Perineural spread of nasopharyngeal carcinoma: radiological and CT demonstration

Perineural spread is well known to be the most insidious form of tumour spread of a number of head and neck malignancies. However, perineural extension of nasopharyngeal carcinoma (NC) is a poorly recognized event. Four cases of perineural metastases from NC have been detected with pluridirectional tomography and CT. In 3 cases involvement of the Vidian nerve (nervus canalis pterygoidei) and pterygoid canal was observed. In a fourth patient, invasion of one pterygopalatine fossa and perineural spread along ipsilateral maxillary nerve with enlargement and erosion of the foramen rotundum was demonstrated. Radiological diagnosis of clinically unsuspected perineural tumour spread is important because it markedly influences treatment planning and prognosis of NC.     

In vivo proton MR spectroscopy of primary and nodal nasopharyngeal carcinoma

BACKGROUND AND PURPOSE: The aim of this study was to determine the feasibility of performing in vivo proton ((1)H) MR spectroscopy of nasopharyngeal carcinoma (NPC) and to document the (1)H spectrum of this cancer. METHODS: Twenty-seven patients with NPC lesions >1 cm(3) underwent localized (1)H MR spectroscopy performed at 1.5 T. Water-suppressed spectra from both primary tumors (nine cases) and metastatic nodes (18 cases) were obtained at TE 136 and 272. Spectra were analyzed in the time domain by using a nonlinear least squares fitting algorithm with incorporation of previous knowledge. Choline (Cho)/creatine (Cr) ratios for primary NPC and metastatic nodes were calculated and compared. Spectra from normal neck muscle of five volunteers were acquired as control data. RESULTS: (1)H MR spectroscopy was successfully obtained in seven (78%) of nine primary tumors and 16 (89%) of 18 metastatic nodes. Intense lipid signals in the range of 0.89 to 2.02 ppm were observed in 95% of spectra at TE 136 and 91% of spectra at TE 272. At TE 136, Cho/Cr for metastatic nodes (5.3 +/- 1.6) was significantly higher than the ratio for primary (2.6 +/- 0.5) NPC lesions (P =.02). Cho/Cr ratios for NPC lesions were higher than those for normal neck muscles, for which values ranged from 0 to 0.97 and 0 to 1.1 at TE 136 and 272, respectively. CONCLUSION: (1)H MR spectroscopy is a feasible technique for the evaluation of NPC tumors >1 cm(3). Cho/Cr ratios for the lesions were high compared with those for normal neck muscle.     

CT and MR features of nasopharyngeal carcinoma in children and young adults

AIM: To clarify CT and MR features of nasopharyngeal carcinoma (NPC) in children and young adults. METHOD: CT and MR findings of 13 patients (30 years old or younger) with a histopathologic diagnosis of NPC were reviewed. RESULTS: Skull base invasion (12/13), lymphadenopathy (10/13), and infiltrative growth (8/8) were common findings. The signal intensity of tumours was slightly higher than that of muscles in six cases and isointense to that of muscles in two cases on T1-weighted images; it was higher than that of muscle and lower than that of cerebellar grey matter on T2-weighted images in all cases. Internal signals were homogeneous in both pre- and post-Gd-enhanced MR images in all cases. CONCLUSIONS: Despite its rarity in this age group, NPC should be included in a differential diagnosis when CT and MR imaging reveal these features.     

Gadolinium-DTPA enhanced MR imaging of intravenous extension of adrenocortical carcinoma

A case of magnetic resonance imaging of adrenocortical carcinoma extending into the inferior vena cava is presented. Magnetic resonance was able to outline the intraluminal extent of tumor thrombus accurately. Signal intensity ratios (mean 0.98 +/- 0.02) of tumor thrombus/primary tumor on T1- and T2-weighted sequences were useful for tissue characterization of tumor thrombus. Time course of the signal intensity of thrombus before and after intravenous administration of 0.1 mmol/kg gadolinium-diethylenetriamine pentaacetic acid was identical to the primary tumor which aided in differentiation from nontumor thrombus.     

Small cell lung carcinoma: Eight types of extension and spread on computed tomography

OBJECTIVE: The aim of this study was to classify the types of tumor extension and spread of small cell lung carcinoma (SCLC) and to recognize the unusual types of spread pattern of SCLC on computed tomography (CT) including multidetector row CT (MDCT) using contrast-enhanced material. MATERIALS AND METHODS: Sixty-eight cases (53 men and 15 women aged 54-83 years old) of pathologically proven SCLC were examined mainly by contrast-enhanced CT scan. In surgically treated 7 cases, CT-pathologic correlations were performed. RESULTS: Eight types of extension and spread were recognized by the examinations of chest CT. The type of central mass + mediastinal extension (n = 20 [29.4%]) was the most common manifestation. The types of central perihilar mass (n = 12 [17.6%]), peripheral mass + mediastinal extension (n = 14 [20.6%]), and peripheral mass (n = 7 [10.3%]) were frequently observed. The primary site of SCLC was in peripheral lung tissue in 21 of 68 cases (30.9%) in this study. Unusual CT manifestations, such as the types of lymphangitic spread (n = 6 [8.8%]), pleural dissemination (n = 4 [5.9%]), lobar replacement (n = 3 [4.4%]), pneumonialike air-space infiltrative spread (n = 2 [2.9%]) were recognized in our study. Stenosis of trachea and main bronchus caused by peribronchial extension were commonly noted. In the advanced cases with mediastinal extension, we observed the extension of SCLC to superior vena cava (n = 22), main pulmonary artery (n = 18), pulmonary vein (n = 11), and thoracic aortic wall (n = 7). Peri-and intracardial invasions were also observed in 9 cases. CONCLUSIONS: Computed tomography including MDCT analysis revealed 8 types of extension and spread of SCLC including unusual forms in 68 SCLC cases. Peribronchial extension and great vessel wall involvement, such as superior vena cava, main pulmonary artery, and peri-/intra-cardial extension, were commonly observed in advanced stage.     

Renal carcinoma: detection of venous extension with gradient-echo MR imaging.

Magnetic resonance (MR) imaging has been proposed as a noninvasive alternative to vena cavography and computed tomography for the detection of venous extension of renal adenocarcinoma. However, spin-echo MR images may be compromised by the presence of flow-related artifacts, extrinsic compression, and respiratory or cardiac motion artifacts. Use of gradient-recalled echo (GRE) sequences is advantageous for imaging of vascular structures. To investigate the detection of vascular extension of tumor with the GRE technique, findings in the preoperative GRE MR images of 26 patients with renal adenocarcinoma were compared with findings at surgery and pathologic examination. Vena cava thrombus was correctly identified in 13 of 13 patients (100%). Renal vein thrombus was correctly identified in 23 of 26 patients (88%), and right atrial thrombus was correctly identified in four of five patients (80%). Use of GRE sequences allows accurate assessment of vascular structures that is sufficient for surgical planning.     

Head and neck carcinoma: detection of extraorgan spread with MR imaging and CT.

A retrospective analysis of the Magnetic resonance (MR) and CT findings in 18 untreated carcinomas of the oral cavity (7), oropharynx (2), hypopharynx (7), and larynx (2) was performed to assess the accuracy in evaluating extraorgan tumor spread and nodal involvement. Surgical and pathologic correlation was available for 13 primary tumors and nodal status was analyzed in 18. Nine primary tumors had extraorgan extension. MR had a tendency to be superior to CT in predicting tumor invasion of the cartilage and muscle. Sensitivity, specificity and accuracy for extraorgan spread of primary tumors were 89%, 100% and 92%, respectively, for MR and 78%, 75% and 77% for CT. Accuracy for nodal classification (83%) and carotid invasion (94%) of MR was equal to that of CT. CT was more sensitive than MR for demonstrating necrosis within the nodes and vice versa for detecting retropharyngeal nodes. MR imaging is a useful radiologic modality in evaluating extraorgan tumor spread and nodal levels of the head and neck carcinomas.     

MR imaging prediction of local control of nasopharyngeal carcinoma treated with radiation therapy and chemotherapy

Objective:

To retrospectively evaluate the association of MRI findings with local control of nasopharyngeal carcinoma (NPC) treated with radiation therapy and chemotherapy (chemoradiotherapy).

Methods:

Pre-treatment MRIs of 101 patients (78 males and 23 females, 23–79 years of age) who had NPC treated with chemoradiotherapy were retrospectively reviewed to evaluate tumour involvement of nasopharyngeal anatomic subsites, tumour volume and MRI appearance. Local control rates were evaluated with respect to these MRI findings.

Results:

Univariate analysis (using the Kaplan–Meier method) showed that invasion of the skull base as determined by MRI was a significant predictor of local control. In terms of clinical characteristics, T stage and pathological subtype were significant predictors of local control. Multivariate analysis (Cox regression model) of the radiologic findings and clinical characteristics revealed that invasion of the skull base (p = 0.003) and pathological subtype (p < 0.001) were independent prognostic factors for local control.

Conclusion:

Invasion of the skull base as determined by MRI predicts the likelihood of local failure and may be helpful in identifying a subset of patients with tumours at risk of local recurrence within 3 years after primary chemoradiotherapy.

Advances in knowledge:

It has now become common practice to use MRI for pre-treatment evaluation of patients with NPC. The potential role for MRI findings in predicting local control and prognosis in patients with NPC has implications for treatment planning.The “local control” rate of nasopharyngeal carcinoma (NPC) has improved significantly in recent years owing to advances in imaging, improved radiotherapy techniques and the use of combined chemotherapy. Unfortunately, 15–20% of such patients still develop recurrence.^1,2 Local recurrence represents a major cause of mortality and morbidity in advanced-stage disease, and the management of local failure remains a challenging issue in NPC.³ Therefore, early identification of patients who are at risk of such failures is an essential step towards improving existing treatments.Several factors have been linked to an increased risk of local recurrence, including advanced tumour (T)-stage, nodal (N)-stage, histological classification, parapharyngeal tumour invasion, tumour volume and treatment choice.^4–7MRI provides excellent soft tissue contrast and has been shown to be effective for diagnosis, characterization, staging and response evaluation in patients with NPC. However, to our knowledge, the association of pre-treatment MRI findings of NPC with the risk of local recurrence has not been well studied.Therefore, the purpose of our study is to retrospectively evaluate the prognostic significance of MRI findings, regarding the local control of NPC treated with chemoradiotherapy.     

Deep extension from carcinoma arising from the gingiva: CT and MR imaging features

BACKGROUND AND PURPOSE: CT and MR imaging are useful for evaluating the extension of carcinomas in the face and neck. We evaluated the involvement by carcinoma arising from the gingiva (ie, gingival cancer) by using CT and MR imaging. METHODS: We retrospectively examined 122 patients with squamous cell carcinoma (SCCA) in the lower (88 patients) and upper (34 patients) gingiva. Extension of SCCA into the spaces of the face and neck was evaluated with CT and MR imaging, and findings were surgically confirmed. RESULTS: Spread into the face and neck spaces occurred in 58% of patients. The buccal space was the most common site of spread, occurring in 42% of the lower and of 47% of the upper gingival cancers. Spread into the masticator space occurred from the lower gingival cancers in the molar region (20%) but not from the anterior region. Masticator space involvement from the upper gingiva was rare (4%). The retromolar triangle and buccal space immediately anterior to the ramus served as a corridor for cancer extension from the lower gingiva into the masticator space. The sublingual space (11%) was a less common site of spread from the lower gingiva. CONCLUSION: Gingival cancers spread into the masticator, buccal, and sublingual spaces depending on the primary sites in the oral cavity. An understanding of the face and neck-space anatomy is important in diagnosing cancer extension in the oral cavity gingiva and in treating patients with such disease.     

重视MR成像在鼻咽癌分期中的作用

鼻咽癌是我国华南地区最常见的头颈部恶性肿瘤,是危及当地人民健康的重大疾病.数十年来广大医务工作者为攻克鼻咽癌进行了不懈的研究和探索.1957年中山医学院的谢志光和梁伯强教授在广州举行了关于鼻咽癌诊疗的学术研讨会,于1961年倡议在广州中山医学院召开了首届全国鼻咽癌学术会议,启动了对鼻咽癌诊断治疗的生物学、流行病学和分子生物学等全面的学术研究[1].随着现代医学水平的提高和科学技术的发展,特别是CT和MRI应用于鼻咽癌诊断以来,对鼻咽癌及其侵犯范围的显示准确率明显提高,因此,影像学检查在鼻咽癌的临床分期和治疗随访工作中发挥了不可取代的重要作用.近年来,精确放射治疗技术快速发展以及MRI技术进一步提高,目前鼻咽癌的5年总生存率由50%提高至68%～83%[24].为此,本刊组织了关于<鼻咽癌2008分期方案>的解读[5]和鼻咽癌影像学研究重点号,介绍鼻咽癌临床分期的历史和重要性.     

Perineural extension of nasopharyngeal carcinoma into the posterior cranial fossa detected by magnetic resonance imaging

We report a case with perineural extension of carcinoma arising from the nasopharynx. Magnetic resonance (MR) imaging with gadolinium-DTPA enhancement detected subtle but evident findings of perineural tumor extension through the jugulare foramen into the posterior cranial fossa.     

Osteoradionecrosis of the upper cervical spine: MR imaging following radiotherapy for nasopharyngeal carcinoma

Purpose

To document the MRI appearances of radiation-induced abnormalities in the cervical spine following treatment for nasopharyngeal carcinoma (NPC).

Methods

Patients with radiation-induced abnormalities in the upper cervical spine were identified from a retrospective analysis of reports from patients undergoing MRI follow-up. Imaging and clinical records of these patients were reviewed. Symmetrical distribution of abnormalities at C1 (anterior arch ± adjacent aspect of the lateral masses) and C2 (dens ± body especially with a characteristic horizontal rim of marrow preservation above the inferior endplate) were considered typical for osteoradionecrosis (ORN).

Results

Abnormalities of C1/2 were identified in 9/884 (1%) patients. The MRI distribution of abnormalities was typical for ORN in four and atypical in five patients. Abnormal soft tissue was present in the atlantoaxial joint in eight patients, forming a florid mass in six. This soft tissue was in direct continuity with the posterior nasopharyngeal wall ulceration via the retropharyngeal region. The final clinical diagnosis was ORN in eight, five of whom had clinical factors which suggested infection could have played a contributory role, and osteomyelitis in one patient. All patients had undergone additional radiotherapy treatment comprising of brachytherapy (7), stereotactic radiotherapy (1) or radiotherapy boost (2) and three had undergone nasopharyngectomy.

Conclusion

ORN of the upper cervical spine following radiotherapy for NPC is more common than previously suspected and is seen in patients with additional treatment, especially brachytherapy. MRI features are often atypical and a contributory role of infection in the development of some cases of ORN is postulated.     

原发性鼻咽癌MRI与内镜及内镜活检诊断正确性的对照研究

目的对照MRI与目前内镜与内镜活检临床标准的正确性,确定MRI可否发现内镜与内镜活检漏诊的亚临床癌,以及MRI能否确定没有鼻咽癌(NPC)不需要接受有创     

MRI与CT在鼻咽癌诊断中的应用价值及分期系统比较

目的 评价MRI与CT检查在鼻咽癌诊断中的应用价值,并对鼻咽癌2008年分期、1992年福州分期及2002年国际抗癌联盟(UICC)分期系统进行比较.方法 分析76例鼻咽癌初诊患者MRI和CT影像资料,依据2008年分期以MRI为标准,评价MRI与CT对鼻咽癌新分期的差异.并以MRI为标准,比较鼻咽癌不同分期系统间的差异.MRI与CT对肿瘤侵犯范围比较采用McNemar法检验.结果 MRI判断鼻咽癌翼内肌(22例)、翼外肌(15例)、颅底(35例)及颅内(11例)侵犯方面与CT(分别为24、11、32、6例)存在差异,但无统计学意义(P＞0.05);MRI在判断咽旁间隙侵犯(50例)、咽后组淋巴结转移(48例)、T1期(18例)、T2期(15例)、N0期(18例)、N1期(33例)上,与CT(分别为61、23、11、22、24、27例)不一致者分别为11例、25例、7例、7例、6例及6例,差异有统计学意义(P＜0.05).CT多显示的11例咽旁间隙侵犯,MRI证实5例为咽旁间隙受压,6例为咽后组淋巴结转移,而MRI较CT共多显示咽后组淋巴结转移25例,以上2点为引起T、N分期差异的主要原因.鼻咽癌2008年分期与1992年分期比较,T分期上升9例,下降1例,N分期上升16例,临床分期上升15例,下降1例;与2002年UICC分期比较,T分期上升7例,N分期上升10例,临床分期上升12例.结论 与鼻咽癌2008分期规定的MR检查比较,CT在显示病变咽旁间隙侵犯及咽后组淋巴结转移方面存在较大差异.相对于1992年分期及2002年UICC分期,鼻咽癌2008分期主要使肿瘤T、N分期上升、临床分期上升.     

原发性肝细胞癌射频消融治疗后MR动态随访研究

目的 探讨原发性肝细胞癌射频消融(RFA)治疗后的MR随访表现特征及规律.方法 回顾性分析2008年8月至12月住院的110例原发性肝细胞癌患者RFA治疗后的MR资料,根据MR检查时间分为3组:消融后48 h内、1～6个月、6个月以上.采用卡方检验分析比较肝细胞癌RFA治疗后肿瘤MR表现的动态变化.结果 110例短期(48 h内)RFA区域在GRE-TtWI表现为高信号,快速自旋回波(TSE)-T2WI则呈低信号,增强扫描无强化.1～6个月,GRE-T1WI示RFA区域信号呈不均匀下降,72例呈高信号,4例呈等低信号;＞6个月时,60例呈高信号,17例呈等低信号,此改变在6个月后与48 h内和1～6个月比较差异均有统计学意义(P值均＜0.015).TSE-T2WI示RFA区域信号呈不均匀轻度增高,1～6个月,65例呈低信号,11例呈等信号;＞6个月时,47例呈等信号,30例呈低信号,而此信号改变在6个月后与48 h内和1～6个月比较差异均有统计学意义(P值均＜0.015).增强后早期RFA区域主要表现为环状强化伴或不伴异常灌注,而随着时间延长趋向无强化,1～6个月,37例无强化;＞6个月,63例无强化,此改变在3组间差异均有统计学意义(P值均＜0.015).6例肿瘤残留或局部进展,表现RFA区边缘结节,TSE-T2WI抑脂像呈中等高信号,GRE-T1WI呈低信号并伴有不同程度的强化.结论 原发性肝细胞癌RFA治疗后,动态MR随访能显示肿瘤完全坏死、肿瘤残留或局部进展及并发症的相关特征.