Percorrer por autor "Jessop, Maryam"
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- Bone scan index as metastatic bone disease quantifier and predictor of radium-223-dichloride biochemical responsePublication . Roque, Valentin; Jessop, Maryam; Pereira, Luisa; Gape, Paul; Dizdarevic, Sabina; Sousa, Eva; Carolino, ElisabeteThis work aims to assess whether the biochemical response of radium-223-dichloride treatment can be predicted based on the pretherapy bone scan, and consequently, if bone scan index (BSI) and maximum lesion intensity have a place as alternatives or as complements to extent of bone disease (EOBD) scoring in predicting biochemical response to treatment. Many cases of advanced prostate cancer have evidence of bone metastasis. Accurate EOBD quantification could help predict the response to radium-223-dichloride therapy. Current EOBD score is simple to use but does not consider size, intensity or localization of lesion BSI might be more suitable for stratification of bone metastases. Patients and methods: Bone scans (n=20) preceding radium-223-dichloride treatment for prostate cancer were assessed retrospectively using automated BSI software (EXINI) and by assessing maximum counts per lesion. Results were then compared to total alkaline phosphatase (ALP) as a measure of biochemical response to therapy using linear regressions and to their EOBD scores using box plot analysis. Results: Moderate correlation was found between ALP response and maximum lesion intensity (R2=0.41) and BSI (R2=0.46). A strong correlation (R2=0.71) was found between baseline ALP and BSI and between lesion number and BSI (R2=0.60). Visual assessment of EOBD score was found to correlate well with baseline ALP and maximum ALP response. Conclusion: BSI is a useful asset in the stratification of patients with metastatic bone disease. It may also have a place in the prediction of biochemical response.
- Influence of computed tomography attenuation correction in myocardial perfusion imaging, in obese patients: classification by sex and body mass indexPublication . Stakhiv, O.; Melo, I.; Clarke, M.; Aplin, M.; Singh, N.; Day, K.; Dizdarevic, S.; Jessop, Maryam; Begley, P.; Carolino, Elisabete; Vieira, Lina; Sousa, EvaFour groups of 71 subjects 47 with body mass index (BMI) between 30 and 35 (27 Male (M1) and 20 Female (F1)) and 24 with BMI above 35 ( 13 Male (M2) and 11 Female (F2)) who underwent stress-rest , SPECT MPI of a two day protocol, by EANM guideline protocol, with and without the incorporation of the Attenuation correction by computed tomography (CTAC), for stress and rest separately. For perfusion percentage quantifications, the 5 walls model of the left ventricle (LV) was used: anterior (ANT), lateral (LAT), inferior (INF), septal (SEP) and apical (API), using the QGS/QPSTM software. For statistical evaluation, it was used the Friedman test. Statistically significant differences were found in comparison of studies with and without attenuation correction (AC) for: F1 in stress and rest studies respectively for LAT (p=0.006 and p=0.034), INF (p=0.000 and p=0.000) and in rest study for SEP (p=0.044) LV walls; F2 group of stress and rest studies respectively for INF (p=0.001 and p=0.008) walls; M1 group of stress and rest study respectively for LAT (p=0.000 and p=0.000), INF (p=0.000 and p=0.000) SEP (p=0.003 and p=0.001) walls and just in rest study for API (p=0.045) LV walls; M2 group of stress and rest studies respectively for INF (p=0.000 and p=0.000), LAT (p=0.020 and p=0.014) and in stress study for SEP (p=0.003) LV walls. The influence of CT-AC is bigger within the groups with BMI between 30 and 35.
- Lesion detection performance: comparative analysis of low-dose CT data of the chest on two hybrid imaging systemsPublication . Jessop, Maryam; Thompson, John D.; Coward, Joanne; Sanderud, Audun; Jorge, José; de Groot, Martijn; Lança, Luís; Hogg, PeterIncidental findings on low-dose CT images obtained during hybrid imaging are an increasing phenomenon as CT technology advances. Understanding the diagnostic value of incidental findings along with the technical limitations is important when reporting image results and recommending follow-up, which may result in an additional radiation dose from further diagnostic imaging and an increase in patient anxiety. This study assessed lesions incidentally detected on CT images acquired for attenuation correction on two SPECT/CT systems. Methods: An anthropomorphic chest phantom containing simulated lesions of varying size and density was imaged on an Infinia Hawkeye 4 and a Symbia T6 using the low-dose CT settings applied for attenuation correction acquisitions in myocardial perfusion imaging. Twenty-two interpreters assessed 46 images from each SPECT/CT system (15 normal images and 31 abnormal images; 41 lesions). Data were evaluated using a jackknife alternative free-response receiver-operating-characteristic analysis (JAFROC). Results: JAFROC analysis showed a significant difference (P < 0.0001) in lesion detection, with the figures of merit being 0.599 (95% confidence interval, 0.568, 0.631) and 0.810 (95% confidence interval, 0.781, 0.839) for the Infinia Hawkeye 4 and Symbia T6, respectively. Lesion detection on the Infinia Hawkeye 4 was generally limited to larger, higher-density lesions. The Symbia T6 allowed improved detection rates for midsized lesions and some lower-density lesions. However, interpreters struggled to detect small (5 mm) lesions on both image sets, irrespective of density. Conclusion: Lesion detection is more reliable on low-dose CT images from the Symbia T6 than from the Infinia Hawkeye 4. This phantom-based study gives an indication of potential lesion detection in the clinical context as shown by two commonly used SPECT/CT systems, which may assist the clinician in determining whether further diagnostic imaging is justified.