A Uniform Description of Perioperative Brain MRI Findings in Infants with Severe Congenital Heart Disease: Results of a European Collaboration.

BACKGROUND AND PURPOSE: A uniform description of brain MR imaging findings in infants with severe congenital heart disease to assess risk factors, predict outcome, and compare centers is lacking. Our objective was to uniformly describe the spectrum of perioperative brain MR imaging findings in infants with congenital heart disease. MATERIALS AND METHODS: Prospective observational studies were performed at 3 European centers between 2009 and 2019. Brain MR imaging was performed preoperatively and/or postoperatively in infants with transposition of the great arteries, single-ventricle physiology, or left ventricular outflow tract obstruction undergoing cardiac surgery within the first 6 weeks of life. Brain injury was assessed on T1, T2, DWI, SWI, and MRV. A subsample of images was assessed jointly to reach a consensus. RESULTS: A total of 348 MR imaging scans (180 preoperatively, 168 postoperatively, 146 pre- and postoperatively) were obtained in 202 infants. Preoperative, new postoperative, and cumulative postoperative white matter injury was identified in 25%, 30%, and 36%; arterial ischemic stroke, in 6%, 10%, and 14%; hypoxic-ischemic watershed injury in 2%, 1%, and 1%; intraparenchymal cerebral hemorrhage, in 0%, 4%, and 5%; cerebellar hemorrhage, in 6%, 2%, and 6%; intraventricular hemorrhage, in 14%, 6%, and 13%; subdural hemorrhage, in 29%, 17%, and 29%; and cerebral sinovenous thrombosis, in 0%, 10%, and 10%, respectively. CONCLUSIONS: A broad spectrum of perioperative brain MR imaging findings was found in infants with severe congenital heart disease. We propose an MR imaging protocol including T1-, T2-, diffusion-, and susceptibility-weighted imaging, and MRV to identify ischemic, hemorrhagic, and thrombotic lesions observed in this patient group.

Dose reduction in standard head CT: first results from a new scanner using iterative reconstruction and a new detector type in comparison with two previous generations of multi-slice CT.

PURPOSE: Computed tomography (CT) accounts for more than half of the total radiation exposure from medical procedures, which makes dose reduction in CT an effective means of reducing radiation exposure. We analysed the dose reduction that can be achieved with a new CT scanner [Somatom Edge (E)] that incorporates new developments in hardware (detector) and software (iterative reconstruction). METHODS: We compared weighted volume CT dose index (CTDI(vol)) and dose length product (DLP) values of 25 consecutive patients studied with non-enhanced standard brain CT with the new scanner and with two previous models each, a 64-slice 64-row multi-detector CT (MDCT) scanner with 64 rows (S64) and a 16-slice 16-row MDCT scanner with 16 rows (S16). We analysed signal-to-noise and contrast-to-noise ratios in images from the three scanners and performed a quality rating by three neuroradiologists to analyse whether dose reduction techniques still yield sufficient diagnostic quality. RESULTS: CTDI(Vol) of scanner E was 41.5 and 36.4 % less than the values of scanners S16 and S64, respectively; the DLP values were 40 and 38.3 % less. All differences were statistically significant (p < 0.0001). Signal-to-noise and contrast-to-noise ratios were best in S64; these differences also reached statistical significance. Image analysis, however, showed "non-inferiority" of scanner E regarding image quality. CONCLUSIONS: The first experience with the new scanner shows that new dose reduction techniques allow for up to 40 % dose reduction while still maintaining image quality at a diagnostically usable level.

Adjuvant therapy after resection of brain metastases. Frameless image-guided LINAC-based radiosurgery and stereotactic hypofractionated radiotherapy.

BACKGROUND: Tumor bed stereotactic radiosurgery (SRS) after resection of brain metastases is a new strategy to delay or avoid whole-brain irradiation (WBRT) and its associated toxicities. This retrospective study analyzes results of frameless image-guided linear accelerator (LINAC)-based SRS and stereotactic hypofractionated radiotherapy (SHRT) as adjuvant treatment without WBRT. MATERIALS AND METHODS: Between March 2009 and February 2012, 44 resection cavities in 42 patients were treated with SRS (23 cavities) or SHRT (21 cavities). All treatments were delivered using a stereotactic LINAC. All cavities were expanded by ≥ 2 mm in all directions to create the clinical target volume (CTV). RESULTS: The median planning target volume (PTV) for SRS was 11.1 cm(3). The median dose prescribed to the PTV margin for SRS was 17 Gy. Median PTV for SHRT was 22.3 cm(3). The fractionation schemes applied were: 4 fractions of 6 Gy (5 patients), 6 fractions of 4 Gy (6 patients) and 10 fractions of 4 Gy (10 patients). Median follow-up was 9.6 months. Local control (LC) rates after 6 and 12 months were 91 and 77 %, respectively. No statistically significant differences in LC rates between SRS and SHRT treatments were observed. Distant brain control (DBC) rates at 6 and 12 months were 61 and 33 %, respectively. Overall survival (OS) at 6 and 12 months was 87 and 63.5 %, respectively, with a median OS of 15.9 months. One patient treated by SRS showed symptoms of radionecrosis, which was confirmed histologically. CONCLUSION: Frameless image-guided LINAC-based adjuvant SRS and SHRT are effective and well tolerated local treatment strategies after resection of brain metastases in patients with oligometastatic disease.

Susceptibility-weighted MR imaging for diagnosis of capillary telangiectasia of the brain.

BACKGROUND AND PURPOSE: BCT is a benign entity, whose appearance on conventional MR imaging makes its differentiation from neoplastic, inflammatory, or subacute ischemic disease challenging. SWI is sensitive to susceptibility effects from deoxyhemoglobin with excellent spatial resolution. Only scarce case reports have described the utility of SWI in cases of BCT. Our aim was to show the diagnostic value of SWI applied to a larger series of cases. MATERIALS AND METHODS: This was an observational retrospective study of 33 BCTs in 27 consecutive patients examined from August 2009 to January 2011 with MR imaging, including SWI. Morphology, signal intensity characteristics, and additional vascular malformations were analyzed. Preceding or follow-up examinations were available in 18 patients with a median time interval of 14.5 months (range, 2-115 months). RESULTS: Twenty-five pontine and 8 supratentorial BCTs demonstrated distinct signal-intensity loss on SWI in combination with postcontrast enhancement. Mean lesion diameter was 4.9 mm (range, 1.5-17 mm). Thirty-nine percent showed slight signal-intensity changes on T1 and/or T2; the remainder were isointense to normal brain. In 30%, a prominent draining vessel was observed. Additional cerebral vascular malformations were found in 5 patients. CONCLUSIONS: SWI represents a valuable tool for confirmation of presumed BCT. Demonstration of signal-intensity loss on SWI in an enhancing focal brain lesion, otherwise unremarkable on conventional MR images, is highly specific for BCT, thus excluding serious pathology and reassuring the patient and referring physician. This is particularly helpful for BCT in less typical locations.

[Comparison of conventional full spine radiographs and fluoroscopic scanning method in young patients with idiopathic scoliosis]. / Vergleich von konventioneller Wirbelsäulenganzaufnahme und fluoroskopischer Scan-Methode bei jungen Patienten mit idiopathischer Skoliose.

PURPOSE: Evaluation of low-dose full spine radiographs using fluoroscopic images for the assessment of the Cobb angle measurement in patients with scoliosis. MATERIAL AND METHODS: Twenty-one consecutive patients (aged 10 - 27 years, mean age 14 years) with a conventional full spine examination (film speed class 800) underwent a follow-up exam using digital pulsed fluoroscopy (Multi Diagnost 4, Philips Medical Systems, Eindhoven, The Netherlands). The mean follow-up was 9 months. During a synchronized scan with a C-arm speed of 4 cm/sec fluoroscopic images were stored with a pulsed frequency of 3 images per second. The single images were merged and reconstructed to one image with the software Easy Spine (Philips medical Systems, Eindhoven, The Netherlands). The corresponding dose-area product values (DAP) of both methods were compared. Three independent observers assessed Cobb angles and image quality for each technique. RESULTS: The mean DAP values for conventional imaging was 94.9 cGy x cm (2) and for fluoroscopy 7.8 cGy x cm (2), respectively. A significant dose reduction of 91.8 % (CI 91 % to 95 %) was calculated. The average absolute angle difference between the observers was found to be 2.7 degrees for conventional imaging and 2.4 degrees for the fluoroscopic method. Interobserver standard deviation of 2.9 degrees was lower than the 5.3 degrees for conventional images. Image quality was better in the conventional images. CONCLUSION: Using the scanning method, we could achieve a mean reduction of the radiation dose of 92 %, while the accuracy of the Cobb angle measurements was comparable for both techniques despite of reduced image quality of digital fluoroscopy.

[Procalcitonin plasma concentrations and systemic inflammatory response following different types of surgery]. / Procalcitoninplasmakonzentration und systemische inflammatorische Antwort nach verschiedenen operativen Eingriffen.

OBJECTIVE: Procalcitonin (PCT) is currently recommended as a suitable parameter to detect and to evaluate the course of bacterial, fungal or parasitic infections. However, recent studies provide evidence that surgical trauma and humoral mediators of inflammation, respectively,may induce PCT synthesis, thereby reducing the validity and reliability of PCT as an "infection-monitoring" parameter. The aim of the present study was to assess and to compare PCT and CRP (C-reactive protein) plasma concentrations in patients presenting without infection following different types of surgery in the absence or presence of a systemic inflammatory response syndrome (SIRS). METHODS: PCT and CRP plasma concentrations were assessed daily on postoperative days 1-5 and maximal values were determined in 94 patients. The patients were allocated to four groups of different types of surgery as follows: A: minor, primarily aseptic surgery, B: major abdominal surgery, C: major vascular surgery and D: thoracic surgery including esophagectomy. All categories were divided into two subgroups representing patients with and without SIRS, respectively. RESULTS. PCT plasma concentrations increased moderately compared to normal values in 21% of patients after minor and aseptic surgery (A), in 27% and 41% after major vascular (C) and thoracic (D) surgery, respectively, and in 65% of patients after major abdominal (B) surgery. The difference between PCT concentrations in patients undergoing major abdominal surgery and the patients after minor, aseptic surgery was significant ( p<0,05: A vs. B). Comparing the patients presenting with or without systemic inflammatory response (SIRS), no significant differences in PCT concentrations between groups could be observed. In the majority of patients PCT values rose to peak levels on the first and second postoperative days, followed by a rapid decline based on the plasma half-life of PCT. In contrast, postoperative CRP plasma concentrations were markedly elevated above normal values in all investigated patients during the whole observation period. Between-categories statistical analysis revealed significant differences comparing patients undergoing minor and aseptic surgery with patients after major vascular, and thoracic surgery, respectively ( p<0,05,A vs.C, D). CRP concentrations were significantly increased in patients with systemic inflammatory response compared to patients with normal postoperative course in surgical categories B, C, and D, respectively ( p<0,05). CONCLUSIONS: Postoperative PCT plasma concentrations in patients presenting without signs of infection are largely influenced by the type of surgical procedure. During the first and second postoperative day PCT concentrations are more frequently elevated in patients after major abdominal, major vascular and thoracic surgery compared to patients undergoing minor, aseptic operations. Thus an "infection monitoring" considering PCT value analysis during the postoperative course may transiently be impeded after major and particularly after intestinal surgery during the first 2 days postoperatively, whereas it appears not to be substantially affected by the presence or absence of systemic inflammatory response.

Endothelin-receptor interactions. Role of a putative sulfhydryl on the endothelin receptor.

The mechanism of action of endothelin-receptor interactions was studied, using radioligand binding assays and SDS-PAGE, to investigate the possibility of disulfide interchange. Electrophoretic analysis suggested involvement of disulfide bond(s) in the receptor-ligand complex. Treatment of Et receptors with sulfhydryl-specific alkylating reagents (NEM or others) resulted in decreased ability to bind [125I]Et-1. [Dpr1-Asp15]Et-1, an antagonist homologous to Et but with an amide link replacing one of the disulfides, bound to Et receptors reversibly, but binding of Et-1 was less reversible. Preincubation of receptors with Et-1, but not with [Dpr1-Asp15]Et-1, protected receptors from alkylation with [14C]NEM. The data suggest that the Et receptor has a sulfhydryl group at or near the Et binding site. A model is proposed in which the role of the putative sulfhydryl group is discussed.

Human orbital fibroblasts in culture bind and respond to endothelin.

Human fibroblasts in primary cell culture were studied for their ability to bind to endothelin (ET), a 21-amino acid peptide with profound vasoconstricting properties. When 125I-labeled ET-1 was incubated with confluent orbital fibroblasts in the presence of increasing concentrations of unlabeled ligand, a single class of binding site was defined with a dissociation constant of 1.42 x 10(-8) M and a maximal binding capacity of 9.1 x 10(-10) mol/micrograms protein. ET-3 was a substantially less potent competitor for 125I-ET-1 binding sites than was unlabeled ET-1. Dermal fibroblasts demonstrated approximately 75% less ET-1 saturation binding activity, on a cellular protein basis, than did those from the orbit. Orbital fibroblasts responded to ET-1 (10(-9) M) with a rapid and transient increase in the free concentration of intracellular Ca2+ ([Ca2+]i) as assessed by monitoring acetoxymethyl ester of fura 2 fluorescence intensity. Rechallenge with the peptide elicited a substantially attenuated response than that seen after the initial treatment. There was no consistent effect of ET-1 on [Ca2+]i in dermal cultures. ET-3 failed to influence [Ca2+]i in either type of fibroblast. It would appear that orbital fibroblasts bind and respond to ET in a manner distinct from that observed in dermal fibroblasts, raising the possibility that the peptide may have site-specific actions in orbital connective tissue.