The accuracy of quantitative parameters in 99mTc‐MAG3 dynamic renography: a national audit based on virtual image data

Assessment of image analysis methods and computer software used in ^99mTc‐MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in ^99mTc‐MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo‐simulated scintillation camera imaging of digital phantoms with time‐varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines. The differential renal function (DRF) and time to maximum renal activity (T_max) were reported by 21 of the 28 Swedish departments performing ^99mTc‐MAG3 studies as of 2012. The reported DRF estimates showed a significantly lower precision for the phantom with impaired renal uptake than for the phantom with normal uptake. The T_max estimates showed a similar trend, but the difference was only significant for the right kidney. There was a significant bias in the measured DRF for all phantoms caused by different positions of the left and right kidney in the anterior–posterior direction. In conclusion, this study shows that virtual scintigraphic studies are applicable for quality assurance and that there is a considerable uncertainty associated with standard quantitative parameters in dynamic ^99mTc‐MAG3 renography, especially for patients with impaired renal function.     

Learning from the placenta: acute atherosis and vascular remodeling in preeclampsia-novel aspects for atherosclerosis and future cardiovascular health

Preeclampsia is a common and potentially lethal pregnancy complication for women and offspring. Women who develop preeclampsia also run a long-term augmented risk of cardiovascular disease and premature death, and two theories are discussed. Women developing preeclampsia and persons developing cardiovascular disease may have common risk factors, which are unmasked by the "stress" of pregnancy. Alternatively, a new risk factor might occur de novo during the preeclamptic pregnancy. In preeclampsia, lipid deposition in walls of the maternal uterine arteries leading to the placenta, named spiral arteries, regularly occurs. These vascular lesions resemble early stages of atherosclerosis and are named "acute atherosis" and is thought to regress after delivery. The mechanisms that contribute to acute atherosis in preeclampsia are largely unknown, but are related to the impaired vascular remodeling of the spiral arteries in the first half of pregnancy. One striking feature is that the development of these "atherosclerosis-like" lesions requires a few months in pregnancy and may be partly linked to invasion of trophoblasts (specialized fetally derived placenta cells). We summarize normal and pathological vessel remodeling in pregnancy and discuss similarities and differences between preeclampsia and arteriosclerosis. The transient appearance of acute atherosis of uterine wall spiral arteries seen in pregnancy complications and the molecular interaction between trophoblast, smooth muscle and vascular cells could add important elements to explain arteriosclerosis and stenosis in cardiovascular disease. Further understanding of the process underlying spiral artery atherosis in the months of pregnancy may cast light on development of cardiovascular disease later in life.     

A novel mutation in the mitochondrial DNA tRNA Leu (UUR) gene associated with late-onset ocular myopathy

We identified a novel G3283A transition in the mitochondrial DNA tRNA(Leu (UUR)) gene in a patient with ptosis, ophthalmoparesis and hyporeflexia. Muscle biopsy showed cytochrome oxidase positive ragged-red fibers, and defects of complexes I, III and IV of the mitochondrial respiratory chain. The mutation was heteroplasmic in muscle of the proband, being absent in her blood. Ragged-red fibers harbored greater levels of mutant genomes than normal fibers. The G3283A mutation affects a strictly conserved base pair in the TPsiC stem of the gene and was not found in controls, thus satisfying the accepted criteria for pathogenicity.     

Imaging the neurobiological substrate of atypical depression by SPECT

Purpose Neurobiological abnormalities underlying atypical depression have previously been suggested. The purpose of this study was to explore differences at functional brain imaging between depressed patients with and without atypical features and healthy controls. Methods Twenty-three out-patients with chronic depressive disorder recruited from a service for patients with audiological symptoms were investigated. Eleven fulfilled the DSM-IV criteria for atypical depression (mood reactivity and at least two of the following: weight gain, hypersomnia, leaden paralysis and interpersonal rejection sensitivity). Twenty-three healthy subjects served as controls. Voxel-based analysis was applied to explore differences in ^99mTc-HMPAO uptake between groups. Results Patients in the atypical group had a higher prevalence of bilateral hearing impairment and higher depression and somatic distress ratings at the time of SPECT. Significantly higher tracer uptake was found bilaterally in the atypical group as compared with the non-atypicals in the sensorimotor (Brodmann areas, BA1–3) and premotor cortex in the superior frontal gyri (BA6), in the middle frontal cortex (BA8), in the parietal associative cortex (BA5, BA7) and in the inferior parietal lobule (BA40). Significantly lower tracer distribution was found in the right hemisphere in the non-atypicals compared with the controls in BA6, BA8, BA44, BA45 and BA46 in the frontal cortex, in the orbito-frontal cortex (BA11, BA47), in the postcentral parietal cortex (BA2) and in the multimodal association parietal cortex (BA40). Conclusion The differences found between atypical and non-atypical depressed patients suggest different neurobiological substrates in these patient groups. The putative links with the clinical features of atypical depression are discussed. These findings encourage the use of functional neuroimaging in psychiatric disorders.     

Sense of coherence and experiences of social support and mastery in the early discharge period after an acute cardiac event

Aims and objectives. The aim of this study was to examine sense of coherence and experiences of change in social support and mastery from a short‐term perspective in patients who had been admitted to hospital with a suspected myocardial infarction. Background. The early discharge period after an acute cardiac event can be a stressful and vulnerable time when psychosocial resources are of the utmost importance. A positive outcome in an encounter with a stressor is thought to be linked to a strong sense of coherence, social support and mastery. Design. A multi‐centre survey was conducted in three hospitals in southern Sweden. Methods. The sample was 300, 241 of whom completed the questionnaires; while in hospital and two weeks postdischarge. Results. In the early discharge period a low sense of coherence was found in over 60% of the sample. There was an association between social support and mastery and between sense of coherence and mastery. Differences in social support ratings, with lower ratings two weeks postdischarge, were found among women and persons over 65 years of age. Conclusions. This study adds knowledge about experiences in the early discharge period. Changes in ratings of social support but not in ratings of mastery were found between baseline and two weeks postdischarge. Relevance to clinical practice. Healthcare professionals need to be sensitive to patients’ sense of coherence, mastery and need for social support during the early discharge period. They can help patients to identify adequate support strategies and prevent future potential complications. However, to routinely assess sense of coherence, social support and mastery, there is a need for a simple and useful instrument in clinical practice.