Effect of negative imaging by an opaque screen

2002 ◽  
Author(s):  
Peter V. Polyanskii ◽  
A. D. Arkhelyuk
Keyword(s):  
Opaque Screen ◽  
Negative Imaging

scholarly journals Detection of Bone Marrow Edema in Patients with Osteoid Osteoma Using Three-Material Decomposition with Dual-Layer Spectral CT

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 953
Author(s):  
Florian T. Gassert ◽  
Johannes Hammel ◽  
Felix C. Hofmann ◽  
Jan Neumann ◽  
Claudio E. von Schacky ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Osteoid Osteoma ◽  
Bone Marrow Edema ◽  
Volume Fraction ◽  
Imaging Findings ◽  
Spectral Ct ◽  
Material Decomposition ◽  
Negative Imaging ◽  
Interreader Agreement ◽  
Marrow Edema

The aim of this study is to assess whether perifocal bone marrow edema (BME) in patients with osteoid osteoma (OO) can be accurately detected on dual-layer spectral CT (DLCT) with three-material decomposition. To that end, 18 patients with OO (25.33 ± 12.44 years; 7 females) were pairwise-matched with 18 patients (26.72 ± 9.65 years; 9 females) admitted for suspected pathologies other than OO in the same anatomic location but negative imaging findings. All patients were examined with DLCT and MRI. DLCT data was decomposed into hydroxyapatite and water- and fat-equivalent volume fraction maps. Two radiologists assessed DLCT-based volume fraction maps for the presence of perifocal BME, using a Likert scale (1 = no edema; 2 = likely no edema; 3 = likely edema; 4 = edema). Accuracy, sensitivity, and specificity for the detection of BME on DLCT were analyzed using MR findings as standard of reference. For the detection of BME in patients with OO, DLCT showed a sensitivity of 0.92, a specificity of 0.94, and an accuracy of 0.92 for both radiologists. Interreader agreement for the assessment of BME with DLCT was substantial (weighted κ = 0.78; 95% CI, 0.59, 0.94). DLCT with material-specific volume fraction maps allowed accurate detection of BME in patients with OO. This may spare patients additional examinations and facilitate the diagnosis of OO.

scholarly journals Imaging Appropriateness in Pediatric Radiology during COVID-19 Pandemic: A Retrospective Comparison with No COVID-19 Period

Children ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 463
Author(s):  
Giampiero Bottari ◽  
Giandomenico Stellacci ◽  
Davide Ferorelli ◽  
Alessandro Dell’Erba ◽  
Maurizio Aricò ◽  
...  
Keyword(s):  
Bone Fractures ◽  
Sharp Decrease ◽  
Pediatric Emergency ◽  
Time Interval ◽  
Imaging Studies ◽  
Retrospective Comparison ◽  
Imaging Appropriateness ◽  
Therapeutic Protocols ◽  
The Impact ◽  
Negative Imaging

During the COVID-19 pandemic, the number of accesses to the Pediatric Emergency Department (pED) in Italy sharply decreased by 30%. The purpose of this study is to evaluate how this novel setting impacted on management of children with trauma, and the use and appropriateness of imaging studies in such patients at the pED. All imaging studies performed in patients with trauma at the pED of a tertiary children’s Hospital during the first wave of the COVID-19 pandemic (between March and May 2020) were reviewed, in comparison with a control time interval (March to May 2019). In the pre-COVID control era, 669 imaging studies documented bone fractures in 145/568 children (25.5%). In the COVID-era, 79/177 (44.6%) pediatric patients showed bone fractures on 193 imaging studies. Comparative analysis shows a 71% decrease in imaging studies, and the proportion of negative imaging studies (with no evidence of bone fractures) dropped in 2020 by 19% compared to the 2019 control era (p < 0.001). The sharp decrease of negative studies suggests that the rate of appropriateness was higher during COVID-era, suggesting some attitude toward defensive medicine in the previous control year, as a result of some degree of imaging inappropriateness. The impact of a pandemic on emergency medicine may offer a unique opportunity to revisit diagnostic and therapeutic protocols in pediatrics.

scholarly journals Paratesticular Liposarcoma: A Case Report and Review of the Literature

2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
Haider Alyousef ◽  
Elsawi M. Osman ◽  
Mohamed A. Gomha
Keyword(s):  
Case Report ◽  
Local Excision ◽  
Wide Local Excision ◽  
Histopathological Examination ◽  
Well Differentiated ◽  
The Right ◽  
Paratesticular Liposarcoma ◽  
Paratesticular Mass ◽  
Negative Imaging

Introduction. Liposarcoma is a rare pathological entity. By far it is the most common histological subtype of genitourinary sarcomas in adults. Approximately two hundred cases were reported in the literature. We are hereby presenting a case with a typical clinical scenario of paratesticular liposarcoma.Case report. A 75-year-old gentleman presented with a painless right hemiscrotal swelling that was progressively increasing in size over the last 6 years. Testicular tumour markers were negative. Imaging showed a heterogenous mass with fat component. Subsequently he underwent wide local excision that included the paratesticular mass along with the right testicle and all right inguinal canal contents up to the deep inguinal ring with the sparing of right illioinguinal nerve. Histopathological examination showed a well differentiated liposarcoma of the spermatic cord. He remained recurrence-free so far after 18 months of followup.Conclusion. Radical orchidectomy with wide local excision comprises the cornerstone of treatment of paratesticular liposarcoma. Due to the rarity of the disease there is no definite universal consensus of opinion as regards the role of radiotherapy and chemotherapy.

scholarly journals Bronchoscopy in Patients With Hemoptysis and Negative Imaging Tests

CHEST Journal ◽  
2018 ◽  
Vol 153 (6) ◽  
pp. 1510-1511 ◽  
Author(s):  
Michele Mondoni ◽  
Paolo Carlucci ◽  
Giuseppe Cipolla ◽  
Alessandro Fois ◽  
Stefano Gasparini ◽  
...  
Keyword(s):  
Negative Imaging

Increased serum thyroglobulin levels and negative imaging in thyroid cancer patients

2010 ◽  
Vol 31 (12) ◽  
pp. 1054-1058 ◽  
Author(s):  
Paolo Zanotti-Fregonara ◽  
Isabelle Keller ◽  
Marie Calzada-Nocaudie ◽  
Adil Al-Nahhas ◽  
Jean-Yves Devaux ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Cancer Patients ◽  
Serum Thyroglobulin ◽  
Negative Imaging

Computed tomography in suspected anastomotic leakage after colorectal surgery: evaluating mortality rates after false-negative imaging

2019 ◽  
Vol 46 (5) ◽  
pp. 1049-1053 ◽  
Author(s):  
Nicolò Tamini ◽  
Diletta Cassini ◽  
Alessandro Giani ◽  
Marco Angrisani ◽  
Simone Famularo ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Colorectal Surgery ◽  
Anastomotic Leakage ◽  
False Negative ◽  
Mortality Rates ◽  
Negative Imaging

Temporal Estimation in the Perception of Occluded Motion

1968 ◽  
Vol 26 (2) ◽  
pp. 407-416 ◽  
Author(s):  
Horace N. Reynolds
Keyword(s):  
Moving Object ◽  
Field Of View ◽  
Stimulus Information ◽  
Opaque Screen ◽  
Factors Affecting ◽  
Background Structure ◽  
Temporal Estimation ◽  
Time Required ◽  
Perceived Speed ◽  
Occluded Motion

Ss were shown a rectangular object which moved transversely across their field of view and passed behind an opaque screen. The purpose was to investigate some of the factors affecting estimates of the time required for the occluded moving object to travel a given distance behind the screen. The factors selected for study were (1) method of viewing the moving object (pursuit, static fixation), (2) background structure (homogeneous, textured), and (3) object size. According to previous studies, these variables affect the perceived speed of a moving object and might therefore be expected to affect estimates of the duration of occluded traversal. The results did not show statistically significant differences among experimental groups, although data trends are discussed. An additional finding was that Ss significantly overestimated the duration of occluded traversal, consistent with a tendency to overestimate traversal distance. The experiment is related to Michotte's studies of “amodal perception” and discussed in terms of Gibson's stimulus information approach to perception.

scholarly journals Acute Pancreatitis Secondary to Hemobilia after Percutaneous Liver Biopsy: A Rare Complication of a Common Procedure, Presenting in an Atypical Fashion

2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
Ramy Mansour ◽  
Justin Miller
Keyword(s):  
Acute Pancreatitis ◽  
Liver Biopsy ◽  
Rare Complication ◽  
Signs And Symptoms ◽  
Transcatheter Embolization ◽  
Percutaneous Liver Biopsy ◽  
Imaging Studies ◽  
Common Procedure ◽  
Elevated Alkaline Phosphatase ◽  
Negative Imaging

Percutaneous Liver Biopsy is an often-required procedure for the evaluation of multiple liver diseases. The complications are rare but well reported. Here we present a case of a 60-year-old overweight female who underwent liver biopsy for elevated alkaline phosphatase. She developed acute pancreatitis secondary to hemobilia, with atypical signs and symptoms, following the biopsy. She never had the classic triad of RUQ pain, jaundice, and upper GI hemorrhage. There were also multiple negative imaging studies, thus complicating the presentation. She was successfully treated with ERCP, sphincterotomy, balloon sweep, and stent placement. Angiography and transcatheter embolization were not required.

Formation of a negative image by an opaque screen

1999 ◽  
Vol 25 (3) ◽  
pp. 221-222
Author(s):  
Sh. D. Kakichashvili
Keyword(s):  
Opaque Screen ◽  
Negative Image
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