CT of the Neck: Image Analysis and Reporting in the Emergency Setting

Checklist: Neck computed tomography in non-traumatic emergencies

Patients attending the emergency department (ED) with cervical inflammatory/infectious symptoms or presenting masses that may involve the aerodigestive tract or vascular structures require a contrast-enhanced computed tomography (CT) scan of the neck. Its radiological interpretation is hampered by the anatomical complexity and pathophysiological interrelationship between the different component systems in a relatively small area. Recent studies propose a systematic evaluation of the cervical structures, using a 7-item checklist, to correctly identify the pathology and detect incidental findings that may interfere with patient management. As a conclusion, the aim of this paper is to review CT findings in non-traumatic pathology of the neck in the ED, highlighting the importance of a systematic approach in its interpretation and synthesis of a structured, complete, and concise radiological report.

Observer- and radiomics model-based computed tomography classification of suppurative versus tuberculous lymphadenitis complicated with nodal necrosis of the neck in children

BACKGROUND

Computed tomography (CT) can be used for the early detection of lymphadenitis. Radiomics is able to identify a large amount of hidden information from images. However, few CT-based radiomics studies on cervical lymphadenitis in children have been published.

OBJECTIVE

This study aimed to investigate the role of visual CT analysis and CT radiomics in differentiating cervical suppurative node necrosis from tuberculous node necrosis in pediatric patients.

MATERIALS AND METHODS

A total of 101 patients with cervical suppurative lymphadenitis (n=52) or cervical tuberculous lymphadenitis (n=49) were included. Clinical data and CT images were retrieved for analysis. For visual observation, 11 major CT features were identified for univariate and multivariate analyses. For radiomics analysis, image segmentation, feature value extraction, and dimension reduction, feature selection and the construction of radiomics-based models were performed through the RadCloud platform.

RESULTS

For the visual observation, significant differences were found between the two groups, including the short diameter of the largest necrotic lymph node (P=0.03), sharp border of the node (P=0.02), fusion of nodes (P=0.02), regular silhouette of the necrotic area (P=0.001), multilocular necrotic area (P=0.02), node calcification (P=0.004), and enhancement degree of the nodal nonnecrotic area (P=0.01). No feature was found to be an independent predictor for suppurative or tuberculous lymphadenitis (P>0.05 for all features). Concerning the radiomics analysis, after feature value extraction and dimension reduction, nine related features were selected. The support vector machine classifier achieved high diagnostic performance in distinguishing suppurative from tuberculous lymphadenitis. The area under the curve, accuracy, sensitivity, and specificity of the support vector machine model test set were 0.89 (95% confidence interval: 0.72-1.00), 0.88, 0.78, and 0.90, respectively.

CONCLUSION

Compared to observer-based CT image analyses, radiomics model-based CT image analyses exhibit better performance in the differential diagnosis of cervical suppurative and tuberculous lymphadenitis complicated with nodal necrosis in children.

Are Computed Tomography Scans Necessary for the Diagnosis of Peritonsillar Abscess?

Background Peritonsillar abscess is one of the most common deep-space infections of the head and neck, accounting for significant healthcare costs in the United States. Contributing to this expenditure is the trend of increased usage of computed tomography (CT), particularly in the emergency department. However, CT can be falsely positive for peritonsillar abscess, prompting unnecessary drainage attempts that yield no purulence. The false positive findings question the accuracy of CT in diagnosing peritonsillar abscess. Objectives The objective of the study was to compare the accuracy of CT with clinical exam to assess if CT is warranted in peritonsillar abscess diagnosis. Methods A retrospective study was performed of patients presenting to eight Orlando emergency departments with throat pain from January 1, 2013, to April 30, 2013. Patients with clinical diagnoses of peritonsillar abscesses were reviewed. A note was made whether CT was performed and if peritonsillar abscess was seen. The reads were compared to the results of procedural intervention for abscess drainage to assess the accuracy of CT in diagnosing peritonsillar abscess. Results There were 116 patients diagnosed with peritonsillar abscess, of which 99 underwent CT scans to aid in diagnosis. Among these 99 patients, 23 received procedural intervention, with 16 having a return of purulence (69.6%), and seven remaining without purulence (30.4%). Conclusion This study highlights the potential inaccuracies of CT scan in diagnosing peritonsillar abscess, as 30.4% of scans interpreted as abscess lacked purulence on intervention. Given these findings, clinicians could serve as better fiscal stewards by using history and exam to guide management in the majority cases with infectious processes of the oropharynx.

Hematologic and inflammatory parameters for determining severity of odontogenic infections at admission: a retrospective study

BACKGROUND

Severe odontogenic infections in the head and neck region, especially necrotizing soft tissue infection (NSTI) and deep neck abscess, are potentially fatal due to their delayed diagnosis and treatment. Clinically, it is often difficult to distinguish NSTI and deep neck abscess in its early stage from cellulitis, and the decision to perform contrast-enhanced computed tomography imaging for detection is often a challenge. This retrospective case-control study aimed to examine the utility of routine blood tests as an adjunctive diagnostic tool for NSTI in the head and neck region and deep neck abscesses.

METHODS

Patients with severe odontogenic infections in the head and neck region that required hospitalization were classified into four groups. At admission, hematologic and inflammatory parameters were calculated according to the blood test results. In addition, a decision tree analysis was performed to detect NSTI and deep neck abscesses.

RESULTS

There were 271 patients, 45.4% in Group I (cellulitis), 22.5% in Group II (cellulitis with shallow abscess formation), 27.3% in Group III (deep neck abscess), and 4.8% in Group IV (NSTI). All hematologic and inflammatory parameters were higher in Groups III and IV. The Laboratory Risk Indicator for Necrotizing Fasciitis score, with a cut-off value of 6 and C-reactive protein (CRP) + the neutrophil-to-lymphocyte ratio (NLR), with a cut-off of 27, were remarkably useful for the exclusion diagnosis for Group IV. The decision tree analysis showed that the systemic immune-inflammation index (SII) of ≥ 282 or < 282 but with a CRP + NLR of ≥ 25 suggests Group III + IV and the classification accuracy was 89.3%.

CONCLUSIONS

Hematologic and inflammatory parameters calculated using routine blood tests can be helpful as an adjunctive diagnostic tool in the early diagnosis of potentially fatal odontogenic infections. An SII of ≥ 282 or < 282 but with a CRP + NLR of ≥ 25 can be useful in the decision-making for performing contrast-enhanced computed tomography imaging.

Magnetic Resonance Imaging of Head and Neck Emergencies, a Symptom-Based Review, Part 1: General Considerations, Vision Loss, and Eye Pain

Use of magnetic resonance (MR) imaging in the emergency department continues to increase. Although computed tomography is the first-line imaging modality for most head and neck emergencies, MR is superior in some situations and imparts no ionizing radiation. This article provides a symptom-based approach to nontraumatic head and neck pathologic conditions most relevant to emergency head and neck MR imaging, emphasizing relevant anatomy, "do not miss" findings affecting clinical management, and features that may aid differentiation from potential mimics. Essential MR sequences and strategies for obtaining high-quality images when faced with patient motion and other technical challenges are also discussed.

Parotid Space, a Different Space from Other Deep Neck Infection Spaces

Deep neck infections (DNIs) such as parotid abscesses are medical emergencies with a seemingly different etiology and treatment course from other DNIs. We sought to confirm this in the present retrospective population-based cohort study. Between August 2016 and January 2020, 412 patients with DNIs seen at a tertiary medical center were enrolled in this study. Infections of the parotid space were compared with those of other deep neck spaces, according to patient characteristics. All patients were divided into parotid space (PS; n = 91, 22.08%) and non-parotid space (NPS; n = 321, 77.92%) subgroups. We further divided the patients into single parotid space (PS-single; n = 50, 12.13%), single non-parotid space (NPS-single; n = 149, 36.16%), multiple parotid space (PS-multiple; n = 41, 9.95%), and multiple non-parotid space (NPS-multiple; n = 172, 41.76%) DNI subgroups. In the PS-single and PS-multiple subgroups, a longer duration of symptoms (p = 0.001), lower white blood cell count (p = 0.001), lower C-reactive protein level (p = 0.010), higher rate of ultrasonography-guided drainage (p < 0.001), and lower rates of surgical incision and drainage (p < 0.001) were observed compared with the NPS-single and NPS-multiple subgroups. The PS group had a higher positive Klebsiella pneumoniae culture rate (p < 0.001), and lower positive Streptococcus constellatus (p = 0.002), and Streptococcus anginosus (p = 0.025) culture rates than the NPS group. In a multivariate analysis, K. pneumoniae was independently associated with parotoid space involvement in comparisons of the PS and NPS groups, PS-single and NPS-single subgroups, and PS-multiple and NPS-multiple subgroups. The clinical presentation of a parotid space infection differs from that of other deep neck space infections.

Lung apical findings in coronavirus disease (COVID-19) infection on neck and cervical spine CT

Purpose

To evaluate the prevalence and features of lung apical findings on neck and cervical spine CTs performed in patients with COVID-19.

Methods

This was a retrospective, IRB-approved study performed at a large academic hospital in the USA. Between March 3, 2020, and May 6, 2020, 641 patients with COVID-19 infection diagnosed by RT-PCR received medical care at our institution. A small cohort of patients with COVID-19 infection underwent neck or cervical spine CT imaging for indications including stroke, trauma, and neck pain. The lung apices included in the field of view on these CT scans were reviewed for the presence of findings suspicious for COVID-19 pneumonia, including ground-glass opacities, consolidation, or crazy-paving pattern. The type and frequency of these findings were recorded and correlated with clinical information including age, gender, and symptoms.

Results

Thirty-four patients had neck or spine CTs performed before or concurrently with a chest CT. Of this group, 17 (50%) had unknown COVID-19 status at the time of neck or spine imaging and 10 (59%) of their CT studies had findings in the lung apices consistent with COVID-19 pneumonia.

Conclusion

Lung apical findings on cervical spine or neck CTs consistent with COVID-19 infection are common and may be encountered on neuroimaging performed for non-respiratory indications. For these patients, the emergency radiologist may be the first physician to suspect underlying COVID-19 infection.