Quantitative (99m)Tc DTPA renal transplant scintigraphic parameters: assessment of interobserver agreement and correlation with graft pathologies.

Various (99m)Tc DTPA scintigraphic quantitative parameters for renal graft function assessment have been recommended, but none is universally accepted. In this study, 439 dynamic renal transplant scintigraphies (DRTS) were retrospectively analysed. In the first set of studies, four observers analysed the 47 random DRTS and interobserver agreement of eleven derived parameters was assessed. In the other set of studies, 181 instances of DRTS, performed on 127 recipients with renal biopsies within five days of each other were selected for correlation with pathology. Hilson's Perfusion index (HI), ΔP, P:Pl, P:U & T10 were selected for this analysis. The pathologies were categorized into renal vascular compromise (RVC; n = 20), acute tubular necrosis (ATN; n = 40), vascular rejection (VR; n = 34), interstitial rejection (IR; n = 33), normal (NOR; n = 36) and unclassified pathologies (n = 18). A majority of the parameters showed good Intraclass correlation (ICC). HI differentiated well between grafts with RVC and the remainder of the study cohort, (p < 0.0001; AUC = 0.84); at a cut-off > 278, it had 84% sensitivity and 78% specificity (Likelihood ratio = 3.8). At < 278, it had 98% 'negative' predictive value for RVC. HI also showed reasonable association with VR (p = 0.02; AUC = 0.62) and IR (p = 0.009; AUC = 0.65). However, significant overlap of HI values between various subgroups was noted. Other parameters had good ICC but were not effective in differentiating graft pathologies. Of the measured parameters, only HI proved to be useful for the pathological assessment, particularly in the identification of vascular compromise. This parameter, however, has lower specificity in differentiating the other pathologies.

A comparison of single-photon emission CT lung scintigraphy and CT pulmonary angiography for the diagnosis of pulmonary embolism.

BACKGROUND: This study compared single-photon emission CT (SPECT) ventilation/perfusion (V/Q) scintigraphy with multislice CT pulmonary angiography (CTPA). METHODS: In a prospective, observational study, 100 patients who were >or= 50 years of age were recruited. Seventy-nine patients underwent both diagnostic 16-detector CTPA, and planar and SPECT V/Q scintigraphy. The agreement between the CTPA and the SPECT V/Q scintigraphy for the diagnosis of pulmonary embolism (PE) was calculated. The sensitivity and specificity of blinded SPECT scintigraphy reporting was calculated against a reference diagnosis made by a panel of respiratory physicians that was provided with CTPA and planar V/Q scintigraphy reports, clinical information, and 3-month follow-up data. RESULTS: The observed percentage of agreement between SPECT V/Q scintigraphy and CTPA data for the diagnosis of PE was 95%. When calculated against the respiratory physicians' reference diagnosis, SPECT V/Q scintigraphy had a sensitivity of 83% and a specificity of 98%. CONCLUSIONS: This study indicates that SPECT V/Q scintigraphy is a viable alternative to CTPA for the diagnosis of PE and has potential advantages in that it was feasible in more patients and had fewer contraindications; lower radiation dose; and, arguably, fewer nondiagnostic findings than CTPA. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry Registration Number: ACTRN12609000089235.

Modulation of adenovirus infection in vitro by antisense oligodeoxynucleotides.

OBJECTIVE: Antisense oligodeoxynucleotides (ODNs) may represent a novel, airway directed approach to the treatment of adenovirus infection of the lung, for which no specific therapy exists. This study assessed the efficacy of antisense ODNs in modulating adenovirus infection in vitro. METHODOLOGY: A biological assay, which quantified viral plaque formation by wild type adenovirus 5 in a lung epithelial cell line (A549), was used to evaluate the inhibitory effect of a number of antisense ODNs targeted to the early (E) 1 A and protein IX genes of adenovirus 5. Antisense ODNs (20-21mers, phosphorothioate end-protected) were designed to straddle the initiation of translation (AUG) codon of the mRNA of the targeted gene. RESULTS: There was a consistent and significant (P < 0.005) reduction in viral plaque formation in those cells treated with an E1A antisense ODN, compared with the nonsense control ODN. Neither the addition of a cationic lipid (Lipofectamine), nor increasing the concentration of ODN from 1 micro mol to 15 micro mol enhanced the original inhibitory effect observed with the E1A antisense ODN. CONCLUSIONS: An antisense ODN targeted to the E1A gene can specifically inhibit adenovirus 5 infection in vitro, suggesting a potential therapeutic role for antisense ODNs in adenovirus infection of the lung.