepatocellular carcinoma: Correlation with histopathologic findings

Evaluation of histologic subtype and degree of differentiation in hepatocellular carcinoma (HCC) is essential because it affects patient prognosis and treatment planning. To evaluate the histologic subtype of HCC with magnetic resonance (MR) imaging, conventional spin-echo and dynamic studies were correlated with histopathologic and angiographic findings in 72 HCCs. Dynamic MR imaging was performed with the fast low-angle shot (FLASH) technique after administration of gadopentetate dimeglumine. There was considerable overlap in signal intensity between various tumor grades on both T1- and T2-weighted images. On dynamic MR images, the peak contrast enhancement ratio correlated with tumor grade (well-differentiated, 29.5 ± 24.7; moderately differentiated, 63.5 ± 24.1; poorly differentiated, 86.9 ± 26.4) or degree of dilatation of the sinusoidlike vascular space between tumor cells. The maximum contrast-to-noise ratio in tumor (relative to surrounding liver) was achieved within 60 seconds in 45 HCCs (mostly of the trabecular or pseudoglandular type). Enhancement was slight or minimal in 17 tumors (mostly small, well-differentiated tumors). In 10 tumors, the degree of enhancement increased with time, with maximum enhancement in the delayed phase (most frequently in scirrhous HCC). These dynamic patterns correlated with angiographic findings. These data indicate that the degree and pattern of enhancement on dynamic MR images reflect tumor differentiation and architecture of HCC.