18F-fluoro-deoxy-glucose focal uptake in very small pulmonary nodules: fact or artifact? Case reports

ABSTRACT: BACKGROUND: F-fluoro-deoxy-glucose (18F-FDG) positron emission tomography integrated/combined with computed tomography (PET-CT) provides the best diagnostic results in the metabolic characterization of undetermined solid pulmonary nodules. The diagnostic performance of 18F-FDG is similar for nodules measuring at least 1 cm and for larger masses, but few data exist for nodules smaller than 1 cm. CASE PRESENTATION: We report five cases of oncologic patients showing focal lung 18F-FDG uptake on PET-CT in nodules smaller than 1 cm. We also discuss the most common causes of 18F-FDG false-positive and false-negative results in the pulmonary parenchyma. In patient 1, contrast-enhanced CT performed 10 days before PET-CT did not show any abnormality in the site of uptake; in patient 2, high-resolution CT performed 1 month after PET showed a bronchiole filled with dense material interpreted as a mucoid impaction; in patient 3, contrast-enhanced CT performed 15 days before PET-CT did not identify any nodules; in patients 4 and 5, contrast-enhanced CT revealed a nodule smaller than 1 cm which could not be characterized. The 18F-FDG uptake at follow-up confirmed the malignant nature of pulmonary nodules smaller than 1 cm which were undetectable, misinterpreted, not recognized or undetermined at contrast-enhanced CT. CONCLUSION: In all five oncologic patients, 18F-FDG was able to metabolically characterize as malignant those nodules smaller than 1 cm, underlining that: 18F-FDG uptake is not only a function of tumor size but it is strongly related to the tumor biology; functional alterations may precede morphologic abnormalities. In the oncologic population, especially in higher-risk patients, PET can be performed even when the nodules are smaller than 1 cm, because it might give an earlier characterization and, sometimes, could guide in the identification of alterations missed on CT

The diagnostic strength of the 24-h pad test for self-reported symptoms of urinary incontinence in pregnancy and after childbirth

The clinical impact of incontinence in pregnancy and after childbirth is growing because some studies report the efficacy of physiotherapy in pregnancy and because obstetric choices are supposed to have significant impact on post-reproductive urinary function (Goldberg et al. in Am J Obstet Gynecol 188:1447–1450, 2003). Thus, the need for objective measurement of urinary incontinence in pregnancy is growing. Data on pad testing in pregnancy are lacking. We assessed the clinical relevance of the 24-h pad test during pregnancy and after childbirth, compared with data on self-reported symptoms of urinary incontinence and visual analogue score. According to the receiver operating characteristic curve, the diagnostic value of pad testing for measuring (severity of) self-reported incontinence during pregnancy is not of clinical relevance. However, for the purposes of research, pad tests, combined with subjective/qualitative considerations, play a critical role in allowing comparisons across studies, quantifying the amount of urine loss and establishing a measure of severity

Arboreality in acacia rats ( Thallomys paedulcus ; Rodentia, Muridae): gaits and gait metrics

International audienc

Introducing external cephalic version to clinical practice

A service offering external cephalic version to all women with breech presentations at 36-38 weeks' gestation was introduced at St George Hospital in July 1997. This paper describes how this service was established and reports the clinical outcomes over the first three years; 116 external cephalic versions (ECV) were attempted on 114 women and success was achieved in 58 women (51%). Of the 58 women, 43 (74%) subsequently had vaginal deliveries. There were no fetal deaths, immediate Caesarean sections, or placental abruptions as a result of the ECV procedure. There were two (2%) episodes of transient fetal bradycardia following ECV, both of which returned to normal with a subsequent normal neonatal outcome. Pre- and post-ECV Kleihauer levels were collected with no increase in levels as a result of the ECV. ECV is a procedure that can, and should, be provided as part of a public hospital service

18F-FDG PET and PET/CT in Burkitt's lymphoma

Objective: To explore the value of 18F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment. © 2009 Elsevier Ireland Ltd

18F-FDG PET/CT: Normal variants, artefacts and pitfalls in lymphoma

FDG PET/CT has become a standard imaging in the staging and response assessment of FDG-avid lymphoma. Accurate interpretation of scan findings is crucial in guiding most effective treatment. It is important to recognise normal variants and potential artefacts and pitfalls in lymphoma FDG PET/CT to achieve optimal results. These potential limitations include the issues applicable to FDG PET/CT in general as well as situations more relevant to lymphoma and its locations