Feed-forward neural networks using cerebral MR spectroscopy and DTI might predict neurodevelopmental outcome in preterm neonates.

OBJECTIVES: We aimed to evaluate the ability of feed-forward neural networks (fNNs) to predict the neurodevelopmental outcome (NDO) of very preterm neonates (VPIs) at 12 months corrected age by using biomarkers of cerebral MR proton spectroscopy (1H-MRS) and diffusion tensor imaging (DTI) at term-equivalent age (TEA). METHODS: In this prospective study, 300 VPIs born before 32 gestational weeks received an MRI scan at TEA between September 2013 and December 2017. Due to missing or poor-quality spectroscopy data and missing neurodevelopmental tests, 173 VPIs were excluded. Data sets consisting of 103 and 115 VPIs were considered for prediction of motor and cognitive developmental delay, respectively. Five metabolite ratios and two DTI characteristics in six different areas of the brain were evaluated. A feature selection algorithm was developed for receiving a subset of characteristics prevalent for the VPIs with a developmental delay. Finally, the predictors were constructed employing multiple fNNs and fourfold cross-validation. RESULTS: By employing the constructed fNN predictors, we were able to predict cognitive delays of VPIs with 85.7% sensitivity, 100% specificity, 100% positive predictive value (PPV) and 99.1% negative predictive value (NPV). For the prediction of motor delay, we achieved a sensitivity of 76.9%, a specificity of 98.9%, a PPV of 90.9% and an NPV of 96.7%. CONCLUSION: FNNs might be able to predict motor and cognitive development of VPIs at 12 months corrected age when employing biomarkers of cerebral 1H-MRS and DTI quantified at TEA. KEY POINTS: • A feed-forward neuronal network is a promising tool for outcome prediction in premature infants. • Cerebral proton magnetic resonance spectroscopy and diffusion tensor imaging can be used for the construction of early prognostic biomarkers. • Premature infants that would most benefit from early intervention services can be spotted at the time of optimal neuroplasticity.

Preoperative prediction of language function by diffusion tensor imaging.

For surgery of eloquent tumors in language areas, the accepted gold standard is functional mapping through direct cortical stimulation (DCS) in awake patients. Ever since, neuroscientists are searching for reliable noninvasive detection of function in the human brain, with variable success. The potential of diffusion tensor imaging (DTI) in combination with computational cortical parcellation to predict functional areas in language eloquent tumors has not been assessed so far. We present a proof-of-concept report involving awake surgery for a temporodorsal tumor. Postoperatively, the imaging was extensively studied and a predictive value of multimodal MR imaging for the possible extent of resection was analyzed. After resection using DCS, the extent of resection and functional outcome were correlated with the processed imaging. Preoperative imaging of our patient was taken to compute the lesion volume as a seed for tractography (DTI) and combined with a tractography of the entire hemisphere. For better spatial resolution, an elastic image fusion was performed to correct the distortion of DTI data. After subtotal resection and imaging analysis, the status of the superior part of the lesion could be identified and predicted as functional cortex. There was a strong correlation between the tumor remnant during surgery and the imaging parameters of DTI connectivity of the eloquent tissue. A combination of complex DTI processing may be able to predict function in a patient suffering eloquent brain tumors and thus allow estimation of extent of resection.

Residual Thromboembolic Material in Cerebral Arteries after Endovascular Stroke Therapy Can Be Identified by Dual-Energy CT.

BACKGROUND AND PURPOSE: Dual-energy CT features the opportunity to differentiate among up to 3 different materials because the absorption of x-rays depends on the applied tube voltage and the atomic number of the material. For example, it is possible to distinguish between blood-brain barrier disruption and an intracerebral hemorrhage following treatment for a stroke. The aim of this study was to evaluate whether dual-energy CT is capable of distinguishing intra-arterial contrast agent from residually clotted vessels immediately after endovascular stroke therapy. MATERIALS AND METHODS: Sixteen patients (9 women, 7 men; mean age, 63.6 ± 13.09 years) were examined. Measurements were made on the postinterventional dual-energy CT virtual noncontrast, iodine map, and "weighted" brain window (weighted dual-energy) series. Postinterventional conventional angiography was used as the criterion standard method. RESULTS: A residual clot was found in 10 patients. On the virtual noncontrast series, the Hounsfield attenuation of the clotted arteries was higher than that in the corresponding perfused contralateral arteries (53.72 ± 9.42 HU versus 41.64 ± 7.87 HU; P < .05). The latter had higher absorption values on the weighted dual-energy series than on the virtual noncontrast series (49.37 ± 7.44 HU versus 41.64 ± 7.87 HU; P < .05). The sensitivity for the detection of a residual clot was 90%; the specificity was 83.3%, and the accuracy was 87.5%. Interrater agreement was good (κ = 0.733). CONCLUSIONS: Dual-energy CT may be valuable in the detection of clot persistence or early re-thrombosis without the necessity of additional contrast administration. However, its relevance for the prediction of outcomes remains to be determined in further studies.

Dual energy CT myelography after lumbar osteosynthesis.

PURPOSE: The purpose of this study was to evaluate the benefits of CT myelography in the DE technique in patients with lumbar osteosynthesis. MATERIALS AND METHODS: In 30 patients a DE-CT scan of the spine with tube voltages of 80 kV and 140 kV was performed and a virtual monochromatic series of 120 kV was generated after intrathecal contrast injection. The impact of metal artifacts on the spinal canal and the spinal foramina was evaluated. The visualization of nerve roots was compared between a VRT series of the dural sac and conventional myelography. RESULTS: With tube voltages of 140 kV, the artifacts were least pronounced. As no overlay disturbance was present, VRT visualization of the nerve roots was more reliable than conventional myelography. CONCLUSION: In patients after osteosynthesis, CT in the DE technique provides minimal artifact disturbance using a tube voltage of 140 kV. "Virtual myelography" seems to be superior to conventional myelography for the evaluation of nerve roots. This could reduce additional conventional radiography, may shorten the entire examination and radiation time and diminish unnecessary painful movements for the patient.

7 Tesla MRI demonstrates vascular pathology in Balo's concentric sclerosis.

Baló's concentric sclerosis (BCS) is an inflammatory demyelinating disease related to multiple sclerosis; its underlying pathology remains unclear. At 7 T MRI in a 19-year-old female BCS patient, microhaemorrhages and ectatic veins were found in T2 hyperintense regions, features which have not been previously reported in conjunction with BCS, and these findings may support the view that vascular pathology plays a role in BCS. MRS data suggest that neuron loss and lipid turnover still took place months after a remission. Plasma exchange was effective in treating a relapse with severe motor deficits, and the off-label use of natalizumab was successful in maintaining remission in this patient.

Magnetic resonance imaging of cranial nerves at 7 Tesla.

PURPOSE: The aim of this study was to demonstrate the feasibility of cranial nerve (CN II-XII) imaging with 7 Tesla magnetic resonance imaging (MRI). METHODS: In this study four sequences were evaluated in three healthy volunteers using magnetization preparation rapid gradient echo (MPRAGE), constructive interference in steady state (CISS), true fast imaging with steady state precession (TrueFISP) and proton density (PD) T2-weighted turbo spin echo (TSE) sequences. RESULTS: It was found that MPRAGE did not always provide sufficient contrast to delineate in particular small CNs but displayed an overall good identification rate. The T2 sequence was not able to adequately differentiate the small CNs but showed a very good contrast between nerves and cerebrospinal fluid (CSF). As at lower magnetic fields steady state sequences displayed a high identification rate of all CNs in the axial plane but CISS suffered from susceptibility and pulsation artifacts, furthermore it was limited as no parallel imaging could be performed. The TrueFISP technique was reliable in identifying most CNs although suffering from banding artifacts. CONCLUSIONS: The TrueFISP sequence showed superior spatial resolution and contrast in comparison to the other sequences for imaging of CNs at 7 T.

Complete endovascular occlusion of a cranial dural fistula using a venous "to the point" approach.

BACKGROUND AND OBJECT: Cranial dural arteriovenous fistulas are commonly treated using an endovascular method. In comparison to intracerebral arteriovenous malformations, it is important to reach the venous part of these malformations to maintain a complete occlusion. Therefore, often the venous side is totally occluded using coils and∕or glue. PATIENT AND METHODS: We describe a patient with an initially Type IIab (Cognard classification) left occipital cranial fistula. The patient suffered from an intense pulsate tinnitus. Therefore, the first embolization was performed using an approach via the dilated left middle meningeal artery using Onyx. The shunt of the fistula was reduced significantly but total occlusion was impossible. Therefore, the venous approach was used. Over a guiding catheter in the sigmoid sinus, the venous side of the fistula could be reached with a microcatheter. This part of the fistula was then completely occluded using coated and bare coils, without occluding the adjacent sinus. Control angiography of all previous feeders showed a complete occlusion of the fistula (used classification: Cognard). RESULTS: The fistula was entirely occluded. The patient's outcome was excellent. The patient did not develop any symptoms and no complication occurred due to the treatment. CONCLUSIONS: Direct occlusion of the venous part of an arteriovenous cranial fistula can be an option before an occlusion of the sinus has to be performed. This approach can lead to reduction of risk during the endovascular procedure and risk reduction in long-term follow-up.

Indication, technique and benefit of intraoperative spinal digital subtraction angiography with a new setting in a patient with spinal arteriovenous malformation.

BACKGROUND AND OBJECT: A new setting of intraoperative spinal angiography within an angiography suite is presented. PATIENT AND METHODS: In a patient with thoracic arteriovenous malformation, the resection was performed within an angiography suite. Therefore a long sheath was applied, which remained sterile during the procedure and allowed a catheter to be introduced which is navigated into the noted segmental artery for contrast injection. RESULTS: Digital subtraction angiography was performed prior to and after the resection at the AVM in order to visualize recent feeders and to ensure the complete occlusion. CONCLUSIONS: This method leads to an increased image quality and a shorter operation time in comparison to an angiography within an operating room.

[Guideline compliance in hip fracture: results of an external quality-assurance program in North Rhine Westphalia: 2003-2005]. / Leitlinienkonforme Versorgung: Hüftgelenknahe Fraktur: Auswertung der QS-Daten NRW 2003 bis 2005.

BACKGROUND: Whereas the Scottish guidelines are audited annually, nobody evaluates guideline compliance in Germany. Thus, can external quality assurance data pursuant to section 137 of the German Social Code Book V be suitable for auditing guideline compliance? MATERIALS AND METHODS: From North Rhine Westphalia, a total of 48,831 cases of femoral fractures near the hip joint were evaluated. Compliance with the guidelines was determined based on preoperative hospital stay, thrombosis, and antibiotic prophylaxis. Guideline rationale was reviewed in terms of mortality and thromboembolism rate. RESULTS: Sixty-four percent of the interventions were performed in a timely manner. Thrombosis prophylaxis was given in 99% of cases. Antibiotics were given as a single shot. There was no connection between mortality and thromboembolism rates or time to surgery. CONCLUSION: Guideline compliance is similar in German and Scotland. The external quality assurance data are suitable for evaluating guideline compliance. The literature recommends a short time to surgery. Given the short observation period, it was not possible to demonstrate any improvement in outcomes.

Assessment of drug addiction. The experience of the Medico Legal Institute of Oporto.

Since 1993 in Portugal, it is possible, by legal enforcement, to request forensic examination to study possible conditions of drug addiction. On the basis of examinations carried out in the Medico Legal Institute of Oporto, we present a study of 494 cases involving the relation to the demographic data of the examined individuals, their family background, legal situation, age at which drug consumption began, consumption profile at the beginning and at time of forensic examination and our conclusions.

The morphometric analysis and recognition an amyloid plaque in microscope images by computer image processing.

This paper presents an approach of the two-dimensional image processing application in recognition of amyloid plaque in microscope images of the brain tissues. The authors propose to create universal amyloid plaque computer pattern and special multivariate image segmentation techniques based on collected images and statistical information. This recognition image procedure is divided into 3-dimensional statistical colour and morphological shape identifications. The developed computer system will collect and store image data and exchange them by network with other collaborated systems.

Structure of the gene encoding the ubiquitin-conjugating enzyme Ubcm4, characterization of its promoter, and chromosomal location.

Ubiquitin-conjugating enzymes (E2 or Ubc) play a key role in the post-translational modification of proteins by ubiquitylation. They are encoded by a large family of genes that are closely related to each other. In this paper we present the first complete structural analysis, including the promoter and the chromosomal location, of a member of this family, the mouse Ubcm4 gene. At the genomic level the Ubcm4 gene spans approx. 50kb and is composed of four exons. Only about 1% of the total gene codes for amino acids. The four different Ubcm4 specific RNAs encode the same protein and differ only in the length of the 3' untranslated region. The polyadenylation signals used by the four different RNAs are all within the 3' terminal exon. At the 5' end of the gene, multiple transcriptional start sites were mapped within a region of 25bp. The region proximal to the initiation sites does not contain a TATA box and is not GC-rich. Transient chloramphenicol acetyltransferase assays, however, showed that this region can promote the expression of a reporter gene and that 15bp upstream of the first initiation site were sufficient for basal expression. The Ubcm4 gene was mapped by interspecific backcross analysis to the proximal region of mouse chromosome 16.

Child sexual abuse: a preliminary study.

In 1997, 52 child victims of sexual abuse were examined at Oporto Institute of Forensic Medicine. The authors analysed the data concerning these cases in an attempt to contribute to the elucidation of child sexual abuse, particularly in the north of Portugal.

Sexual abuse within the marital relationship.

The authors aim to characterise sexual abuse within the marital relationship. They analyzed the reports of the clinical examinations performed at the Institute of Legal Medicine of Oporto on victims of sexual abuse from January 1990 until December 1994. They also randomly interviewed victims of physical abuse at the Institute to determine if sexual abuse was performed by their partners. This study shows that complaints are rarely reported by victims of sexual abuse in marital relationships, and in all the cases studied where sexual abuse was verified it was accompanied by other forms of abuse.

Provirus integration into a gene encoding a ubiquitin-conjugating enzyme results in a placental defect and embryonic lethality.

Ubiquitin-conjugating enzymes (E2 or Ubc) constitute a family of conserved proteins that play a key role in ubiquitin-dependent degradation of proteins in eukaryotes. We describe here a transgenic mouse strain where retrovirus integration into an Ubc gene, designated UbcM4, results in a recessive-lethal mutation. UbcM4 is the mouse homologue of the previously described human UbcH7 that is involved in the in vitro ubiquitination of several proteins including the tumor suppressor protein p53. The provirus is located in the first intron of the gene. When both alleles are mutated the level of steady-state mRNA is reduced by about 70%. About a third of homozygous mutant embryos die around day 11.5 of gestation. Embryos that survive that stage are growth retarded and die perinatally. The lethal phenotype is most likely caused by impairment of placenta development as this is the only organ that consistently showed pathological defects. The placental labyrinth is drastically reduced in size and vascularization is disturbed. The UbcM4 mouse mutant represents the first example in mammals of a mutation in a gene involved in ubiquitin conjugation. Its recessive-lethal phenotype demonstrates that the ubiquitin system plays an essential role during mouse development.