Digital subtraction angiography in the evaluation of chemodectomas

During the last 2 years eleven patients with surgically confirmed chemodectomas have been investigated by means of digital subtraction angiography (DSA). Seven patients underwent i.v. DSA, which revealed eight carotid body tumours, and in the remaining four with jugulotympanic chemodectomas intra-arterial (i.a.) DSA was performed. We found i.V. DSA an easy and satisfactory method for the investigation of carotid body tumours but when glomus intravagale, tympanicum or jugulare is suspected an i.a. selective injection is required.     

颈静脉孔区及鼓室内颈静脉球瘤1例并文献复习

目的探讨颈静脉孔区及鼓室内颈静脉球瘤的临床表现、影像和病理特征及其鉴别诊断。方法回顾性分析1例经手术病理证实的颈静脉孔区及鼓室内颈静脉球瘤病人的影像及病理资料,并复习相关文献。结果CT检查示左侧颈静脉孔、中耳鼓室、鼓窦及乳突气房内可见软组织密度影,局部乳突骨质破坏,并突入左侧外耳道;颅底MRI示左侧颈静脉孔区不规则条状肿物,沿左侧颈静脉孔突出颅外,并伸入左侧咽旁间隙,凸向左侧中耳鼓室及乳突气房。术后病理诊断为副神经节瘤。免疫组织化学结果:Syn、NSE、CD56、CD34、Cg A阳性,CK阴性,ki-67增殖活性较低(1%),提示副神经节瘤。结论颈静脉孔及鼓室骨质破坏以及病变明显强化和速升速降的动态曲线支持颈静脉球瘤和鼓室球瘤的诊断。联合CT和MRI能够明确病变的范围。     

鼓室球瘤的影像学表现

目的 探讨鼓室球瘤的影像学诊断价值。方法 回顾性分析10例经手术病理证实的鼓室球瘤的CT和MRI表现，总结其影像学表现特点及其诊断价值。结果 8例行颞骨高分辨率CT检查，2例行常规CT扫描；其中7例轴面及冠状面均能显示鼓室软组织结节影，3例示中耳乳突内充满了略低密度软组织影，CT仅诊断为慢性中耳乳突炎，漏诊了其内的鼓室球瘤，所有病例未见骨质破坏。行MR检查者8例，T2WI显示肿瘤为较高信号（6例）和高信号（2例），增强后以明显强化为特点；3例伴有慢性中耳乳突炎者，T2WI可区分肿瘤的较高信号和周围炎症的高信号，增强MRI亦能显示强化的肿瘤和不强化的周围炎症。结论 MRI对鼓室球瘤的显示优于CT，伴有中耳乳突炎时MRI优势更明显。     

头颈部副神经节瘤影像学诊断

目的:探讨头颈部副神经节瘤的影像学特征。方法:回顾性分析19例头颈部副神经节瘤的CT、MRI和DSA表现,其中颈静脉球瘤3例,鼓室球瘤2例,颈动脉体瘤12例,迷走体瘤2例。结果:颈静脉球瘤的CT特征为颈静脉孔扩大和虫蚀骨质破坏,1例双侧因肿瘤为1cm首次平扫漏诊;鼓室球瘤均较小,发生于鼓岬区,临床特征为搏动性耳鸣和鼓膜充血;颈动脉体瘤位于颈总动脉分叉处,特征为颈内、外动脉分离和动脉镶嵌于肿瘤边缘或肿瘤内;迷走体瘤与颈动脉体瘤的区别在于颈内、外动脉受压后均向前移位。增强后肿瘤均见明显强化,MRA图像有助于确认肿瘤内的滋养血管,术前栓塞是治疗的有效方法,能减少约50%~70%肿瘤供血。结论:头颈部副神经节瘤具有特定的解剖学位置和影像学表现,对临床诊断和治疗有重要价值。     

Computed tomography of the middle ear in the evaluation of cholesteatomas and other soft-tissue masses: comparison with pluridirectional tomography

Computed tomographic (CT) scans and tomograms of 60 patients with various soft-tissue masses of the middle ear, including 30 with cholesteatomas, were studied. CT produced excellent images of middle ear soft-tissue masses and appears to be the diagnostic method of choice for cholesteatomas, glomus tympanicum tumors, and other soft-tissue masses. In one patient CT demonstrated pneumolabyrinth resulting from postsurgical fracture of the footplate of the stapes. Pneumolabyrinth is a newly reported CT finding in stapes footplate fracture.     

Selective arteriography of glomus tympanicum and jugulare tumors: techniques, normal and pathologic arterial anatomy

Glomus tympanicum and jugulare tumors arise within the middle ear and jugular fossa, respectively, but often extend into the adjacent areas of the skull base and posterior fossa. Multiple branches of the external carotid, internal carotid, and vertebral arteries may contribute to the vascular supply of these lesions. The arteriograms of 15 patients with glomus tumors were correlated with the surgical findings to determine if selective arteriography could define precisely the involvement within the middle ear, jugular fossa, and mastoid. The arteriographic mapping correlated well with the surgical findings in nine of 13 cases that had surgery, but a few important limitations were found. Therefore, a new arteriographic projection, called a transcanalicular view, is proposed that separates the middle ear from the jugular fossa, allowing for better visualization and assessment of the tumor blush.     

Glomus tumours of the ear: an imaging regime

Jugulotympanic glomus tumours usually present in the middle ear either primarily or as a result of extension upwards from the jugular fossa. Usually they are the initial responsibility of the otologist. If the jugular fossa is involved, special head and neck surgical expertise is required in treatment and spread into the cranial cavity will involve the neurosurgeon. Previously, angiography was used for diagnosis and assessment of the extent of the tumour but it possesses disadvantages. A new protocol has been evolved using high resolution CT combined with MRI including sequences before and after gadolinium-DTPA enhancement. This regimen has been applied successfully in 25 glomus tumours (14 tympanicum and 11 jugulare).     

Nasopharyngeal extension of glomus tympanicum: an unusual clinical and imaging manifestation

Nasopharyngeal extension of the glomus tympanicum is rare. Only 2 cases have been reported in the literature to date. We present a reported case of a large nasopharyngeal extension of recurrent glomus tympanicum, with various kinds of imaging and histopathology and a review of the literature.     

Paragangliomas of the jugular bulb and carotid body: MR imaging with short sequences and Gd-DTPA enhancement

Twenty-six patients with glomus jugulare (16), glomus tympanicum (three), or carotid glomus (seven) tumors were examined with contrast-enhanced CT scans and MR scans without and with Gd-DTPA. MR and CT scans had similar sensitivities, but the enhanced MR scans were diagnostically more specific than either CT or nonenhanced MR. Dynamic MR scanning permitted measurement of the degree of Gd-DTPA enhancement over time. We recommend contrast-enhanced MR with short sequences and a dynamic approach in patients with suspected carotid, tympanic, and jugular paragangliomas.     

Vascular masses in the middle ear

High resolution computed tomography (CT) is of great value in demonstrating soft tissue masses in the middle ear cavity. However, tissue characterisation even for vascular masses after contrast enhancement has proved disappointing. Differentiation therefore depends upon the site and anatomical configuration of the mass, and in many cases angiography is mandatory for diagnosis. Examples of high ectopic jugular bulb, glomus jugulare and glomus tympanicum tumours and aberrant internal carotid artery are presented and their differential diagnosis considered. The value of CT and more traditional techniques, particularly lateral tomograms to show the spur of bone between the jugular bulb and internal carotid artery, are discussed.     

Computed tomography of jugulotympanic paragangliomas

Seven cases of jugulotympanic paragangliomas were studied with computed tomography (CT) and verified by angiography and surgery. All of five glomus jugulare tumors were detected and their extent accurately demonstrated by CT. Two small glomus tympanicum tumors were not convincingly demonstrated. Computed tomography is useful in investigating this neoplasm when it extends beyond the tympanic cavity or is associated with bone destruction.     

Angiographic observations on chemodectomas of the head and neck.

Angiographic experience with chemodectomas in 21 patients is reviewed. Arterial supply was identified from the vertebral artery, the internal carotid artery, and branches of the external carotid artery. A striated cephalad extension from a cervical chemodectoma (five patients) is believed to represent arterial supply to tumor in vein. In two patients, internal and external carotid arteriograms did not opacify important arteries originating near the carotid bifurcation. Retrograde filling of sigmoid sinus (four patients), tumor mass in jugular vein (two patients), and arteriovenous shunting (nine patients) were observed during the venous phase. Thorough angiogra phy is essential for evaluation of chemodectomas of the head and neck.     

Imaging of tinnitus: a review

Tinnitus, a buzzing or ringing in the ear, may be pulsatile or continuous (nonpulsatile). The distinction, with a detailed clinical evaluation, determines the most appropriate imaging study. Pulsatile tinnitus suggests a vascular neoplasm, vascular anomaly, or vascular malformation. Most of the neoplasms are glomus tympanicum and glomus jugulare tumors. Vascular anomalies may cause pulsatile tinnitus, but the mechanism is unknown, and another (treatable) cause should be sought. Most neoplasms and anomalies are best seen on bone algorithm computed tomographic (CT) studies. Dural vascular malformations are often elusive on all cross-sectional imaging studies; conventional angiography may be necessary to make this diagnosis. Flow-sensitive magnetic resonance (MR) images show vascular loops compressing the eighth cranial nerve. Carotid dissections, aneurysms, atherosclerosis, and fibromuscular dysplasia can be identified on both MR imaging or MR angiographic studies and CT or CT angiographic studies. Otosclerosis and Paget disease are CT diagnoses. Benign intracranial hypertension often has no abnormal imaging findings. For patients with nonpulsatile tinnitus, MR imaging is the study of choice to exclude a vestibular schwannoma or other neoplasm of the cerebellopontine angle cistern. Multiple sclerosis and a Chiari I malformation are rare causes of pulsatile tinnitus, also best seen on MR studies. Many patients with tinnitus have no abnormal imaging findings.     

The CT scan and subtraction angiography in chemodectomas.

The value of subtraction angiography and CT scanning in the diagnosis of chemodectomas are illustrated by two cases, a glomus jugulare tumour which exhibited true malignant behaviour, and a carotid body tumour. The characteristic early arterial blush of a chemodectoma, which can be obscured by bone, is clearly seen following subtraction techniques revealing tumours as small as 0.5 cm. The chemodectoma appeared as an isodense tumour on the CT scan with uniform contrast enhancement and well-defined margins. The appearances, however, are not diagnostic of a chemodectoma and may be simulated by other tumours.     

Angiography of chemodectomas of the neck

In 18 chemodectomas of the neck (6 carotid body tumours, 1 vagal body tumour and 11 tympanojugular tumours) the arterial supply and circulatory characteristics were evaluated at angiography. The arterial supply of the carotid body tumours was derived from all adjacent vessels including direct carotid body branches of the proximal external carotid artery. The arterial supply in tympanojugular tumours constantly came from both the ascending pharyngeal and retroauricular arteries and often also from the anterior tympanic artery. Other branches contributed less constantly and only to a minor degree, except for the vertebral artery in cases with tumour extension intracranially. The circulatory characteristics were constant in the series: a short arterial phase was rapidly followed by a phase of relatively long duration with marked, somewhat granular accumulation of contrast medium and also by an early filling of draining veins. The planning of the angiographic procedure in cases of chemodectoma is discussed.     

MR imaging of paragangliomas

MR imaging of 15 paragangliomas in 10 patients was compared with CT of 13 of the lesions in eight patients. All lesions were confirmed with angiography. All lesions were detected by MR and CT with the exception of one small glomus tympanicum tumor that was seen only in retrospect with MR. CT better demonstrated subtle osseous changes of the skull base and the relation of the tumor to the middle ear structures. MR better demonstrated the relation of the tumor to the adjacent internal jugular vein and carotid artery. The paragangliomas had a characteristic MR appearance based on their vascularity. Serpiginous areas of signal void representing high vascular flow were interspersed among areas of high signal intensity caused by slowly flowing blood and tumor cells. This "salt-and-pepper" pattern was seen in all lesions greater than 2 cm in maximal dimension. MR was therefore able to accurately characterize the tumors as highly vascular. Multiplanar imaging and good tissue contrast and anatomic detail permitted display of the relations of these neoplasms to surrounding carotid sheath vessels and to intracranial structures better than did CT. In this experience, the MR appearance of paragangliomas was quite characteristic and differed markedly from meningiomas, neuromas, and metastatic disease of the skull base.     

Foramen tympanicum, or foramen of Huschke: pathologic cases and anatomic CT study

BACKGROUND AND PURPOSE: A persistent foramen tympanicum, or foramen of Huschke, is an anatomic variation of the tympanic portion of the temporal bone due to a defect in normal ossification in the first 5 years of life. The foramen is located at the anteroinferior aspect of the external auditory canal (EAC), posteromedial to the temporomandibular joint (TMJ). We sought to define its prevalence, location, and size on high-resolution spiral CT (HRCT). METHODS: We prospectively examined 102 consecutive HRCT studies of the temporal bone (204 ears). HRCT was performed by using 120 kV, 400 mAs, an ultra-high-resolution filter, 0.6-mm section thickness, 0.3-mm section increment, 728 x 728 matrix, and 160-mm field of view. We noted the size and location of the foramen tympanicum relative to the tympanic membrane and calculated its prevalence. Patients with focally decreased tympanic bone thickness of <1 mm at the anteroinferior EAC (between the 3- and 6-o'clock positions) were considered separately. RESULTS: We found a foramen tympanicum was found in six (4.6%) of 130 ears. Mean axial diameter was 4.2 mm, and mean sagittal diameter was 3.6 mm. Focally reduced bone thickness in the same location was found in 45 (35%) ears, with a female preponderance (P = .003). CONCLUSION: HRCT is sensitive for detection of the foramen tympanicum because of its thin sections, high spatial resolution, and multiplanar capabilities. Awareness of this anatomic entity may be useful in evaluating patients with transient otorrhea in whom no otologic cause (e.g., ear infection, TMJ disease) is identified.     

Aberrant internal carotid artery lying within the middle ear

Summary The CT signs of aberrant course of the internal carotid artery are presented and are contrasted against those of anomalously high jugular bulb, glomus tympanicum and cholesterol granuloma.     

Unusual eustachian tube mass: glomus tympanicum

SUMMARY: A case of recurrent glomus tympanicum presenting with epistaxis is described. CT and MR imaging revealed a homogeneously enhancing mass extending along the entire course of the eustachian tube, with a portion protruding into the nasopharynx. Glomus tumors tend to spread along the path of least resistance and may extend into the eustachian tube. The unique imaging appearance should place a glomus tumor high on the list of differential diagnoses.