A pain in the neck--imaging in neck sepsis

Deep neck infection has a high morbidity and mortality and the extent of infection is often difficult to estimate clinically. The complex anatomy and the communication between neck spaces means that infection can spread along fascial planes leading to life-threatening complications such as airway compromise, vascular erosion/thrombosis, neural dysfunction, and ultimately descending necrotizing mediastinitis. Imaging has an important role to play in identifying the extent of infection and the presence of complications.     

颈部感染及其在颈筋膜间隙中蔓延的CT观察

目的 研究颈部感染的CT征象以及感染在筋膜间隙中的蔓延特点。资料与方法 回顾分析44例临床确诊的有CT资料的颈部感染病例资料。所有病例均为横断面扫描，扫描范围为颅底至颈根部，其中31例为增强扫描，13例未作增强。结果 在44例颈部感染患者中，咽旁间隙9例，咽后间隙9例，椎前间隙5例，扁桃体5例，咀嚼肌间隙4例，颌下间隙2例，颈浅部2例，气管前间隙1例，另有7例为多间隙感染。30例有颈阔肌及其周围脂肪的异常改变，CT表现为颈阔肌明显均匀增粗，边缘模糊无强化。颈部筋膜间隙感染主要表现为间隙内的脂肪影消失，间隙旁组织肿胀。2例坏死性筋膜炎CT表现有：颈阔肌增粗、中断，胸锁乳突肌表面筋膜强化，颈深筋膜间隙内积液，颈间隙内气体积聚，纵隔内有感染。2例咽旁感染扩散到舌下间隙，1例到会厌前间隙；3例咽后间隙感染扩散到纵隔，2例到气管旁间隙；2例咀嚼肌间隙感染蔓延到颞肌间隙，2例到咽旁间隙，1例到颊肌间隙；1例椎前间隙感染蔓延到胸部。结论 CT可以准确诊断颈部感染并判断其范围，为临床诊治提供极大的帮助。同时，通过对颈部感染在颈部筋膜间隙中蔓延的CT表现进行分析，可以对颈部筋膜及其间隙的解剖进行更深入的研究。     

Infections of the neck leading to descending necrotizing mediastinitis: Role of multi-detector row computed tomography

Descending necrotizing mediastinitis is an acute, polymicrobial infection of the mediastinum, originating from odontogenic, oropharyngeal and cervical infections. Anatomical continuity of the fascial spaces between the neck and the mediastinum leads to an occasional mediastinal extension of deep neck infection as a serious sequela. An understanding of the anatomy of the deep spaces of the neck and familiarity with the imaging findings in descending necrotizing mediastinitis may allow rapid diagnosis and treatment of this rare and life-threatening complication of deep neck space infection. In this article, we discuss the current role of radiology in diagnosing descending necrotizing mediastinitis, in determining the level of infection and the pathways of spread of infections from the neck to the mediastinum and in planning a successful treatment.     

Mediastinal abscess resulting from dental infection

A case of dental sepsis is presented which resulted in a deep neck infection and eventually caused a mediastinal abscess. The microbiology of such a mixed infection is briefly discussed with emphasis on the synergistic activity of the organisms. The anatomy of the fascial spaces is also described to draw attention to the possible routes of spread of this potentially life threatening condition.     

Peripheral nerve blocks in the cervical region: from anatomy to ultrasound-guided techniques

Cervical plexus nerve blocks have been employed in various head and neck operations. Both adequate anaesthesia and analgesia are attained in clinical practice. Nowadays, ultrasound imaging in regional anaesthesia is driven towards a certain objective that dictates high accuracy and safety during the implementation of peripheral nerve blocks. In the cervical region, ultrasound-guided nerve blocks have routinely been conducted only for the past few years and thus only a small number of publications pervade the current literature. Moreover, the sonoanatomy of the neck, the foundation stone of interventional techniques, is very challenging; multiple muscles and fascial layers compose a complex of compartments in a narrow anatomic region, in which local anaesthetics are injected. Therefore, this review intends to deliver new insights into ultrasound-guided peripheral nerve block techniques in the neck. The sonoanatomy of the cervical region, in addition to the cervical plexus, cervical ganglia, superior and recurrent laryngeal nerve blocks are comprehensively discussed.     

Computed tomography of cervical infections

Computed tomography of 31 patients with infections of the face and neck was reviewed and correlated with the clinical and surgical results. Computed tomography was found to be valuable for (a) distinguishing cellulitis from abscess, (b) defining the precise location and extent of complex infections, (c) demonstrating secondary complications, and (d) occasionally suggesting the etiology of infection. Based on this review, we concluded that CT provides important diagnostic information that aids clinical assessment and guides medical and surgical management of cervical infections. The anatomic relationships of selected cervical spaces are reviewed with respect to pathways of spread and potential complications of cervical infections.     

颈胸交界区感染、积气性病变MDCT表现特征及其解剖、病理学基础

目的：明确颈胸交界区感染、积气病变的MDCT影像表现特点和规律,结合尸体断面解剖观察,探讨其影像学表现与解剖、病理学基础的相关性。方法：观察尸体断面标本11具（5例横断面、4例矢状面和2例冠状面）,主要观察颈胸交界区组织结构的位置、形态特征,并结合经临床或病理证实的颈胸交界区感染、积气性病变84例的MDCT表现特点及规律,阐明影像学表现与解剖、病理学的相关性。结果：ll例尸体断面解剖发现：咽后间隙、椎前间隙与上纵隔食管后间隙自然相通;椎前间隙向外下方经腋鞘与腋窝相连通;颈动脉鞘向下与上纵隔血管周围间隙相延续;颈部气管前间隙向下与上纵隔相通。84例患者的MDCT影像表现：咽后间隙感染可向下达后纵隔;椎前间隙感染可向下蔓延至后纵隔,向两侧蔓延至腋窝;颈动脉鞘感染可向下延伸至上纵隔;积气性病变可同时分布于纵隔、颈部、腋窝区。结论：MDCT能够详细反映颈胸交界区感染、积气病变的局部表现和向周围扩散的情况;尸体断面发现的解剖特点决定了此区域病灶的优势分布．     

Empyema as a complication of retropharyngeal and neck abscesses in children

Empyema developing from retropharyngeal abscess is a rare complication. Two infants with clinical symptomatology and inital chest radiographic findings of pleural fluid which suggested the possibility of retrophoryngeal abscess are described. A child with submandibular and cervical abscesses is also reported; pleural fluid and mediastinal abscess developed less than 24 hours after admission. Pathological processes in the neck can spread into the chest or conversely, either by direct continuity or by dissection through the fascial planes enveloping the cervical compartments. The middle or visceral space which is in direct continuity with the mediastinum is generally the area in which cervicothoracic disease inter-relates.     

Endoscopically assisted fasciotomy: description of technique and in vitro assessment of lower-leg compartment decompression

We describe a reliable method of endoscopically assisted fasciotomy for treating chronic exertional compartment syndrome in the lower leg and for assessing compartment decompression in an in vitro model. Endoscopically assisted fasciotomy was performed in the anterior and lateral compartments of 14 matched, fresh-frozen, through-the-knee amputation specimens using a 30 degrees endoscope. A one-incision technique used in 4 specimens failed to provide complete visualization, and a two-incision technique was then performed in 10 specimens. After decompression, the skin and subcutaneous tissues were removed to assess adequacy of release, nerve decompression, anatomic course of the superficial peroneal nerve, and potential complications. Endoscopic visualization of the fascial layer and subcutaneous neurovascular structures permitted consistent compartment decompression. Fascial release, expressed as a percentage of length from the proximal origin of the fascia to the inferior retinaculum, was 99.8% (range, 98.4% to 100%) for the anterior compartment and 96.4% (range, 82% to 100%) for the lateral compartment. There were no retained fascial bands, unrecognized fascial defects, or neurovascular injuries. Optimal visualization with endoscopically assisted fasciotomy may improve clinical outcome through 1) reliable compartment decompression, 2) identification of fascial defects, 3) decompression of nerve branches at the fascial foramen, and 4) reduction of iatrogenic risk to neurovascular and muscular structures.     

Computed tomography of maxillofacial infection.

Eighteen patients with maxillofacial infections, who had trismus and swelling of the masseteric region, were investigated by CT. Spread of infection was evaluated with particular reference to the fascial spaces. The masticator space was divided into four parts and the changes in each were assessed together with the surrounding fascial spaces. There were changes in the masseter muscle and infection had spread into the upper parts of the masticator space in more than half of the patients. There was a fall in the CT value in the affected muscles, whereas it was raised in the parotid gland and adipose tissue. The clinical importance of CT is shown to have a significant role in the diagnosis and follow-up of maxillofacial infections.     

Lower extremity compartmental anatomy: clinical relevance to radiologists

A thorough understanding of compartmental anatomy is necessary for the radiologist participating in the care of a patient with a lower extremity musculoskeletal malignancy. Localization of tumor to compartment of origin and identification of extracompartmental spread preoperatively are needed to correctly stage a tumor and determine the appropriate surgical management. An understanding of the locations of fascial boundaries, extracompartmental tissues, and neurovascular structures of the thigh and lower leg facilitates this diagnostic process. For the radiologist planning to biopsy a suspicious musculoskeletal lesion, consultation with the referring orthopaedic surgeon is recommended in order to jointly select an appropriate percutaneous biopsy approach. Adequate preprocedural planning ensures selection of an approach which prevents iatrogenic tumor spread beyond the compartment of origin, protects neurovascular structures, and allows complete resection of the biopsy tract and scar at the time of surgical resection without jeopardizing a potential limb-sparing procedure. Cross-sectional anatomic review and case examples demonstrate the importance of a detailed understanding of compartmental anatomy when approaching the patient with a lower extremity musculoskeletal tumor.     

Differential diagnosis of head and neck lesions based on their space of origin. 2. The infrahyoid portion of the neck

The infrahyoid portion of the neck can be considered as a series of contiguous fascial planes and intervening spaces that lend themselves well to axial imaging. These spaces can serve as a basis on which to formulate differential diagnoses for diseases in this region. This pictorial essay describes the fascia and fascial spaces of the infrahyoid portion of the neck. The contents of each space, the common abnormalities affecting the space, and the characteristic displacements produced by disease in each space are reviewed.     

Infrahyoid spread of deep neck abscess: anatomical consideration

The aim of this study was to determine the pathway of infrahyoid extension of the oropharyngeal abscess considering the anatomy of the fascial spaces by cross-sectional imaging. CT scans and MR images were retrospectively reviewed in ten patients with known infrahyoid extension of oropharyngeal abscesses (eight with acute tonsillitis, two with acute phlegmonous oropharyngitis). In seven of eight patients tonsillar abscesses descended along the deep cervical fascia converging on the hyoid bone and further accumulated in the anterior cervical space through which extension to the mediastinum took place in four patients. In seven patients the abscesses involved the retropharyngeal space at the infrahyoid neck. In two of these seven patients the abscesses directly extended down into the upper mediastinum through the retropharyngeal space. In one patients of the seven mediastinal spread of an abscess occurred through the posterior cervical space, not through the retropharyngeal space. Cross-sectional imaging is valuable in the evaluation of deep neck abscesses and the pathway of spread. The anterior cervical space in the infrahyoid neck is important for mediastinal extension of pharyngeal abscesses. Received: 10 April 1997; Revision received 23 October 1997; Accepted 12 January 1998     

颈深筋膜间隙的薄层断面解剖与MRI、CT对照研究

目的：为颈深筋膜间隙疾病的影像识别与诊断提供断层解剖学依据。方法：利用低温冰冻技术，将15例成年男性尸体头颈制成厚度为3mm的连续横断面标本，并与相应层面的MRI、CT对照，观察颈深筋膜间隙。结果：颈部MRI轴位图像上可清楚显示颈深筋膜各间隙的形态和毗邻关系，并提出颈深部间隙的几个最佳显示平面。结论：颈深部疾病影像检查应首选MRI；影像诊断中，咽旁间隙是关键性结构，根据其位置的改变，可对颈深部疾病进行定位诊断。     

Imaging evaluation of head and neck infections

Infections of the head and neck are frequent and usually have a good prognosis even though complications may sometimes be life threatening. In addition to airway compromise, intracranial and thoracic extension may occur. Diagnosis usually is made on clinical examination and imaging may play a significant role in assessing the extent of the disease, detecting complications and assist in surgical planning. The imaging protocol should be appropriate for the proposed diagnosis and suspected complications. CT of the soft tissues of the neck and chest is the imaging test of choice. Interpretation requires knowledge of the anatomy to understand the modalities of local and distant spread of the disease. Imaging evaluation is important but should not delay emergently needed treatment for entities such as epiglottitis and necrotizing fasciitis.     

Deep facial infections of odontogenic origin: CT assessment of pathways of space involvement.

PURPOSEWe investigated the pathways of spread of odontogenic infection in the facial and neck spaces.METHODSCT scans of 45 patients with extensive spread of odontogenic infection into the facial and neck spaces were analyzed to document pathways of spread.RESULTSOdontogenic infections arising in the mandible first spread upward, into the masseter and/or medial pterygoid muscles in the masticator space, and downward, into the sublingual and/or submandibular spaces, and then spread into the spaces or muscles adjacent to one or more of these locations. Infections from the masseter muscle spread into the parotid space to involve the temporalis and lateral pterygoid muscles. Infections from the medial pterygoid muscle spread into the parapharyngeal space to involve the lateral pterygoid muscle. Infections in the maxilla did not spread downward; instead, they tended to spread upward and superficially into the temporal and/or masseter spaces and deeply involve the lateral and/or medial pterygoid muscles in the medial masticator space.CONCLUSIONCT may be useful to depict the extent of infection and to plan treatment of extensive odontogenic infection, which can be life threatening when therapy is ineffective.     

The Right Way to Do Sit-Ups

In brief: Many college athletes must forgo participation in competitive events because they are plagued by third molars (wisdom teeth) that do not completely erupt. The molar may remain partially impacted with a flap of gingival tissue that serves as a food trap and host for bacteria, which produce toxins that initiate an inflammatory reaction and a purulent exudate. If the exudate is trapped, the ensuing infection may spread to the buccal, sublingual, pterygomandibular, or submasseteric spaces via the fascial planes and lead to death. Treatment may include warm saline lavage with a blunted 18-gauge needle, antibiotic therapy, and analgesics. Palliative care can prevent infection or delay surgery until a more convenient time.     

Is soft-tissue inflammation in pedal infection contained by fascial planes? MR analysis of compartmental involvement in 115 feet

OBJECTIVE: The purpose of this study was to analyze compartmental involvement and patterns of spread of soft-tissue inflammation in pedal infection. MATERIALS AND METHODS: We reviewed 115 contrast-enhanced 1.5-T MR examinations of the foot in 41 women and 74 men with a mean age of 58.4 years who had undergone bone biopsy or surgery for suspected osteomyelitis. Presence of inflammation (contrast enhancement, fat signal intensity loss on T1-weighted images, and high signal intensity on T2-weighted images) was noted by two musculoskeletal radiologists in the following foot compartments: toes, medial, central, lateral, interosseous, dorsal, hindfoot, malleoli, and lower leg. Proximal and distal extension of soft-tissue inflammation was analyzed. The compartment closest to the ulcer that showed MR signs of direct contiguous infection was designated the primarily infected compartment. RESULTS: Spread of inflammation across fascial planes into neighboring compartments originated from the following primary compartments: medial (3/10, 30%), central (7/16, 44%), and lateral (16/20, 80%). Spread from the hindfoot and malleoli into adjacent compartments was seen in only 7% of such cases (2/24). Inflammation from toe infections spread in 34% of cases to forefoot compartments (15/44). Inflammation from forefoot or toe infections spread in 4.5% of cases to the midfoot and in 2% of cases to the hindfoot; ascension into the calf was rare (1% of cases). Spread of inflammation into neighboring compartments was not correlated with the presence of diabetes (p = 0.81) or with osteomyelitis (p = 0.34). CONCLUSION: Soft-tissue inflammation of the forefoot tends to spread into neighboring compartments, with little respect for fascial planes. Hindfoot inflammation tends to stay confined. Spread from the foot to the lower leg is rare.     

Evaluation and localization of lymphatic drainage and sentinel lymph nodes in patients with head and neck melanomas by hybrid SPECT/CT lymphoscintigraphic imaging

In patients with head and neck tumors, preoperative lymphoscintigraphy can be used to map lymphatic drainage patterns and identify sentinel lymph nodes. However, it is very difficult to determine the exact locations of head and neck sentinel nodes on preoperative lymphoscintigraphy without the use of anatomic landmarks. Lymph nodes in the head and neck are grouped into 7 regions, or levels, on the basis of anatomic landmarks. In patients undergoing standard lymphoscintigraphy, obtaining lateral marker images that show important anatomic landmarks can help with the localization of sentinel nodes. However, technical problems often render marker images of little or no use. Hybrid SPECT/CT lymphoscintigraphic imaging facilitates the localization of sentinel nodes by reliably showing the relationships between sentinel nodes and important anatomic structures. After reading this article, the reader should understand the lymph node level classification system for head and neck melanomas, be able to describe the technique used for the imaging of sentinel nodes in the head and neck region, and be able to demonstrate how SPECT/CT lymphoscintigraphic imaging can enable precise sentinel node localization and thus help to ensure minimal dissection.     

Head and neck imaging: the role of CT and MRI

High-resolution computed tomography (CT) and magnetic resonance imaging (MRI) have become indispensable tools for the evaluation of conditions involving the head and neck. Complex anatomic structures and regions, such as the orbit, skull base, paranasal sinuses, deep spaces of the neck, larynx, and lymph nodes, require that the radiologist be familiar with the imaging modalities available and their appropriate applications. The purpose of this article is to review the techniques of CT and MRI and the roles they play in clinical practice, including head and neck disorders.