Correlation between computed tomography and surgical findings in retropharyngeal inflammatory processes in children

Diagnostic accuracy of contrast-enhanced CT for neck abscesses: A systematic review and meta-analysis of positive predictive value

OBJECTIVES

To review the diagnostic accuracy of contrast-enhanced computed tomography (CT) in differentiating abscesses from cellulitis in patients with neck infections, using surgical findings as the reference standard.

MATERIALS AND METHODS

Previous studies in the last 32 years were searched from PubMed and Embase. Because of partial verification bias (only positive abscess findings are usually verified surgically), sensitivity and specificity estimates are unreliable, and we focused on positive predictive value (PPV). For all studies, PPV was calculated as the proportion of true positives out of all positives on imaging. To estimate pooled PPV, we used both the median with an interquartile range and a model-based estimate. For narrative purposes, we reviewed the utility of common morphological CT criteria for abscesses, such as central hypodensity, the size of the collection, bulging, rim enhancement, and presence of air, as well as sensitivity and specificity values reported by the original reports.

RESULTS

23 studies were found reporting 1453 patients, 14 studies in children (771 patients), two in adults (137 patients), and seven including all ages (545 patients). PPV ranged from 0.67 to 0.97 in individual studies, had a median of 0.84 (0.79-0.87), and a model-based pooled estimate of 0.83 (95% confidence interval 0.80-0.85). Most morphological CT criteria had considerable overlap between abscesses and cellulitis.

CONCLUSIONS

The pooled estimate of PPV is 0.83 for diagnosing neck abscesses with CT. False positives may be due to limited soft tissue contrast resolution. Overall, none of the morphological criteria seem to be highly accurate for differentiation between abscess and cellulitis.

Retropharyngeal, Parapharyngeal and Peritonsillar Abscesses

Deep neck infections (DNIs) include all the infections sited in the potential spaces and fascial planes of the neck within the limits of the deep layer of the cervical fascia. Parapharyngeal and retropharyngeal infections leading to parapharyngeal abscess (PPA) and retropharyngeal abscess (RPA) are the most common. DNIs remain an important health problem, especially in children. The aim of this narrative review is to describe the management of peritonsillar, retropharyngeal and parapharyngeal abscesses in pediatric age. Despite relatively uncommon, pediatric DNIs deserve particular attention as they can have a very severe course and lead to hospitalization, admission to the intensive care unit and, although very rarely, death. They generally follow a mild upper respiratory infection and can initially present with signs and symptoms that could be underestimated. A definite diagnosis can be made using imaging techniques. Pus collection from the site of infection, when possible, is strongly recommended for definition of diseases etiology. Blood tests that measure the inflammatory response of the patient may contribute to monitor disease evolution. The therapeutic approach should be targeted toward the individual patient. Regardless of the surgical treatment, antibiotics are critical for pediatric DNI prognosis. The diagnostic-therapeutic procedure to be followed in the individual patient is not universally shared because it has not been established which is the most valid radiological approach and which are the criteria to be followed for the differentiation of cases to be treated only with antibiotics and those in which surgery is mandatory. Further studies are needed to ensure the best possible care for all children with DNIs, especially in this era of increased antimicrobial resistance.

MRI Findings in Acute Tonsillar Infections

BACKGROUND AND PURPOSE

Previous literature is vague on the prevalence and exact nature of abscesses in tonsillar infections, ranging from intratonsillar and peritonsillar collections to deep extension involving the parapharyngeal and retropharyngeal spaces. MR imaging has excellent diagnostic accuracy in detecting neck infections and can potentially clarify this issue. We sought to characterize the spectrum of MR imaging findings regarding tonsillar infections.

MATERIALS AND METHODS

We conducted a retrospective cohort study of emergency neck MR imaging scans of patients with tonsillar infections. Imaging data were assessed in terms of signs of infection and the location of abscesses and were compared with clinical findings, final diagnoses, and surgical findings as reference standards.

RESULTS

The study included 132 patients with tonsillar infection. Of these, 110 patients (83%) had ≥1 abscess (99 unilateral, 11 bilateral; average volume, 3.2 mL). Most abscesses were peritonsillar, and we found no evidence of intratonsillar abscess. Imaging showed evidence of parapharyngeal and retropharyngeal extension in 36% and 10% of patients, respectively. MR imaging had a high positive predictive value for both abscesses (0.98) and deep extension (0.86). Patients with large abscesses and widespread edema patterns had a more severe course of illness.

CONCLUSIONS

Emergency neck MR imaging can accurately describe the extent and nature of abscess formation in tonsillar infections.

Usefulness of Virtual Monochromatic Images and Iodine Maps Derived from Dual-Energy Computed Tomography for Diagnosing Deep Neck Abscesses

OBJECTIVE

We aimed to determine whether dual-energy computed tomography (CT) is useful for evaluating deep neck abscesses.

METHODS

This study included 22 consecutive patients who were clinically suspected of having a deep neck abscess and underwent dual-energy CT. Conventional 120-kVp images, 70- and 40-keV virtual monochromatic images (VMIs), and iodine maps were inspected to calculate the contrast ratio of the abscess rim (AR) to the abscess center (AC) or to the adjacent muscle (M). The diagnostic certainty of abscesses was assessed on these images.

RESULTS

Twenty (91%) of 22 patients had a definitive diagnosis. The contrast ratio for AR/AC and AR/M was significantly higher on 40-keV VMIs and iodine maps than on 120-kVp images and 70-keV VMIs (P < 0.05). On both 40-keV VMIs and iodine maps, the diagnostic certainty of abscess improved in 3 (15%) cases compared with 120-kVp images and 70-keV VMIs.

CONCLUSIONS

Dual-energy CT-based 40-keV VMIs and iodine maps are useful for evaluating deep neck abscesses and may improve diagnostic certainty.

Neck swelling from a retropharyngeal abscess caused by penicillin-resistant Streptococcus pneumoniae: a case report

Background

In small children, retropharyngeal abscesses usually occur after upper respiratory tract infections. Unlike in adults, these abscesses are difficult to diagnose in small children, and can rapidly develop into deep neck or mediastinal abscesses.

Case presentation

A 2-year-old Japanese boy recently presented to our department with a chief complaint of neck swelling. Physical examination revealed bilateral tonsillitis and swelling of the left posterior pharyngeal wall. Emergency neck computed tomography angiography showed a contrast-enhanced abscess cavity posterior to the left retropharyngeal space, and a low-density area surrounded by an area without contrast enhancement in the posterior neck. The latter was suspected to be a deep neck infection secondary to a retropharyngeal abscess. After surgery, the patient was diagnosed with a retropharyngeal abscess and concurrent cystic lymphangioma. The lesions improved after intraoral incision and drainage, and administration of antibiotics.

Conclusion

Lymphangiomas and retropharyngeal abscesses are both known to be more common in children than in adults. However, we found no other reports of concomitant presentation of lymphangioma and retropharyngeal abscess in the literature.

Management of intratonsillar abscess in children

BACKGROUND

The aim of this study was to assess outcomes of medical and surgical treatment of intratonsillar abscess in children.

METHODS

The medical charts of children with intratonsillar abscess were reviewed to obtain information on history and physical examination, imaging, management, and follow-up assessment.

RESULTS

Eleven children (six male, five female; age range, 4-18 years) were identified. The common complaints included sore throat, fever, and odynophagia. Asymmetric tonsil hypertrophy was present in nine patients and erythema of tonsils in all patients. Peritonsillar fullness was present in three patients. One patient needed emergency intubation due to respiratory compromise. Computed tomography indicated unilateral intratonsillar abscess in nine patients, bilateral intratonsillar abscess in one, and unilateral phlegmon in one. Inflammatory changes were observed in the parapharyngeal space in all patients, retropharyngeal space in one, and pyriform sinus and aryepiglottic folds in two. Antibiotic treatment included clindamycin in seven patients, ampicillin/sulbactam in one, and clindamycin plus ceftriaxone in three. The patients with respiratory compromise underwent surgery prior to antibiotic treatment. Patients with isolated intratonsillar abscess or phlegmon had resolution of their symptoms with i.v. antibiotic treatment. Patients with combination of intratonsillar and peritonsillar abscess required incision and drainage of peritonsillar abscess.

CONCLUSIONS

Clinically stable children with intratonsillar abscess or phlegmon respond to i.v. antibiotic therapy. Surgical drainage can accomplish clinical resolution in the presence of a combination of intra- and peri-tonsillar abscess, airway compromise, or unresponsiveness to medical treatment.

Children with Deep Space Neck Infections

Objective

To identify clinical features associated with unsuccessful medical therapy in children with deep space neck infections (DSNIs).

Study Design

Consecutive case series with chart review.

Setting

Tertiary-care, academic children’s hospital.

Subjects and Methods

One hundred seventy-eight pediatric patients treated for retropharyngeal or parapharyngeal infections between July 1, 2007, and May 23, 2012.

Results

Median age was 34.5 months (2.9 years; range, 2-142 months); two-thirds were male. Increased surgical drainage was found in children age ≤15 months ( P = .002) and for abscesses >2.2 cm ( P = .0001). Risk factors associated with increased likelihood of medical therapy failure included age ≤51 months, intensive care unit admission, and computed tomography findings consistent with abscess size >2.2 cm. Methicillin-resistant Staphylococcus aureus infections were found more often in younger children, with the highest incidence in those ≤15 months of age ( P = .001). All children had resolution of infection.

Conclusion

Deep space neck infections in children can often be successfully managed with medical therapy alone, but life-threatening complications may occur. We recommend that young patients be managed cautiously.

Comparison of preoperative computed tomography and surgical findings in maxillofacial infections

PURPOSE

To examine the accuracy of computed tomography (CT) in predicting the presence of surgically confirmed abscess in patients presenting with deep maxillofacial infections (DMIs).

MATERIALS AND METHODS

The medical records of 36 patients with clinically suspected DMI were reviewed. All patients underwent preoperative CT scan to determine whether abscess or cellulitis was present. The operative reports of all patients were compared with their preoperative CT scan findings.

RESULTS

Of 36 patients, 30 had abscess predicted by preoperative CT scan. The positive predictive value for DMI based on CT findings interpreted by an oral surgeon and confirmed as an abscess at operation was 90%, whereas the negative predictive value was 33%. When findings were interpreted by a radiologist, the positive predictive value was 94.1% whereas the negative predictive value was 26.3%. Thirty patients had abscess predicted by preoperative CT scan when interpreted by an oral surgeon, whereas seventeen had abscess predicted by a radiologist. At operation, 3 of 30 patients had cellulitis whereas 27 had abscess, for a false-positive rate of 60% and false-negative rate of 12.9%. On the basis of preoperative radiography, 1 of 17 patients had cellulitis whereas 16 had abscess, for a false-positive rate of 16.7% and a false-negative rate of 46.7%. The agreement between CT and operative findings in predicting abscess by an oral surgeon was 80.6% and by a radiologist was 58.3%.

CONCLUSION

CT yielded high sensitivity for the detection of DMI abscess but poor specificity, likely because of the paucity of cellulitis.

Clinical features and treatment of retropharyngeal abscess in children

OBJECTIVE: To characterize presentation, treatment, and outcomes of pediatric retropharyngeal abscess (RPA) and determine optimal treatment.

STUDY DESIGN: Retrospective cohort.

SUBJECTS AND METHODS: Chart review of 162 pediatric patients with RPA.

RESULTS: Initial treatment was surgery in 126 and intravenous antibiotics in 36, of which 17 required surgery. Findings were negative in 30, murky fluid in 34, and pus in 79. Factors predicting positive surgical drainage were duration of symptoms for more than 2 days, prior antibiotic treatment, and CT lesion cross-sectional area >2.0 cm2. A history of rash was a negative predictor. The mean length of stay (LOS) was 4.8 vs 3.6 days ( P = 0.14), and duration of fever (DOF) was 2.5 vs 1.4 days ( P = 0.01) for patients with no fluid and fluid at surgery, respectively. For antibiotic vs surgery groups, LOS was 4.4 vs 3.6 days ( P = 0.14) and DOF was 2.4 versus 1.5 days ( P = 0.0061).

CONCLUSIONS: These predictive factors may be useful in selecting patients with retropharyngeal abscesses who might be treated with intravenous antibiotics alone.

Predicting deep neck space abscess using computed tomography

PURPOSE

To investigate objective measures that could increase the positive predictive value of computed tomography (CT) in diagnosing deep neck space infections (DNSIs).

METHODS

A retrospective analysis of patients surgically treated at a tertiary care hospital for DNSIs for more than 2 years were reviewed. Patients who had had CT with contrast scanning suggestive of deep neck space abscess within 24 hours before surgery were included. The average Hounsfield units for each abscess were calculated. Based on the intraoperative finding of pus, the patients were divided into groups. Student t tests compared the average Hounsfield units, white blood cell count, and maximum temperature between the groups. Outcomes were measured by comparing overall length of hospital stay, length of postoperative stay, and complications.

RESULTS

Of the 32 patients surgically drained, 24 (75%) had discreet collections of pus, whereas 12 (25%) did not. Hounsfield unit measurement was not reliable in distinguishing abscess from phlegmon. None of the other clinical variables studied to distinguish abscess from phlegmon were statistically different either. A statistical difference between the 2 groups was not identified.

CONCLUSION

Although CT with contrast plays an important role in the diagnosis and management of DNSIs, the decision for surgical drainage of an abscess should be made clinically. A negative exploration rate of nearly 25% despite careful selection criteria should be expected.

History of possible foreign body ingestion in children: don??t forget the rarities

Foreign body ingestion in children is a common presenting complaint to the emergency department. Although the majority of ingested foreign bodies pass through the gastrointestinal tract unaided, some children will require either non-surgical or surgical intervention. Retained oesophageal foreign bodies may cause a multitude of problems, including mucosal ulceration, inflammation or infection, and more seriously paraoesophageal or retropharyngeal abscess formation, mediastinitis, empyema, oesophageal perforation and aorta-oesophageal fistula formation. We present a case of a 12-month-old child in whom delayed diagnosis of glass ingestion resulted in the development of a retropharyngeal abscess, oesophageal perforation and mediastinitis. Such complications following foreign body ingestion in children are rare but potentially fatal. A high index of suspicion must be maintained in young children presenting with a possible history of foreign body ingestion as a delayed diagnosis may lead to significant morbidity and mortality. We review the literature surrounding paediatric retropharyngeal abscesses and mediastinitis.

Cystic malformations of the neck in children

The most common cystic malformations of the neck are the result of abnormal embryogenesis involving the thyroglossal duct (TGD), lymphatic primordia and the branchial apparatus. When the basic embryology of these structures is considered, a reasonable differential diagnosis-and in some cases a definitive diagnosis-can be achieved based on the location and the imaging characteristics of the cystic mass.

Retropharyngeal and parapharyngeal infections in children: the Toronto experience

OBJECTIVE

To review the Hospital of Sick Children, Toronto's experience of the diagnosis and management of retropharyngeal and parapharyngeal infections with particular emphasis on the role of computed tomography (CT) imaging in diagnosing the presence of an abscess.

METHODS

A retrospective analysis of all patients diagnosed with retropharyngeal and parapharyngeal infections from 1987 to 1999 was performed. Demographic data, presenting symptoms, season of presentation, management and complications were reviewed. The CT scans of 27 patients who underwent surgical treatment were retrospectively examined by two neuroradiologists who were blinded to the patient's history and outcome. The sensitivity, specificity and predictive values for the specific features and overall assessment were calculated.

RESULTS

Fifty-four children were identified. There were 46 retropharyngeal infections, 6 parapharyngeal infections and 2 patients had both retropharyngeal and parapharyngeal infections. All patients were treated with parenteral antibiotics. Thirty-seven patients underwent surgical drainage and in 27 there was a positive finding of pus. The retrospectively assessed CT scans of the 21 patients who underwent surgery were found to have a sensitivity of 81% in detecting an abscess by CT scan but the specificity was 57%. There were four complications including mediastinitis, aspiration pneumonia, internal jugular vein thrombosis and common carotid artery aneurysm. All patients recovered but abscess recurred in five patients.

CONCLUSION

Not all patients with retropharyngeal and parapharyngeal abscesses require surgery. Whilst CT scans are helpful in diagnosing and assessing the extent of these infections they are not always accurate in detecting an abscess. A decision to drain an abscess should therefore not be made based solely on the CT findings.

[Retropharyngeal and lateral pharyngeal abscesses in children]

OBJECTIVE

Review of the diagnostic and management of retropharyngeal and lateral pharyngeal abscesses in children.

PATIENTS AND METHODS

Retrospective study of 5 children's cases hospitalized during year 2003.

RESULTS

Diagnosis included CT scan which is often helpful to differentiate cellulitis from abscesses. First medical management consists in an intravenous broad-spectrum antibiotics. Surgical drainage may be considered in cases of failure or clinical aggravation. Closed observation is mandatory in all cases to prevent major complication.

CONCLUSION

Retropharyngeal and lateral pharyngeal abscesses in children are life-threatening infectious. Therapeutic consists in intravenous broad-spectrum antibiotics associated, if necessary, with surgical drainage in cases of persistent abscess.

Retropharyngeal cellulitis in a 5-week-old infant

An infant who presents with acute, unexplained crying requires a thorough examination to identify the source of distress. We report the case of a 5-week-old infant who had sudden irritability and was found to have retropharyngeal cellulitis caused by group B Streptococcus.

Retropharyngeal abscess: epiglottitis of the new millennium

From 1993 through 1999, 26 children with retropharyngeal abscess and 2 children with acute epiglottitis were cared for by pediatric otolaryngologists in northern Virginia. Fever, sore throat, dysphagia, refusal to swallow, dysphonia, drooling, and neck extension are common presenting signs and symptoms in acute epiglottitis and in retropharyngeal abscess. Contrast-enhanced computed tomography of the oropharynx was performed in all cases and was the most helpful diagnostic test.