动态对比增强MRI在鼻咽癌中的应用进展

鼻咽癌(NPC)是鼻咽部最常见恶性肿瘤,其发生发展与血管生成密切相关。动态对比增强MRI(DCE-MRI)能定量反映病灶内的血流灌注及血管通透性,从形态学和功能学角度准确评估肿瘤恶性程度,有助于指导临床选择治疗方案。本文对DCE-MRI在NPC中的应用进展进行综述。     

乳腺动态增强核磁共振检查的临床应用价值

目的　研究乳腺动态增强MRI在临床的应用价值。方法　5 6例患者接受了乳腺动态增强MRI检查。其中37例、4 5个实性病灶经病理证实。结合手术、病理回顾性分析乳腺MRI的临床价值。结果　除1例为双乳多发囊性肿块外,其余4 5个实性肿块中,良性17个,恶性2 8个。MRI显示了所有肿块,包括2例多发乳腺癌隐性癌灶、1例乳腺癌保乳术后残留、2例导管内癌,其中肿块最小直径为4mm。MRI对病灶的显示率为10 0 % ,诊断的敏感度、特异度和准确率分别是92 %、92 %、90 %。结论　乳腺动态增强MRI,对发现肿瘤病灶具有非常高的敏感性,并且能较为准确的进行定性诊断。     

The value of real-time contrast-enhanced ultrasound combined with CT enhancement in the differentiation of subtypes of renal cell carcinoma

AimThis study aimed to evaluate the value of real-time contrast-enhanced ultrasound (CEUS) combined with contrast-enhanced computed tomography (CECT) in the differential diagnosis of clear cell renal cell carcinoma (CCRCC), papillary renal cell carcinoma (PRCC), and chromophobe renal cell carcinoma (CRCC).Materials and methodsIn the present study, 82 patients with CCRCC, 24 patients with PRCC, and 19 patients with CRCC were confirmed by pathology of the resected tumor. All patients were evaluated by CEUS and CECT before the operation. In addition, the contrast enhancement mode of CEUS and CECT and the contrast parameters of the region of interest (ROI) time-intensity curve between the lesions and the surrounding normal renal parenchyma by CEUS were compared and analyzed.ResultsCompared with the pathological results, the diagnostic accuracy of ultrasound in the 3 groups was 87.8% (72/82), 83.3% (20/24) and 73.7% (14/19). There was no significant difference between CEUS and CECT in the diagnostic accuracy of all groups (P>0.05). Meanwhile, compared with the surrounding renal parenchyma by CEUS, 82.5% (66/80) of CCRCC lesions showed “fast-forward and fast/slow-retrograde,” while 83.3% (20/24) of PRCC, and 84.2% (16/19) showed “slow-forward and fast/slow-retrograde.” Significant differences in the enhancement modes of CEUS were found among the CCRCC, PRCC, and CRCC lesions (P < 0.05). And the enhancement modes could be quantitatively analyzed by the ROI time-intensity curve of the lesion. Moreover, lesions enhanced by CECT and 74.4% (61/82) of CCRCC lesions showed “fast-forward and fast/slow-retrograde,” while 66.7% (16/24) of PRCC and 84.2% (16/19) of CRCC showed “slow-forward and fast/slow-retrograde.” The contrast modes and enhancement uniformity of CEUS and CECT showed no significant differences among the CCRCC, PRCC, and CRCC lesions (P > 0.05).ConclusionCEUS and quantitative analysis of ROI time-intensity curve can be used for differential diagnosis of the 3 RCC subtypes. The combination of CEUS and CECT can help us differentiate RCC subtypes and is of great significance for clinical treatment strategies and prognostication.     

Dynamic contrast-enhanced MRI for the assessment of spinal tumor vascularity: correlation with angiography

Purpose

To determine if dynamic contrast-enhanced MRI (DCE-MRI) could correlate well with invasive angiography in the characterization of spinal tumor vascularity.

Methods

Totally 40 patients with untreated spinal tumors underwent MRI before preoperative angiography and embolization. Tumors were assigned to hypervascular, moderate, or hypovascular groups based on angiographic appearance. Tumor vascularity was also evaluated with enhancement degree on standard MR and with DCE-MRI parameters via ROI analysis of enhanced tumor area. The Spearman correlation coefficient was calculated to determine the correlation between the degree of angiographic vascularity and enhancement on MRI and DCE-MRI parameters. ROC analysis was conducted to assess the appropriate cut-off value.

Results

There were 12 hypervascular, 12 moderate, and 16 hypovascular tumors, respectively. The Spearman correlation coefficient between DCE-MRI parameter and the degree of angiographic vascularity was 0.899 (RSlope_max), 0.847 (Slope_max), 0.697 (E _max), 0.694 (ER_max), and ?0.587 (TTP), respectively, which showed excellent-to-moderate relationships. The RSlope_max cut-off value of 1.325 provided the highest specificity of 100 % and sensitivity of 87.5 % in predicting hypovascular tumors and the value of 1.85 provided the highest sensitivity of 100 % and specificity of 96.4 % in characterizing hypervascular ones.

Conclusions

DCE-MRI is an accurate technique for the assessment of spinal tumor vascularity, which may have a potential value in the decision-making of preoperative embolization.

     

Leiomyosarcoma of the renal vein: Arterial encasement on contrast-enhanced dynamic computed tomography

We report a case of leiomyosarcoma of the renal vein, which is a rare tumor with no more than 30 cases found in the published English language literature. This case demonstrates encasement of the renal artery by the tumor mass, a previously unreported manifestation. The present study could be useful in considering this rare tumor in the differential diagnosis of renal hilar tumors.     

动态对比增强磁共振成像评价腰椎间盘血供的价值

[目的]通过动态对比增强磁共振成像对评价不同年龄段椎间盘血供情况,探讨炎性因子进入椎间盘的方式。[方法]采用GESIGNAEXCITE 1.5T超导型MR成像仪及脊柱表面线圈,扫描采用快速自旋回波脉冲序列及DCE-MR扫描序列。根据Pfirrmann等的椎间盘退变分级标准,采用盲法在矢状位T2WI上对符合纳入标准的100例500个腰椎间盘进行分级,并对跨膜转运常数进行测量,得到K-trans值。[结果]腰椎间盘随年龄增长迅速退变,椎间盘评级Ⅰ级到Ⅳ级时,随着腰椎间盘退变等级的增加,K-trans值与之正相关(P0.05);在相同评级时,年龄与K-trans值正相关,在Ⅲ级时,相关度最高。[结论]年龄与椎间盘退变存在明显的相关性,年龄越大退变越严重。微血管的浸润与年龄及腰椎间盘退变等级均具有一定的相关性。     

Methodology for quality-of-life assessment: a critical appraisal

The methodology for QOL assessment covers a wide range of topics. It involves a proper choice of instruments with appropriate psychometric properties, the administration of these instruments, frequency of measurements, missing data problems, and the method of analysis. There are currently debates on the meaning and interpretation of the HRQOL domains taking the form of arguing how to define minimal clinically meaningful difference and whether this can be used in regulatory approval for drug development. From a practical point of view, the authors proposed that a disease-specific checklist or symptom domains incorporated within a HRQOL questionnaire may be a middle ground to gain general agreements among academic institutions, manufacturers, and regulatory agencies to use a specific symptom checklist or domain as the primary end point for clinical trials together with other HRQOL domains as ancillary data for the study. Antiemetic trial with HRQOL assessments is an example. Most would agree, however, that no matter what HRQOL domains or symptoms are being studied, it should be based on a patient self-administered questionnaire as shown by the lack of sensitivity in the example in this article. Missing data are a problem in the data collection and handling. The authors have examined a few commonly used approaches and performed simulation to study their properties. The subscale-mean method when one has more than 50% of the information on a subscale generally reflects the true values. In practice, one still would have missing data that cannot be handled completely by imputation. The method of analysis must be flexible enough to incorporate the nature of these data. Two approaches have been discussed, and they are both flexible in terms of using all available information being obtained in a longitudinal fashion with variable visiting schedules and potential missing data. The HRQOL response variable approach is simple and easy to understand. The growth curve models approach provides more detailed information on average trends between treatment arms. In general, these two methods agree on the results of the example. They can be used to report clinical trial results using HRQOL data as end points.     

A critical assessment of the prognostic value of clear cell,papillary and chromophobe histological subtypes in renal cell carcinoma: a population‐based study

OBJECTIVE

To assess the magnitude of the effect of histological subtype (HS, the three most common being clear cell, papillary and chromophobe) on cause‐specific mortality (CSM) from renal cell carcinoma (RCC).

PATIENTS AND METHODS

Univariable and multivariable Cox regression models included data from 11 618 patients treated with nephrectomy between 1988 and 2004 in nine Surveillance Epidemiology and End Results registries. We tested whether HS represents an independent predictor of CSM, and whether HS adds to the ability of other variables to predict CSM. The covariates comprised age, year of surgery, T stage, nodal status, M stage and Fuhrman grade.

RESULTS

In a multivariable model predicting CSM, HS was an independent predictor (P = 0.03), but failed to improve the accuracy of the model (+0.1% gain when HS was included in the model).

CONCLUSION

Although we confirmed that HS is an independent predictor for CSM, there was no gain in accuracy when HS was added to standard predictors of CSM. From a practical perspective, this implies that patients with clear cell, papillary and chromophobe HS share similar natural histories after nephrectomy, provided that other cancer characteristics are accounted for. From a statistical perspective, in multivariable models of CSM, the clear cell, papillary and chromophobe HS might be included as a single entity.     

Preoperative assessment of breast cancer: Multireader comparison of contrast-enhanced MRI versus the combination of unenhanced MRI and digital breast tomosynthesis

PurposeTo compare the sensitivity for breast cancer (BC) and BC size estimation of preoperative contrast-enhanced magnetic resonance imaging (CEMRI) versus combined unenhanced magnetic resonance imaging (UMRI) and digital breast tomosynthesis (DBT).Patients and methodsWe retrospectively included 56 women who underwent DBT and preoperative 1.5 T CEMRI between January 2016–February 2017. Three readers with 2–10 years of experience in CEMRI and DBT, blinded to pathology, independently reviewed CEMRI (diffusion-weighted imaging [DWI], T2-weighted imaging, pre- and post-contrast T1-weighted imaging) and a combination of UMRI (DWI and pre-contrast T1-weighted imaging) and DBT. We calculated per-lesion sensitivity of CEMRI and UMRI + DBT, and the agreement between CEMRI, UMRI and DBT versus pathology in assessing cancer size (Bland-Altman analysis). Logistic regression was performed to assess features predictive of cancer missing.ResultsWe included 70 lesions (64% invasive BC, 36% ductal carcinoma in situ or invasive BC with in situ component). UMRI + DBT showed lower sensitivity (86–89%) than CEMRI (94–100%), with a significant difference for the most experienced reader only (p = 0.008). False-positives were fewer with UMRI + DBT (4–5) than with CEMRI (18–25), regardless of the reader (p = 0.001–0.005). For lesion size, UMRI showed closer limits of agreement with pathology than CEMRI or DBT. Cancer size ≤1 cm was the only independent predictor for cancer missing for both imaging strategies (Odds ratio 8.62 for CEMRI and 19.16 for UMRI + DBT).ConclusionsUMRI + DBT showed comparable sensitivity and less false-positives than CEMRI in the preoperative assessment of BC. UMRI was the most accurate tool to assess cancer size.     

Comparison of FDG-PET and dynamic contrast-enhanced MRI in the evaluation of suggestive breast lesions

The aim of our study was a direct comparison of the ability of positron-emission tomography with FDG-PET and of magnetic resonance imaging (MRI) to determine whether breast lesions were benign or malignant and of the two imaging methods capability of depicting eventual multifocal disease. We performed both PET and MRI in 36 patients (40 lesions) who were scheduled for surgery because of suggestive mammographic, sonographic and/or clinical findings. A final histological classification was available for all lesions. Tumour size ranged from 5 to 45 mm (mean 16.7 mm). Sensitivity for lesions, sensitivity for patients, specificity for lesions and specificity for patients were 68.0%, 76.2%, 73.3%, and 73.3% for PET and 92.0%, 95.2%, 73.3%, and 73.3% for MRI, respectively. MRI was more sensitive than FDG-PET in disclosing malignant breast tumours and was also more accurate than FDG-PET in the assessment of multifocal disease. The lower sensitivity of FDG-PET than of MRI seems to be due to difficulties in reliable imaging of carcinomas smaller than 10 mm and of lobular carcinomas.     

Early vascular control for renal trauma: a critical review

To determine the incidence of, indications for and sequelae of temporary vascular occlusion in the management of renal trauma the records of 90 patients with 92 renal injuries were reviewed. Patients who required temporary vascular occlusion were compared to patients with similar injuries who also required renal surgery but not vascular occlusion. Only 11 of 92 renal injuries (12 per cent) required temporary vascular occlusion for reconstruction and control of renal bleeding. Neither the type nor the extent of renal and associated injury was a significant predictor of the need for occlusion. Renal injuries associated with large or expanding retroperitoneal hematomas were more likely to require temporary vascular occlusion than injuries without such associated hematomas. Temporary vascular occlusion was not associated with an increase in postoperative azotemia or mortality. The procedure is safe and effective, and allows for confident inspection and reconstruction of the kidney in patients who otherwise would be at high risk for nephrectomy.     

肾癌的病理类型与预后的关系

目的探讨肾癌的病理类型与预后的关系。方法对315例肾癌患者根据病情选择相应的手术治疗和病理分型,并进行病例随访。以Kaplan-Meier法计算生存率。Cox回归模型对预后影响因子进行分析。结果其中透明细胞癌202例(71.9%),颗粒细胞癌51例(18.1%),混合性腺癌15例(5.3%),乳头状腺癌7例(2.5%),集合管癌4例(1.4%),肉瘤样肾癌2例(0.7%)。Cox回归模型多因素分析显示病理类型可能是一个独立的影响预后的因子。透明细胞癌、颗粒细胞癌和混合性腺癌患者的3年、5年生存率差别无统计学意义。7例乳头状腺癌仅1例死亡。4例集合管癌和2例肉瘤样癌均已死亡,两者平均存活时间分别为6.3和5.5月。结论肾癌的病理分型对预后有一定的预测价值;乳头状腺癌预后优于其他类型肾癌;集合管癌和肉瘤样癌预后较差。     

3.0T磁共振3DF AME动态增强序列对肝脏局灶性病变的诊断价值

目的：探讨3.0T磁共振3D FAME动态增强序列对肝脏局灶性病变的诊断价值。方法：对65例肝脏局灶性病变（原发性肝细胞癌30例,胆管癌4例,转移瘤8例,肝血管瘤12例,肝囊肿11例）相继进行MR常规平扫及3D FAME序列多期动态增强扫描,包括肝动脉期、门静脉期、平衡期及延迟期,观察病灶各期的强化特征,并利用动态强化自动分析软件及时间-信号强度曲线分析各种病变的曲线类型。结果：不同的肝脏局灶性病变具有特征性的强化方式,时间-信号强度曲线较客观反映不同病变的血流动力学特性。肝细胞癌的时间-信号强度曲线分为3种类型：Ⅰ型（速升速降）、Ⅱ型（速升缓降）、Ⅲ型（缓升缓降）,30例肝细胞癌中60.0%（18/30）表现为Ⅰ型曲线类型,26.7%（8/30）表现Ⅱ型曲线类型,13.3%（4/30）表现Ⅲ型曲线类型。肝血管瘤的动态增强曲线分为2种类型：Ⅰ型（缓升平坦型）、Ⅱ型（速升平坦型）,12例血管瘤中66.7%（8/12）表现为Ⅰ型曲线类型,33.3%（4/12）表现Ⅱ型曲线类型。4例胆管癌动态增强曲线为缓慢上升型。转移瘤表现为2种强化方式,2例（25.0%）表现为早期周边环状强化,6例（75.0%）表现为轻度强化。11例肝囊肿增强扫描各期均无强化。结论：3D FAME动态增强序列有助于肝脏局灶性病变的定性诊断。     

Non-invasive assessment of kidney oxygenation: a role for BOLD MRI

Blood oxygen level-dependent (BOLD) contrast magnetic resonance imaging (MRI) has been applied to investigate kidney oxygenation in human patients. These investigations reflect the progress of radiology from a primarily anatomic discipline to one that provides insight into tissue physiology. In particular, magnetic resonance imaging (MRI) is non-invasive, uses no ionizing radiation, and provides insight into disease development and tissue physiology.