Utilization rates of neuroradiology across neuroscience specialties in the private office setting: who owns or leases the scanners on which studies are performed?

BACKGROUND AND PURPOSE

Recent literature shows an increasing portion of imaging studies being conducted and interpreted by nonradiologists, especially across the modalities with the highest RVUs. We examined the trends in the Medicare technical charges for private office neuroradiology studies submitted by subspecialists to identify utilization trends among MR and CT scanner owners or lessees over the last decade.

MATERIALS AND METHODS

The number of neuroradiology studies performed on MR and CT machines owned or leased in private offices was determined from the CMS PSPSMF for 1998-2008. Studies billed through technical and global charges were aggregated. Utilization rates and utilization rate CAGRs were computed by specialty and by imaging study.

RESULTS

Between 1998 and 2008, MR studies grew by a factor of 2.5 and CT studies grew by 2.1. In 2008, radiologists charged the technical/global fee in 1,386,669 (56.6%), neurologists in 82,360 (3.4%), neurosurgeons in 29,218 (1.2%), multi/IDTF in 617,933 (25.2%), and other specialists in 334,843 (13.7%) of neuroradiology cases. Changes from the 1998 base rate to the 2008 rate per 1000 Medicare beneficiaries were 24.1 to 39.7 for radiologists, 1.03 to 2.4 for neurologists, 0.15 to 0.84 for neurosurgeons, 2.2 to 17.7 for multi/IDTF, and 1.3 to 9.6 for other specialists. All specialties, except for multi/IDTF, showed greater MR utilization increases than CT. Neurology (CAGR of 10.6%), neurosurgery (22.1%), multi/IDTF (23.2%), and other specialists' (24.6%) MR growth outpaced that of radiology's (5.3%).

CONCLUSIONS

All nonradiologists showed greater overall utilization growth in private office neuroradiology than did radiology. Also, nonradiologists generally showed greater utilization increases in MR than CT. Radiologists' private office neuroradiology technical fee share shrank from 83.6% to 56.6% between 1998 and 2008.

Hallux valgus interphalangeus and a novel mutation in HOXA13. Part of the broadening spectrum of Hand-Foot-Genital syndrome

When evaluating foot and hand malformations in children, the orthopaedic surgeon must always consider the possibility of a more serious underlying syndrome with other accompanying abnormalities of organogenesis. We report the case of a 13-year-old female with Hand-Foot-Genital syndrome presenting to our foot and ankle clinic with tarsal coalition and hallux valgus interphalangeus - an unusual variation on the previously reported hallux varus associated with the syndrome. She was subsequently found to have a novel mutation in the HOXA13 gene. To our knowledge, this is the first report of Hand-Foot-Genital syndrome in the orthopaedic literature.

Neuropeptide coding of sympathetic preganglionic neurons; focus on adrenally projecting populations

Chemical coding of sympathetic preganglionic neurons (SPN) suggests that the chemical content of subpopulations of SPN can define their function. Since neuropeptides, once synthesized are transported to the axon terminal, most demonstrated chemical coding has been identified using immunoreactive terminals at the target organ. Here, we use a different approach to identify and quantify the subpopulations of SPN that contain the mRNA for pituitary adenylate cyclase activating polypeptide (PACAP) or enkephalin. Using double-labeled immunohistochemistry combined with in situ hybridization (ISH) we firstly identified the distribution of these mRNAs in the spinal cord and determined quantitatively, in Sprague-Dawley rats, that many SPN at the T4-T10 spinal level contain preproPACAP (PPP+, 80 ± 3%, n=3), whereas a very small percentage contain preproenkephalin (PPE+, 4 ± 2%, n=4). A similar neurochemical distribution was found at C8-T3 spinal level. These data suggest that PACAP potentially regulates a large number of functions dictated by SPN whereas enkephalins are involved in few functions. We extended the study to explore those SPN that control adrenal chromaffin cells. We found 97 ± 5% of adrenally projecting SPN (AP-SPN) to be PPP+ (n=4) with only 47 ± 3% that were PPE+ (n=5). These data indicate that adrenally projecting PACAPergic SPN regulate both adrenal adrenaline (Ad) and noradrenaline (NAd) release whereas the enkephalinergic SPN subpopulation must control a (sub) population of chromaffin cells - most likely those that release Ad. The sensory innervation of the adrenal gland was also determined. Of the few adrenally projecting dorsal root ganglia (AP-DRG) observed, 74 ± 12% were PPP+ (n=3), whereas 1 ± 1% were PPE+ (n=3). Therefore, if sensory neurons release peptides to the adrenal medulla, PACAP is most likely involved. Together, these data provide a neurochemical basis for differential control of sympathetic outflow particularly that to the adrenal medulla.

Activin signaling functions upstream of Gbb to regulate synaptic growth at the Drosophila neuromuscular junction

Activins are members of the TGF-ss superfamily of secreted growth factors that control a diverse array of processes in vertebrates including endocrine function, cell proliferation, differentiation, immune response and wound repair. In Drosophila, the Activin ligand Dawdle (Daw) has been shown to regulate several aspects of neuronal development such as embryonic axonal pathfinding, neuroblast proliferation in the larval brain and growth cone motility in the visual system. Here we identify a novel role for Activin signaling in regulating synaptic growth at the larval neuromuscular junction (NMJ). Mutants for Daw, the Activin type I receptor Baboon (Babo), and the signal transducer dSmad2, display reduced NMJ size suggesting that Daw utilizes a canonical Activin signal-transduction pathway in this context. Additionally, loss of Daw/Babo activity affects microtubule stability, axonal transport and distribution of Futsch, the Drosophila microtubule associated protein 1B (MAP1B) homolog. We find that Babo signaling is required postsynaptically in the muscle, in contrast to the well-characterized retrograde BMP/Gbb signal that is required for synaptic growth and function in presynaptic cells. Finally, we show that the Daw/Babo pathway acts upstream of gbb, and is involved in maintenance of muscle gbb expression, suggesting that Activins regulate NMJ growth by modulating BMP activity through transcriptional regulation of ligand expression.

No association between ambient particulate matter exposure during pregnancy and stillbirth risk in the north of England, 1962-1992

OBJECTIVES

Research evidence suggests that exposure to ambient air pollutants can adversely affect the growth and development of the foetus and infant survival. Much less is known regarding the potential for an association between black smoke air pollution and stillbirth risk. This potential association was examined using data from the historical cohort UK Particulate Matter and Perinatal Events Research (PAMPER) study.

METHODS

Using data from paper-based neonatal records from the two major maternity hospitals in Newcastle upon Tyne (UK), a birth record database of all singletons born during 1961-1992 to mothers resident in the city was constructed. Weekly black smoke levels were obtained from routine data recorded at 20 air pollution monitoring stations over the study period. A two-stage statistical modelling strategy was used, incorporating temporally and spatially varying covariates to estimate black smoke exposure during each trimester and for the whole pregnancy period for each individual pregnancy. Conditional logistic regression models, with stratification on year of birth, were used to assess potential associations between black smoke exposures in pregnancy and stillbirth risk.

RESULTS

The PAMPER database consists of 90,537 births, between 1962 and 1992, with complete gestational age and residential address information, of which 812 were stillborn. There was no association between black smoke exposures in any trimester or across whole pregnancy and risk of stillbirth. Adjustment for potential confounders did not alter these results.

CONCLUSIONS

While black smoke in pregnancy is likely to be related to other pregnancy outcomes, our findings do not suggest that black smoke air pollution exposure during pregnancy increases the risk of stillbirth.

Incidence and clinical features of Langerhans cell histiocytosis in the UK and Ireland

OBJECTIVES

There are few published studies on the epidemiology of Langerhans cell histiocytosis (LCH). We undertook a survey to ascertain all newly diagnosed cases aged 0-16 years in the UK and Republic of Ireland.

DESIGN

Three methods of ascertainment were used: the British Paediatric Surveillance Unit (BPSU) system, a survey by Newcastle University, and the Children's Cancer and Leukaemia Group (CCLG) registry. Deaths data were obtained from the UK Office for National Statistics and the Central Statistics Office in Ireland. Clinicians who reported cases were sent a questionnaire to obtain demographic and clinical details.

RESULTS

Over the 2-year period, 94 cases were identified. The age-standardised incidence rate of LCH in children aged 0-14 years was 4.1 per million per year. The sex ratio (M:F) was 1.5:1 and the median age at diagnosis was 5.9 years. Single system disease (predominantly bony involvement) accounted for 73% of cases and 27% had multisystem disease of whom 7% had involvement of "risk organs" (liver, lung, spleen and bone marrow). Three children died, two of whom were diagnosed after death.

CONCLUSIONS

This is the first study of LCH to use an active surveillance method with additional sources of ascertainment. Our incidence is comparable with those in other national reports, although it is likely to be an underestimate as each method may have missed some cases, either diagnosed or undiagnosed.

Dasl(n)e: the challenge of developing a regional database for autism spectrum disorder

The setting up of a database of children with autism spectrum disorder (ASD) in the north east of England is described. Best practice has been followed and included involving parents in planning and implementation at all stages, oversight by a multi-agency group, management by a multidisciplinary steering group, and independent administration of the database. From a potential listing of 986 children with ASD aged 3-12 years, the parents of 511 have so far responded (51.8%), although response rate varies considerably by local authority. Data checking has shown the information to be valid and case ascertainment broadly representative. The uses to which the data are being put and the continuing challenges are outlined.