Prostate cancer measurements on serial MRI during active surveillance: it’s time to be PRECISE

Objective:The PRECISE criteria for reporting multiparametric MRI in patients on active surveillance (AS) for prostate cancer (PCa) score the likelihood of clinically significant change over time using a 1–5 scale, where 4 or 5 indicates radiological progression. According to the PRECISE recommendations, the index lesion size can be reported using different definitions of volume (planimetry or ellipsoid formula) or by measuring one or two diameters. We compared different measurements using planimetry as the reference standard and stratified changes according to the PRECISE scores.Methods:We retrospectively analysed 196 patients on AS with PCa confirmed by targeted biopsy who had two MR scans (baseline and follow-up). Lesions were measured on T₂ weighted imaging (T₂WI) according to all definitions. A PRECISE score was assessed for each patient.Results:The ellipsoid formula exhibited the highest correlation with planimetry at baseline (ρ = 0.97) and follow-up (ρ = 0.98) imaging, compared to the biaxial measurement and single maximum diameter. There was a significant difference (p < 0.001) in the yearly percentage volume change between radiological regression/stability (PRECISE 2–3) and progression (PRECISE 4–5) for planimetry (39.64%) and for the ellipsoid formula (46.78%).Conclusion:The ellipsoid formula could be used to monitor tumour growth during AS. Evidence of a significant yearly percentage volume change between radiological regression/stability (PRECISE 2-3) and progression (PRECISE 4-5) has been also observed.Advances in knowledge:The ellipsoid formula is a reasonable surrogate for planimetry in capturing tumour volume changes on T₂WI in patients on imaging-led AS. This is also associated with radiological changes using the PRECISE recommendations.     

Nephrogenic systemic fibrosis: non-gadolinium options for the imaging of CKD/ESRD patients

Nephrogenic systemic fibrosis (NSF) is a severe systemic disorder developing apparently exclusively in patients in advanced renal failure who receive a gadolinium chelate contrast-enhancing agent for magnetic resonance imaging. Some other apparent risk factors have been identified but their status remains uncertain. Physicians are frequently confronted with patients at risk of NSF who need imaging. An approach to planning imaging in patients at risk to develop NSF is outlined.     

Quantitative MRI of colonic mural enhancement: segmental differences exist in endoscopically proven normal colon

Objectives Abnormal contrast enhancement on MRI is advocated as a biomarker for inflammation in colitis, although the enhancement kinetics of normal colon are poorly described. Our purpose was to quantitatively assess mural enhancement in normal colon and test for intersegmental differences. Methods Eight patients without prior history of inflammatory bowel disease underwent standard MRI colonography followed by normal same-day colonoscopy. Acquired sequences included a volumetric interpolated breath-hold examination (VIBE) to encompass the whole colonic volume, performed at 5°, 10° and 35° flip angles for T(1) quantitation and then at a fixed 35° flip angle three times prior to and every 30 s following intravenous gadoterate meglumine for 220 s. Ascending colon, descending colon and rectal R(1) (1/T(1)) was plotted against time. Mean pre-contrast R(1), initial change of R(1) (ΔR(1)), early and late "plateau phase" enhancement and the area under the R(1)-time (AUC-R(1)) curve were compared between segments using the Student's paired t-test. Results There was no significant difference of pre-contrast R(1) between segments (p=0.49 to 0.62). ΔR(1) was higher for ascending colon compared with descending colon (0.0023±0.0012 ms(-1) vs 0.0010±0.0011 ms(-1), p=0.03). There was no significant difference for early or late plateau phase R(1) between colonic segments (p=0.08 to 1.00). AUC-R(1) was greater for ascending than descending colon (0.54±0.19 vs 0.30±0.14, p=0.03). Conclusions Intersegmental differences in colonic enhancement are present and should be considered when interpreting differential segmental enhancement.     

Degree of polymerization between adjacent visible light-cured composite areas

The degree of polymerization between 2 adjacent visible light-cured composite areas was characterized by hardness measurements and scanning electron microscopy. It was observed that minimum of 20 s exposure for 1 mm overlap and 40 s for 0.5 mm overlap, between 2 light-exposed areas, produced optimal hardness. The interface between the areas was uniformly cured. The 1 mm overlap would produce a homogeneous structure, optimal hardness and eliminate any possibility of partially cured area in the filling.     

Diffusion weighted imaging of female pelvic cancers: Concepts and clinical applications

Early applications of diffusion weighted magnetic resonance imaging (DWI) were limited to neuroimaging, concentrating either on stroke or brain tumours. With recent advances in MRI hardware and software DWI is now increasingly being investigated for cancer assessment throughout the body.Clinical applications of DWI relating to female pelvic cancers have largely concentrated on detection, localisation and staging of disease. More recently investigators have started to evaluate the ability of DWI for determining tumour histology and even predicting the outcome of chemoradiation treatment.This article reviews the physical concepts of MR diffusion weighting, illustrates the biophysical basis of diffusion contrast and reports the clinical applications of DWI for cervical, endometrial, ovarian, rectal and bladder tumours.     

Dental and medical students' knowledge and opinions of infant oral health

Primary care providers' involvement with and perceptions of the epidemic of early childhood caries could be related to attitudes and knowledge of the disease as well as to differences in discipline-based recommendations. A cross-sectional survey of demographics, opinions on infant oral health care visits and importance of infant oral health care, knowledge of tooth eruption, and knowledge of health care guidelines of the American Academy of Pediatrics (AAP) and American Academy of Pediatric Dentistry (AAPD) was administered by several methods to first- and fourth-year dental and medical students at two University of Illinois campuses. Some expected variations were found among dental and medical students pertaining to perceptions and knowledge of infant oral health. Higher proportions of dental students responded correctly or considered the issues very important. However, Rockford medicine students were more likely to know when children should be weaned, yet less likely to agree with recommendations for time of first dental visit. Furthermore, fourth-year dental students were less likely than first-year dental students to give the recommended answer for age of first dental visit. Variances of opinions and basic knowledge of infant oral health of dental and medical students showed inconsistencies with desired outcomes of educational and clinical experiences. Further research is needed to understand the role of experience and other factors to effectively educate primary care providers in this area.