Plasma cell granuloma of the supraglottic larynx

The occurrence of plasma cell granuloma of the larynx appears to be unusual. Review of the literature revealed only two previously reported cases. We present an additional case of plasma cell granuloma of the larynx. The diagnosis was made by histological and immunohistochemical examinations. The tumour was successfully treated by radiation therap

Severe subcutaneous and deep cervicofacial emphysema of unusual etiology

Subcutaneous and deep cervical emphysema (SCE) in the head and neck are found in a wide spectrum of conditions. Most of them are seen in patients with midfacial trauma or oropharyngeal infections. Subcutaneous and deep cervical emphysema can also be a symptom of life-threatening mediastinitis and/or necrotizing fasciitis, both of which need immediate surgery. Rarely however does SCE occur in isolation as a consequence of elevated intraoral pressure in combination with or without visible lacerations of the oral mucosa. As a consequence, air penetrates the mucosal tears and results in subcutaneous emphysema even extending down to the mediastinum in severe cases. This article describes a series of five cases of isolated SCE. It discusses the diagnosis, the pathomechanism, the differential diagnosis and the treatment. It underlines the importance of anamnesis and careful physical and laboratory examinations in order to differentiate isolated SCE from more severe conditions such as necrotizing fasciitis or mediastinitis, which necessitate immediate surger

Unilateral widening of the inferior alveolar nerve canal: a rare anatomic variant mimicking disease

We report a case of an asymptomatic healthy 49-year-old male patient with an incidental finding of enlargement of the right inferior alveolar nerve (IAN) canal (9 vs. 4mm). After 2years, follow-up magnetic resonance imaging (MRI) revealed no change in the findings. In addition, MR-based diffusion tensor imaging with tractography of the right and left mandibular nerves showed that the difference in size between the right and left nerves was caused by an increased number of nerve fibers in the right IAN. During the entire follow-up period of 4years, the patient remained symptom-free. Therefore, we suggest that the enlargement in our patient was a pure anatomic variant. However, a multitude of conditions are known to produce the identical radiological appearance in conventional radiology, including benign and malignant tumors, vascular malformations, and inflammatory disorders. We describe these pathologies in more detail as well as the possibilities for examinations with different MRI sequence

Diffusion tensor imaging (DTI) and tractography of the brachial plexus: feasibility and initial experience in neoplastic conditions

Introduction: The objective of this study was to assess the feasibility and potential clinical applications of diffusion tensor imaging (DTI) and tractography in the normal and pathologic brachial plexus prospectively. Methods: Six asymptomatic volunteers and 12 patients with symptoms related to the brachial plexus underwent DTI on a 1.5T system in addition to the routine anatomic plexus imaging protocol. Maps of the apparent diffusion coefficient (ADC) and of fractional anisotropy (FA), as well as tractography of the brachial plexus were obtained. Images were evaluated by two experienced neuroradiologists in a prospective fashion. Three patients underwent surgery, and nine patients underwent conservative medical treatment. Results: Reconstructed DTI (17/18) were of good quality (one case could not be reconstructed due to artifacts). In all volunteers and in 11 patients, the roots and the trunks were clearly delineated with tractography. Mean FA and mean ADC values were as follows: 0.30 ± 0.079 and 1.70 ± 0.35mm2/s in normal fibers, 0.22 ± 0.04 and 1.49 ± 0.49mm2/s in benign neurogenic tumors, and 0.24 ± 0.08 and 1.51 ± 0.52mm2/s in malignant tumors, respectively. Although there was no statistically significant difference in FA and ADC values of normal fibers and fibers at the level of pathology, tractography revealed major differences regarding fiber architecture. In benign neurogenic tumors (n = 4), tractography revealed fiber displacement alone (n = 2) or fiber displacement and encasement by the tumor (n = 2), whereas in the malignant tumors, either fiber disruption/destruction with complete disorganization (n = 6) or fiber displacement (n = 1) were seen. In patients with fiber displacement alone, surgery confirmed the tractography findings, and excision was successful without sequelae. Conclusion: Our preliminary data suggest that DTI with tractography is feasible in a clinical routine setting. DTI may demonstrate normal tracts, tract displacement, deformation, infiltration, disruption, and disorganization of fibers due to tumors located within or along the brachial plexus, therefore, yielding additional information to the current standard anatomic imaging protocol

Functional imaging of head and neck squamous cell carcinoma with diffusion-weighted MRI and FDG PET/CT: quantitative analysis of ADC and SUV

Purpose: Head and neck squamous cell carcinoma (HNSCC) may cause a decreased apparent diffusion coefficient (ADC) on diffusion-weighted magnetic resonance imaging (DW MRI) and an increased standardized uptake value (SUV) on fluorodeoxyglucose (FDG) positron emission tomography (PET/CT). We analysed the reproducibility of ADC and SUV measurements in HNSCC and evaluated whether these biomarkers are correlated or independent. Methods: This retrospective analysis of DW MRI and FDG PET/CT data series included 34 HNSCC in 33 consecutive patients. Two experienced readers measured tumour ADC and SUV values independently. Statistical comparison and correlation with histopathology was done. Intra- and inter-observer agreement for ADC and SUV measurements was assessed. Results: Intraclass correlation coefficient (ICC) analysis showed almost perfect reproducibility (>0.90) for ADCmean, ADCmin, SUVmax and SUVmean values for intra-observer and inter-observer agreement. Mean ADCmean and ADCmin in HNSCC were 1.05 ± 0.34 × 10−3 mm2/s and 0.65 ± 0.29 × 10−3 mm2/s, respectively. Mean SUVmean and mean SUVmax were 7.61 ± 3.87 and 12.8 ± 5.0, respectively. Although statistically not significant, a trend towards higher SUV and lower ADC was observed with increasing tumour dedifferentiation. Pearson's correlation analysis showed no significant correlation between ADC and SUV measurements (r −0.103, −0.051; p 0.552, 0.777). Conclusion: Our data suggest that ADC and SUV values are reproducible and independent biomarkers in HNSC

Approaches for the optimization of MR protocols in clinical hybrid PET/MRI studies

Magnetic resonance imaging (MRI) is the examination method of choice for the diagnosis of a variety of diseases. MRI allows us to obtain not only anatomical information but also identification of physiological and functional parameters such as networks in the brain and tumor cellularity, which plays an increasing role in oncologic imaging, as well as blood flow and tissue perfusion. However, in many cases such as in epilepsy, degenerative neurological diseases and oncological processes, additional metabolic and molecular information obtained by PET can provide essential complementary information for better diagnosis. The combined information obtained from MRI and PET acquired in a single imaging session allows a more accurate localization of pathological findings and better assessment of the underlying physiopathology, thus providing a more powerful diagnostic tool. Two hundred and twenty-one patients were scanned from April 2011 to January 2012 on a Philips Ingenuity TF PET/MRI system. The purpose of this review article is to provide an overview of the techniques used for the optimization of different protocols performed in our hospital by specialists in the following fields: neuroradiology, head and neck, breast, and prostate imaging. This paper also discusses the different problems encountered, such as the length of studies, motion artifacts, and accuracy of image fusion including physical and technical aspects, and the proposed solution

Detection and quantification of focal uptake in head and neck tumours: 18F-FDG PET/MR versus PET/CT

Purpose: Our objectives were to assess the quality of PET images and coregistered anatomic images obtained with PET/MR, to evaluate the detection of focal uptake and SUV, and to compare these findings with those of PET/CT in patients with head and neck tumours. Methods: The study group comprised 32 consecutive patients with malignant head and neck tumours who underwent whole-body 18F-FDG PET/MR and PET/CT. PET images were reconstructed using the attenuation correction sequence for PET/MR and CT for PET/CT. Two experienced observers evaluated the anonymized data. They evaluated image and fusion quality, lesion conspicuity, anatomic location, number and size of categorized (benign versus assumed malignant) lesions with focal uptake. Region of interest (ROI) analysis was performed to determine SUVs of lesions and organs for both modalities. Statistical analysis considered data clustering due to multiple lesions per patient. Results: PET/MR coregistration and image fusion was feasible in all patients. The analysis included 66 malignant lesions (tumours, metastatic lymph nodes and distant metastases), 136 benign lesions and 470 organ ROIs. There was no statistically significant difference between PET/MR and PET/CT regarding rating scores for image quality, fusion quality, lesion conspicuity or anatomic location, number of detected lesions and number of patients with and without malignant lesions. A high correlation was observed for SUVmean and SUVmax measured on PET/MR and PET/CT for malignant lesions, benign lesions and organs (ρ = 0.787 to 0.877, p < 0.001). SUVmean and SUVmax measured on PET/MR were significantly lower than on PET/CT for malignant tumours, metastatic neck nodes, benign lesions, bone marrow, and liver (p < 0.05). The main factor affecting the difference between SUVs in malignant lesions was tumour size (p < 0.01). Conclusion: In patients with head and neck tumours, PET/MR showed equivalent performance to PET/CT in terms of qualitative results. Comparison of SUVs revealed an excellent correlation for measurements on both modalities, but underestimation of SUVs measured on PET/MR as compared to PET/CT

Impact of macro-structural reforms on the productivity growth of regions: distance to the frontier matters

Using a panel of 265 regions from 24 OECD countries from 1997 to 2007, we explore the impact of nation-wide macroeconomic and structural policies on the productivity growth of subnational regions. We find that average relationships between nation-wide policies and regional productivity growth can hide strong differentiated effects according to the distance to the frontier: relaxing employment protection legislation on temporary contracts, lowering barriers to trade and investment and increasing trade openness enhances productivity growth in lagging regions, whereas reducing barriers to entrepreneurship or higher levels of government debt has a positive effect on regions closer to the productivity frontier

The Cutaneous Lesions of Dioxin Exposure: Lessons from the Poisoning of Victor Yushchenko

Several million people are exposed to dioxin and dioxin-like compounds, primarily through food consumption. Skin lesions historically called "chloracne” are the most specific sign of abnormal dioxin exposure and classically used as a key marker in humans. We followed for 5 years a man who had been exposed to the most toxic dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), at a single oral dose of 5 million-fold more than the accepted daily exposure in the general population. We adopted a molecular medicine approach, aimed at identifying appropriate therapy. Skin lesions, which progressively covered up to 40% of the body surface, were found to be hamartomas, which developed parallel to a complete and sustained involution of sebaceous glands, with concurrent transcriptomic alterations pointing to the inhibition of lipid metabolism and the involvement of bone morphogenetic proteins signaling. Hamartomas created a new compartment that concentrated TCDD up to 10-fold compared with serum and strongly expressed the TCDD-metabolizing enzyme cytochrome P450 1A1, thus representing a potentially significant source of enzymatic activity, which may add to the xenobiotic metabolism potential of the classical organs such as the liver. This historical case provides a unique set of data on the human tissue response to dioxin for the identification of new markers of exposure in human populations. The herein discovered adaptive cutaneous response to TCDD also points to the potential role of the skin in the metabolism of food xenobiotic