Characterization of tumors of jaw:Additive value of contrast enhancement and dual-energy computed tomography

BACKGROUND Currently,the differentiation of jaw tumors is mainly based on the lesion’s morphology rather than the enhancement characteristics,which are important in the differentiation of neoplasms across the body.There is a paucity of literature on the enhancement characteristics of jaw tumors.This is mainly because,even though computed tomography(CT)is used to evaluate these lesions,they are often imaged without intravenous contrast.This study hypothesised that the enhancement characteristics of the solid component of jaw tumors can aid in the differentiation of these lesions in addition to their morphology by dual-energy CT,therefore improving the ability to differentiate between various pathologies.AIM To evaluate the role of contrast enhancement and dual-energy quantitative parameters in CT in the differentiation of jaw tumors.METHODS Fifty-seven patients with jaw tumors underwent contrast-enhanced dual-energy CT.Morphological analysis of the tumor,including the enhancing solid component,was done,followed by quantitative analysis of iodine concentration(IC),water concentration(WC),HU,and normalized IC.The study population was divided into four subgroups based on histopathological analysis-central giant cell granuloma(CGCG),ameloblastoma,odontogenic keratocyst(OKC),and other jaw tumors.A one-way ANOVA test for parametric variables and the Kruskal-Wallis test for nonparametric variables were used.If significant differences were found,a series of independent t-tests or Mann-Whitney U tests were used.RESULTS Ameloblastoma was the most common pathology(n=20),followed by CGCG(n=11)and OKC.CGCG showed a higher mean concentration of all quantitative parameters than ameloblastomas(P<0.05).An IC threshold of 31.35×100μg/cm^(3) had the maximum sensitivity(81.8%)and specificity(65%).Between ameloblastomas and OKC,the former showed a higher mean concentration of all quantitative parameters(P<0.001),however when comparing unilocular ameloblastomas with OKCs,the latter showed significantly higher WC.Also,ameloblastoma had a higher IC and lower WC compared to“other jaw tumors”group.CONCLUSION Enhancement characteristics of solid components combined with dual-energy parameters offer a more precise way to differentiate between jaw tumors.

Imaging evaluation of hemoptysis in children

Hemoptysis is an uncommon but distressing symptom in children. It poses a diagnostic challenge as it is difficult to elicit a clear history and perform thorough physical examination in a child. The cause of hemoptysis in children can vary with the child's age. It can range from infection, milk protein allergy and congenital heart disease in early childhood, to vasculitis, bronchial tumor and bronchiectasis in older children. Acute lower respiratory tract infections are the most common cause of pediatric hemoptysis. The objective of imaging is to identify the source of bleeding, underlying primary cause, and serve as a roadmap for invasive procedures. Hemoptysis originates primarily from the bronchial arteries. The imaging modalities available for the diagnostic evaluation of hemoptysis include chest radiography, multi-detector computed tomography(MDCT), magnetic resonance imaging(MRI) and catheter angiography. Chest radiography is the initial screening tool. It can help in lateralizing the bleeding with high degree of accuracy and can detect several parenchymal and pleural abnormalities. However, it may be normal in up to 30% cases. MDCT is a rapid, non-invasive multiplanar imaging modality. It aids in evaluation of hemoptysis by depiction of underlying disease, assessment of consequences of hemorrhage and provides panoramic view of the thoracic vasculature. The various structures which need to be assessed carefully include the pulmonary parenchyma, tracheobronchial tree, pulmonary arteries, bronchial arteries and non-bronchial systemic arteries. Since the use of MDCT entails radiation exposure, optimal low dose protocols should be used so as to keep radiation dose as low as reasonably achievable. MRI and catheter angiography have limited application.

Intraparotid facial nerve schwannoma: A case report

Facial nerve schwannoma occurring within the parotid gland is a rare tumour. We report a case of schwannoma within the parotid gland in a young female patient, who underwent ultrasound and magnetic resonanceimaging(MRI) and subsequent surgical excision of the lesion. The lesion showed hyperintensity on T2-weighted and diffusion-weighted MRI. There was no adjacent lymphadenopathy. Although hyperintensity on diffusionweighted MRI could suggest malignant tumours, the characteristic "string sign" provided the clue for the diagnosis of schwannoma.

Contrast-enhanced multidetector computed tomography features and histogram analysis can differentiate ameloblastomas from central giant cell granulomas

BACKGROUND No qualitative or quantitative analysis of contrast-enhanced computed tomography(CT)images has been reported for the differentiation between ameloblastomas and central giant cell granulomas(CGCGs).AIM To describe differentiating multidetector CT(MDCT)features in CGCGs and ameloblastomas and to compare differences in enhancement of these lesions qualitatively and using histogram analysis.METHODS MDCT of CGCGs and ameloblastomas was retrospectively reviewed to evaluate qualitative imaging descriptors.Histogram analysis was used to compare the extent of enhancement of the soft tissue.Fisher’s exact tests and Mann–Whitney U test were used for statistical analysis(P<0.05).RESULTS Twelve CGCGs and 33 ameloblastomas were reviewed.Ameloblastomas had a predilection for the posterior mandible with none of the CGCGs involving the angle.CGCGs were multilocular(58.3%),with a mixed lytic sclerotic appearance(75%).Soft tissue component was present in 91%of CGCGs,which showed hyperenhancement(compared to surrounding muscles)in 50%of cases,while the remaining showed isoenhancement.Matrix mineralization was present in 83.3%of cases.Ameloblastomas presented as a unilocular(66.7%),lytic(60.6%)masses with solid components present in 81.8%of cases.However,the solid component showed isoenhancement in 63%.No matrix mineralization was present in 69.7%of cases.Quantitatively,the enhancement of soft tissue in CGCG was significantly higher than in ameloblastoma on histogram analysis(P<0.05),with a minimum enhancement of>49.05 HU in the tumour providing 100%sensitivity and 85%specificity in identifying a CGCG.CONCLUSION A multilocular,lytic sclerotic lesion with significant hyperenhancement in soft tissue,which spares the angle of the mandible and has matrix mineralization,should indicate prospective diagnosis of CGCG.

Pediatric vs adult pulmonary tuberculosis:A retrospective computed tomography study

AIM: To compare the manifestations of chest tuberculosis(TB) in pediatric and adult patients based on contrast enhanced computed tomography of chest.METHODS: This was a retrospective study consisting of 152 patients of chest TB including 48 children and 104 adults who had undergone contrast enhanced computed tomography of chest prior to treatment. The patterns and severity of parenchymal, mediastinal and pleural manifestations were analyzed and compared among different age groups.RESULTS: Parenchymal changes observed include consolidation, air space nodules, miliary TB, cavitation, bronchiectasis and fibrosis and these were noted in 60% of children, 71% of adolescents and 76.9% of adults. These changes were more common in right upper lobe in all age groups. There was no significant difference in the frequency of these changes(except nodules) in different age groups. Centrilobular nodules were seen less commonly in children less than 10 years(P = 0.028). Pleural effusion was noted in 28(18.42%) patients and pericardial effusion in 8(5.3%) patients. No significant difference in the serosal involvement is seen among children and adults. Mediastinal adenopathy was seen 70% of children, 76.3% adolescents and 76.9% of adults and paratracheal nodes were seen most frequently. Nodes had similar features(except matting) among all age groups. Matting of nodes was seen more commonly in children(P = 0.014). CONCLUSION: Pediatric chest tuberculosis can have severe parenchymal lesions and nodal involvement similar to adults. The destructive lung changes observed in children needs immediate attention in view of the longer life span they have and hence in formulating optimal treatment strategies.

Multidetector computed tomography of temporomandibular joint: A road less travelled

This article reviews the imaging anatomy of temporomandibular joint(TMJ), describes the technique of multi-detector computed tomography(MDCT) of the TMJ, and describes in detail various osseous pathologic afflictions affecting the joint. Traumatic injuries affecting the mandibular condyle are most common, followed by joint ankylosis as a sequel to arthritis. The congenital anomalies are less frequent, hemifacial microsomia being the most commonly encountered anomaly involving the TMJ. Neoplastic afflictions of TMJ are distinctly uncommon, osteochondroma being one of the most common lesions. MDCT enables comprehensive evaluation of osseous afflictions of TMJ, and is a valuable tool for surgical planning. Sagittal, coronal and 3D reformatted images well depict osseous TMJ lesions, and their relationship to adjacent structures.

craniofacial 软骨肉瘤的二个稀罕案例

The craniofacial region is a rare site for chondrosarcomas.These tumors may have osseous or extraosseous origin.Extraosseous chondrosarcomas have the same histological features as osseous chondrosarcomas.Chondrosarcomas usually present in the fifth to seventh decades of life,although several cases with younger age at presentation have been reported.They usually present as a painless mass that gradually progresses to various complaints,such visual impairment,nasal obstruction,and dental abnormalities.In this article,we present two cases of chondrosarcoma occurring at rather unusual locations.It is important to keep this rare malignancy in the list of differential diagnoses for a mass in the head and neck region,as these tumors may not always show the features typical of this malignancy.

Ominous lung cavity “Tambourine sign”

Mucinous adenocarcinoma represents a rare subtype of adenocarcinoma of the lung, which is frequently invasive and has a poorer prognosis. Of its wide range of imaging appearances, air-space consolidation is the most frequent pattern while cavitary form has only rarely been reported. Despite imaging advancements, the differentiation of benign and malignant cavitary lung lesions sometimes remains imperfect. We propose "Tambourine" sign on computed tomography to raise the suspicion of mucinous adenocarcinoma in a lung cavity, under appropriate clinical settings. The sign indicates an irregular cavity with undistorted prominent thick walled bronchioles within the wall and draping along thereby resembling the musical instrument "tambourine". Adjacent ground glass and internal septations may also be seen.

Multidetector computed tomography imaging of congenital anomalies of major airways:A pictorial essay

Congenital airway anomalies can be asymptomatic or may cause severe respiratory distress requiring immediate treatment.These anomalies can present early in life,or may be just incidental findings.It is important to recognize these entities to realize their clinical significance and to avoid false diagnosis.In this article, the various congenital airway anomalies and their imaging features by multidetector computed tomography (MDCT)are reviewed in order of occurrence during the embryological timeline.This pictorial essay reviews the various distinct congenital airway lesions and their MDCT manifestations.It also provides insight into the embryological basis of the congenital airway lesions encountered.

Diagnosis of osteopetrosis in bilateral congenital aural atresia: Turning point in treatment strategy

Aural atresia is a rare congenital malformation of the external and middle ear. There are several syndromic associations of this anomaly with those involving the first and second branchial arches. Occurrence of aural atresia with sclerosing skeletal dysplasia is unknown and has never been reported. The coexistence of a sclerosing dysplasia can make the surgical treatment in aural atresia difficult and risky; and the auditory improvement may not be as expected. Moreover, internal auditory canal narrowing and hence sensorineural hearing loss in sclerosing dysplasia might add to the already existing conductive hearing loss in such patients. In this case report we have described an unknown association of bilateral microtia with sclerosing skeletal dysplasia(autosomal dominant osteopetrosis) and clinical implications of these two conditions occurring together leading to a change in the management plan.