Value Of Dynamic Contrast-enhanced MRI Research Articles

Diagnostic value of dynamic contrast-enhanced MRI in the staging of endometrial cancer

Objective To explore the relationship between the characteristics of dynamic contrast-enhanced MRI (DCE-MRI) and the stages of endometrial cancer. Methods A retrospective analysis of DCE-MRI manifestation in 55 patients with scratch-pathologically confirmed endometrial cancer was performed.All patients were divided into different groups according to differentiation,muscle layer infiltration,cervix involvement and metastasis.The enhanced rate,including the arterial phase relative signal increase ratio (ARSI%),the maximal relative signal increase ratio (MRSI%) and the signal enhancement ratio (SER%),was calculated at different time (i.e.16 s,32 s,48 s,64 s and 300 s),respectively.Time-intensity curves (TIC) of lesions were also obtained and divided into 4 subtypes.Two sample t test was performed to compare the MRSI% among groups,and the Mann-WhitneyUtest was performed in ARSI% and SER% as well. Results The early phase enhanced rate of normal tissue was 894±355,higher than that of tumor 716±215 (t=-2.911,P<0.01).The delayed phase enhanced rate of normal tissue was 1111±289,higher than that of tumor 803±289 (t Key words: Endometrial neoplasms; Magnetic resonance imaging

Screening high risk women with MRI alone?

Breast cancer affects up to 1:7 to 1:11 women in Western countries. Although breast cancer is mainly a sporadic disease, about 15% of cases are clustered in families with highly or moderately elevated incidence. Pathogenic mutations in high-risk genes at autosomic dominant inheritance are held responsible for about 5% of BCs, in which the disease may have early onset, with an estimated cumulative lifetime risk as high as 50% to 85%. About 50% of hereditary BCs can be explained by mutations in BRCA1 and BRCA2 genes [1,2]. In women at high risk of breast cancer, screening mammography has shown a lower sensitivity (29–50%) compared with that of the screening addressed to the general female population (70–80%), with higher percentages of interval cancers (35–50% versus 20–25%) and a higher rate of nodal involvement (20–56% versus 22%) [1,3]. In the last decade a number of prospective, non-randomized studies have been conducted in Europe and North America to assess the value of dynamic contrast-enhanced MRI as a screening tool to be used as an adjunct to mammography, or to mammography plus ultrasonography (US) for the surveillance of women at high geneticfamiliar risk of BC [4–12]. The general result of these studies is that MRI largely outperforms mammography and/or US in detecting breast cancers in asymptomatic high-risk women, as confirmed by reviews and meta-analyses [13–17]. In 2007, on the basis of early evidence available in the literature, the American Cancer Society issued a recommendation in favor

The diagnostic value of dynamic contrast-enhanced MRI for thyroid tumors

Background and purposeThe exact place for dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the diagnosis and management of thyroid tumors is still under debate. We performed the study to analyze and compare the parameters generated from DCE-MRI for thyroid lesions. Materials and methodsFor each thyroid lesion, time intensity curves (TIC), time of peak enhancement (Tpeak), maximum enhancement ratio (ERmax) and maximum rise slope (Slopemax) were plotted and calculated. Receiver operator characteristics (ROC) analysis was conducted to assess the diagnostic ability and appropriate cut-off value. The area under the ROC curve (AUC) and the confidence intervals (CIs) were also assessed. ResultsForty-two patients were consecutively included. All 21 lesions demonstrated the rapid inflow and washout pattern (type-I) were benign. The 12 cases with delayed inflow pattern (type-III) were all malignant. When compared with the benign lesions, the thyroid carcinoma showed significantly lower Slopemax and higher Tpeak (P<0.05). No statistical difference of ERmax was found between malignant and benign ones (P=0.15). The AUC of ERmax, Slopemax and Tpeak in differentiating benign thyroid lesions from malignant ones were 0.63, 0.93and 1, respectively. The ERmax cut-off value of 73.86 (sensitivity, 71.4%; specificity, 64.3%), Slopemax cut-off value of 2.4126 (sensitivity, 92.9%; specificity, 82.1%) and Tpeak value of 28 (sensitivity, 100%; specificity, 100%) offered the best diagnostic performances. ConclusionsDCE-MRI, especially the pattern of TIC and the value of Slopemax and Tpeak, could be helpful in differentiating thyroid carcinoma from benign thyroid lesions.

Diagnostic value of dynamic contrast-enhanced MRI for submucosal palatal tumors

ObjectivesTo evaluate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) for differentiating between benign and malignant tumors in the palate. Materials and methods26 patients with submucosal palatal tumors were preoperatively examined using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), and washout ratios (WR300 and WR600) were determined from contrast index curves. The submucosal palatal tumors were divided into two groups according to their Tmax values: the early enhancement group (Tmax<300s) consisted of 9 malignant tumors and 6 benign tumors, while the late enhancement group (Tmax≥300s) included one malignant tumor and 10 benign tumors. We compared the following DCE-MRI parameters between the benign and malignant tumors: CImax and Tmax in all cases and CImax, Tmax, and the washout ratios in the early enhancement group. In addition, we performed a regression analysis of the relationships between tumor size and DCE-MRI parameters; i.e., CImax, Tmax, and washout ratios, among the malignant salivary gland tumors and pleomorphic adenomas. ResultsIn all cases and the early enhancement group, significant differences in Tmax were detected between the benign and malignant tumors (P<0.001 and P<0.05, respectively), and the optimal Tmax cutoff value for differentiating between them was found to be 165s. None of the other parameters displayed significant differences between the benign and malignant tumors. Only the WR600 of the pleomorphic adenomas was significantly correlated with tumor size (R2=0.92, P<0.001). ConclusionsTmax is a useful parameter for distinguishing between benign and malignant submucosal palatal tumors.

Minor salivary gland tumors in the oral cavity: Diagnostic value of dynamic contrast-enhanced MRI

ObjectiveTo evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for minor salivary gland tumors in the oral cavity. Materials and methodsThirty-two patients with minor salivary gland tumors were examined preoperatively using DCE-MRI. Their maximum contrast index (CImax), time of CImax (Tmax), Tpeak; i.e., the time that corresponded to the CImax×0.90, and washout ratios (WR300 and WR600) were determined from contrast index (CI) curves. We compared these parameters between benign and malignant tumors and among the different histopathological types of minor salivary gland tumors. Then, we categorized the patients’ CI curves into four patterns (gradual increase, rapid increase with high washout ratio, rapid increase with low washout, and flat). ResultsStatistically significant differences in Tmax (P=0.004) and Tpeak (P=0.002) were observed between the benign and malignant tumors. Regarding each histopathological tumor type, significant differences in Tmax (P<0.001), Tpeak (P<0.001), and WR600 (P=0.026) were observed between the pleomorphic adenomas and mucoepidermoid carcinomas. It was difficult to distinguish between benign and malignant tumors using our CI curve classification because that two-thirds of the cases were classified into the same type (gradual increase). ConclusionThe DCE-MRI parameters of minor salivary gland tumors contributed little to their differential diagnosis compared with those for major salivary gland tumors. During the diagnosis of minor salivary gland tumors, Tmax is useful for distinguishing between benign and malignant tumors.

Diagnostic value of dynamic contrast-enhanced MRI for unilocular cystic-type ameloblastomas with homogeneously bright high signal intensity on T2-weighted or STIR MR images

Typical MR images of ameloblastomas on T2-weighted image (WI) or short inversion time inversion-recovery (STIR) show multiple bright high-signal-intensity loci on a high-signal-intensity background. Unilocular cystic-type ameloblastomas show homogeneously bright high signal intensity on T2WI or STIR as a water-like signal intensity. Therefore, it is difficult to distinguish unilocular cystic-type ameloblastoma from other cystic lesions such as keratocystic odontogenic tumors, radicular cysts (residual cysts) and dentigerous cysts only on the basis of MRI signal intensity. In the present study, we evaluated whether contrast-enhanced (CE)-T1WI and dynamic CE-MRI (DCE-MRI) could provide additional information for differential diagnosis in unilocular cystic-type ameloblastoma. Images from 12 cases of suspected unilocular cystic-type ameloblastoma were evaluated in the present study. Of them, 5 had areas suspected of indicating a solid component on T1WI and T2WI (or STIR). Ten had undergone additional CE-T1WI and DCE-MRI. On 5 of 10 cases of CE-T1WI, a tiny enhancement area was detected. On 6 of 10 DCE-images, a time-course enhanced area which was suspected to be a solid component was detected. CE-T1WI was helpful in the diagnosis of ameloblastoma because the tiny enhanced areas were taken to indicate possible solid components. Moreover, the rim-enhancement area on CE-T1WI could be divided into small regions of interest, and some of these showed slightly increased enhancement on DCE-MRI, which was taken to indicate a solid component and/or intramural nodule with focal invasion of ameloblastoma tissue. DCE-MRIs of the four remaining cases, which provided no clues to the diagnosis of ameloblastoma in the manner of the above descriptions, showed thicker rim enhancement than odontogenic cysts. Thus, CE-T1WI and DCE-MRI were helpful in the differential diagnosis of unilocular cystic-type ameloblastomas with homogeneously bright high signal intensity on T2WI or STIR.

Usefulness of dynamic contrast-enhanced MR imaging in the evaluation of pulmonary isolated lesions

Objective The aim of our study was to investigate the value of dynamic contrast-enhanced MRI for evaluating differential diagnosis of pulmonary isolated lesions.

A case report of pseudoprogression followed by complete remission after proton-beam irradiation for a low-grade glioma in a teenager: the value of dynamic contrast-enhanced MRI

A fourteen years-old boy was treated post-operatively with proton therapy for a recurrent low-grade oligodendroglioma located in the tectal region. Six months after the end of irradiation (RT), a new enhancing lesion appeared within the radiation fields. To differentiate disease progression from radiation-induced changes, dynamic susceptibility contrast-enhanced (DSCE) MRI was used with a T2* sequence to study perfusion and permeability characteristics simultaneously. Typically, the lesion showed hypoperfusion and hyperpermeability compared to the controlateral normal brain. Without additional treatment but a short course of steroids, the image disappeared over a six months period allowing us to conclude for a pseudo-progression. The patient is alive in complete remission more than 2 years post-RT.

Value of dynamic contrast-enhanced MRI in assessment of early response to neoadjuvant chemotherapy in breast cancer

To assess the value of dynamic contrast-enhanced MRI (DMRI) in predicting early response to neoadjuvant chemotherapy (NAC) in patients with locally advanced breast cancer (LABC) and to assess the accuracy of MRI in evaluation of residual disease after NAC. Forty-three women with LABC (44 lesions, all were invasive ductal carcinoma) underwent DMRI before, after the first and final cycles of NAC. For each patient, the tumor volume, early enhancement ratio (E1), maximum enhancement ratio (Emax), and maximum enhancement time (Tmax), dynamic signal intensity-time curve were obtained during treatment. The residual tumor volumes obtained by DMRI were compared with pathological findings to assess the accuracy of DMRI. After the first cycle of NAC, the mean volume of responders decreased insignificantly (P = 0.055), but after NAC, mean volume of residual tumor decreased significantly (P = 0.000). Morphological changes: 29 cases showed a concentric shrinkage pattern while 7 cases showed a dendritic shrinkage pattern. Significant differences were found in E1, Emax and Tmax between responders and non-responders (P < 0.05). After the first cycle of NAC, E1, Emax and Tmax of responders changed significantly (P < 0.001), while there was no significant change in non-responders (P > 0.05). After NAC, the dynamic signal intensity-time types were changed in responders, and tended to be significantly flattening, while no significant change was found in non-responders. The residual tumor volume correlation coefficient between MRI and pathology measurements was very high (r = 0.866, P < 0.01). DMRI is useful to evaluate the early response to NAC in LABC. The presence and volume of residual tumor in LABC patients treated with NAC can be accurately evaluated by DMRI.

Value of Dynamic Contrast-Enhanced MRI and Correlation with Tumor Angiogenesis in Bladder Cancer

The aim of this study was to investigate dynamic contrast-enhanced MRI (DCE-MRI) for the noninvasive measurement of bladder cancer angiogenesis by correlation with microvessel density, histologic grade, and tumor staging, and to predict the outcome of local recurrence. Twenty-four patients with bladder cancer were examined using DCE-MRI. Hemodynamic parameters obtained by DCE-MRI included peak time enhancement in the first minute (E(max/1)) after contrast administration, second minute (E(max/2)), third minute (E(max/3)), fourth minute (E(max/4)), and fifth minute (E(max/5)), and the steepest slope. Microvessel density was identified by immunostaining of endothelial cells using FVIII-related antigen. The Mann-Whitney U test, multivariate discriminant analysis, Spearman's correlation coefficient, and analysis of variance were used for statistical analysis. Correlation was seen between DCE-MRI parameters (E(max/1) and steepest slope) and microvessel density (p < 0.05). E(max/1) and steepest slope were found to have a statistically significant correlation with histologic grade (p < 0.05 and p < 0.01, respectively). A significant difference was seen between groups of patients with and without local recurrence with regard to two of the DCE-MRI parameters (p < 0.05 for E(max/1) and E(max/2)). The contrast enhancement patterns on DCE-MRI are influenced by tumor angiogenesis, as reflected by elevated microvessel density expression. Therefore, they are valuable indicators for assessing tumor angiogenic activity and tumor neovascularization in bladder cancers.

Quantitative dynamic contrast-enhanced MRI for the assessment of mandibular invasion by squamous cell carcinoma

The objective of this study was to determine the value of dynamic contrast-enhanced MRI (DCE-MRI) for the preoperative assessment of mandibular invasion in squamous cell carcinomas (SCC), adjacent or fixed to the mandible. DCE-MRI was performed with gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Data were obtained from 25 patients. From pharmacokinetic analysis of the tissue uptake of Gd-DTPA, the DCE-MRI parameters (k(ep), K(trans) and v(e)) were determined, with k(ep) representing the exchange rate constant, K(trans) the volume transfer constant and v(e) the volume of extracellular space per unit volume of tissue. The histology of the resection specimens was used as gold standard for the extent of mandibular invasion. SCC with medullary invasion showed higher mean k(ep) and K(trans) compared with SCC without medullary invasion (ANOVA, p<0.001). ROC analysis of k(ep) and K(trans) revealed reliable threshold values for medullary invasion. In conclusion, DCE-MRI can discriminate SCC with medullary invasion from SCC without medullary invasion and may serve as a valuable tool in preoperative tumour staging with regard to the delineation of medullary invasion.

Diagnostic value of dynamic contrast-enhanced MRI in the salivary gland tumors

To evaluate the diagnostic value of dynamic contrast-enhanced MRI (DCE-MRI) in salivary gland tumors, thirty-five patients (47 lesions) who underwent MR examinations and were histopathologically diagnosed with salivary gland tumors in Okayama University Hospital, between April 1998 and March 2005, were entered in the present study. The parameters included CI(max300) or CI(max600), which was the contrast index (CI) at maximal contrast enhancement upon 300 s or 600 s, and Tmax, which was the time that corresponded to the CI(max300). Washout ratio (WR(300) or WR(600)) was defined as follows: CI(max300)-CI(300s)/CI(max300) or CI(max600)-CI(600s)/CI(max600)x100 (%), where CI(300) or CI(600) was the CI at 300s or 600s after contrast medium administration. We obtained the following results from the analysis of DCE-MRI parameters; (a) The salivary gland tumors were categorized into three CI curve types according to Tmax and WR300; Pleomorphic adenoma; Tmax > 210 s and WR300 < 10%, Warthin tumor; Tmax < 60 s and WR300 > 40%, and malignant tumor; 60s < Tmax < 210 s and 10% < WR300 < 30%; (b) On the basis of the relationship between Tmax and CImax or WR, all pleomorphic adenomas were successfully differentiated from Warthin tumor lesions. Of the 20 pleomorphic adenomas, 18 (90.0%) were successfully differentiated from malignant tumors. All Warthin tumor lesions were successfully differentiated from pleomorphic adenomas and malignant tumors. Of 12 the malignant tumors, 11 (91.7%) were successfully differentiated from pleomorphic adenomas. All malignant tumors were successfully differentiated from Warthin tumors. Thus, DCE-MRI parameters are useful in diagnosing salivary gland tumors on the basis of the combined assessment of Tmax and CImax or WR.

Prostate cancer: diagnostic value of dynamic contrast-enhanced MRI, diffusion weighted imaging and 3D 1H-MR spectroscopy

目的 探讨MR动态增强扫描(DCE-MRI)、扩散加权成像(DWI)和三维氢质子MR波谱分析(3D 1H-MRS)在前列腺癌诊断中的价值.方法经穿刺活检、手术病理或随访证实的32例前列腺癌及64例前列腺增生患者,以及29例健康志愿者经MR常规扫描、DCE-MRI、DWI和MRS扫描,分别测量前列腺癌、前列腺增生病灶和正常前列腺中央腺区和正常周围带强化后的相对信号强度值、DWI信号强度值和表观扩散系数(ADC)值,以及胆碱/枸橼酸盐(Cho/Cit)和[Cho+肌酸(Cr)]/Cit比值,并经方差分析比较不同组织和病灶间差异.结果经DCE-MRI检查,22例前列腺癌患者中18例病灶区呈早期明显强化,并快速下降;40例前列腺增生患者中38例呈早期明显强化并逐渐上升至中晚期达峰值后缓慢下降,除0及120 s两时间段前列腺癌与前列腺增生组织两者之间差异无统计学意义(P＞0.05)外,正常周围带、增生与癌三者的相对信号强度在其余每个时段均差异有统计学意义(P＜0.05).经DWI检查前列腺癌患者26例于ADC图上病灶呈明显低信号,ADC值为(104.23±26.15)×10-5mm2/s,43例前列腺增生患者病灶区平均ADC值为(175.21±64.86)×10-5mm2/s,除正常前列腺周围带与前列腺增生之间ADC值差异无统计学意义(P＞0.05)外,前列腺癌、前列腺增生和正常前列腺中央腺区之间差异均有统计学意义(P＜0.05).MRS检查前列腺癌17例,其病灶区Cho/Cit比值为2.26±0.91,(Cho+Cr)/Cit比值为2.85±1.01,35例前列腺增生患者病灶区平均Cho/Cit比值为0.46±0.23,(Cho+Cr)/Cit比值为0.57±0.20.除正常前列腺周围带与正常前列腺中央腺区之间差异无统计学意义(P＞0.05)外,前列腺癌、前列腺增生和正常前列腺组织其余各组间差异均有统计学意义(P＜0.05).DCE-MRI、DWI和MRS 3种检查方法在前列腺癌诊断敏感度、特异度和准确度均达70%以上,而通过3种检查方法的联合应用,其敏感度、特异度和准确度分别达87.50%、94.74%、92.59%.结论DCE-MRI、DWI和MRS 3种检查方法在前列腺癌诊断中具有特征性表现,而3种检查方法的联合应用又将极大地提高MRI诊断前列腺癌的正确诊断率。