Acromioclavicular joint cyst: nine cases of a pseudotumor of the shoulder

Objective: (1) To analyse the imaging appearances of nine patients with acromioclavicular joint cysts presenting as shoulder masses for tumor staging with operative, histopathological and joint aspiration findings. Design and patients: Retrospective review of imaging and correlation with clinical, operative and surgical notes. Images were reviewed by two musculoskeletal radiologists by consensus. Nine patients who presented clinically with a shoulder mass were evaluated by radiographs (n=9), ultrasound (n=1), conventional arthrography (n=3), MRI (n=6; with direct MR arthrography n=2, indirect MR arthrography n=4). Results: All patients had a focal mass superior to the AC joint, with a size ranging from 1.5cm to 6cm and a mean of 3.27cm. Correlation was available with surgery (n=7), histopathology (n=2) and cyst aspiration (n=2). Two patients were managed conservatively. Geyser sign was positive in all three arthrograms. All MRIs revealed extensive rotator cuff tears with a column of fluid extending from the glenohumeral joint through the rotator cuff tear into the acromioclavicular joint and acromioclavicular cyst. Chondrocalcinosis was seen in the acromioclavicular joint cyst (n=2) and in the glenohumeral joint (n=1). Aspirate in two patients contained calcium pyrophosphate dihydrate crystals. Conclusion: Acromioclavicular joint cysts may present as a tumor mass. They are associated with extensive rotator cuff tears and there is usually communication of the cyst with the joint space. This feature excludes a diagnosis of tumor. AC joint cysts may be associated with calcium pyrophosphate dihydrate deposition diseas

Diffusion-weighted MR imaging including bi-exponential fitting for the detection of recurrent or residual tumour after (chemo)radiotherapy for laryngeal and hypopharyngeal cancers

Objectives: To assess whether diffusion-weighted magnetic resonance imaging (DW-MRI) including bi-exponential fitting helps to detect residual/recurrent tumours after (chemo)radiotherapy of laryngeal and hypopharyngeal carcinoma. Methods: Forty-six patients with newly-developed/worsening symptoms after (chemo)radiotherapy for laryngeal/hypopharyngeal cancers were prospectively imaged using conventional MRI and axial DW-MRI. Qualitative (visual assessment) and quantitative analysis (mono-exponentially: total apparent diffusion coefficient [ADCT], and bi-exponentially: perfusion fraction [FP] and true diffusion coefficient [ADCD]) were performed. Diffusion parameters of tumour versus post-therapeutic changes were compared, with final diagnosis based on histopathology and follow-up. Mann-Whitney U test was used for statistical analysis. Results: Qualitative DW-MRI combined with morphological images allowed the detection of tumour with a sensitivity of 94% and specificity 100%. ADCT and ADCD values were lower in tumour with values 120 ± 49 × 10−5mm2/s and 113 ± 50 × 10−5mm2/s, respectively, compared with post-therapeutic changes with values 182 ± 41 × 10−5mm2/s (P < 0.0002) and 160 ± 47 × 10−5mm2/s (P < 0.003), respectively. FP values were significantly lower in tumours than in non-tumours (13 ± 9% versus 31 ± 16%, P < 0.0002), with FP being the best quantitative parameter for differentiation between post-therapeutic changes and recurrence. Conclusions: DW-MRI in combination with conventional MRI substantially improves detection and exclusion of tumour in patients with laryngeal and hypopharyngeal cancers after treatment with (chemo)radiotherapy on both qualitative and quantitative analysis, with FP being the best quantitative parameter in this context. Key Points : • DW-MRI is increasingly used to detect tumour recurrence. • DW-MRI allows accurate post-treatment recurrence detection in laryngeal or hypopharyngeal cancer • ADC values in recurrent tumour are lower than in benign tissue alterations • Both qualitative and quantitative DW-MRI approaches allow detection of recurrence • DW-MRI can easily be added to daily clinical routine imagin

Magnetic resonance imaging of parotid gland tumors: a pictorial essay.

Imaging of parotid gland tumors is challenging due to the wide variety of differential diagnoses. Malignant parotid tumors can have very similar features to benign ones, such as slow growth and displacement instead of infiltration of neighboring structures. Malignant and benign tumors may therefore not be clinically distinguishable. Correct characterization of parotid tumors (i.e., benign or malignant) determines preoperative treatment planning and is important in optimizing the individualized surgical plan. Magnetic resonance imaging (MRI) is the imaging modality of choice for evaluation of suspected parotid gland lesions and differentiation between benign and malignant lesions. Certain conventional MRI features can suggest whether a mass is more likely to be a benign or low-grade malignancy or a high-grade malignancy and adding diffusion-weighted imaging or advanced MRI techniques like perfusion can aid in this distinction. Morphological features seen on MRI, such as low signal on T2-w, infiltrative changes or ill-defined margins, change over time and diffusion restriction can point to the malignant nature of the lesion. MRI is useful for detection and localization of the lesion(s), and associated findings like perineural spread of tumor, lymph node involvement and infiltrative changes of the surrounding tissues. In this pictorial essay, we present selected images of a variety of benign and malignant parotid tumors and emphasize the MRI features that may be useful in their characterization

Cross-sectional imaging in cancers of the head and neck: how we review and report.

Cancer of the head and neck is the sixth most frequent cancer worldwide and associated with significant morbidity. The head and neck area is complex and divided into various anatomical and functional subunits. Imaging is performed by cross-sectional modalities like computed tomography, magnetic resonance imaging, ultrasound and positron emission tomography-computed tomography, usually with fluorine-18-deoxy-D-glucose. Therefore, knowledge of the cross-sectional anatomy is very important. This article seeks to give an overview of the various cross-sectional imaging modalities used in the evaluation of head and neck cancers. It briefly describes the anatomy of the extracranial head and neck and the role of imaging as well as the imaging appearance of tumours and their extension to lymph nodes, bone and surrounding tissue. The advantages and disadvantages as well as basic requirements of the various modalities are described along with ways of optimizing imaging quality. A general guideline for prescription of the various modalities is given. Pitfalls are many and varied and can be due to anatomical variation, due to pathology which can be misinterpreted and technical due to peculiarities of the various imaging modalities. Knowledge of these pitfalls can help to avoid misinterpretation. The important points to be mentioned while reporting are also enumerated

Cancer of the oral cavity and oropharynx

Tumours in the oral cavity and oropharynx differ in presentation and prognosis and the detection of spread of tumour from one subsite to another is essential for the T-staging. This article reviews the anatomy and describes the pattern of spread of different cancers arising in the oral cavity and oropharynx; the imaging findings on computerized tomography and magnetic resonance imaging are also described. Brief mention is made on the role of newer imaging modalities such as [18F]fluorodeoxyglucose-positron emission tomography/computed tomography, perfusion studies and diffusion-weighted magnetic resonance imaging

Imaging in head and neck cancers: Update for non-radiologist.

Head and neck cancer (HNC) is the fifth most frequent cancer worldwide and associated with significant morbidity. Along with clinical examination and endoscopic evaluation, imaging plays an important role in pre- and posttherapeutic evaluation of patients with HNC. Cross-sectional Imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography / computed tomography (PET/CT) are routinely used in the assessment of these patients. This review provides an overview of the various cross-sectional imaging modalities used in the evaluation of HNC and will give a short summary of the latest imaging technologies regarding head and neck cancer diagnosis