Signal Intensity Mass Research Articles

Primary sinonasal chondroid chordoma in a pediatric patient: a diagnostic challenge

BackgroundChordomas are rare, malignant tumors typically centered in midline structures such as the clivus and sacrum, with peak prevalence in the fourth decade. Clival chordomas may secondarily extend to involve the nasopharynx and nasal cavity; however, primary extra-osseous chordomas are even more uncommon. We present an unusual case of a primary sinonasal chondroid chordoma arising from the maxillary sinus in a 5-year-old child. This is the second case of primary sinonasal chordoma reported in the literature so far, after Tao ZZ et al. and the first case of the chondroid variant.Case presentationA 5-year-old male presented with right-sided nasal obstruction, nasal congestion, and snoring for 2 months. Physical examination showed a reddish polypoidal mass in the right nasal cavity obstructing the choana with nasal septal deviation toward left side. Radiological examination with CT confirmed the presence of a well-defined, heterogeneously hyperdense lobulated mass in right maxillary sinus extending into right nasal cavity with intralesional coarse calcifications. MRI revealed expansile solid altered signal intensity mass, which appears to be isointense on T1-weighted imaging (T1WI) and heterogeneously hyperintense on T2-weighted imaging (T2WI) with a heterogeneous honeycomb pattern of enhancement. Differentials considered were rhabdomyosarcoma, nasopharyngeal carcinoma, and neuroblastoma metastasis. However, the lesion was pathologically proven as a chondroid chordoma. No association with skull base or clival lesion was found on review.ConclusionsPrimary sinonasal chordomas are rare in occurrence but should be considered a differential for sinonasal masses in the presence of characteristic MRI features, despite their uncommon location.

Abstract 13395: Dapagliflozin Reduces Myocardial Sodium Content and Correlates With Reverse Cardiac Remodeling in Nondiabetic Patients With Heart Failure and Preserved Ejection Fraction (Dapa-Sodium)

Introduction: Myocardial sodium overload is a major determinant of adverse cardiac remodeling in heart failure (HF). Sodium tissue content by 23Na magnetic resonance imaging (23Na-MRI) has been validated in human studies. SGLT-2 inhibition blocks sodium reabsorption in renal proximal tubular cells with remarkable cardiovascular outcomes in HF due to mechanisms not yet fully understood. Hypothesis: SGLT-2 inhibition will decrease myocardial sodium content and it will correlate with reverse remodeling in HFpEF. Aim: To determine whether Dapagliflozin leads to decreased myocardial sodium content and reverses pathological hypertrophy in HFpEF. Methods: Prospective, single-center, open-label study of sixty nondiabetic outpatients with HFpEF underwent baseline 23Na-MRI and initiated with dapagliflozin 10 mg once daily according to GDMT. Absolute changes in myocardium relative sodium signal intensity (rSSI) and left ventricular mass index (LVMi) were analyzed from baseline and at 3-month follow-up with 23Na-MRI. Results: All patients exhibited significantly high baseline myocardium rSSI [0.32 (0.28, 0.34)]; 66% above median [0.24 (0.20, 0.27), P = 0.004], decreasing -30% to [0.27 (0.22, 0.30), P<0.001] at 3 months with Dapagliflozin therapy. These changes were correlated with a significant reduction in LVMi of -13 g/m 2 [from 84 g/m 2 (72, 120) to 71 g/m 2 (63, 95), P<0.001]. Conclusions: Dapagliflozin reduces myocardial sodium content and reverses pathological hypertrophy in patients with HFpEF. These findings suggest that SGLT-2 inhibition acts directly on cardiomyocytes and explains the cardioprotective effects demonstrated though large randomized trials.

Intraoral Endoscopic Approach to Excision of an Infratemporal Fossa Tumour

Introduction: The infratemporal fossa is an inverted pyramid shaped structure that lies at the skull base, posterior to the maxillary sinus. It has a complex anatomy due to its relationship to various important vascular and neural channels. Surgical approaches to this region, via the lateral skull base and access mandibulotomies, have high morbidity. By our minimally invasive intra-oral endoscopic technique, an external incision, bony osteotomies and cranial nerve palsies were avoided with an expedited road to recovery and shorter hospital stay. Case Report: A middle aged lady who presented with left sided facial swelling and numbness was evaluated for the same with a Diagnostic nasal endoscopy and imaging. MRI of the maxilla with contrast revealed a well-defined left infra-temporal fossa soft tissue signal intensity mass, which was subsequently planned for intra-oral endoscopic removal. The surgery was performed via a transvestibular-paramandibular incision through which the endoscope was passed, structures delineated and tumour removed piece meal. Immunohistochemical analysis confirmed that it was a Spindle cell Rhabdomyosarcoma. Hence, she was given post operative chemoradiotherapy and is currently one year post surgery, with good outcomes. Discussion The infratemporal fossa has a varied and complex anatomy, due to its interior location and multiple important neurovascular structures within it. This intra-oral endoscopic approach, although challenging for the novice surgeon, avoided an external scar, providing better cosmesis and also had lesser patient morbidity related to wound gaping and dehiscence. It also allowed a direct and magnified visualization of the neuro-vascular structures in that region, aiding in tumour removal.

Mass signal intensity of Ag2+ ions desorbed from a single gold–silver core-shell nanorod

Capillary action of an Au–Ag core-shell nanorod solution between a copper wire (ϕ = 0.18 mm) and an indium tin oxide (ITO) plate controlled deposition of nanorods. Nanorods were sparsely deposited on a plate, and optical dark-field microscopy revealed the numbers of nanorods in laser-irradiated spots of a laser desorption/ionization (LDI) mass spectrometry. When the numbers of the laser-irradiated nanorods were smaller than 50, silver-ion signal intensities (Ag2+, m/z 214, 216, and 218) were linearly dependent of the nanorod numbers. The mass signal intensity from a single nanorod was estimated in the range of 93–143.

Correlation of Paraspinal Muscle Mass With Decompensation of Sagittal Adult Spinal Deformity After Setting of Fatigue Post 10-Minute Walk.

ObjectiveThe purpose of this study was to investigate the changes in spinopelvic parameters before and after the setting of muscle fatigue along with its correlation with pre-existing paraspinal and psoas muscle mass. MethodsSingle-center retrospective review of prospectively collected data was conducted on 145-adults with symptomatic loss of lumbar lordosis (LL). Radiographs were taken before and after walking for 10 minutes. Magnetic resonance imaging was used to calculate paraspinal muscle (PSM) cross-sectional area (CSA), mean signal intensity, fatty infiltration (FI), and lean muscle mass at thoracolumbar junction (T12) and lower lumbar level (L4). Psoas CSA was calculated at L3. Patients were divided into 2 groups namely compensated sagittal deformity (CSD) (SVA≤4 cm, PT>20°) and decompensated sagittal deformity (DSD) (SVA>4 cm, PT>20°) based on prewalk measurements. ResultsInitial mean SVA was 1.8 cm and 11 cm for CSD and DSD respectively (p < 0.01). After walking, significant deteriorations in SVA, PT–LL (p < 0.01) were observed in CSD without significant change in thoracic kyphosis (TK). All sagittal parameters in DSD deteriorated significantly. DSD group had significantly poorer PSM quality at T12 and L4 compared to CSD group. In CSD group, sagittal decompensation correlated with muscle quality, i.e., decreases in LL (ΔLL) correlated with CSA of PSM/vertebral body (VB) at L4 (r=-0.412, p=0.046) while increases in TK (ΔTK) correlated with CSA of PSM/VB at T12 (r=0.477, p=0.018). ΔSVA and ΔPT correlated with FI at L4 (r=0.577, p=0.003 and r=-0.407, p=0.048, respectively). DSD group, had weak correlations (-0.3<r<-0.1) between changes in sagittal and PSM parameters. ConclusionPSM quality in adults with spinal deformity correlates with patients’ ability to maintain an upright posture and sagittal decompensation after walking for 10 minutes.

Arteriovenous Malformations in the Setting of Giant Elephantiasis Neuromatosa

A 65-year-old man presented with giant elephantiasis of the left leg, accompanied by skin pigmentation and local ulceration (Figure A), which had started to grow since he was 4. Numerous café-au-lait spots were found across the trunk. The patient had previously undergone surgery 4 times during recent 10 years and had been diagnosed with neurofibromatosis type 1 (NF-1) based on clinical symptoms and histopathological results. Magnetic resonance imaging revealed extensive inhomogeneous signal intensity masses consisting of multiple flow void vascular structures.

Comparative study of multiwall carbon nanotube nanocomposites by Raman, SEM, and XPS measurement techniques

Substantial research efforts are under way to optimize the production of composites enhanced by the incorporation of nanomaterial fillers such as multiwall carbon nanotubes (MWCNTs). It is therefore critical to develop robust methods to detect and characterize MWCNTs in nanocomposites to measure product performance and potential risks from release of the MWCNTs. In this study, the effectiveness of X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and scanning electron microscopy (SEM) methods is assessed on a series of MWCNT-epoxy nanocomposites samples. A general trend of positive correlation between signal intensity and MWCNT mass loading was observed by both Raman spectroscopy and XPS. Raman spectroscopy was capable of detecting MWCNTs at the lowest nominal concentration tested (0.01%), while for XPS, MWCNTs were detected down to a threshold of approximately 0.5%. Analysis of the same locations of two nanocomposite samples with nominal MWCNT mass fractions of 0.3% and 1% using Raman chemical imaging and SEM revealed a similar detectability of MWCNT clusters and with the higher mass loading sample having a greater number of MWCNT-rich domains. Overall, these results show a good comparability among the different techniques and therefore provide comprehensive, nondestructive microscopy methods to characterize nanocomposites.

Insights on the Working Principles of Secondary Electrospray Ionization High-Resolution Mass Spectrometry for Quantitative Analysis of Aerosol Chemical Composition

Real-time mass spectrometry (MS) has attracted increasing interest in environmental analysis due to its advantages in high time resolution, minimization of sampling artifact, and avoidance of time-consuming sample pretreatment. Among real-time MS methods, secondary electrospray ionization MS (SESI-MS) is showing great promise for the detection of organic compounds in atmospheric particulate matter. In this study, we demonstrated the working principles of secondary nanoelectrospray ionization (Sec-nESI) for real-time measurement of laboratory-generated organic aerosols using l-tartaric acid (TA) as a model compound. Factors affecting the detection of TA particles using a homemade Sec-nESI source coupled with a high-resolution mass spectrometer are systematically investigated. Temperature of ion transport capillary (ITC) was found to be the key factor in determining the ion signal intensity, which shows an increase of intensity by a factor of 100 from ITC temperature of 100–300 °C and could be attributed to more efficient desolvation and ionization. The characteristic fragment ion at m/z 72.99 was selected for quantitative analysis of TA at normalized collision energy of 50%, the optimal value applied during MS/MS analysis. Detection limit of 0.14 µg/m3 and a linear range of 0.2–2.97 µg/m3 are achieved. Satisfactory correlations between ion signal intensity and particle surface area (R2 = 0.969) and mass concentration (R2 = 0.967) were obtained. Although an equally good correlation was observed between signal intensity and particle surface area, the good correlation between signal intensity and particle mass concentration indicates that high solubility of TA ensures efficient dissolution of TA in the primary ESI droplets for further ionization.

Interatrial septal aneurysm mimicking an atrial myxoma on multiparametric cardiovascular magnetic resonance imaging

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Interatrial septal aneurysm (IASA) appears as a localised saccular deformity usually detected during routine echocardiography or stroke evaluation. Imaging hallmarks are &amp;gt;15mm prolapsing motion across the interatrial septum (IAS) and identical content to blood-pool, which are in contrast to this patient. Clinical case An 81-year-old asymptomatic man underwent transesophageal echocardiographic (TEE) right atrial mass assessment revealing a well-circumscribed, mobile mass attached to the interatrial septum suggestive of myxoma. Given previously-excised renal cell carcinoma, gadolinium contrast-enhanced cardiovascular magnetic resonance (CMR) imaging was performed for mass characterisation. Mass signal intensity (SI) was distinct to blood-pool, in keeping with mass content not being blood. Cine imaging revealed an isointense, mobile mass (Figure 1, Video 1) attached to the fossa ovalis. The mass was of intermediate SI isointense to myocardium on T1-weighted, and bright and hyperintense on T2-weighted imaging. First-pass perfusion (Video 2) and early enhancement imaging demonstrated a hypointense, non-perfusing mass. The mass hyperenhanced on late enhancement imaging excluding the differential of thrombus. Imaging findings were entirely consistent with atrial myxoma. Intraoperatively, the excised mass was actually confirmed as an IASA with exquisitely tight neck. Discussion This is the first case of IASA mimicking atrial myxoma on CMR imaging. We postulate that it behaved like a non-perfusing mass as its uniquely narrow neck resulted in extremely slow flow in and out. This permitted minimal blood with contrast entry which remained ‘trapped’ within, resulting in distinct SI to blood pool, and late hyperenhancement. Left atrial pressures forced the mass into the right atrium, preventing typical lateral IASA motion. Conclusion The diagnosis of IASA is best established with TEE while CMR imaging is the reference standard imaging modality for tissue characterization. It is vital to be able to identify and differentiate such entities to avoid misdiagnosis of an IASA as a cardiac myxoma or a malignant cardiac tumour. Nevertheless, we recognize the presence of limitation of imaging in this extraordinary case. Abstract Figure 1

Reproducible Ionization of Gold Nanospheres and Nanostars in Gelatin Sections

Abstract Gold nanospheres were dispersed in gelatin sections (10–100 µm thickness) and their laser desorption/ionization (LDI) efficiencies of gold ions (Au+, Au2+, Au3+) under pulsed-laser irradiation were examined. The mass signal intensities were linear to the surface densities ranging from 6 × 104 to 6 × 106 particles/mm2. When the thickness of the sections was thinner than or equal to 50 µm, the LDI efficiency of gold nanospheres was independent of the thickness. Thus, the mass intensity was dependent on the surface densities of gold nanospheres in the gelatin sections. It was also found that the LDI efficiencies were affected by the concentration of gelatin solutions. Based on the high reproducibility of mass signals obtained from gelatin sections, the LDI efficiencies of star-shaped gold nanoparticles (gold nanostars) were also evaluated. It was found that the nanostars showed higher LDI efficiencies than gold nanospheres, but the enhancement was not more than 25%.

Effects of high intensity ultrasound on disaggregation of a macromolecular procyanidin-rich fraction from Vitis vinifera L. seed extract and evaluation of its antioxidant activity

The impact of high intensity ultrasound (US, 45 and 20 kHz) on a purified macromolecular fraction (more than 85% of polymeric procyanidins) from grape seed extract was investigated. Matrix-Assisted Laser Desorption/Ionisation (MALDI-TOF), Reverse Phase High Performance Liquid Chromatography (RP-HPLC) and Fourier-transform infrared spectroscopy (FTIR) revealed a modification in the chemical structure of these macromolecules treated by US and, particularly, bath US produced a considerable increase of up to 49, 41 and 35%, respectively, of catechins and oligomeric and polymeric procyanidin contents of the treated purified fraction. Bath US also produced an important increase in the number of procyanidins with higher molecular mass (up to decamers) and an overall increase in the mass signal intensities in most of the detected B-type procyanidin series, as well as an important increase of the antioxidant activity of the macromolecular fraction of procyanidins. These results could be ascribed to a certain disaggregation of procyanidins linked to other biopolymers, such as proteins and/or polysaccharides, indicating that US is an efficient technology to modify the chemical structure and hence the bioactivity of tannins.

Quantitative relation between the ESR signal intensities in Ge and E’ centers and quartz mass

Establishing the quantitative relation between electron spin resonance (ESR) signal intensity and quartz mass can help both to improve ESR signal measurement and to allow a greater understanding of the characteristics of ESR color centers. However, this relation has not as yet been clearly defined. We measured the ESR signal intensities in the Ge and E′ centers in the pure quartz in our samples. We applied both standard and additional doses of irradiation by using two different types of spectrometers across different timeframes in an attempt to establish the quantitative relation between the ESR signal intensities in Ge and E’ centers and quartz mass. The linear correlation established between ESR signal intensity and quartz mass was significant for the samples treated with additional irradiation, but there was, overall, no close correlation between ESR signal intensity and quartz mass for samples which were not given additional irradiation doses. A significant correlation between ESR signal intensity and quartz masses of weight ≥0.35 g was established for Ge center, but this was not the case for quartz masses of weight ≤0.3 g. This would suggest that the apparent instability of Ge center is likely aroused by the application of weak signals. The quantitative relation between ESR signal intensity and quartz mass might therefore provide a possible solution for the correction of signal intensities in aliquots of unequal weight in laboratory measurements, particularly for non-irradiated aliquots on the dose growth curve. We would propose that larger quartz masses be used for the clear identification of Ge center signal, for enhancing ESR signal intensity, and for improving the quality of signal measurement.

Adrenal schwannoma: CT, MR manifestations and pathological correlation.

This study aimed to describe the computed tomography (CT), magnetic resonance imaging (MRI) imaging features of adrenal schwannoma and to correlate imaging findings with histopathologic findings. The findings from multiphase CT or MRI examinations of seventeen patients with histopathologically confirmed adrenal schwannoma were reviewed. The imaging criteria included shape, size, margin, attenuation, signal intensity, secondary degeneration, and internal mass enhancement pattern. All cases were unilateral, round or oval solitary tumors, with diameters ranging from approximately 2.5 to 8.8 cm (median = 4.5 cm). Of the twelve cases assessed using CT, adrenal schwannoma appeared as well-circumscribed round or oval low-density suprarenal masses with a mean attenuation values of 30.1 HU of solid portions during unenhanced phase. Ten cases exhibited heterogeneous cyst formation, and one case showed calcification. Internal septa were noted in 5 cases. All solid areas displayed early mild heterogeneous enhancement and delayed progressive enhancement. Regarding MRI, solid portions of five masses were hypointense to the liver parenchyma on T1-weighted imaging (T1WI) and were heterogeneously hyperintense on T2-weighted imaging (T2WI). The enhanced pattern of solid areas of adrenal schwannoma on MRI is similar to that of CT. Cystic or hemorrhagic changes were noted in 4 cases and internal septa were noted in 3 cases. Although schwannoma is a rare entity in the adrenal gland, we believe that the following signs may suggest the diagnosis of this entity: a non-lipid containing mass, a well-defined border, a unilateral mass with cystic or hemorrhagic degeneration, septa with delayed enhancement and a characteristic progressive contrast enhancement pattern of the solid portions.

Simultaneous Presentation of Cerebellopontine Angle Pleomorphic Xanthoastrocytoma and Malignant Melanoma in a Known Case of Neurofibromatosis 1; Probable Role of BRAF Gene: A Case Report and Review of Literature

Introduction: Pleomorphic Xanthoastrocytoma (PXA) is a rare astrocytic neoplasm which mostly affects supratentorial region. The vast majority are sporadic, with only rare examples described in association with neurofibromatosis 1 (NF1), a genetic disorder with neurocutaneous manifestations. Co-occurrence of these 2 rare entities with neoplasm of melanocytes, Cutaneous Malignant Melanoma (CMM), is described in this report for the first time. Case Presentation: A 34-year-old female with established diagnosis of NF1 and left optic nerve glioma from childhood was presented with visual field impairment, decreased level of consciousness and right VI and VII cranial nerves paresis. An irregular hyperpigmented skin lesion was also noted on thoracic area, which histopathological and immunohistochemistry (IHC) study with S100 confirmed CMM. Brain MRI demonstrated high signal intensity mass in right cerebellopontine. Right retro-mastoid craniectomy and total resection of tumor was performed and histopathological investigation of excised lesion along with IHC study with glial fibrillary acidic protein (GFAP), confirmed PXA. Sanger sequencing showed positive BRAF T1799A mutation in both PXA and melanoma’s tissue. Conclusions: The association between BRAF gene mutations and human cancers such as PXA and CMM was discovered. This first ever co-occurrence of mentioned rare disorders emphasizes on probable role of BRAF gene in pathogenesis and whether its inhibitors could serve as an adjuvant agent to facilitate surgical approaches to complex lesions.

ToF-SIMS study of differentiation of human bone-derived stromal cells: new insights into osteoporosis

Lipids have numerous important functions in the human body, as they form the cells' plasma membranes and play a key role in many disease states, presumably also in osteoporosis. Here, the fatty acid composition of the outer plasma membranes of cells differentiated into the osteogenic and adipogenic direction is studied with surface-sensitive time-of-flight secondary ion mass spectrometry (ToF-SIMS). For data evaluation, principal component analysis (PCA) is applied. Human (bone-derived) mesenchymal stromal cells (hMSCs) from an osteoporotic donor and a control donor are compared to reveal differences in the fatty acid composition of the membranes. The chemical information is correlated to staining and real-time quantitative polymerase chain reaction (rt-qPCR) results to provide insight into the gene expression of several differentiation markers on the RNA level. Adipogenic differentiation of hMSCs from a non-osteoporotic donor correlates with increased relative intensities of all fatty acids under investigation. After osteogenic differentiation of non-osteoporotic cells, the relative mass signal intensities of unsaturated fatty acids such as oleic and linoleic acids are increased. However, the osteoporotic cells show increased levels of palmitic acid in the plasma membrane after exposure to osteogenic differentiation conditions, which correlates to an immature differentiation state relative to non-osteoporotic osteogenic cells. This immature differentiation state is confirmed by increased early osteogenic differentiation factor Runx2 on RNA level and by less calcium mineralization spots seen in von Kossa staining and ToF-SIMS images. Graphical abstract Time-of-flight secondary ion mass spectrometry is applied to analyze the fatty acid composition of the outer plasma membranes of cells differentiated into the adipogenic and osteogenic direction. Cells from an osteoporotic and a control donor are compared to reveal differences due to differentiation and disease stage of the cells.

MALDI MS-based analysis of oligosaccharides using 4-(diphenylphosphinyl) benzenamine as non-reductive amination derivatization reagent

Analysis of native oligosaccharides by MS has been a challenge due in part to their limited ionization capacity. To circumvent the problem, oligosaccharides may be chemically derivatized to improve their ionization efficiency. Here, a phosphorus-containing aniline derivative, 4-(diphenylphosphinyl)-benzeneamine (4-DPPBA) was used as a reagent for oligosaccharides non-reductive amination derivatization. In general, without the tedious purification process, a significant increase about 5-fold in the mass signal intensities and 4-fold in S/N ratio were obtained. The derivatization rate is above 98% under the optimized reaction conditions. Compared with aniline, 4-DPPBA shows some merits, such as high derivatization rate, signal intensity, S/N ratio and the changeless fragment pattern between derivative and non-derivative oligosaccharide chains. Based on the advantages, 4-DPPBA is of great potential to be one kind of oligosaccharides derivatization reagent with high performance and widely used in the analysis of oligosaccharides.

Primary Hepatic Neuroendocrine Carcinoma with Multiple Liver Metastases Presenting as Jaundice Due to CBD Obstruction

Background: Whereas more than 80% of NETs found in the liver are metastatic, primary hepatic neuroendocrine tumors (PHNETs) are very rare. We experienced a case of primary hepatic neuroendocrine carcinoma (PHNEC) with multiple liver metastases presenting as jaundice due to the mid CBD obstruction. To the best of our knowledge, few studies have reported similar cases like ours in the English literature. Case presentation: A 81-year-old man was admitted with jaundice of two week's duration. His initial laboratory findings were total bilirubin 19.75 mg/dl, direct bilirubin 15.72 mg/dl, aspartate aminotransferase 65 IU/L, alanine aminotransferase 71 IU/L, alkaline phosphatase 525 U/L, gamma-glutamic transpeptidase 313 U/L and CA19-9 529 U/ml. Abdominal CT revealed marked dilatation of intrahepatic bile duct (IHD) and proximal CBD due to CBD invasion by conglomerated lymphadenopathies in the hepatoduodenal ligament and showed subtly enhancing lesion with central hypodense portion in the liver segment 8/5. MRI with MRCP showed multiple variable sized T2 high signal intensity masses (the largest 3.6 cm) in the both hemiliver, which showed diffusion restriction and delayed enhancement, and diffuse IHD and proximal CBD dilatation with conglomerated lymph nodes at portocaval space and hepatoduodenal ligament. Percutaneous transhepatic biliary drainage was performed, but biopsy could not be done because of concomitant hemobilia. So, we performed sono-guided liver biopsy at the intrahepatic masses. Histopathology revealed poorly differentiated carcinoma. The immunohistochemical staining for CD56, synaptophysin and thyroid transcription factor-1 (TTF-1) revealed positive reaction. So, the diagnosis of neuroendocrine carcinoma, large cell type was confirmed. Chest CT for excluding metastasis from extrahepatic primary site or distant metastatic involvement showed no mass-like lesion in the both lung fields. He refused any methods of treatment such as chemotherapy or transhepatic arterial chemoembolization, and wanted only conservative treatment. Therefore, he was discharged after insertion of self-expandable metal stent at the mid CBD obstruction site and he was died 5 months later. Conclusion: Our case suggests that PHNEC can be presented as multiple intrahepatic masses with CBD obstruction even though PHNETs are very rare. Therefore, it is important to confirm the pathology even in such cases.Figure 1Figure 2

Spatial Autocorrelation in Mass Spectrometry Imaging.

Mass spectrometry imaging (MSI) is a powerful molecular imaging technique. In microprobe MSI, images are created through a grid-wise interrogation of individual spots by mass spectrometry across a surface. Classical statistical tests for within-sample comparisons fail as close-by measurement spots violate the assumption of independence of these tests, which can lead to an increased false-discovery rate. For spatial data, this effect is referred to as spatial autocorrelation. In this study, we investigated spatial autocorrelation in three different matrix-assisted laser desorption/ionization MSI data sets. These data sets cover different molecular classes (metabolites/drugs, lipids, and proteins) and different spatial resolutions ranging from 20 to 100 μm. Significant spatial autocorrelation was detected in all three data sets and found to increase with decreasing pixel size. To enable statistical testing for differences in mass signal intensities between regions of interest within MSI data sets, we propose the use of Conditional Autoregressive (CAR) models. We show that, by accounting for spatial autocorrelation, discovery rates (i.e., the ratio between the features identified and the total number of features) could be reduced between 21% and 69%. The reliability of this approach was validated by control mass signals based on prior knowledge. In light of the advent of larger MSI data sets based on either an increased spatial resolution or 3D data sets, accounting for effects due to spatial autocorrelation becomes even more indispensable. Here, we propose a generic and easily applicable workflow to enable within-sample statistical comparisons.

Homogeneous T1 Hyperintense Renal Lesions with Smooth Borders: Is Contrast-enhanced MR Imaging Needed?

Purpose To retrospectively determine if homogeneous high T1 signal intensity (SI) masses with smooth borders on unenhanced magnetic resonance (MR) images can be characterized as benign. Materials and Methods Institutional review board approval was obtained for this HIPAA-compliant retrospective study, with waiver of informed consent. MR images in 84 patients with hemorrhagic or proteinaceous cysts and 50 patients with renal cell carcinoma (RCC) were evaluated. Sixty-three cysts and 49 RCCs underwent unenhanced computed tomography (CT). SI ratio and CT attenuation were determined. Two radiologists evaluated lesions as follows: score 1, homogeneous with smooth borders; score 2, mildly heterogeneous with mildly lobulated borders; score 3, moderately heterogeneous and irregular borders; and score 4, markedly heterogeneous with markedly irregular borders. Statistical analysis was performed by using multivariable logistic regression, Welch t test, Z test, Fisher-exact test, Shapiro-Wilk test, and receiver operating characteristic curve analysis. A diagnostic criterion was formulated by using classification and regression tree analysis. Results SI ratio and attenuation of hemorrhagic or proteinaceous cysts were significantly higher than those of RCCs (SI ratio: cyst 2.4 ± 0.8, RCC 1.5 ± 0.3; attenuation: cyst 51.9 ± 21.5, RCC: 34.8 ± 10.0). Reader 1 scored morphology of 68 (81%) hemorrhagic or proteinaceous cysts as score 1 on MR images and as score 45 (71%) on CT scans. Reader 2 scored morphology of 59 (70%) hemorrhagic or proteinaceous cysts as score 1 on MR images and as score 43 (68%) on CT scans. Two-step classification tree suggested that homogeneous high T1 SI lesions with smooth borders and SI ratio of greater than 1.6 predict the lesion as benign cysts. Similar algorithm for CT suggested threshold of 51 HU. Increasing threshold to 2.5 for SI ratio and 66 for Hounsfield units resulted in 99.9% confidence for characterizing benign cysts. Conclusion The retrospective assessment shows that morphologic assessment and SI quantification on unenhanced T1-weighted MR images can be used to differentiate benign hemorrhagic or proteinaceous cysts from RCC, although prospective assessment will be needed to confirm these results. (©) RSNA, 2016.

Guanidinylations of albumin decreased binding capacity of hydrophobic metabolites.

As post-translational modifications of proteins may have an impact on the pathogenesis of diseases such as atherosclerosis, diabetes mellitus and chronic kidney disease (CKD), post-translational modifications are currently gaining increasing interest. In this study, a comprehensive method for analysis of these post-translational modifications is established for the clinical diagnostic routine. Here, we analysed albumin - the most abundant plasma protein in human - isolated from patients with CKD and healthy controls by chromatographic steps and identified by MALDI mass spectrometry. Post-translational modifications of albumin were identified after digestion by analysing mass signal shifts of albumin peptides using pertinent mass databases. Albumin isolated from plasma of patients with CKD but not from healthy control subjects was specifically post-translationally modified by guanidinylation of lysines at positions 249, 468, 548, 565 and 588. After identification of guanidinylations as post-translational modifications of albumin isolated from patients with CKD, these modifications were quantified by mass spectrometry demonstrating a significant increase in the corresponding mass signal intensities in patients with CKD compared to healthy controls. The relative amount of guanidinylation of lysine at position 468 in patients with CKD was determined as 63 ± 32% (N = 3). Subsequently, we characterized the pathophysiological impact of the post-translational guanidinylation on the binding capacity of albumin for representative hydrophobic metabolic waste products. In vitro guanidinylation of albumin from healthy control subjects caused a decreased binding capacity of albumin in a time-dependent manner. Binding of indoxyl sulphate (protein-bound fraction) decreased from 82 ± 1% of not post-translationally modified albumin to 56 ± 1% after in vitro guanidinylation (P < 0.01), whereas the binding of tryptophan decreased from 20 to 4%. These results are in accordance with the binding of indoxyl sulphate to albumin from healthy control subjects and patients with CKD (88 ± 3 vs. 74 ± 10, P < 0.01). Thus, in vitro post-translational guanidinylation of albumin had a direct effect on the binding capacity of hydrophobic metabolites such as indoxyl sulphate and tryptophan. We used a mass spectrometry-based method for the characterization of post-translational modification and demonstrated the pathophysiological impact of a representative post-translational modification of plasma albumin. The data described in this study may help to elucidate the pathophysiological role of protein modifications.