MRI in detection of brain metastases at initial staging of small-cell lung cancer

We prospectively investigated 40 patients with small-cell carcinoma of the lung (SCLC) for signs of brain metastasis by neurological examination and MRI of the brain, to determine the significance of MRI for staging. MRI could not be completed in one patient, who was excluded from the study. The MRI studies of the remaining patients showed no abnormalities in 12, cerebral infarcts in 2 and brain metastases in 11 patients, of whom 3 no relevant symptoms. Nonenhancing white matter lesions were found in 14 patients. In 3 of the 4 patients with an abnormal neurological examination at diagnosis, nonenhancing white matter lesions later developed into contrast enhancing lesions compatible with brain metastases; in 2, this occurred during the course of the chemotherapy. MRI did not change the clinical staging in patients with asymptomatic brain metastases.     

MRI staging of low rectal cancer

Low rectal tumours, especially those treated by abdominoperineal excision (APE), have a high rate of margin involvement when compared with tumours elsewhere in the rectum. Correct surgical management to minimise this rate of margin involvement is reliant on highly accurate imaging, which can be used to plan the planes of excision. In this article we describe the techniques for accurate magnetic resonance imaging (MRI) assessment and a novel staging system for low rectal tumours. Using this staging system it is possible for the radiologist to demonstrate accurately tumour-free planes for surgical excision of low rectal tumours.     

Extra-thoracic staging of lung cancer

This article reviews the staging of extra-thoracic metastatic lung cancer. The imaging strategy, including when to screen as well as the different modalities available for different sites of spread of disease are discussed. The emerging role of whole body positron emission tomography in screening for metastases is also explored.     

PET in lung cancer staging.

The primary clinical application of FDG-PET is in the evaluation of patients with lung cancer and includes diagnosis, staging and restaging of non-small cell lung cancer. PET has a very high accuracy (sensitivity = 97%, specificity = 78%) for characterizing nodules that are indeterminate by chest radiograph and computed tomography. The major utility of PET in the evaluation of patients with lung cancer is the staging of the entire body. PET is more accurate than the conventional imaging modalities of CT and bone scans in the detection of metastatic disease. PET is accurate in the staging of the mediastinum, adrenal glands, and the skeletal system. PET is not as accurate in the detection of brain metastases because of their small size and the normal cortical accumulation.     

Local staging of prostate cancer with MRI

Accurate local staging of prostate cancer is essential for patient management decisions. Conventional and evolving magnetic resonance imaging (MRI) techniques, such as diffusion- weighted imaging, dynamic contrast-enhanced MRI, and MR spectroscopy, are promising techniques in prostate cancer imaging. In this article, we will review the current applications of conventional and advanced MRI techniques in the local staging of prostate cancer.     

Endorectal coil MRI in local staging of rectal cancer

PURPOSE: The choice of the therapeutic strategies in patients affected with rectal cancer is strictly dependent by the tumor stage. So, in order to obtain an improvement in preoperative staging accuracy, new imaging modalities are now under investigation. The aim of this work is the evaluation of endorectal-coil MRI in the local staging of rectal cancer. MATERIAL AND METHODS: Fourty-three patients affected with histologically proven rectal cancer, have been evaluated by an high-field strength magnet (1.5 T). In 14/43 patients neoadjuvant pre-operative chemotherapy had been previously performed. In all cases axial SE T1w and FSE T2w sequences and coronal or sagittal FSE T2w sequences, with and without fat suppression, were performed. Basing upon the TNM staging system and the previously reported MRI signs the local extent of the tumor was evaluated, focusing about the rectal wall infiltration and the perirectal lymph nodes involvement. All the patients underwent surgery and a comparative evaluation of MRI and pathological staging was done. RESULTS: At MRI the tumor was detected in 38/43 patients. In evaluating wall infiltration the MRI results agreed with pathological results in 89% of patients and showed 92% accuracy in T1-T2 stage and 94% in T3. In evaluating perirectal lymph nodes metastases MRI showed 69% accuracy, 82% sensitivity and 55%specificity. DISCUSSION AND CONCLUSIONS: The poor accuracy of CT and body-coil MRI in evaluating wall involvement in patients with rectal cancer is mainly related to their inability to demonstrate the single layers of the rectal wall. So transrectal ultrasound is now the first choice modalitiy in local staging of rectal cancer. However transrectal ultrasound showed low sensitivity in detecting perirectal lymph nodes metastases and low accuracy in evaluating the patients previously undergone to neoadjuvant chemotherapy or radiotherapy. On the other hand the improvement of MRI sequences and the availability of the endorectal coils allowed to visualize the single layers of the rectal wall so making the endorectal-coil MRI a reliable imaging technique to stage rectal cancer. The results of our work demonstrate a good diagnostic accuracy of endorectal-coil MRI in local staging of rectal cancer, in particular the degree of rectal wall infiltration was well demonstrated, while the perirectal lymph nodes metastases were demonstrated with less accuracy. The long examination time, the costs and the movement-related artefacts are the main limits of MRI. In particular the movement-related artifacts sometime do not allow the visualization of the wall layers so lowering the diagnostic accuracy in demonstrating the tumor wall infiltration. In conclusion, even though endorectal coil MRI proved to be a reliable imaging technique in local staging of rectal cancer, at present we are not able to state what may be its real role in diagnostic evaluation of the patients with rectal cancer, in particular if compared to endorectal ultrasound. Further, comparative studies, based upon larger patients series are probably needed to draw a definitive conclusion.     

膀胱癌的MRI诊断与分期对照

膀胱癌是泌尿系统常见的恶性肿瘤,对其有效治疗,膀胱癌的准确诊断和术前分期十分重要。笔者收集本院2002年3月～2008年3月经膀胱镜及手术病理证实的38例膀胱癌患者的MRI资料及临床病理资料,进行回顾分析。     

MRI in local staging of rectal cancer: an update

Preoperative imaging for staging of rectal cancer has become an important aspect of current approach to rectal cancer management, because it helps to select suitable patients for neoadjuvant chemoradiotherapy and determine the appropriate surgical technique. Imaging modalities such as endoscopic ultrasonography, computed tomography, and magnetic resonance imaging (MRI) play an important role in assessing the depth of tumor penetration, lymph node involvement, mesorectal fascia and anal sphincter invasion, and presence of distant metastatic diseases. Currently, there is no consensus on a preferred imaging technique for preoperative staging of rectal cancer. However, high-resolution phased-array MRI is recommended as a standard imaging modality for preoperative local staging of rectal cancer, with excellent soft tissue contrast, multiplanar capability, and absence of ionizing radiation. This review will mainly focus on the role of MRI in preoperative local staging of rectal cancer and discuss recent advancements in MRI technique such as diffusion-weighted imaging and dynamic contrast-enhanced MRI.Colorectal cancer is the second most common cancer in women and the third most common cancer in men with 570 100 and 663 600 estimated new cases per year worldwide, respectively (1). Rectal cancer accounts for approximately 42% of colorectal cancers with 45 000 estimated new cases per year in the United States (2). Prognosis of rectal cancer is determined by depth of invasion, number of involved lymph nodes, and involvement of circumferential resection margin. Management of rectal cancer has evolved over the years with preoperative imaging playing an increasingly prominent role. Initial strategy of clinical diagnosis followed by surgery and postoperative chemotherapy had a high local recurrence rate (27%) and poor survival (48% 5-year survival) (3). Later studies showed that neoadjuvant chemoradiation improves survival and decreases local recurrence rates significantly (4). In addition, it reduces tumor size, facilitates curative resection (5), and may enable sphincter sparing surgery in cancers close to the anorectal junction (6). Neoadjuvant chemoradiotherapy is not indicated in stage I tumors (confined to rectal wall with no nodal involvement), but is recommended for stage II (extends beyond the rectal wall, no nodal involvement) and stage III tumors (regional lymph node involvement). Therefore, in order to avoid unnecessary chemoradiation in stage I cancers, a reliable imaging modality is crucial to precisely define depth of invasion and to identify lymph node involvement (7). Current approach in the management of rectal cancer includes preoperative staging with different imaging modalities followed by neoadjuvant chemoradiotherapy (for stage II/III cancers). This approach has lowered the local recurrence rate (11%) and improved survival (58% 5-year survival) (3).Preoperative imaging for rectal cancer staging is also useful to determine which surgical technique would be more appropriate: recently-developed local excision method of transanal resection or traditional radical resections such as low anterior resection or abdominoperineal resection. Physical examination, endoscopic evaluation, and imaging modalities are used for preoperative staging of rectal cancer. Ideal imaging modality should accurately assess the depth of tumor penetration (T), lymph node involvement (N), presence of distant metastatic disease (M), mesorectal fascia involvement, and anal sphincter involvement. Currently, there is no consensus on a preferred imaging technique for preoperative staging of rectal cancer.Endoscopic ultrasonography, one of the oldest and most widely used imaging modalities, is reported to assess T staging with 67%–97% accuracy and nodal involvement with 64%–88% accuracy (8–11). Although it has a role in staging of early cancers confined to the wall of the rectum, endoscopic ultrasonography may not assess deeper or higher nodes in the mesorectum and can misinterpret inflammatory or fibrotic changes as metastasis (12). Its value is also limited in the evaluation of near-obstructing tumors, tumors in the upper rectum, and mesorectal fascia involvement (12, 13).Computed tomography (CT) is commonly used in rectal cancer because of its ability to assess entire pelvic anatomy and presence or absence of distant metastasis. However, CT has limited soft tissue contrast for local staging. A meta-analysis of 83 studies showed that CT has 73% accuracy for T staging and 22%–73% accuracy for nodal staging (14). In a recent study, Sinha et al. (15) showed T stage accuracy of 87.1% and N stage accuracy of 87.1%. Although newer multidetector CT technology with multiplanar reformations has improved the accuracy, soft tissue resolution of CT is still inadequate to evaluate early rectal cancers.On the other hand, high-resolution phased-array MRI is recommended as a standard imaging modality for pre-operative local staging of rectal cancer, with excellent soft tissue contrast, functional imaging ability, and multi-planar capability (Figs. 1 and ​and2).2). With these inherent proprieties, MRI fills a gap in clinical practice and helps accurate local staging of rectal cancer prior to management decisions. This review will mainly focus on the role of MRI in preoperative local staging of rectal cancer and discuss recent advancements in MRI technique.Open in a separate windowFigure 1. a, b.Axial (a) and coronal (b) fast spin-echo T2-weighted MR images obtained with a phased-array coil on a 3.0 T magnet show the normal anatomy of the pelvis. The rectum (a, arrowhead) is distended with water. Note uterus (a, arrow), and oval-shaped fatty-centered left iliac node (a, curved arrow), which is likely reactive. The iliococcigeal part of the levator ani muscle (b, arrows) extends from the pelvic sidewalls to the anus and joins with the puborectalis muscle (b, arrowheads) to form the external sphincter of the anus (b, curved arrow).Open in a separate windowFigure 2.Axial T2-weighted MR image obtained with an endorectal coil shows the layers of the rectum. Hyperintense submucosa (curved arrows) is surrounded by hypointense muscularis propria (arrows). The mucosa cannot be differentiated from the submucosa, and both layers appear as a single hyperintense layer. Note the levator ani muscle (curved arrows).     

PET/CT在非小细胞肺癌分期中的应用

非小细胞肺癌（NSCLC）分期对治疗方法的选择及判断预后具有重要价值。传统的方法主要是CT及MRI，近年由于PET的出现，特别是PET／CT的应用，实现了分子影像与解剖影像的有机融合，使疾病的诊断从宏观解剖结构深入到微观细胞分子水平，可对病灶进行精确的定性、定位、定期和定量。     

Consistency and prognostic value of preoperative staging and postoperative pathological staging using 18 F-FDG PET/MRI in patients with non-small cell lung cancer

Annals of Nuclear Medicine - In recent years, positron emission tomography/magnetic resonance imaging (PET/MRI) has been clinically used as a method to diagnose non-small cell lung cancer (NSCLC)....     

MRI for pretreatment lymph node staging in uterine cervical cancer

OBJECTIVE: The purpose of this article is to assess the accuracy of MRI in detecting pelvic and paraaortic lymph node metastasis from uterine cervical cancer using various imaging criteria. CONCLUSION: Although MRI analysis resulted in relatively low sensitivity, size and margin (spiculated or lobulated) were useful criteria for predicting lymph node metastasis from cervical cancer.     

磁共振扩散加权成像对直肠癌术前分期的价值

目的:探讨MR扩散加权成像在直肠癌诊断中的临床应用价值。方法:回顾性分析43例直肠癌患者的MRI资料,所有患者均行常规序列T1WI、T2WI及DWI检查,将MRI诊断结果与手术病理结果进行对照分析。结果:常规序列T1分期的诊断符合率为60.0%(3/5),T2、T3、T4分期分别为80.0%(12/15)、66.7%(12/18)和80.0%(4/5);常规序列联合DWI的T1分期诊断符合率为100%(5/5),T2、T3、T4分期分别为100.0%(15/15)、83.3%(15/18)和100.0%(5/5)。常规序列及常规序列联合DWI的直肠癌T分期总诊断符合率分别为72.1%和93.0%。结论:MR扩散加权成像结合常规序列能够对直肠癌T分期做出较准确的诊断。     

Evaluation of diffusion-weighted MRI in the preoperative staging of rectal cancer

目的:探讨MR扩散加权成像在直肠癌诊断中的临床应用价值.方法:回顾性分析43例直肠癌患者的MRI资料,所有患者均行常规序列T1 WI、T2 WI及DWI检查,将MRI诊断结果与手术病理结果进行对照分析.结果:常规序列T1分期的诊断符合率为60.0％(3/5),T2、T3、T4分期分别为80.0％(12/15)、66.7％(12/18)和80.0％(4/5);常规序列联合DWI的T1分期诊断符合率为100％(5/5),T2、T3、T4分期分别为100.0％(15/15)、83.3％(15/18)和100.0％(5/5).常规序列及常规序列联合DWI的直肠癌T分期总诊断符合率分别为72.1％和93.0％.结论:MR扩散加权成像结合常规序列能够对直肠癌T分期做出较准确的诊断.     

Classification,staging and prognosis of lung cancer

Lung cancer has increased in incidence throughout the twentieth century and is now the most common cancer in the Western World. It has a poor prognosis, only 10-15% of patients survive 5 years or longer. Outcome is dependent on clinical stage and cancer cell type. Lung cancer is broadly subclassified on the basis of histological features into squamous cell carcinoma, adenocarcinoma, large cell carcinoma and small cell carcinoma. The histopathological type of lung cancer correlates with tumour behaviour and prognosis. Staging based on prognosis is essential in clinical trials comparing different management strategies, and enables universal communication regarding the efficacy of different treatments in specific patient groups. The anatomic extent of disease determined either preoperatively using imaging supplemented by invasive procedures such as mediastinoscopy, and anterior mediastinotomy or following resection are described according to the T-primary tumour, N-regional lymph nodes, M-distant metastasis classification. The International System for Staging Lung Cancer attempts to group together patients with similar prognosis and treatment options. Various combinations of T, N, and M define different clinical or surgical-pathological stages (IA-IV) characterised by different survival characteristics. Refinements in staging based on imaging findings have enabled clinical staging to more accurately reflect the surgical-pathological stage and therefore more accurately predict prognosis. Recent advances including the use of positron emission tomography in combination with conventional staging promises to increase the accuracy of staging and therefore to reduce the number of invasive staging procedures and inappropriate thoracotomies.     

直肠MRI对直肠癌术前T分期评估的研究进展

直肠MRI是直肠癌术前分期的首选检查方法。高分辨T2WI可显示直肠癌的位置、形态及信号,通过判别肿瘤的浸润深度来评估直肠癌的T分期;还可以识别直肠癌壁外血管内侵犯、环周切缘阳性等预后不良因素,从而指导选择最佳治疗方案。增强T1WI可显示病变区是否存在完整的黏膜下强化带,结合形态学特征准确地区分T1及T2期肿瘤。基于直肠壁各层及周围结构的MRI征象,对直肠MRI评估直肠癌术前局部T分期的研究进展进行综述。