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.     

Head and neck haemangiomas: contrast-enhanced three-dimensional MR angiography

We evaluated the clinical effectiveness of contrast-enhanced three-dimensional (3D) magnetic resonance angiography (MRA) for diagnosing head and neck haemangiomas. We studied six patients using a magnetization prepared rapid acquisition gradient-echo (MP-RAGE) sequence on a 1.5-T system. Conventional T1- and T2-weighted and contrast-enhanced images were also obtained. The images were compared with histological findings. In four cavernous haemangiomas, a mass was partially visible as an enhancing lesion on the early phase of MRA, and was completely visible as a larger enhancing lesion in the late phase, showing slow blood flow. In two capillary haemangiomas, a mass was completely visible in the early phase showing fast flow. In all patients, MRA clearly showed both the haemangiomas and the external carotid artery branches. MRA allowed assessment of the relationship between the haemangiomas and the feeding arteries, and of the haemodynamics. Received: 17 April 1998 Accepted: 5 June 1998     

颈部间隙囊性肿块的CT和MRI诊断

目的分析颈部囊性肿块的MR I和CT特征。方法回顾性分析44例经手术病理证实的颈部囊性肿块,其中淋巴结病变12例,脓肿2例,涎腺病变4例,神经鞘瘤3例,甲状舌管囊肿7例,鳃裂囊肿9例,囊性水瘤5例,皮样囊肿1例,喉气囊肿1例。结果增强CT和MR I可以显示肿块的囊性特征。淋巴结病变为液化坏死所致,有较厚的囊壁;涎腺囊性病变表现各异;先天性囊肿常表现为光滑、薄壁和无增强的肿块,多数囊肿具有特定的解剖位置,如甲状舌管囊肿主要位于颈前中线和舌骨水平,第二鳃裂囊肿多位于颌下腺后方和颈动脉间隙外侧,囊性水瘤最常见于颈后间隙,皮样囊肿位于口底。结论MR I和CT影像学检查能准确评价肿块的性质和位置,对诊断和术前理想方案制订具有重要价值。     

MRI findings of solitary fibrous tumours in the head and neck region

Objectives:

To analyse the MRI findings of solitary fibrous tumours in the head and neck region.

Methods:

We retrospectively reviewed MR images in eight patients with solitary fibrous tumours proven on histological examination. All the patients underwent conventional MRI, and four patients also underwent dynamic contrast-enhanced MRI and diffusion-weighted imaging in five cases. Image characteristics were analysed.

Results:

All lesions were found as solitary well-defined masses ranging in size from 1.9 to 6.8 cm (mean, 4.1 cm). They were mostly homogeneous and isointense to the muscle on T₁ weighted images and heterogeneous and mildly hyperintense on T₂ weighted images. After gadolinium administration, areas that were mildly hyperintense on T₂ weighted images were strongly enhanced. They were mildly hyperintense on diffusion-weighted imaging. The average tumour-apparent diffusion coefficient values were 0.001 157 ± 0.000 304 9 mm s⁻² compared with the muscle 0.000 760 ± 0.000 265 0 mm s⁻², and there was a statistical difference of p = 0.002. The time–intensity curves exhibited a rapidly enhancing and a slow washout pattern on dynamic contrast-enhanced MRI.

Conclusions:

Solitary fibrous tumours should be considered in cases of heterogeneous hypervascular tumours in the head and neck region. Areas of mild hyperintense intensity on T₂ weighted images that are strongly enhanced after gadolinium injection are suggestive of this diagnosis. Non-restricted diffusion and rapidly enhancing and slow washout pattern time–intensity curves may be additional valuable features.     

儿童头颈部横纹肌肉瘤的CT及MR影像学特点

 目的 探讨儿童头颈部横纹肌肉瘤(rhabdomyosarcoma,RMS)的CT及MR影像学特点。方法 回顾性分析29例病理证实的儿童头颈部RMS的影像学资料,其中23例行MRI检查,18例行CT检查。结果 10例发病部位位于鼻咽部,4例位于鼻腔及鼻窦,5例位于鼻翼部,3例位于颌面部,6例位于耳部,1例位于左侧颞下窝。肿瘤形态不规则,呈浸润性生长,多侵蚀破坏邻近骨质。CT图像病灶密度不均匀,瘤体内均无钙化。MR检查T₁WI呈等或稍低信号,T₂WI呈稍高信号,信号不均匀,增强后瘤灶明显不均匀强化。8例侵犯眼眶,13例进入并侵犯鼻腔,14例侵犯副鼻窦,15例侵犯颞骨乳突,12例侵犯颞骨岩部,14例突破颅底,累及硬脑膜,同时4例侵犯邻近脑组织,2例发生脑脊液转移。结论 儿童头颈部RMS好发于脑膜旁区。CT能够很好地显示肿瘤对周围骨质结构的破坏,而MR能更清楚显示肿瘤软组织受累范围,两者结合可提供更全面的影像信息。     

Non-Hodgkin's lymphoma of the nasopharynx: CT and MR imaging

OBJECTIVE: Nasopharyngeal (NP) non-Hodgkin's lymphoma (NHL) is an uncommon tumour. The aim of the study was to describe the appearances on CT and MR imaging, and identify the features which help to distinguish NPNHL from other NP tumours. MATERIALS AND METHODS: The CT (n=8) and MR (n=10) images of 14 patients with NPNHL were reviewed retrospectively. Patients with NPNHL were divided into primary NPNHL, where the primary tumour was in the NP (n=7) and secondary NPNHL where the primary tumour was at another extranodal site in the head and neck (n=7). All NPNHL were assessed for tumour size and distribution, appearance and local tumour invasion, in addition lymphadenopathy was assessed in primary NPNHL. RESULTS: The NPNHL ranged in size from 20-75 mm (mean of 55 mm for primary and 30 mm for secondary NHL) and were homogeneous on CT in eight (100%) and MR in seven (70%) and mildly heterogeneous on MR in three (30%) patients. NPNHL involved all walls of the NP in 10 (71%) (n=1). Primary NPNHL extended superficially in five (71%) to involve the nasal cavity (n=3) and oropharynx (n=2) and lymphadenopathy was present in five (71%) being bilateral and involving multiple nodal sites (n=4) with necrosis (n=2) and matting (n=3). CONCLUSION: NPNHL is a homogeneous tumour that tends to diffusely involve all walls of the nasopharynx and spread in an exophytic fashion to fill the airway, rather than infiltrating into the deep tissues. Deep tumour infiltration, when it occurs, is found in those patients with primary NHL and is usually limited in extent and of small volume. and extended in an exophytic fashion to fill the NP cavity in six (43%). Deep tumour invasion was present in two (14%) both patients with primary NHL, the extent and volume of this tumour invasion was small and involved the prevertebral muscles (n=2), parapharyngeal fat space (n=1) and skull base Primary NHL more commonly spreads superficially to involve the nasal cavity or oropharynx, lymphadenopathy is frequent and extensive. A large tumour that fills the nasopharynx, with no or minimal invasion into deep structures, and a propensity to extend down into the tonsil, rather than up into the skull base, may suggest the diagnosis of NHL over nasopharyngeal carcinoma.     

Early detection treatment response for head and neck carcinomas using intravoxel incoherent motion-magnetic resonance imaging: a meta-analysis

Objectives:To evaluate the diagnostic accuracy of intravoxel incoherent motion-MRI (IVIM-MRI) for predicting the treatment response in head and neck squamous cell carcinomas (HNSCC) patients.Methods:A comprehensive literature search was performed to identify original articles on diagnostic performance of IVIM in predicting treatment response in HNSCC patients receiving chemoradiotherapy. The IVIM parameters studied were diffusion coefficient (D), pseudodiffusion coefficient (D*), perfusion fraction (f), and apparent diffusion coefficient. Summary estimates of diagnostic accuracy were obtained by using a random-effects model. Of 65 studies screened, 8 studies with 347 patients were finally included.Results:The pooled sensitivities and specificities were 76% [95% confidence interval (CI) 69–82%] and 81% (95% CI 70–89%) for pre-treatment D, and 70% (95% CI 58–80%) and 82% (95% CI 66–92%) for △D, respectively. In addition, the sensitivities and specificities ranged from 41.7 to 94% and 67 to 100% for pre-treatment f, and from 55.7 to 76.5% and 72.2 to 93.3% for pre-treatment apparent diffusion coefficient, respectively.Conclusions:The diffusion-related coefficients pre-treatment D and △D demonstrated good accuracy in predicting early treatment response in HNSCC patients. However, because of the variability in reference test and other limitations of included literature, further investigation is needed before implementing any IVIM strategy into clinical practice.     

USPIO-enhanced magnetic resonance imaging for nodal staging in patients with head and neck cancer

PURPOSE: To determine the accuracy of ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance imaging (MRI) for nodal staging in patients with head and neck cancer. MATERIALS AND METHODS: Twenty patients with carcinomas of the upper aerodigestive tract were prospectively enrolled. MRI was performed before and 24-36 hours after intravenous infusion of an USPIO agent, ferumoxtran-10 (Sinerem; Guerbet, France; and Combidex; Advanced Magnetics) at a dose of 2.6 mg Fe/kg using T2-weighted spin-echo and gradient-echo sequences. Surgery was performed the same day or the day after the ferumoxtran-10-enhanced MR examination. Based on MRI, selected nodes were surgically removed and directly correlated with pathology using hematoxylin-eosin (H&E) and Perls stainings. RESULTS: A total of 63 nodes were studied; 36 were nonmetastatic, 25 metastatic, and two inflammatory. Ferumoxtran-10-enhanced MRI allowed diagnosis of 24 metastatic and 30 nonmetastatic nodes, yielding a sensitivity of 96%, a specificity of 78.9%, a positive predictive value of 75%, and a negative predictive value of 96.8%, compared to 64%, 78.9%, 66.6%, and 76.9%, respectively, for nonenhanced MRI. Accuracy of ferumoxtran-10-enhanced MRI was 85.7%. The gradient-echo T2-weighted sequence was the most accurate to detect signal loss in nonmetastatic nodes. CONCLUSION: USPIO-enhanced MRI is useful for nodal staging of patients with head and neck cancers.     

颈动脉间隙肿瘤的MRI诊断

目的：探讨颈动脉间隙肿瘤的MRI影象特征及其病理、解剖学基础和诊断价值。材料和方法：分析25例颈动脉间隙肿瘤的MRI征象，并与手术病理或血管造影比较。结果：多数肿瘤的病理改变或血管造影的特征能在MRI图像上反映，囊变和含丰富粘液的神经源性肿瘤T2加权像呈边界光滑的极高信号，化学感受器瘤瘤内的血管表现为扭曲条状和圆点状的极低信号，颈内动脉瘤信号分层，转移瘤边界毛糙或不清；不同来源的肿瘤与颈内、外动脉或颈总动脉和颈内静脉的位置关系有解剖上的相关性，有利于准确的定位和鉴别诊断；25例中术前诊断正确22例（88％）。结论：MRI对颈动脉间隙肿瘤的定位和定性具有重要的诊断价值，结合病史可减少误诊。     

Diagnostic performance of MRI relative to CT for metastatic nodes of head and neck squamous cell carcinomas

PURPOSE: To compare the diagnostic abilities of magnetic resonance imaging (MRI) and computed tomography (CT) based on the architectural changes in the nodal parenchyma. MATERIALS AND METHODS: We retrospectively studied histologically proven 70 metastatic and 52 reactive nodes in the necks of 38 patients with head and neck squamous cell carcinomas who had undergone both CT and MRI. We assessed the detectability of the architectural changes in the nodal parenchyma that were suggestive of cancer focus (cancer nest, necrosis, and keratinization). The diagnostic abilities of CT and MRI were assessed by three observers separately for the small (<10 mm in minimum axis diameter) and large (>or=10 mm) nodes. RESULTS: MRI was significantly more effective than CT in diagnosing small metastatic nodes, yielding 83% sensitivity, 88% specificity, and 86% accuracy. However, the diagnostic abilities of MRI and CT were similar for large metastatic nodes; MRI yielded 100% sensitivity, 98% specificity, and 99% accuracy. receiver operating characteristic analysis also indicated that the Az values were significantly higher for MRI than for CT (0.927 vs. 0.822, P = 0.00054) for the detection of small nodes. CONCLUSION: MRI is superior to CT in the diagnosis of metastatic nodes from head and neck squamous cell carcinomas.     

头颈部孤立性纤维瘤的影像学表现

目的：探讨头颈部孤立性纤维瘤(SFT)的影像特征,提高对该病的认识。方法回顾性分析10例经手术病理证实的头颈部 SFT 患者的 CT 和 MR 表现。10例均行 CT 平扫及双期增强扫描、2例行 MR 检查。结果10例病灶均表现为孤立的肿块,最大径20~115 mm,中位最大径约35.5 mm。肿瘤发生于眼眶2例、鼻腔鼻窦4例,腮腺、面颊、锁骨上区及枕部各1例。病变边界清楚8例、模糊2例,呈椭圆形7例,分叶状3例。CT 平扫呈等或稍低密度,其中4例密度均匀,6例密度不均匀(2例见多发囊变区,1例见结节状钙化灶)。增强后9例呈明显均匀(n=3)或不均匀(n=6)强化,1例呈轻度均匀强化。CT 双期增强强化模式包括快速强化缓慢廓清8例、快速强化快速廓清1例和延迟强化1例。与脑实质相比,T1 WI 呈均匀等信号1例,等、低混杂信号1例;T2 WI 呈均匀等信号1例,等、高混杂信号(多发囊变)1例;增强后分别呈均匀和不均匀显著强化。结论头颈部不均匀的富血供肿瘤要考虑到 SFT 的可能。瘤体 T2 WI 与脑实质相比呈等或稍低信号,CT 增强扫描明显强化,双期增强呈快速强化缓慢廓清的强化模式可能是有诊断价值的影像特点。     

Value of retrospective image fusion of F-FDG PET and MRI for preoperative staging of head and neck cancer: Comparison with PET/CT and contrast-enhanced neck MRI

Purpose

To assess the clinical value of retrospective image fusion of neck MRI and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET for locoregional extension and nodal staging of neck cancer.

Materials and methods

Thirty patients with carcinoma of the oral cavity or hypopharynx underwent PET/CT and contrast-enhanced neck MRI for initial staging before surgery including primary tumor resection and neck dissection. Diagnostic performance of PET/CT, MRI, and retrospective image fusion of PET and MRI (fused PET/MRI) for assessment of the extent of the primary tumor (T stage) and metastasis to regional lymph nodes (N stage) was evaluated.

Results

Accuracy for T status was 87% for fused PET/MRI and 90% for MRI, thus proving significantly superior to PET/CT, which had an accuracy of 67% (p = 0.041 and p = 0.023, respectively). Accuracy for N status was 77% for both fused PET/MRI and PET/CT, being superior to MRI, which had an accuracy of 63%, although the difference was not significant (p = 0.13). On a per-level basis, the sensitivity, specificity and accuracy for detection of nodal metastasis were 77%, 96% and 93% for both fused PET/MRI and PET/CT, compared with 49%, 99% and 91% for MRI, respectively. The differences for sensitivity (p = 0.0026) and accuracy (p = 0.041) were significant.

Conclusion

Fused PET/MRI combining the individual advantages of MRI and PET is a valuable technique for assessment of staging neck cancer.     

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.     

Impact of extended written information on patient anxiety and image motion artifacts during magnetic resonance imaging

Purpose: To evaluate whether increased written information to patients prior to magnetic resonance imaging (MRI) decreases patient anxiety and image motion artifacts.

Material and Methods: A two-group controlled experimental design was used. Of 242 patients, 118 received routinely given basic written information (control group) while 124 were given increased written information (intervention group). To measure patient anxiety before and during scanning, the self-report psychometric test State-Trait Anxiety Inventory (STAI) was used. After MR examination, the patients answered a questionnaire on satisfaction with the written information. The images were assessed with regard to motion artifacts.

Results: Motion artifacts were present in fewer patient images in the intervention group than in the control group (4.0% versus 15.4%; P = 0.003). There was no significant difference between the control and the intervention group regarding patient anxiety and satisfaction with the information. Women in both groups showed a higher level of anxiety than the men did.

Conclusion: Increased information about the MRI scanning procedure and expected experiences during the scan may help patients to lie still during the sequences, with a decrease in motion artifacts. However, further research is needed to evaluate the effect of other interventions on patient anxiety during MRI scanning.     

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。     

Robustness of a Combined Modified Dixon and PROPELLER Sequence with Two Interleaved Echoes in Clinical Head and Neck MRI

Purpose:The combination of modified Dixon (mDixon) and periodically rotated overlapping parallel lines with enhanced reconstruction sequence with two interleaved echoes, which promotes uniform fat-suppression and motion insensitivity, has recently become available for commercial magnetic resonance imaging (MRI) scanners. To compare the robustness of this combination sequence with that of standard Cartesian mDixon sequence for fat-suppressed T₂-weighted imaging in clinical head and neck MRI.Methods:Fifty patients with head and neck tumors were involved this study. All patients underwent MRI using both the combination and standard sequences. Two radiologists independently scored motion artifacts and water–fat separation error using a 4-point scale (1, unacceptable; 4, excellent). Furthermore, comprehensive comparative evaluation was performed using a 5-point scale (1, substantially inferior; 5, substantially superior). Data were statistically analyzed using the Wilcoxon signed-rank test.Results:In the motion artifact assessment, ratings of 3 or 4 points were assigned to 45% (observer-1, 58.0%; observer-2, 32.0%) and 97% (100%; 94.0%) of images for the standard and combination sequences, respectively (P < 0.001). For the water–fat separation error assessment, ratings of 3 or 4 points were assigned to 100% (100%; 100%) and 85% (84.0%; 86.0%) of images, respectively (P < 0.001). In the comprehensive evaluation, of the 100 cases (observer-1, 50; observer-2, 50), 96 were rated at four or five points. In cases with slight or no motion artifacts and water–fat separation errors, the combination sequence was superior to the standard sequence in term of noise and sharpness, and equal in terms of contrast.Conclusion:Although water–fat separation errors increased significantly in the combination sequence, most of these were acceptable. The significantly decreased motion artifacts in the combination sequence significantly improved image quality overall.     

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.     

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.     

MR imaging of recurrent head and neck tumours following flap reconstructive surgery

AIM: The purpose of this study was to evaluate the magnetic resonance imaging (MRI) characteristics of recurrent tumours in patients who had undergone resection of primary head and neck tumours with flap reconstruction. MATERIALS AND METHODS: MR examinations obtained from 25 patients who had undergone resection and flap reconstructive surgery for malignancy were analysed retrospectively. Tumour recurrence was confirmed by biopsy in 22 patients, and clinically in 3 patients. The features of the recurrent tumours in the scars were reviewed. RESULTS: Twenty-one patients had a locally recurrent mass, while 4 had a locally recurrent mass in addition to regional lymph node metastases. Twenty-four of the recurrent tumours were localized in the recipient flap beds, near the anastomotic site. In 9 of 25 (36%) patients, the recurrent tumours extended intracranially, either directly, or through the foramina at the skull base. CONCLUSION: Tumour recurrence after flap reconstruction most often occurred at or near the anastomotic site. MRI is useful for detection of recurrence after flap reconstructive surgery in patients with head and neck cancer.