Undetermined Mass Research Articles

Contrast-Enhanced Ultrasound in the Diagnosis of Solid Renal Lesions.

The availability of imaging methods has enabled increased detection of kidney lesions, which are a common clinical problem. It is estimated that more than half of patients over the age of 50 have at least one undetermined mass in the kidney. The appropriate characterization and diagnosis of lesions imaged in the kidney allows for proper therapeutic management. Previously, contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) have been used in their extended diagnosis. However, the limitations of these techniques, such as radiation exposure, renal toxicity, and allergies to contrast agents, must be considered. Contrast-enhanced ultrasound (CEUS) is increasingly being used as an examination to resolve interpretive doubts that arise with other diagnostic methods. Indeed, it can be considered both as a problem-solving technique for diagnosing and distinguishing lesions and as a technique used for observation in preservative treatment. Evaluation of the enhancement curve over time on CEUS examination can help to differentiate malignant renal cell carcinoma (RCC) subtypes that should be resected from benign lesions, such as oncocytoma or angiomyolipoma (AML), in which surgery can be avoided. It allows for distinguishing between benign and malignant tumors, renal and pseudotumors, and solid and cystic tumors. Therefore, with recent advances in ultrasound technology, CEUS has emerged as a fast, reliable, and cost-effective imaging tool in the preoperative evaluation and diagnosis of solid renal masses.

Undetermined masses in adrenal topography: experience of a compound by a tertiary health center

Undetermined masses in adrenal topography: experience of a compound by a tertiary health center

Impact of radiomics on the breast ultrasound radiologist’s clinical practice: From lumpologist to data wrangler

ObjectiveThe study aims to assess the impact of radiomics in the clinical practice of breast ultrasound, to determine which lesions are undetermined by the software, and to discuss the future of the radiologist’s role. MethodsConsecutive analyses of 207 ultrasound masses from January 2018 to April 2019 referred for percutaneous breast biopsy. Breast masses were classified using dedicated ultrasound software (AI). The AI software automatically classified the masses on a scale of 0–100, where 100 is the most suspicious. We adopt the histology results as the gold standard. The cut-off point of malignancy by radiomics was determined, with ±10 % of margin error according to the Youden’s index. We considered these lesions as undetermined masses. The performance of the AI software and the radiologist classification was compared using the area under roc curves (AUROC). We also discuss the impact of radiologist validation of AI results, especially in undetermined lesions. ResultsOf the 207 evaluated masses, 143 were benign, and 64 were malignant. The Youden’s index was 0.516, including undetermined masses with a varied range of 10 % (0.464−0.567). Twenty-one (14.58 %) benign and twelve (19.05 %) malignant masses were in this range. The best accuracy performance to classify masses was the combination of the reader and AI (0.829). The most common undetermined masses in AI were fibroadenoma, followed by phyllodes tumor, steatonecrosis as benign. Whereas, low-grade, and high-grade invasive ductal carcinoma represents the malignant lesions. ConclusionsArtificial Intelligence has a reliable performance in ultrasound breast masses classification. Radiologist validation is critical to determine the final BI-RADS assessment, especially in undetermined masses to obtain the best classification performance

Shear-wave elastography quantitative assessment of the male breast: added value to distinguish benign and malignant palpable masses.

To evaluate the ability of shear-wave elastography (SWE) to distinguish between benign and malignant palpable masses of the adult male breast. Clinical examination, mammography, B-mode and Doppler ultrasound findings and SWE quantitative parameters were compared in 50 benign lesions (including 40 gynaecomastias) and 15 malignant lesions (invasive ductal carcinomas) from 65 patients who were consecutively addressed for specialized advice at our comprehensive cancer centre. Mean elasticity (El mean), maximum elasticity (El max), El mean of the surrounding fatty tissue and lesion to fat ratio (El ratio) were reported for each patient. Malignant masses displayed significantly higher El mean (p < 0.0001), El max (p < 0.0001) and El ratio (p < 0.0001) compared to benign masses without overlap of values between the two groups. By adding SWE to clinical examination, mammography and ultrasound, all the lesions would have been retrospectively correctly diagnosed as benign or malignant. One false positive could have been downstaged, 14/65 undetermined masses could have been correctly reclassified as 4 malignant and 10 benign lesions, for which biopsies could have consequently been avoided. Evaluation of male breast palpable masses by SWE demonstrates that malignant masses are significantly stiffer lesions and may improve diagnostic management when clinical examination, mammography and conventional ultrasound are doubtful. Advances in knowledge: Quantitative SWE is feasible in male breast and could be of great interest to help classify doubtful lesions after classical clinical and radiological evaluations, probably because of different anatomy and different tumours epidemiology compared with female breast.

PM2.5 chemical composition at a rural background site in Central Europe, including correlation and air mass back trajectory analysis

PM2.5 mass concentrations and chemical compositions sampled over a 13-month period at a Central European rural background site (Košetice) are presented in this work. A comprehensive chemical analysis of PM2.5 was performed, which provided elemental composition (Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Y, Zr, and Pb) and the concentration of water-soluble inorganic anions (SO42−, NO3−. Cl−, NO2−, Br−, and H2PO4−) and cations (Na+, NH4+, K+, Ca2+, and Mg2+), elemental and organic carbon (EC and OC), and levoglucosan. Spearman correlation coefficients between individual chemical species and particle number concentrations were calculated for the following six size ranges: 10–25nm (N10–25), 25–50nm (N25–50), 50–80nm (N50–80), 80–150nm (N80–150), 150–300nm (N150–300), and 300–800nm (N300–800).Average concentrations of individual species were comparable with concentrations reported from similar sites across Central Europe. Organic matter (OM) accounted for 45% of the PM2.5 mass (calculated from OC by a factor of 1.6), while the second most common component were secondary aerosols (SO42−: 19%, NO3−: 14%, NH4+: 10%), which accounted for 43% of the mass. Based on levoglucosan analysis, 31% of OM was attributed to emissions associated with biomass burning (OMBB). EC concentrations, determined using the EUSAAR_2 thermal optical protocol, contributed 4% to PM2.5 mass. A total of 1% of the mass was attributed to a mineral matter source, while the remaining 6% was from an undetermined mass. Seasonal variations showed highest concentrations of NO3− and OMBB in winter, nitrate share in spring, and an increase in percentage of SO42− and mineral matter in summer. The largest seasonal variation was found for species associated with wood and coal combustion (levoglucosan, K+, Zn, Pb, As), which had clear maxima during winter. Correlation analysis of different size fraction particle number concentrations was used to distinguish the influence of fresh, local aerosol and aged, long-range transport aerosol.The influences of different air masses were also investigated. The lowest concentrations of PM2.5 were recorded under the influence of marine air masses from the NW, which were also marked by increased concentrations of marine aerosol. In contrast, the highest concentrations of PM2.5 and most major chemical components were measured during periods when continental easterly air masses were dominant.

Avoiding Inappropriate Surgery on Undetermined Mass: May the Combination of Magnetic Resonance Imaging (MRI) and Ovarian Markers Be Helpful?

Avoiding Inappropriate Surgery on Undetermined Mass: May the Combination of Magnetic Resonance Imaging (MRI) and Ovarian Markers Be Helpful?

Identification of perirenal or renal splenosis from undetermined masses: case report and review of the literature

The incidental finding of tumor-llke perirenal or renal splenosis (PRS) creates a challenge to the renal physicians, because its benign nature has to be distinguished from a malignancy. This paper describes the case of a 40-year-old man referred from a local clinic for further evaluation of an incidental finding of left abdominal masses by ultrasonogram suspecting neoplasm, but was eventually confirmed as PRS by obtaining a history of splenectomy that pointed to splenosis and subsequently by a fusion image from single photon emission computed tomography using 99mTc-labelled heat-denatured erythrocytes and computed tomography (hybrid SPECT/CT). In addition, a review of 27 cases of PRS in a MEDLINE search including the present case revealed the following: all the masses were found incidentally and were associated with a history of previous splenectomy or splenic injury; the initial impressions were neoplastic tumor/PRS (n = 9), PRS (n = 10), and neoplastic tumor without consideration of splenosis (n = 8); surgical exploration was undertaken in all the 8 cases of suspected neoplastic tumor only, whereas non-invasive radiological or radionuclide imaging confirmed splenosis in the rest of the cases (n = 19). To avoid unnecessary tests and invasive surgery for undetermined perirenal or renal masses accompanying previous splenic injury, we stress the paramount importance of careful history-taking, physical examination, and a high index of suspicion for splenosis. Also, fusion imaging of hybrid SPECT/CT was reconfirmed as a useful diagnostic technique for accurately detecting and localizing splenic tissues by PRS.

Elastography: Theory into Clinical Practice

To the Editor:Ultrasonography has increasingly been consideredas a useful tool for the diagnosis and management ofbreast lesions (1). With the introduction of highfre-quency digital transducers ranging from 7 to 14 mHz,it is now possible to assess the morphology of theselesions and to categorize them according to the criteria suggested by the most recent BIRADS lexicon (2).However, the study of undetermined masses remains agreat challenge as these lesions present benign sonographic features but no additional data that allowthem to be classified as benign (3). Trials are beingconducted using complementary diagnostic methodsthat allow the categorization of theses masses asbenign, probably benign or suspicious for malignancyand in this context elastography is a promising devel-opment (47).The ultrasound elastography study represents anextension of the most ancient tool used in medicine,i.e., palpation, where the physician assesses the shapeand rigidity of the target organ (8). When externalpressure is applied (stress) onto a target area, thispressure causes tissue deformation (strain). Using specific softwares, tissue deformation is expressed ascolor variation on the ultrasound and may be n usefultool, particularly for the study of breast lesions basedon the assumption that malignant lesions tend to be510 times more rigid than benign (47).This technique was first described by JonathanOphir et al. (4) during the 1990s. Currently, there aretwo main research lines to determine ultrasound elas-tography clinical applicability. The first line ofresearch is based on the assessment of the mass sizebefore and after compressing the target areas with theuse of a software that makes soft lesions appearlighter and rigid lesions appear darker, and in whichmalignant lesions tend to appear more evident thanthe benign lesions (5,6). The other research line isbased on the use of a software that applies a differentcolor spectrum to tissues according to their rigidity,ranging from red to soft tissues, green to intermediatetissues, and dark blue to rigid tissues (Figs. 1 and 2)(7). There is no consensus as to which is the best technique or a classification defining its clinical application, which main limitations are the interobservervariability described in previous studies and how compression should be performed for the study.In a recent study conducted at Santa Casa deMiserico´rdia de Sa˜o Paulo and Centro de TomografiaComputadorizada (CTCGeˆnese) using the ultrasoundsystem Sonix SP (Ultrasonix Medical Corporation,Vancouver, BC, Canada) with multifrequency linearprobes of 514 MHz, and a special software designedfor the device, 256 lesions were evaluated based onthe color spectrum variability. Lesions were classified,using a 4point scoring system developed by theauthors, in two phases: during compression and afterdecompression (almost static compressions). From 256lesions, 215 were benign and 41 malignant; the positive predictive value was 81.8%, the negative predictive value was 97.17%, sensibility was 85.71%,specificity was 96.26%, and the diagnostic accuracywas 94.53%. When compared with conventionalultrasound, a significant improvement in the ability ofobservers to distinguish benign from malignant lesionswas observed (Fig. 3). Through the comparison ofimages during compression and after decompression,it is possible to create parameters to compare thebehavior of target lesions with the adjacent breast tis-sue. The variation in lesion size seen during the studywas not considered a good diagnostic criterion as themargins were not well defined during the dynamicstudy and this was believed to have contributed forthe interobserver variability described in previousseries.The main application of elastography is in the complementary study of undetermined masses, usuallyclassified as BIRADS 3, which mainly comprise complicated cysts, fibroadenomas, and carcinomas withatypical appearance. These lesions are often source ofanxiety, stress, and fear for patients who frequentlyend up choosing to have a biopsy to histologically

Diagnostic Yield of Computed Tomography-Guided Coaxial Core Biopsy of Undetermined Masses in the Free Retroperitoneal Space: Single-Center Experience

The purpose of this study was to evaluate the diagnostic yield of core biopsy in coaxial technique under guidance of computed tomography (CT) for retroperitoneal masses. We performed a retrospective analysis of CT-guided coaxial core biopsies of undetermined masses in the non-organ-bound retroperitoneal space in 49 patients. In 37 cases a 15-G guidance needle with a 16-G semiautomated core biopsy system, and in 12 cases a 16-G guidance needle with an 18-G biopsy system, was used. All biopsies were technically successful. A small hematoma was seen in one case, but no relevant complication occurred. With the coaxial technique, up to 4 specimens were obtained from each lesion (mean, 2.8). Diagnostic accuracy in differentiation between malignant and benign diseases was 95.9%. A specific histological diagnosis could be established in 39 of 42 malignant lesions (92.9%). Correct subtyping of malignant lymphoma according to the WHO classification was possible in 87.0%. Benign lesions were correctly identified in seven cases, although a specific diagnosis could only be made in conjunction with clinical and radiological information. In conclusion, CT-guided coaxial core biopsy provides safe and accurate diagnosis of retroperitoneal masses. A specific histological diagnosis, which is essential for choosing the appropriate therapy, could be established in most cases of malignancy.

Favorable Acute and Long-Term Outcomes after the Resection of Pulmonary Aspergillomas

This retrospective study was designed to examine the acute and long-term outcomes after surgical treatment of patients with pulmonary aspergillomas. From 1992 to 2006, 24 patients (21 men, mean age 58.4 years) with pulmonary aspergillomas underwent pulmonary resection. Operative indications were massive or repetitive hemoptysis in 6 patients, medically unmanageable localized infection in 14 patients, and undetermined mass in 4 patients. Eighteen patients (75.0 %) had background pulmonary diseases and four patients (16.7 %) were mildly immunocompromised. Eight patients had simple aspergillomas, while sixteen patients had complex aspergillomas. Two patients with pleural empyema had their pleural spaces sterilized before pulmonary resections. Fungus balls and pulmonary cavities along with the surrounding lung were removed in all patients. Surgical procedures consisted of 13 lobectomies, 5 pneumonectomies including one completion pneumonectomy, 2 segmentectomies and 4 wedge resections. Postoperative complication occurred in 10 patients (41.6 %) and one patient died from aortic bleeding due to postoperative empyema. Other major complications were prolonged air leaks, bleeding, and chylothorax. In the follow-up period, all but one patient were free from aspergillosis. Hemoptysis was not seen in any patient. Overall survival rates at 2, 5, and 10 years were 86.6 %, 79.4 % and 79.4 %, respectively. Disease-free survival rates from aspergillosis were 86.6 %, 72.6 % and 72.6 % at 2, 5, and 10 years, respectively. Pulmonary resection for aspergilloma showed favorable acute and long-term outcomes when surgical treatment was applied in selected patients.

A rare case of primary chondrosarcoma of the heart

We describe a case of a rare primary chondrosarcoma of the heart in a 62-year-old woman who was referred to our institution with a diagnosis of left atrial undetermined mass. Despite utilization of transesophageal echocardiography and multislice computed tomography imaging, the definitive diagnosis of chondrosarcoma was achieved only with histology of the operative specimen. The tumor was extending from the left atrium to the left pulmonary veins causing obstruction of the venous drainage and a clinical and radiological picture of persistent respiratory infection. Surgery achieved only partial resection of the mass, including the removal of the obstruction to the pulmonary venous drainage. After surgery, a rapid healing of the respiratory infection was observed; however, 3 months later, the tumor was already regrowing rapidly.

Precision measurements of neutrino mixing parameters

Future very long baseline experiments with intense neutrino beams from neutrino factories will allow high precision measurements of the leading oscillation parameters and a search for the presently undetermined mass and mixing parameters.

A search for substellar companions to southern solar-type stars

view Abstract Citations (98) References (52) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Search for Substellar Companions to Southern Solar-Type Stars Murdoch, Kaylene A. ; Hearnshaw, J. B. ; Clark, M. Abstract At the Mount John University Observatory relative radial velocities of solar-type stars have been obtained with a characteristic random error of 55 m/s using a fiber-fed echelle system and digital cross-correlation techniques. A program of obtaining radial velocities of 29 solar-type stars and 10 giant IAU radial-velocity standard stars was carried out over 2.5 years with a view to the detection of low-mass companions to the dwarf stars. One dwarf star turned out to have a previously undiscovered stellar companion but no dwarfs showed radial-velocity variability suggestive of the presence of substellar companions, although one showed a possible variation. In contrast, at least half the giant or supergiant 'standard' stars were variable in radial velocity. Four and possibly five of the giant standards are probably intrinsic (pulsating) red or yellow variables. Two further standards showed long-period variability suggestive of companions of undetermined mass. The lack of brown dwarfs observed in this program is consistent with the results of other recent surveys. Publication: The Astrophysical Journal Pub Date: August 1993 DOI: 10.1086/173003 Bibcode: 1993ApJ...413..349M Keywords: Binary Stars; Companion Stars; Radial Velocity; Stellar Mass Ejection; Brown Dwarf Stars; Random Errors; Stellar Luminosity; Astronomy; STARS: BINARIES: SPECTROSCOPIC; STARS: LOW-MASS; BROWN DWARFS; STARS: LUMINOSITY FUNCTION; MASS FUNCTION full text sources ADS | data products SIMBAD (39)

In-Flight Mass Measurement of Small Fragments and Projectiles

Penetration and cratering studies at hypervelocities make use, primarily, of light gas guns and explosive devices to accelerate projectiles for the impact study. The highest velocities achievable to date with other than micron-sized projectiles are obtained from explosive accelerators (shaped charge) or modified light gas guns incorporating a third stage. Such devices produce one or more randomly shaped particles of undetermined mass; and meaningful impact studies at very high velocities require a method of accurate measurement of the mass of a small fragment after acceleration but before impact. An experimental technique for mass measurement, which is simple in concept and operation, has been developed and demonstrated. A high-speed flash X-ray system is used to photograph the projectile or projectiles in flight. A theoretical treatment utilizing the X-ray mass absorption coefficient of the projectile material, and the linearity of the film density as a function of the logarithm of the exposure, is used to demonstrate that the density change over a finite area of the film is directly proportional to the mass in the path of the X-ray beam. The measurement is independent of ``blurring'' due to the finite exposure time and tumbling of the projectile. Analysis of the exposed film can be conducted in a few minutes and requires only the measurement of average density at five or six positions on the film. Independent measurements of the masses of all projectiles in the field of view are possible. The demonstrated accuracy of the technique is better than ±5 percent.