FDG-PET delayed imaging for the detection of head and neck cancer recurrence after radio-chemotherapy: comparison with MRI/CT

In advanced head and neck cancer, an organ-sparing approach comprising radiation therapy combined with intra-arterial chemotherapy has become an important technique. However, the high incidence of residual masses after therapy remains a problem. In this study, we prospectively evaluated the use of 2-[¹⁸F]fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) delayed imaging for the detection of recurrence of head and neck cancer after radio-chemotherapy, and compared the FDG-PET results with those of magnetic resonance imaging (MRI) or computed tomography (CT). Forty-three lesions from 36 patients with head and neck cancer suspected to represent recurrence after radio-chemotherapy (median interval from therapy, 4 months) were studied. PET was performed at 2 h after FDG injection, and evaluated. The results were compared to those of contrast studies with MRI or CT performed within 2 weeks of the PET study, and to histological diagnosis (in all patients suspected of having recurrence) or clinical diagnosis. The lesion-based sensitivity (visual interpretation) and negative predictive value of FDG-PET (88% and 91%, respectively) were higher than those of MRI/CT (75% and 67% respectively). The specificity, accuracy and positive predictive value of FDG-PET (78%, 81% and 70%, respectively) were significantly (P<0.05) higher than those of MRI/CT (30%, 47% and 39% respectively). Three of six patients with false positive findings had post-therapy inflammation. Receiver operating characteristic (ROC) analysis showed that retrospective evaluation with the standardised uptake ratio yielded the best results (sensitivity 87.5%, specificity 81.5%), followed by visual interpretation and then the tumour/neck muscle ratio. An FDG-PET delayed imaging protocol yielded significantly better results for the detection of recurrence of head and neck cancer after radio-chemotherapy than MRI/CT. Because of the high negative predictive value of FDG-PET (91.3%), if PET is negative, further invasive procedures may be unnecessary.     

木村病的影像表现及文献复习

目的 探讨不同部位木村病的CT及MRI表现.方法 收集本院经病理证实19例木村病患者的CT和MRI行回顾性分析,并结合文献讨论.结果 19例木村病中累及头颈部16例、肺内1例、胸壁1例、肝脾受累1例.头颈部木村病CT表现为结节、团块及弥漫性密度异常,平扫与肌肉密度相似,T1WI呈等或稍低信号,T2WI呈高信号,CT和MRI增强扫描多为中度或明显强化.肺内及胸壁木村病表现为软组织肿块,增强扫描肺内病灶呈中度强化,胸壁病灶呈环形强化.肝脾同时受累木村病病灶呈散在结节状轻度强化灶.结论 木村病影像学表现缺乏特征性,需结合实验室检查及病理综合判断.     

MR imaging of the head and neck

The purpose of this paper is to describe current imaging protocols for MR imaging of the head and neck region and to define results and clinical impact. Depending on the clinical question, different MRI protocols are presented for imaging of the head and neck. The appearance of different pathologic findings on imaging studies and how adapted imaging protocols help to improve differential diagnosis is discussed. In summary, MRI is the method of choice for imaging of the head and neck.     

Current status of nuclear medicine clinical application of FDG-PET for cancer diagnosis. Head and neck cancer

Accurate detection of head and neck cancer is crucial in patients' quality of life. The head and neck area consists of many complicated anatomical structures. Conventional imaging procedures such as CT and MRI provide much detailed information, but accurate estimation of the spread of cancer is still limited. Positron emission tomography (PET) using 2-deoxy-2-[18F]fluoro-D-glucose (FDG) is clinically useful in detecting head and neck cancer, providing accurate estimates of head and neck primary cancer especially in cases that are equivocal on CT and/or MRI. FDG-PET is able to show metastatic lymph nodes that may appear normal on CT and/or MRI. Further, whole body FDG-PET makes it possible to detect distant metastases. The clinical usefulness of FDG-PET in head and neck cancer is discussed in this review.     

Slipped capital femoral epiphysis: a physeal lesion diagnosed by MRI, with radiographic and CT correlation

Objective. To define and compare early lesions associated with slipped capital femoral epiphysis (SCFE) on magnetic resonance imaging (MRI), computed tomography (CT) and radiography. Design and patients. Thirteen patients with 15 symptomatic hips due to SCFE underwent radiography and MRI; CT was performed in 12 patients. SCFE was graded on radiographs, head/neck angles and qualitative changes were evaluated on CT, and morphologic/signal abnormalities were determined on MRI. Results. Physeal widening, apparent on T1-weighted MRI, was evident in every case of SCFE, including one presumed “pre-slip.” T2-weighted images demonstrated synovitis and marrow edema but obscured physeal abnormalities. CT head/neck angles ranged from 4–57° for symptomatic to 0–14° for asymptomatic hips. Physeal and metaphyseal changes were variably identified on both radiographs and CT in all cases of SCFE, but not in the pre-slip. Conclusion. MRI clearly delineates physeal changes of both pre-slip and SCFE, and demonstrates very early changes at a time when radiographs and CT may appear normal.     

Magnetic resonance imaging of head and neck tumors

Magnetic resonance imaging (MRI) provides several advantages over computed tomography (CT) in the evaluation of head and neck region tumors. The improved soft-tissue contrast among normal and abnormal tissues provided by MRI now permits the exact delineation of tumor margins in the nasopharynx, oropharynx, and skull base regions. In addition, the ability to depict cross-sectional anatomy and pathology in three planes without intravenous contrast, patient manipulation, or ionizing irradiation is a distinct advantage of MRI over CT scanning. Drawbacks of MRI include the detection of subtle osseous abnormalities, patient motion, and artifacts introduced by ferromagnetic dental appliances. These drawbacks appear minimal when compared to the benefits of improved soft-tissue contrast and the ability to image exact tumor volumes.     

早期成人股骨头缺血坏死的对比影像学诊断研究

目的：探讨早期成人股骨头缺血坏死（FHN）的MRI、CT、单光子发射计算机体层摄影（SPECT）和DR 4种影像学检查方法之间的对应关系及其敏感性,建立早期诊断的影像学检查途径。方法：分析和总结22例30髋随访具有典型影像学表现的早期（ARCOⅠ～Ⅱ期）成人FHN患者的髋关节影像学资料。全部病例均行同期MRI、CT、SPECT、DR检查。结果：MRI 30髋出现“线样征”,其中15髋为“单线征”,15髋为“双线征”;CT上对应部位显示为较模糊的高密度硬化线14髋,硬化线下伴行低密度带7髋;高密度硬化斑点5髋;SPECT上股骨头呈环形和弧形放射性浓聚带23髋,DR上模糊硬化条带13髋。结论：MRI上“线样征”、CT上承重区高密度硬化线和硬化线下低密度带,SPECT上股骨头环形和弧形放射性浓聚带以及DR片上模糊硬化带相互对应为诊断早期FHN的特异性征象。综合比较对早期成人FHN诊断的敏感性MRI最高。     

头颈部血管瘤及血管畸形的CT、MRI诊断

目的:分析头颈部血管瘤及血管畸形的CT、MRI表现,探讨其诊断及鉴别诊断价值。方法:搜集经手术病理或DSA证实,临床及影像资料完整的47例头颈部血管瘤或血管畸形病例的资料,对其进行回顾性分析。CT检查33例,MRI检查14例。结果:海绵状血管瘤21例,T1WI呈均匀等或低信号,T2WI呈高信号,增强扫描呈中等不均匀强化并可见纡曲血管强化;CT平扫呈不均匀等密度、囊状低密度,3例可见圆点状静脉石,增强扫描轻至中等度强化,其中6例见线条状粗大纡曲血管影。蔓状血管瘤23例,病变弥漫,无明显边界。T1WI呈等信号,T2WI呈不均匀高信号,其内见粗大的流空血管影及低信号静脉石,增强扫描明显不均匀强化;CT平扫等密度,见高密度圆点状静脉石,增强明显强化,可见蚯蚓状粗大血管团。淋巴管瘤3例,边界清楚,平扫为低密度,增强扫描无明显强化。结论:CT及MRI可较好显示头颈部血管畸形,蔓状血管瘤为动静脉畸形或高流速血管畸形,影像见粗大纡曲的血管影。低流速的静脉畸形、淋巴管畸形须与头颈部其它囊性病变鉴别。     

人工智能在急性缺血性脑卒中成像中的应用进展

人工智能（AI）技术可采用多种算法模拟人类认知和信息处理过程,与CT和MRI相结合可用于急性缺血性脑卒中成像,包括梗死灶的检测、影像分割、头颈大血管闭塞的检测和病人预后预测等。采用AI技术分析或构建模型有助于临床医师对脑卒中病人的尽早诊疗、及时干预和随访评估。概述AI的概念,并就其在急性缺血性脑卒中病人CT平扫、CT血管成像（CTA）、CT灌注成像（CTP）、MRI中的应用进展进行综述。     

外周原始神经外胚层肿瘤的 CT及MRI 表现

目的：探讨外周原始神经外胚层肿瘤（pPNET ）的CT 及MRI表现。方法回顾性分析9例经病理证实的pPNET 的CT、MRI表现及病理特点。其中8例行CT平扫和（或）增强扫描;5例行MRI平扫和（或）增强扫描。结果病灶位于头颈部2例,胸部3例,阴囊1例,右肩胛区1例,下肢2例。病灶7例为单发,呈类圆形或不规则形,分叶状,最长径约为1．6～13．8cm,平均6．2cm。8例与周围组织分界不清。CT平扫呈以等密度为主的混杂密度;MRI平扫 T1WI为等稍低信号,T2WI多为不均匀高信号。增强扫描呈多种强化表现,常见为中度以上不均匀强化。其中3例与邻近骨关系密切,表现为溶骨性骨质破坏。结论 pPNET CT及M RI表现缺乏特征性,对临床的定位及定性诊断有一定的帮助。     

Rhabdomyolysis of the head and neck: computed tomography and magnetic resonance imaging findings

Rhabdomyolysis is rare in the head and neck. Early diagnosis and treatment is essential to prevent serious complications such as hyperkalaemia, acidosis, acute renal failure and disseminated intravascular coagulation. We present a case of rhabdomyolysis of the head and neck. CT and MRI findings supported the diagnosis of rhabdomyolysis with the patient's clinical and laboratory findings. While imaging is not crucial, it can aid in the detection of rhabdomyolysis and narrow the differential diagnosis along with laboratory findings and physical examination.     

Trends in head and neck radiology

Trends in clinical research of head and neck radiology are well described within four articles published in the European Radiology in the last 2?years. One constant top issue is to gain more, better or new morphological information by so-called "conventional" methods (CT, MRI) with thin-sliced imaging including special reconstructions. The addition of functional or metabolic methods (e.g. diffusion-weighted MRI, dynamic contrast-enhanced MRI, positron emission tomography) to anatomical imaging is a further general trend in oncological radiology over the last few years and has been invaluable in head and neck radiology.     

头颈部腺样囊性癌的CT、MRI诊断

目的 探讨CT、MR1对头颈部腺样囊性癌的诊断价值.方法 回顾性分析20例经病理证实的头颈部腺样囊性癌的临床及CT、MRI资料.结果 病变发生于上腭者5例,口底4例,腮腺4例,鼻腔及上颌窦3例,颌下腺2例,泪腺及面颊部各1例.CT表现为类圆形或不规则形的软组织肿块,增强后不均匀强化,侵犯邻近骨质3例.MRI平扫病灶呈等或稍长T1信号,长T2信号,增强后病灶明显不均匀强化,2例可见神经侵犯征象.结论 CT对肿瘤周围骨质破坏情况显示较好,MR1能够更清晰显示病变形态、轮廓及侵犯范围.两者结合可为该病的诊断和治疗提供更全面的影像信息.     

咽淋巴环外头颈结外淋巴瘤影像分析

本文报告了13例咽淋巴环外头颈结外淋巴瘤的CT和MRI表现，其中单纯结外性4例，结外合并结性3例，单纯结外混合型2例，结外混合型合并结性4例。文内讨论了头颈淋巴瘤分类，咽淋巴环外结外淋巴瘤病变CT和MRI表现和鉴别诊断。     

Value of 2-[18F]-fluoro-2-deoxy-D-glucose imaging with dual-head gamma camera in coincidence mode: comparison with computed tomography/magnetic resonance imaging in patients with suspected recurrent head and neck cancers

OBJECTIVE: The aim of the present study was to assess the value of dual-head gamma-camera (DHGC) imaging in the coincidence mode using 2-[18F]-fluoro-2-deoxy-D-glucose in differentiating recurrent tumor from posttreatment changes in previously treated head and neck cancer. METHODS: This was a single-center prospective study performed with the approval of our Institutional Review Board. Twenty-nine patients with suspected recurrent head and neck cancers were prospectively enrolled in this study. Dual-head gamma-camera imaging in the coincidence mode followed computed tomography (CT; n = 24)/magnetic resonance imaging (MRI; n = 5) within a period of 1 week (mean = 3.5 days) in all patients. Thirteen patients had definite pathologic confirmation of recurrence by undergoing a biopsy. Sixteen patients, however, did not have a definite pathologic confirmation and were followed clinically. The mean duration of follow-up for the subgroup of patients who were followed clinically was 22.8 months (range: 4-48 months). Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for CT/MRI and DHGC imaging in the coincidence mode were calculated. RESULTS: The sensitivity, specificity, PPV, NPV, and accuracy of CT/MRI in the detection of recurrent cancer were 76.5%, 58.3%, 72.2%, 63.6%, and 69%, respectively. In contrast, the sensitivity (100%), NPV (100%), and accuracy (82.8%) of DHGC imaging in the coincidence mode were superior to that of CT/MRI. Dual-head gamma-camera imaging in the coincidence mode had a specificity (58.3%) and PPV (77.3%) comparable to those of CT/MRI. CONCLUSION: Our data suggest that modified positron emission tomography with DHGC imaging in the coincidence mode is a useful tool in the assessment of recurrent head and neck cancer.     

Computed tomography and magnetic resonance imaging appearances of cystic lesions in the suprahyoid neck: a pictorial review

Cystic lesions in the head and neck are important entities that are increasingly investigated by cross-sectional imaging. The patient usually presents with a neck swelling and, after initial clinical examination, an ultrasound scan may demonstrate the cystic nature of the lesion. Further imaging with CT and MRI are often necessary to elucidate the aetiology and deep extent of the lesion. This pictorial review describes and illustrates the typical appearances and locations of a range of cystic lesions in the suprahyoid neck on CT and MRI.     

Head and neck tumors: imaging recurrent tumor and post-therapeutic changes with CT and MRI

OBJECTIVE: To evaluate criteria for detection of tumor recurrence and post-treatment changes in patients with head and neck malignancies in computed tomography (CT) and magnetic resonance imaging (MRI). METHODS AND MATERIALS: Thirty-nine patients with head and neck carcinoma receiving radiochemotherapy were examined before, during and after therapy with MRI. Changes in signal intensity were correlated to histology or clinical course. Three hundred and thirty-one patients with head and neck malignancies were examined with CT after therapy. CT diagnoses were correlated with histology or clinical course. RESULTS: Main criteria for recurrent/residual tumor in MRI was infiltrative mass with high signal intensity in T2-weighted images and enhancement after Gd-DTPA in T1-weighted images. Radiation-induced changes led to false positive diagnosis in 46% in the interval up to 3 months after therapy and in 58% in the interval 3-6 months after therapy. The combination of a circumscribed, infiltrative mass with contrast enhancement in CT had a sensitivity of 86% and a specificity of 80%. CONCLUSION: CT could accurately demonstrate postoperative changes and tumor recurrence. MRI had advantages in differentiation of tumor and scar, but edema after radiation therapy can spoil diagnosis.     

Staging primary head and neck cancers with <Superscript>18</Superscript>F-FDG PET/CT: is intravenous contrast administration really necessary?

Purpose  The aim of our study was to prospectively evaluate whether intravenous contrast media in integrated positron emission tomography and computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) significantly contributes to evaluation of primary head and neck cancers compared with unenhanced PET/CT, regional contrast-enhanced CT of head and neck (neck CE-CT) and regional magnetic resonance imaging of head and neck (neck MRI). Methods  Subjects were 42 consecutive patients (35 men, 7 women; age range: 36–91 years) with biopsy-proven primary head and neck cancers. Lesion detection of primary and nodal sites and TNM classification were assessed on a per-patient basis. McNemar test and κ statistics were employed for statistical analyses. Results  Forty patients (95%) were successfully followed up: 24 patients had nodal disease and 3 had distant metastasis. Contrast-enhanced and unenhanced PET/CT detected 98 and 95% of the primary tumours, respectively, and both detected 92% of patients with nodal disease, which revealed no statistically significant difference. Accuracy for T status was 75 and 73%, respectively, which proved significantly more accurate than neck CE-CT, which had an accuracy of 53% (p = 0.0133 and 0.0233, respectively). Neck MRI correctly classified the T status in 58% of patients; however, no statistically significant difference was found between PET/CT and neck MRI. Contrast-enhanced PET/CT, unenhanced PET/CT, neck CT and neck MRI correctly staged the N status in 90, 90, 79 and 90% of patients, respectively, with no statistically significant difference. Overall TNM classification was correctly classified in 68 and 65% of patients, respectively. Weighted κ values between enhanced and unenhanced PET/CT for primary tumour detection, nodal detection, T status and N status were 0.655, 1.000, 0.935 and 1.000, respectively. Conclusion  We found almost perfect correlation between enhanced and unenhanced PET/CT for lesion detection and initial staging of primary head and neck cancers. Routine contrast administration for PET/CT imaging may not be justified.     

Different imaging techniques in the head and neck: Assets and drawbacks

In this review, the gold standard imaging techniques for the head and neck and the latest upcoming techniques are presented, by comparing computed tomography (CT), magnetic resonance imaging and positron emission tomography-CT, as well as ultrasound, depending on the examined area. The advantages and disadvantages of each examination protocol are presented. This article illustrates the connection between the imaging technique and the examined area. Therefore, the head and neck area is divided into different sections such as bony structures, nervous system, mucous membranes and squamous epithelium, glandular tissue, and lymphatic tissue and vessels. Finally, the latest techniques in the field of head and neck imaging such as multidetector CT, dual-energy CT, flash CT, magnetic resonance angiography, spectroscopy, and diffusion tensor tractography using 3 tesla magnetic resonance are discussed.     

股骨颈疝窝的CT和MRI表现

目的：探讨股骨颈疝窝的CT和MRI影像表现。方法：回顾性分析27例临床确诊股骨颈疝窝患者的髋关节27例CT和14例MRI的表现。结果：27例股骨颈疝窝中,双侧7例、右侧12例和左侧8例。病灶均位于股骨头基底和股骨颈近段前外侧皮质下,呈圆形、类圆形或分叶状,最大径3-13mm,平均9±0.5mm。CT表现为边界清晰,周边有硬化环的低密度影,并见有一裂隙向外穿越邻近骨皮质。MRI因疝窝内容物成分不同而呈不同信号。结论：股骨颈疝窝位于股骨头基底和股骨颈近段前部皮质下,多伴有清晰的薄层硬化缘。邻近皮质与病灶相通的裂隙样缺损是诊断股骨颈疝窝为特异的征象。CT具有确诊价值,MRI具有辅助诊断价值。