Computed tomography and magnetic resonance imaging of maxillofacial lesions in renal osteodystrophy

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.

Uremic Leontiasis Ossea: Theoretical Concepts and Practical Considerations

Leontiasis ossea (LO) in chronic kidney disease patients, also known as Sagliker syndrome, is an exceptionally uncommon uremic complication of long-lasting and severe secondary hyperparathyroidism. The prominent features of uremic LO (ULO) encompass the characteristic clinical trial of massive thickening of maxillary and mandibular bones, widening of interdental spaces, and flattening of nasal bridges and nares. Moreover, during the transformation of craniofacial architecture, significant structural and functional consequences may appear, including upper airway patency, visual and hearing acuity, oral phase of swallowing as well as various neurological and psychiatric disorders. Only few cases of ULO have been reported in the literature until now, making challenging not only the traditional diagnostic procedures but also the optimal therapeutic approach. In this narrative review, we aim to explore the underlying pathophysiological mechanisms, summarize the evidence for adverse outcomes, and highlight the current therapeutic strategies for ULO prevention and treatment, given that precise genetic determinants remain elusive.

CT Assessment of Otic Capsule Bone Density in Paget's Disease of the Temporal Bone and Its Relationship With Hearing Loss

OBJECTIVES

To study computed tomography findings in Paget's disease of temporal bone (PDTB) and analyze the relations between otic capsule bone mineral density values measured in Hounsfield Units (HU) and hearing loss (HL).

STUDY DESIGN

Observational case-control study.

SETTING

Tertiary referral center.

PATIENTS

Radiographically confirmed PDTB cases and control group.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURES

Hearing thresholds and computed tomography bone density values.

RESULTS

Twenty-three ears in the case group (PDTB) and 27 control ears were included. In the PDTB group, HL was found in 87% of the ears (43% mixed) and an air-conduction threshold of 50.7 dB (SD = 19.8). In the control group, 48% of the ears showed HL (7% mixed) and an air-conduction threshold of 34.5 dB (SD = 20.6) was found; the difference was statistically significant (p < 0.05). Measurements of bone density (HU) in the otic capsule (regions of interest [ROI] 1 and 2) and in the petrous bone (ROI 3) were significantly lower (p < 0.05) in the PDTB group than in controls.The PDTB group presented a significant association between otic capsule bone density in ROI 1 and mean otic capsule density with air and bone-conduction thresholds (p < 0.05). In controls, no association was observed between any density value and audiometric thresholds.

CONCLUSION

PDTB patients showed more frequent HL, lower thresholds, and a higher proportion of mixed HL than controls. Bone density (HU) was decreased in all ROIs in PDTB patients in comparison with controls. Bone density in the otic capsule was associated with HL in PDTB patients, but no association was observed between bone density and HL in controls.

Intense Soft Tissue Calcification of the Head and Neck Following Tracheostomy

ABSTRACT

Dystrophic calcification is the accumulation of calcium salts, especially calcium phosphate, which can occur anywhere in the body. Unlike other heterotopic calcifications, it occurs in damaged tissue when there is no calcium imbalance. The most common sites are the heart muscle and valve and it is rarely seen in the head and neck region. It can appear by any cause of soft tissue degeneration such as trauma, infection, inflammation, and neoplasia. It is not symptomatic unless a dystrophic calcification mass is present and is usually detected incidentally. Determination of the etiology plays an important role in the planning of the treatment so that the patient's history, laboratory findings, and imaging methods are very important.

Bone-related disorders of the jaw: A clinico-radiological diagnostic algorithm

Bone-related disorders of the jaw (BRDJ) include a spectrum of non-neoplastic and neoplastic lesions of the maxillofacial region that have been recently classified into fibro-osseous lesions, giant cell lesions and osseous tumours. The histopathological features of BRDJ can be similar and overlie each other. Imaging is important in order to reach a specific diagnosis. However, the appearance of BRDJ on imaging is non-specific in some cases. Computed tomography (CT) and magnetic resonance imaging (MRI) are used for accurate localisation, characterisation of the tumour matrix, delineation of the lesion extension and establishment of the relation of BRDJ to the surrounding structures. Imaging is usually done to detect the relationship with the adjacent surrounding vital structures and to diagnose aggressive forms, malignant transformation and associated syndromes. The correlation of the demographic findings, the location and the clinical presentations with the imaging features are important for the diagnosis of BRDJ. The proposed clinico-radiological diagnostic algorithm with CT and MRI helps a specific diagnosis to be reached in some cases.

Three Rare Concurrent Complications of Tertiary Hyperparathyroidism: Maxillary Brown Tumor, Uremic Leontiasis Ossea, and Hungry Bone Syndrome

A 48-year-old woman in her 40’s with end-stage renal disease and tertiary hyperparathyroidism (HPT) presented for a rapidly progressive maxillary tumor. Initial workup was notable for elevated intact parathyroid hormone (PTH) and diffuse thickening of skull and facial bones on computed tomography, and maxillary tumor biopsy with multinucleated giant cells. She underwent subtotal parathyroidectomy (with removal of a parathyroid adenoma and 2 hyperplastic glands) and partial resection of maxillary brown tumor. The patient’s post-operative course was complicated by hungry bone syndrome, with hypocalcemia refractory to aggressive calcium repletion. Teriparatide (recombinant PTH) was utilized with rapid resolution of hypocalcemia. To our knowledge, this is the first case of maxillary brown tumor in tertiary HPT to be reported in the USA. This case also supports teriparatide as a novel therapeutic for hungry bone syndrome refractory to aggressive calcium repletion.

Craniocerebral metastases from a supraglottic squamous cell carcinoma: A case report and literature review

Craniocerebral metastases as the initial spread of supraglottic squamous cell carcinoma (SCC) are exceptional. The presence of several months' history of dysphagia, dyspnea, cachexia, tobacco/alcohol abuse, and seizure(s) is suspicious of craniocerebral metastases from an advanced-stage supraglottic SCC. Physicians should be aware since early diagnosis and treatment may increase patient survival.

Imaging of brown tumours: a pictorial review

Brown tumours do not represent neoplastic process, but they are focal bony lesions due to bone remodelling from either primary or secondary hyperparathyroidism. Their incidence is also low. The current literature on brown tumour is mainly in the form of case reports that focus on single affected sites. This pictorial review describes the full imaging workup and pathway of suspected brown tumour in the setting of both primary and secondary hyperparathyroidism. It aims to illustrate the management strategy to aid both clinicians and radiologists in suspected cases of brown tumour. We highlight the complementary roles that different imaging modalities can play in different settings including the importance of parathyroid ultrasound, ^99mTc-sestamibi scintigraphy and SPECT/CT in the localisation of the parathyroid adenoma. We present cases with full clinical and imaging workup in both the acute and chronic setting and scenarios that require exclusion of primary and secondary bone malignancies.

Three-dimensional printing of facial contour based on preoperative computer simulation and its clinical application

Facial contouring is a complex procedure performed to alter tissue contents and restore facial appearance. However, it is difficult to measure the amount of the tissue volume that is needed. This study demonstrated the use of preoperative computer simulation (PCS) and 3-dimensional (3D) printing in contouring procedure to maximize outcomes.Three-dimensional surface imaging (3DSI) or computed tomography imaging (CTI) data were reconstructed into a 3D model by Mimics software. PCS was performed by simulating the changes in bone and soft tissue. The stimulating volume change was calculated by Boolean operations. Finally, the virtual model was exported into 3D printer to produce physical templates to guide surgical plan. PCS and actual postoperative results were compared using objective rating scales and by cephalometrical measurements.With the direct guidance of PCS and 3D templates, contouring procedure was performed accurately. Satisfactory facial contouring was achieved with less operative time. As the plastic surgery panel rated, 45.8% of the 3DSI results and 41.7% of the CTI results were identical with the actual outcome, and 0% of them was poor. There were no significant differences in patient satisfaction between the PCS of 3DSI and CTI.Preoperative computer simulation is an accurate method for designing contour adjustment plans, and can be an efficient and reliable predictor of outcomes with customized templates.

Radiological manifestations of renal osteodystrophy in the orofacial region: a case report and literature review

Renal osteodystrophy (ROD) is a metabolic skeletal pathology that frequently affects the orofacial region and presents with characteristic radiological manifestations. This paper reports a case of ROD causing diffused orofacial bone alterations in a female patient with end-stage chronic kidney disease. The radiological features on panoramic, posteroanterior and lateral skull and computed tomography radiographs are described for this case. Previous reports in the literature are reviewed and discussed with a focus on radiological characteristics and differential diagnoses.

Uremic Leontiasis Ossea

Interesting Medical Image

CNNM2 homozygous mutations cause severe refractory hypomagnesemia, epileptic encephalopathy and brain malformations

Magnesium (Mg²⁺) plays a crucial role in many biological processes especially in the brain, heart and skeletal muscle. Mg²⁺ homeostasis is regulated by intestinal absorption and renal reabsorption, involving a combination of different epithelial transport pathways. Mutations in any of these transporters result in hypomagnesemia with variable clinical presentations. Among these, CNNM2 is found along the basolateral membrane of distal tubular segments where it is involved in Mg²⁺ reabsorption. To date, heterozygous mutations in CNNM2 have been associated with a variable phenotype, ranging from isolated hypomagnesemia to intellectual disability and epilepsy. The only homozygous mutation reported so far, is responsible for hypomagnesemia associated with a severe neurological phenotype characterized by refractory epilepsy, microcephaly, severe global developmental delay and intellectual disability. Here, we report the second homozygous CNNM2 mutation (c.1642G > A,p.Val548Met) in a Moroccan patient, presenting with hypomagnesemia and severe epileptic encephalopathy. Thus, we review and discuss the phenotypic spectrum associated with CNNM2 mutations.

Usefulness of preoperative ultrasonographic localization for diagnosis of a rare disease: Intrathyroid parathyroid lesions

The aim of this article is to explore the value of ultrasonic diagnosis and localization of intrathyroid parathyroid diseases.The medical records of 15 patients with surgically confirmed intrathyroid parathyroid diseases were reviewed. We analyzed the diagnosis process and recorded sonographic features of these intrathyroid parathyroid lesions.The patients included 11 females (73%, 11/15) and 4 males (27%, 4/15) with a mean age of 46.2 ± 10.2 years and a mean lesion size of 2.1 ± 1.1 cm. A total of 11 intrathyroid parathyroid lesions in this study presented as hypoechoic (73.3%, 11/15). Nine lesions were located in the right lobe of the thyroid (60%, 9/15), and most of the lesions were located in the middle and inferior thyroid (80%, 12/15). All of the 15 intrathyroid parathyroid lesions were variable in shape and well defined. Only 1 lesion showed microcalcification, which was confirmed as parathyroid adenocarcinoma by the postoperative pathological diagnosis. The blood supply of 13 lesions was plentiful (86.7%, 13/15). A hyperechoic line on the parathyroid lesion was detected in 13 lesions (86.7%, 13/15). Based on the degree to which the parathyroid gland was embedded in the thyroid gland, 12 cases were classified as the complete type (80%, 12/15), and 3 cases were classified as the incomplete type (20%, 3/15). Ultrasound was used to diagnose 10 cases, and sestamibi-SPECT was used to diagnose 11 cases preoperatively; the 2 imaging methods were complementary.Ultrasonic preoperative localization could be helpful in the diagnosis and management of intrathyroid parathyroid diseases.

Craniofacial Manifestations of Systemic Disorders: CT and MR Imaging Findings and Imaging Approach

Many systemic diseases or conditions can affect the maxillofacial bones; however, they are often overlooked or incidentally found at routine brain or head and neck imaging performed for other reasons. Early identification of some conditions may significantly affect patient care and alter outcomes. Early recognition of nonneoplastic hematologic disorders, such as thalassemia and sickle cell disease, may help initiate earlier treatment and prevent serious complications. The management of neoplastic diseases such as lymphoma, leukemia, or Langerhans cell histiocytosis may be different if diagnosed early, and metastases to the maxillofacial bones may be the first manifestation of an otherwise occult neoplasm. Endocrinologic and metabolic disorders also may manifest with maxillofacial conditions. Earlier recognition of osteoporosis may alter treatment and prevent complications such as insufficiency fractures, and identification of acromegaly may lead to surgical treatment if there is an underlying growth hormone-producing adenoma. Bone dysplasias sometimes are associated with skull base foraminal narrowing and subsequent involvement of the cranial nerves. Inflammatory processes such as rheumatoid arthritis and sarcoidosis may affect the maxillofacial bones, skull base, and temporomandibular joints. Radiologists should be familiar with the maxillofacial computed tomographic and magnetic resonance imaging findings of common systemic disorders because these may be the first manifestations of an otherwise unrevealed systemic process with potential for serious complications. Online supplemental material is available for this article. ^©RSNA, 2018.

[Calcifications of the parotid space. A review]

INTRODUCTION

Parotid lithiasis is the main cause of calcifications in the parotid space. However, there are many other less known causes. The aim of our study was to point out the non-lithiasic causes of calcifications in the parotid space.

MATERIAL AND METHODS

We conducted an exhaustive review of the literature by mean of PubMed, using the keywords "parotid" and "calcification" and limiting our analysis to the original articles in humans published in English and in French. Articles reporting about microscopic calcifications and who were not dealing with parotid calcifications were excluded.

RESULTS

Twenty articles met the inclusion criterions. Tumoral and non-tumoral local causes and systemic causes of parotid calcification were found. The way they revealed was variable. The main tumoral local causes were pleomorphic adenomas, salivary duct carcinomas and adenocarcinomas. The main non-tumoral local causes included vascular malformations and calcified parotid lymph nodes. The main systemic causes were chronic kidney diseases, HIV infection, chronic alcoholism, elevated levels of alkaline phosphatase and auto-immune diseases.

DISCUSSION

Eighteen different etiologies of parotid space calcifications could be identified. First line exploration of these lesions relies mainly on conventional radiography and ultrasound examination that are easily available. CT scan remains the reference examination.

Imaging of connective tissue diseases of the head and neck

We review the imaging appearance of connective tissue diseases of the head and neck. Bilateral sialadenitis and dacryoadenitis are seen in Sjögren's syndrome; ankylosis of the temporo-mandibular joint with sclerosis of the crico-arytenoid joint are reported in rheumatoid arthritis and lupus panniculitis with atypical infection are reported in patients with systemic lupus erythematosus. Relapsing polychondritis shows subglottic stenosis, prominent ear and saddle nose; progressive systemic sclerosis shows osteolysis of the mandible, fibrosis of the masseter muscle with calcinosis of the subcutaneous tissue and dermatomyositis/polymyositis shows condylar erosions and autoimmune thyroiditis. Vascular thrombosis is reported in antiphospholipid antibodies syndrome; cervical lymphadenopathy is seen in adult-onset Still's disease, and neuropathy with thyroiditis reported in mixed connective tissue disorder. Imaging is important to detect associated malignancy with connective tissue disorders. Correlation of the imaging findings with demographic data and clinical findings are important for the diagnosis of connective tissue disorders.

Severe maxillofacial renal osteodystrophy in two patients with chronic kidney disease

Renal osteodystrophy (ROD) is the bone pathology that occurs as an uncommon complication related to the several alterations in mineral metabolism present in patients with chronic kidney disease (CKD). This paper describes two cases of severe ROD affecting the maxilla and mandible and causing facial disfigurement of a young and a middle-aged female patient with CKD. Both patients had a history of secondary hyperparathyroidism, previously treated by surgery. The pathogenesis of the disease, as well as its clinical, imaging, and histopathological features, and management of the patient are discussed.