High resolution MRI of nail tumors and tumor-like conditions.

Although the nail is a small anatomical structure, it can be affected by various tumors and tumor-like conditions. Because of the distinctive nail anatomy, the clinical presentation of tumors is modified, thus rendering the diagnosis challenging. As nail biopsy and surgery are painful procedures associated with an increased risk of permanent onychodystrophy, pre-operative diagnosis is desirable. Although conventional radiographs are still the first-line radiologic examination for the assessment of bony structures beneath the nail matrix, they do not allow detailed evaluation of the phalangeal soft tissues. High resolution MRI allows accurate detection and mapping of nail lesions and can suggest a specific diagnosis. This review focuses on high resolution MRI of nail tumors and tumor-like lesions. We review the nail anatomy and the optimal MRI protocol. We then discuss a variety of tumors and tumor-like lesions in relation to the clinical presentation, anatomic location, histological features and imaging characteristics. We herewith describe common benign tumors (glomus tumor, onychomatricoma, keratoakanthoma, fibroma, subungual exostosis, hemangioma, chondroma, pyogenic granuloma), malignant tumors (subungual melanoma, subungual squamous cell carcinoma), as well as tumor mimics (mucoid cyst, epidermoid cyst). Although not entirely specific, MRI is a valuable tool in treatment planning of these tumors.

Masses of developmental and genetic origin affecting the paediatric craniofacial skeleton.

Although rare, masses and mass-like lesions of developmental and genetic origin may affect the paediatric craniofacial skeleton. They represent a major challenge in clinical practice because they can lead to functional impairment, facial deformation and disfigurement. The most common lesions include fibrous dysplasia, dermoid cysts, vascular malformations and plexiform neurofibromas. Less common lesions include torus mandibularis and torus palatinus, cherubism, nevoid basal cell carcinoma syndrome, meningoencephalocele and nasal sinus tract. This article provides a comprehensive approach for the evaluation of children with masses or mass-like lesions of developmental and genetic origin affecting the craniofacial skeleton. Typical findings are illustrated and the respective roles of computed tomography (CT), cone beam CT (CBCT), magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) sequences and ultrasonography (US) are discussed for the pre-therapeutic assessment, complex treatment planning and post-treatment surveillance. Key imaging findings and characteristic clinical manifestations are reviewed. Pitfalls of image interpretation are addressed and how to avoid them. TEACHING POINTS: • Masses of developmental and genetic origin may severely impair the craniofacial skeleton. • Although rare, these lesions have characteristic imaging features. • CT, MRI and ultrasonography play a key role in their work-up. • Recognition of pivotal imaging pearls and diagnostic pitfalls avoids interpretation errors.

Esophageal pulmonary fistula - a rare complication of radiation therapy: a case report.

BACKGROUND: Esophageal respiratory fistulae are abnormal communications between the esophagus and the respiratory system. They are either congenital or acquired. Most acquired esophageal respiratory fistulae are of the esophageal tracheal and esophageal bronchial type and are caused by infections or malignant neoplasms, whereas esophageal pulmonary fistulae are rare. CASE PRESENTATION: We report a case of a 72-year-old Caucasian man with squamous cell carcinoma of the lung presenting with abrupt-onset dyspnea during localized mediastinal radiotherapy. His laboratory test results suggested major respiratory infection. A chest x-ray revealed left apical lung radiopacity along with excavated lesions, consistent with secondary tumor infection. No clinical improvement was observed despite antibiotic treatment. A contrast-enhanced computed tomographic scan of the chest confirmed persistent lung infection with unfavorable progression and air in the mediastinum; the latter suggested a fistula from the upper third of the esophagus to the upper left pulmonary lobe. Videofluoroscopy confirmed the diagnosis of an acquired esophageal pulmonary fistula. The patient underwent endoscopy, and an esophageal self-expandable metallic stent was deployed. CONCLUSIONS: Esophageal pulmonary fistulae must be suspected whenever patients undergoing local mediastinal radiotherapy present with acute pulmonary complications, particularly pneumonia resistant to antibiotic treatment. Esophageal pulmonary fistulae are diagnosed by means of radiological imaging. Because esophageal respiratory fistulae are acute life-threatening conditions, prompt treatment with an endoscopically placed covered stent proves vital.

Congenital Vomer Agenesis: A Rare and Poorly Understood Condition Revealed by Cone Beam CT.

Isolated congenital vomer agenesis is a very rare and poorly understood condition. In the context of dental work-up by cone-beam computed tomography (CBCT), the explored volume of the facial bones occasionally reveals incidental abnormalities. We report the case of a 13-year old Caucasian female who underwent CBCT for the pre-treatment evaluation of primary failure of tooth eruption affecting the permanent right upper and inferior molars. CBCT depicted a large defect of the postero-inferior part of the nasal septum without associated soft tissue abnormality and without cranio-facial malformation or cleft palate. In the absence of a history of trauma, chronic inflammatory sinonasal disease, neoplasia and drug abuse, a posterior nasal septum defect warrants the diagnosis of vomer agenesis. A discussion of this condition and of salient CBCT features is provided.

Pleomorphic Adenoma Originating from Heterotopic Salivary Tissue of the Upper Neck: A Diagnostic Pitfall.

Pleomorphic adenoma directly arising in the neck is thought to originate from heterotopic salivary gland tissue. In this article, we present the case of a 55-year-old female patient with a histologically proven pleomorphic adenoma located at the left mandibular angle, anteriorly to the sternocleidomastoid muscle and posteroinferiorly to the submandibular gland. As the patient also had an ipsilateral thyroid nodule with coarse calcifications, clinical and radiological features suggested a possible level II metastatic lymph node. However, ultrasound-guided fine needle aspiration cytology and postsurgery histopathological examination revealed a pleomorphic adenoma arising from heterotopic salivary gland tissue unrelated to a benign thyroid nodule. In this article, we provide a review of the existing literature on heterotopic salivary gland tissue and related neoplasms and discuss their imaging presentation.

Carotidynia: A Rare Diagnosis for Unilateral Neck Pain Revealed by Cross-Sectional Imaging.

Idiopathic carotidynia (IC) is a rare and poorly understood syndrome consisting of unilateral neck pain, tenderness, and increased pulsations over the affected carotid bifurcation. A growing body of evidence supports the hypothesis that IC is a distinct clinicopathologic entity with characteristic imaging features. We report the case of a 34-year-old Caucasian male presenting with intense unilateral neck pain in the emergency setting. Computed tomography and ultrasonography revealed fusiform eccentric thickening of the ipsilateral carotid bifurcation without vessel narrowing. Contrast-enhanced magnetic resonance imaging depicted major perivascular enhancement without evidence of dissection. Further imaging and laboratory work-up excluded vasculitis. The diagnosis of IC was made. The patient was treated with nonsteroidal anti-inflammatory drugs and symptoms and imaging findings disappeared within a few weeks. Cross-sectional imaging allows not only ruling out IC mimickers but also making the correct diagnosis of this rare condition, in particular, as the clinical presentation of IC is often nonspecific.

Non-odontogenic tumors of the facial bones in children and adolescents: role of multiparametric imaging.

Tumors of the pediatric facial skeleton represent a major challenge in clinical practice because they can lead to functional impairment, facial deformation, and long-term disfigurement. Their treatment often requires a multidisciplinary approach, and radiologists play a pivotal role in the diagnosis and management of these lesions. Although rare, pediatric tumors arising in the facial bones comprise a wide spectrum of benign and malignant lesions of osteogenic, fibrogenic, hematopoietic, neurogenic, or epithelial origin. The more common lesions include Langerhans cell histiocytosis and osteoma, while rare lesions include inflammatory myofibroblastic and desmoid tumors; juvenile ossifying fibroma; primary intraosseous lymphoma; Ewing sarcoma; and metastases to the facial bones from neuroblastoma, Ewing sarcoma, or retinoblastoma. This article provides a comprehensive approach for the evaluation of children with non-odontogenic tumors of the facial skeleton. Typical findings are discussed with emphasis on the added value of multimodality multiparametric imaging with computed tomography (CT), magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI), positron emission tomography CT (PET CT), and PET MRI. Key imaging findings and characteristic histologic features of benign and malignant lesions are reviewed and the respective role of each modality for pretherapeutic assessment and post-treatment follow-up. Pitfalls of image interpretation are addressed and how to avoid them.

Model-based iterative reconstruction versus adaptive statistical iterative reconstruction in low-dose abdominal CT for urolithiasis.

OBJECTIVE: The purpose of this study was to determine whether there is added benefit to model-based iterative reconstruction as compared with adaptive statistical iterative reconstruction on low-dose abdominal CT in the clinical context of known or suspected urolithiasis. MATERIALS AND METHODS: Fifty-three consecutive patients (35 men, 18 women; mean [SD] age, 52.3 ± 16.6 years) underwent unenhanced low-dose abdominal CT for detection or follow-up of urinary tract stones. Ureteral definition was evaluated subjectively by two blinded readers who scored it from 1 (excellent definition) to 4 (not distinguishable) and objectively by calculating contrast-to-noise ratio (CNR) for soft tissue and fat on a standard 40% adaptive statistical iterative reconstruction and on the corresponding model-based iterative reconstruction series. The position, maximal density, and diameter on the axial plane of stones were also evaluated on both series. RESULTS: There was an almost perfect agreement (κ = 0.872) between readers for subjective evaluation of ureteral definition. The ureteral definition was significantly better for the model-based iterative reconstruction series (mean [SD] score, 1.998 ± 0.839) compared with adaptive statistical iterative reconstruction (mean score, 2.536 ± 0.799) (p < 0.0001). Mean CNR was significantly better on the model-based iterative reconstruction (17.82 ± 4.84) compared with adaptive statistical iterative reconstruction (6.066 ± 1.985) (p < 0.0001). Sixty-nine stones were found in total. Their maximal density measured from model-based iterative reconstruction was significantly higher (754.4 ± 376.5 HU) than that measured from adaptive statistical iterative reconstruction (559.4 ± 352.4 HU) (p < 0.0001). Size of stones was overevaluated on model-based iterative reconstruction (mean diameter, 4.91 ± 2.61 mm) compared with adaptive statistical iterative reconstruction (4.52 ± 2.63 mm) (p < 0.0001). CONCLUSION: Model-based iterative reconstruction of low-dose abdominal CT can offer significantly better ureteral definition than adaptive statistical iterative reconstruction, and its systematic use could thus be recommended. However, it has the tendency to systematically overevaluate the stones' densities and sizes.

Urinary stone detection and characterisation with dual-energy CT urography after furosemide intravenous injection: preliminary results.

OBJECTIVES: To investigate the added advantage of IV furosemide injection and the subsequent urine dilution in the detection of urinary calculi in the excretory phase of dual-source dual-energy (DE) computed tomography (CT) urography, and to investigate the feasibility of characterising the calculi through diluted urine. METHODS: Twenty-three urinary calculi were detected in 116 patients who underwent DECT urography for macroscopic haematuria with a split bolus two- or three-acquisition protocol, including a true unenhanced series and at least a mixed nephrographic excretory phase. Virtual unenhanced images were reconstructed from contrast-enhanced DE data. Calculi were recorded on all series and characterised based on their X-ray absorption characteristics at 100 kVp and 140 kVp in both true unenhanced and nephrographic excretory phase series. RESULTS: All calculi with a diameter more than 2 mm were detected in the virtual unenhanced phase and in the nephrographic excretory phase. Thirteen of these calculi could be characterised in the true unenhanced phase and in the mixed nephrographic excretory phase. The results were strictly identical for both phases, six of them being recognised as non-uric acid calculi and seven as uric acid calculi. CONCLUSIONS: Mixed nephrographic excretory phase DECT after furosemide administration allows both detection and characterisation of clinically significant calculi, through the diluted urine. KEY POINTS: • Urinary tract stones can be detected on excretory phase through diluted urine. • Urinary tract stone characterisation with dual-energy CT (DECT) is possible through diluted urine. • A dual energy split-bolus CT urography simultaneously enables urinary stone detection and characterisation.