SwePub
Tyck till om SwePub Sök här!
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "L773:1473 5628 ;pers:(Jonson Björn)"

Sökning: L773:1473 5628 > Jonson Björn

  • Resultat 1-2 av 2
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Almquist, H, et al. (författare)
  • Performance of simultaneous emission-transmission systems for attenuation-corrected SPEct: a method for validation applied to two camera systems
  • 2001
  • Ingår i: Nuclear Medicine Communications. - 1473-5628. ; 22:7, s. 759-766
  • Tidskriftsartikel (refereegranskat)abstract
    • Several commercially available systems for attenuation correction in single photon emission computed tomography (SPECT) based on a transmission scan have been introduced that vary in performance. A test procedure for attenuation correction in SPECT is described and applied to two principally different gamma camera systems (the Siemens Multispect 3 triple-headed system [3HS] and the ADAC Genesys Vertex double-headed system [2HS]). The test procedure was based on geometrically well-defined phantoms. A torso phantom was used to illustrate the attenuation correction methods. The test procedure can be used without detailed knowledge of or access to the algorithms used for attenuation correction. The influence on the transmission measurement of radioactivity in a phantom was higher for the 2HS than for the 3HS. The 3HS produced satisfactory attenuation maps and corrected emission count rates to a constant value independent of phantom density and size. With the 2HS, there was a progressive decrease in the correction of emission count rates with increasing phantom density, and about 30% lower corrected count rates in the large compared with the small phantom. A decrease in measured attenuation coefficients in the vicinity of an emission source was demonstrated in large but not small phantoms. A likely explanation is erroneous correction of downscatter into the transmission energy window. This study demonstrates the need for independent evaluation of systems for attenuation correction in SPECT.
  •  
2.
  • Jögi, Jonas, et al. (författare)
  • Heart failure diagnostics based on ventilation/perfusion single photon emission computed tomography pattern and quantitative perfusion gradients.
  • 2008
  • Ingår i: Nuclear Medicine Communications. - 1473-5628. ; 29:8, s. 666-673
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE: Left heart failure (LHF) is a common and frequently overlooked condition owing to insufficient diagnostic methods. This can potentially delay onset of treatment. Our clinical experience with ventilation/perfusion single photon emission computed tomography (V/P SPECT) indicates that perfusion shows an antigravitational distribution pattern in LHF. The aim of the study was to test the hypothesis that LHF diagnosis can be made on the basis of V/P SPECT, and to develop and perform a first evaluation of objective parameters for LHF diagnostics in terms of perfusion gradients. METHODS: This retrospective study included 247 consecutive patients with clinical suspicion of pulmonary embolism (PE), who were examined with V/P SPECT. Perfusion gradients were developed and quantified in dorso-ventral and cranio-caudal directions. Quantitative results were compared with visual interpretation of patients with normal and heart failure patterns. Patients with LHF pattern were retrospectively followed up by review of medical records to confirm or discard heart failure diagnosis at the time of V/P SPECT examination. RESULTS: LHF pattern on V/P SPECT was identified in 36 patients (15%), normal ventilation/perfusion pattern was found in 67 patients (27%), and PE in 62 patients (25%). The follow-up confirmed heart failure diagnosis in 32 of the 36 cases with LHF pattern, leading to a positive predictive value of 88% for LHF diagnosis based on V/P SPECT. Dorso-ventral perfusion gradients discriminated normal from LHF patients. CONCLUSION: In patients with suspected PE, LHF is common. Appropriate V/P SPECT pattern recognition, supported by objectively determined dorso-ventral perfusion gradients, allows the diagnosis of LHF. A positive perfusion gradient in the dorso-ventral direction should lead to consideration of heart failure as a possible explanation for the symptoms in these patients.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-2 av 2
Typ av publikation
tidskriftsartikel (2)
Typ av innehåll
refereegranskat (2)
Författare/redaktör
Wollmer, Per (1)
Jögi, Jonas (1)
Bajc, Marika (1)
Almquist, H (1)
Norrgren, K (1)
visa fler...
Palmer, J (1)
Palmer, John (1)
visa färre...
Lärosäte
Lunds universitet (2)
Språk
Engelska (2)
Forskningsämne (UKÄ/SCB)
Medicin och hälsovetenskap (2)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy