Magnetic resonance imaging features of the superior cervical ganglion and expected changes after radiation therapy to the head and neck in a long-term follow-up.

PURPOSE: This study aimed to assess the magnetic resonance (MRI) features of the superior cervical ganglion (SCG) and to track changes to it induced using radiotherapy across a long-term follow-up. METHODS: In total, 75 patients who underwent radiotherapy for head and neck malignancies and who were studied with MRI were recruited from two centers. MRI was performed before and after radiotherapy, with a median long-term follow-up of 4.5 years. Baseline SCG features were assessed. Changes in axial cross-sectional area, T2-normalized signal, and apparent diffusion coefficient (ADC) (the latter available in about half of the patients) were analyzed. Repeated measures analysis of variance with Bonferroni's correction was used to analyze changes in the aforementioned parameters (significance level 0.05). RESULTS: Out of a potential 149 SCGs, 136 were visible at baseline MRI. A variable spatial relationship with the internal carotid artery was found. SCGs showed the "black dot" sign in almost all of the patients. ADC was higher in SCGs than in regional lymph nodes. Cross-sectional area, normalized T2, and ADC increased in the period up to 1 year after radiotherapy and then remained stable in subsequent longer-term follow-up. CONCLUSION: The SCG has unusual features that allow differentiation from the regional lymph nodes. Changes in morphology and signal after radiotherapy must be taken into account by radiologists to avoid misdiagnosis as recurrent nodal disease. Changes induced using radiotherapy are stable in long-term follow-up and are thus likely attributed to other factors (such as Schwann cell hypertrophy/proliferation) rather than edema.

Are superior cervical sympathetic ganglia avid on whole body 68Ga-PSMA-11 PET/magnetic resonance?: a comprehensive morphologic and molecular assessment in patients with prostate cancer.

OBJECTIVES: Recent reports warn against erroneous mistaking of celiac and stellate sympathetic ganglia for metastatic lymph nodes on multimodal prostate-specific membrane antigen (PSMA)-ligand PET imaging. The aim was to check the intensity of Ga-PSMA-11 uptake and magnetic resonance (MR) features of superior cervical ganglia (SCG) on PET/MR imaging. METHODS: In 89 patients 106 SCG were reliably identified on Ga-PSMA-11 PET/MR. For each SCG, qualitative assessment (visual subjective avidity, diffusion restriction, shape, and the presence of central hypointensity) and quantitative measurements [dimensions, maximal standardized uptake value (SUVmax), mean apparent diffusion coefficient (ADC)] were performed. RESULTS: Mean SUVmax in SCG amounted to 1.88 ± 0.63 (range: 0.87-4.42), with considerable metabolic activity (SUVmax ≥ 2) in 37.7% of SCG; mean thickness was 3.18 ± 1.08 mm. In subjective visual evaluation, SCG avidity was classified as mistakable or potentially mistakable with underlying malignancy in 32.1% of cases. Mean ADC values amounted 1749.83 ± 428.83 × 10mm/s. In visual assessment, 74.5% of ganglia showed moderate to high diffusion restriction. An oval or longitudinal shape on transverse MR plane was presented by 59.4% of SCG. The central hypointensity was detected on MR T2-weighted images only in 10.4% of SCG. CONCLUSION: SCG, similar to other sympathetic ganglia, show Ga-PSMA-11 uptake. SCG avidity may be of significance, especially in view of frequently occurring SCG oval or longitudinal shape, and moderate to high diffusion restriction in visual assessment, potentially suggesting malignancy on transverse MR plane. Diagnostic imaging specialists and clinicians should be aware of the above.

Computing neurite outgrowth and arborization in superior cervical ganglion neurons.

Dendrites are the primary site of synaptic activity in neurons and changes in synapses are often the first pathological stage in neurodegenerative diseases. Molecular studies of these changes rely on morphological analysis of the imaging of somas and dendritic arbors of cultured or primary neurons. As research on preventing or reversing synaptic degeneration develops, demands increase for user-friendly 2D neurite analyzers without undermining accuracy and reproducibility. The most common method of 2D neurite analysis is manual by using ImageJ. This method relies completely on the user's ability to distinguish the shape and size of dendrites and trace morphology with a series of straight connected lines. Semi-automatic methods have also been developed, such as the NeuronJ plugin for ImageJ. These methods still rely on the user to identify the start and end of the dendrites, but automatically determine the shape, reducing the likelihood of user bias and speeding the process. Some automatic methods have been developed through image processing software, like ImagePro. These programs tend to be expensive, but have been shown to be fast and effective, limiting user interaction. In this study, we compare three methods of neurite analysis-ImageJ, NeuronJ, and ImagePro-in measuring the soma size, number of dendrites, and length of dendrites per cell of embryonic sympathetic rat neurons with BMP-7-induced dendritic growth. Our results indicate that ImageJ and NeuronJ measurements were of similar effectiveness and consistent throughout various images and multiple trials. NeuronJ required less user interaction in measuring the length of dendrites than the manual method and therefore, was faster and less labor intensive. Conversely, ImagePro tended to be inconsistent across images, overestimating both soma size and the number of dendrites per cell while underestimating the length of dendrites. Overall, NeuronJ, in conjunction with ImageJ, is the most reliable and efficient method of 2D neurite analysis tested in the present study.

Serial magnetic resonance imaging evaluations of irradiated superior cervical sympathetic ganglia: Not every retropharyngeal enlarging mass is a sign of malignancy.

INTRODUCTION: To describe serial changes in irradiated superior cervical sympathetic ganglia (SCSGs) on MRI (magnetic resonance imaging) evaluation in patients with head and neck squamous cell carcinoma (HNSCC) and to find the features differentiating them from the metastatic retropharyngeal lymph nodes. MATERIALS AND METHODS: This retrospective study evaluated 52 consecutive patients with definitive radiotherapy with/without chemotherapy for pathologically confirmed HNSCC and pre- and postradiation MRI follow-up evaluations. MR images of SCSGs were analyzed including enhancement pattern, margin, and the presence of intraganglionic hypointensity. RESULTS: MRI evaluations were performed in 36 men and 16 women with HNSCC with an average age of 58 years, range 23-80 years before irradiation (n=52), and at 6 (n=21) and 13-18 (n=52)months follow-up. Mean total radiation dose was 6351±483 cGy (range, 5640-7000 cGy). Intraganglionic hypointensity, homogeneous enhancement pattern, and well-defined margins were observed in 96%, 97%, and 97% of ganglia on the last follow-up, which showed no difference between pretreatment and 6-month follow-up (P>0.05). Mixed linear model analysis revealed significant increases in diameter and normalized T2SI of SCSGs after irradiation (P< 0.05). CONCLUSIONS: Despite of the increase in diameter and normalized T2SI of SCSGs, preservation of intraganglionic hypointensity, well-defined margins and homogeneous enhancement might be helpful for radiologists to identify SCSGs during the follow-up of HNSCC patients.

MR Imaging of the Superior Cervical Ganglion and Inferior Ganglion of the Vagus Nerve: Structures That Can Mimic Pathologic Retropharyngeal Lymph Nodes.

BACKGROUND AND PURPOSE: The superior cervical ganglion and inferior ganglion of the vagus nerve can mimic pathologic retropharyngeal lymph nodes. We studied the cross-sectional anatomy of the superior cervical ganglion and inferior ganglion of the vagus nerve to evaluate how they can be differentiated from the retropharyngeal lymph nodes. MATERIALS AND METHODS: This retrospective study consists of 2 parts. Cohort 1 concerned the signal intensity of routine neck MR imaging with 2D sequences, apparent diffusion coefficient, and contrast enhancement of the superior cervical ganglion compared with lymph nodes with or without metastasis in 30 patients. Cohort 2 used 3D neurography to assess the morphology and spatial relationships of the superior cervical ganglion, inferior ganglion of the vagus nerve, and the retropharyngeal lymph nodes in 50 other patients. RESULTS: All superior cervical ganglions had homogeneously greater enhancement and lower signal on diffusion-weighted imaging than lymph nodes. Apparent diffusion coefficient values of the superior cervical ganglion (1.80 ± 0.28 × 10-3mm2/s) were significantly higher than normal and metastatic lymph nodes (0.86 ± 0.10 × 10-3mm2/s, P < .001, and 0.73 ± 0.10 × 10-3mm2/s, P < .001). Ten and 13 of 60 superior cervical ganglions were hypointense on T2-weighted images and had hyperintense spots on both T1- and T2-weighted images, respectively. The latter was considered fat tissue. The largest was the superior cervical ganglion, followed in order by the retropharyngeal lymph node and the inferior ganglion of the vagus nerve (P < .001 to P = .004). The highest at vertebral level was the retropharyngeal lymph nodes, followed, in order, by the inferior ganglion of the vagus nerve and the superior cervical ganglion (P < .001 to P = .001). The retropharyngeal lymph node, superior cervical ganglion, and inferior ganglion of the vagus nerve formed a line from anteromedial to posterolateral. CONCLUSIONS: The superior cervical ganglion and the inferior ganglion of the vagus nerve can be almost always differentiated from retropharyngeal lymph nodes on MR imaging by evaluating the signal, size, and position.

Superior cervical ganglion mimicking retropharyngeal adenopathy in head and neck cancer patients: MRI features with anatomic, histologic, and surgical correlation.

INTRODUCTION: To describe the unique MRI findings of superior cervical ganglia (SCG) that may help differentiate them from retropharyngeal lymph nodes (RPLNs). METHODS: A retrospective review of post-treatment NPC patients from 1999 to 2012 identified three patients previously irradiated for NPC that were suspected of having recurrent nodal disease in retropharyngeal lymph nodes during surveillance MRI. Subsequent surgical exploration revealed enlarged SCG only; no retropharyngeal nodal disease was found. A cadaveric head specimen was also imaged with a 3T MRI before and after dissection. In addition, SCG were also harvested from three cadaveric specimens and subjected to histologic analysis. RESULTS: The SCG were found at the level of the C2 vertebral body, medial to the ICA. They were ovoid on axial images and fusiform and elongated with tapered margins in the coronal plane. T2-weighted (T2W) signal was hyperintense. No central elevated T1-weighted (T1W) signal was seen within the ganglia in non-fat-saturated sequences to suggest the presence of a fatty hilum. Enhancement after gadolinium was present. A central "black dot" was seen on axial T2W and post-contrast images in two of the three SCG demonstrated. Histology showed the central black line was comprised of venules and interlacing neurites within the central portion of the ganglion. CONCLUSIONS: The SCG can be mistaken for enlarged RPLNs in post-treatment NPC patients. However, there are features which can help differentiate them from RPLNs, preventing unnecessary therapy. These imaging findings have not been previously described.

Block of the superior cervical ganglion, description of a novel ultrasound-guided technique in human cadavers.

OBJECTIVE: Injection of opioids to the superior cervical ganglion (SCG) has been reported to provide pain relief in patients suffering from different kinds of neuropathic facial pain conditions, such as trigeminal neuralgia, postherpetic neuralgia, and atypical facial pain. The classic approach to the SCG is a transoral technique using a so-called "stopper" to prevent accidental carotid artery puncture. The main disadvantage of this technique is that the needle tip is positioned distant from the actual target, possibly impeding successful block of the SCG. A further limitation is that injection of local anesthetics due to potential carotid artery puncture is contraindicated. We hypothesized that the SCG can be identified and blocked using ultrasound imaging, potentially increasing precision of this technique. INTERVENTIONS: In this pilot study, 20 US-guided simulated blocks of the SCG were performed in 10 human cadavers in order to determine the accuracy of this novel block technique. After injection of 0.1 mL of dye, the cadavers were dissected to evaluate the needle position and coloring of the SCG. RESULTS: Nineteen of the 20 needle tips were located in or next to the SCG. This corresponded to a simulated block success rate of 95% (95% confidence interval 85-100%). In 17 cases, the SCG was completely colored, and in two cases, the caudal half of the SCG was colored with dye. CONCLUSIONS: The anatomical dissections confirmed that our ultrasound-guided approach to the SCG is accurate. Ultrasound could become an attractive alternative to the "blind" transoral technique of SCG blocks.

Imaging of carotid canal sympathetic plexus schwannoma.

One case report of a schwannoma involving the sympathetic plexus in the carotid canal has been reported previously. This article presents 2 additional cases of this rare entity with associated clinical and unique radiographic findings. All patients presented with diplopia among other symptoms, and they had enhancing masses that smoothly expanded the carotid canal on cross-sectional imaging. Comparison with the index case and differential diagnosis of more common pathologies in this area are discussed.

Imaging characteristics of schwannoma of the cervical sympathetic chain: a review of 12 cases.

BACKGROUND AND PURPOSE: SCSCs are rare. This study reviews our experience with CT and MR imaging of SCSCs. MATERIALS AND METHODS: We retrospectively reviewed the CT and MR imaging studies as well as clinical data of 12 patients (6 men, 6 women; mean age, 41 years; range, 27-55 years) with surgicopathologic evidence of SCSC, referred to our institution between January 1999 to October 2008. Images were evaluated with respect to the location, number, morphology, attenuation/signal intensity, enhancement characteristics, and patterns of mass effect of the schwannomas. RESULTS: The schwannomas were solitary, well-circumscribed, and medial to the carotid sheath. Seven were hypoattenuated to skeletal muscle on CT with poor postcontrast enhancement, 4 were isoattenuated, and a single lesion showed intense heterogeneous enhancement. At MR imaging, they were heterogeneously bright on T2WI with intense inhomogeneous postgadolinium enhancement. The ICA was displaced anteriorly in 9 patients with a component of lateral displacement in 8 of these patients. The ICA was in a neutral position in 2 patients and posterolaterally displaced in 1 patient. A single patient demonstrated separation of the ICA and IJV. There was splaying of the carotid bifurcation in 4 patients. CONCLUSIONS: We present the patterns of mass effect and the spectrum of CT and MR imaging characteristics of SCSC, including certain observations that are infrequently described in the published literature.

[Block of the superior cervical ganglion of the Truncus sympathicus. Why it often is not possible!]. / Blockade des Ganglion cervicale superius des Truncus sympathicus. Ursachen für Fehlblockaden.

BACKGROUND: For the transoral block of the superior cervical ganglion (SCG) of the sympathetic trunk we investigated the dissemination of three of three different volumes. The aim was to find an ideal volume and reasons for a failure of the technique. MATERIAL AND METHODS: 40 preserved heads were investigated. 35 were injected with the contrast agent Jopamiro. 1 ml was applied on the left side of 30 heads, 2 ml on all right sides. 5 heads were injected with 5 ml into the parapharyngeal space (PPS) on the right and into the prevertebral space (PVS) on the left side. All heads were investigated by CT-Scans and 3D reconstruction. 5 cadavers were injected with 5 ml blue coloured water for dissection. RESULTS: 1 or 2 ml showed very similar dissemination. To reach the PPS, the needle had to be pushed laterally or, if the direction was changed more medially, the needle had to be pulled back. Feeling two resistances, the PVS was reached instead of the SCG. 5 ml spread to other regions of the head. CONCLUSION: 1 ml seems to be sufficient to block the SCG. The guidelines have to be strictly followed to avoid failure of the block. 5 ml disseminate to unexpected and undesirable regions.