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| 2. |
- Fischer, Sara, et al.
(författare)
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Intracranial volume is normal in infants with sagittal synostosis.
- 2015
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Ingår i: Journal of plastic surgery and hand surgery. - 2000-6764. ; 49:1, s. 62-64
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Premature sagittal synostosis results in an elongated, narrow skull shape, scaphocephaly. It has been unclear whether the intracranial volume (ICV) of these children is different from that of normal children. The aim of the present study was to precisely determine the ICV in a large cohort of children with premature sagittal synostosis and to compare it to the ICV of a sex- and age-matched control group. All patients (n = 143) with isolated sagittal synostosis registered in the Göteborg Craniofacial Registry until the end of 2012 with a preoperative CT examination were identified. For each case, a sex- and age- (±30 days) matched control was identified from children who had undergone CT for post-traumatic or neurological reasons. The ICV was measured in a semi-automatic MATLAB program with functions such as region growing, watershed, and thresholding in axial CT slices. The ICV was calculated using the Cavalieri principle. The mean (± SEM) values of ICV for children with sagittal synostosis and for corresponding controls were 866 ± 13 ml and 870 ± 15 ml, respectively. The mean ages of these groups were 173 ± 8 days and 172 ± 8 days, respectively. Subgroup analysis of sex and age at CT (≤180 days and >180 days) did not reveal any differences in ICV between cases and controls. Precise determination of ICV in addition to the use of adequate controls has made it possible to conclude that children with premature isolated sagittal synostosis have a normal ICV.
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| 3. |
- Hagmarker, Linn, et al.
(författare)
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A new quantitative image-based method for evaluation of bony temporal hollowing in metopic synostosis
- 2016
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Ingår i: Journal of Plastic Surgery and Hand Surgery. - : Medical Journals Sweden AB. - 2000-656X .- 2000-6764. ; 50:6, s. 343-348
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Premature craniosynostosis is a congenital disorder causing a skull deformity. For both functional and cosmetic reasons, the deformity is surgically treated with a cranioplasty before the age of 1 year. Temporal hollowing is a common and undesirable remaining deformity after cranioplasty for metopic synostosis. The most common method to determine the degree of temporal hollowing is subjective judgement of the temporal region. The aim of the present project was to develop a quantitative semi-automatic computer tool for objective measurement of bony temporal hollowing. Methods: Using MATLAB, a tool was developed to segment computed tomography images, defining the outermost contour. The images were dorsally limited to the widest point of the head. In each case, a sex-and age-matched control was identified and the contours compared. The bony temporal hollowing of the cases was calculated. Results: The intra-user coefficient of variation (CV) was 5.0% (95% CI = 4.2%-6.2%) and the inter-user CV was 3.0% (95% CI = 2.1%-8.6%). For clinical testing purposes, the tool was used in 14 patients, seven of whom had been operated on with a spring-assisted cranioplasty and seven with a cranioplasty using a bone graft. Conclusions: In summary, this study presents a new tool for objective measurement of the surgical result after cranioplasty for metopic synostosis.
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| 4. |
- Magnander, Tobias, et al.
(författare)
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A novel statistical analysis method to improve the detection of hepatic foci of (111)In-octreotide in SPECT/CT imaging.
- 2016
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Ingår i: EJNMMI physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Low uptake ratios, high noise, poor resolution, and low contrast all combine to make the detection of neuroendocrine liver tumours by (111)In-octreotide single photon emission tomography (SPECT) imaging a challenge. The aim of this study was to develop a segmentation analysis method that could improve the accuracy of hepatic neuroendocrine tumour detection.
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| 5. |
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| 6. |
- Magnander, Tobias, et al.
(författare)
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Improved detection rate and visualization of liver uptake foci in diagnostic 111In-octreotide SPECT/CT investigations with a novel segmentation analysis
- 2015
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Ingår i: Optimisation in X-ray and Molecular Imaging 2015 - the Fourth Malmö Conference on Medical Imaging, Gothenburg, Sweden, 28-30 May 2015.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Purpose: Detection of liver tumors will change the course of treatment of neuroendocrine tumours. In nuclear medicine 111In-octreoscan is of high value for detection of neuroendocrine tumours. However, neuroendocrine tumours disseminated to the livers is often challenging to detect from 111In-octreoscan SPECT images due to low uptake, high noise, poor resolution and low contrast. The aim of the present study was to develop a segmentation analysis method for increased diagnostic accuracy of neuroendocrine liver tumours. Methods: For the SPECT reconstruction 120 projections are acquired with 3 degrees spacing around the patient injected with 111In-octreoscan. The projections are reconstructed into a 128x128x128 voxel matrix using OSEM with CT based attenuation correction. The liver is segmented from the SPECT or CT using either an isosurface, region growing or a GPU accelerated level set algorithm. Manual editing finishes the segmentation of the liver. The segmented liver volume of interest, liver VOI, is thresholded at 125 equidistant threshold values between 0 and the maximum voxel value. At each threshold value a connected component labeling algorithm is used to calculate the number of uptake foci (NUF). The normalized NUF (nNUF) is then plotted against the threshold index (ThI), defined as ThI=(cmax-cthr)/cmax, where cmax is the maximal voxel value in the VOI, and cthr is the voxel threshold value. The method is named nNUFTI - normalized Number of Uptake Foci vs ThI. The ThI at 0.25 nNUF was used for analysis of liver tumour involvement. SPECT images from 53 patients without tumour involvement (i.e SPECT negative) in the liver were analysed with nNUFTI. A three year follow up with MRI, SPECT, PET/CT and CT was used to separate the patients into two groups: the healthy group, with still no liver tumours, and the malignant group, shown to have developed tumours in the liver. Results: 40 patients ended up in the healthy group and 13 in the malignant group. The ThI at 0.25 nNUF was significantly different between the groups (p<0.01). A probability function for the ThI values was constructed from the obtained data. This relationship might be a useful guide in the diagnostic decision making. Conclusions: Our new developed method nNUFTI has been shown to perform well. More studies on the nNUFTI method are needed.
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| 7. |
- Maltese, Giovanni, 1974, et al.
(författare)
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Intracranial volume before and after surgical treatment for isolated metopic synostosis.
- 2014
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Ingår i: The Journal of craniofacial surgery. - 1536-3732. ; 25:1, s. 262-266
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Tidskriftsartikel (refereegranskat)abstract
- Metopic synostosis results in a keel-shaped forehead, hypotelorism, and an increased interparietal width. This study aimed to measure the frontal and total intracranial volume in patients with metopic synostosis before and after surgery and to compare the effect of 2 different operation methods. All patients operated for isolated metopic synostosis between 2002 and 2008 at Sahlgrenska University Hospital who had undergone preoperative and/or postoperative computed tomographic examination (at 3 y of age) were included. The patients were grouped according to operation method: (1) forehead remodeling in combination with a bone graft or (2) forehead remodeling in combination with a spring. Sex- and age-matched controls were identified. A previously developed MATLAB computer program was used to measure the frontal and total intracranial volumes. Sixty patients and 198 controls were included. Preoperatively, the patients with metopic synostosis had significantly lower frontal volumes than those of the controls (P < 0.001) but equal total intracranial volumes. The operations redistributed the intracranial volume and resulted in an improved, frontal-total intracranial volume ratio. However, at 3 years of age, the frontal volume (P < 0.001), total intracranial volume (P ≤ 0.002), and ratio between the 2 (P < 0.001) were significantly lower in the patients than in the controls. The 2 operation methods were equally efficient in creating an improved frontal-total ratio. Surgery for metopic synostosis improves the distribution of the intracranial volume but does not result in normal total intracranial volume or frontal volume at 3 years of age.
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| 8. |
- Söfteland, Madiha Bhatti, 1977, et al.
(författare)
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Temporal Deformity Objectively Measured before and after Surgery for Metopic Synostosis: Retrusion Rather than Hollowing
- 2017
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Ingår i: Journal of Craniofacial Surgery. - 1049-2275. ; 28:7, s. 1757-1760
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Tidskriftsartikel (refereegranskat)abstract
- The temporal contour deformity typical of metopic synostosis is often referred to as temporal hollowing, but has not been quantitatively defined. This deformity is present before surgery and remains to a varying extent at long-term follow-up. The present study aimed to objectively evaluate the degree of this contour deformity in metopic synostosis before and after surgical correction. All children surgically treated for metopic synostosis at Sahlgrenska University Hospital between 2002 and 2014 (n = 120) with appropriate computed tomography scans (n = 160) performed preoperatively and/or at follow-up at 3 years of age were included. Depending on age, 1 of 2 surgical techniques was used. Children presenting before the age of 6 months were treated with frontal remodeling in combination with a spring (S group), whereas children older than 6 months were treated with a bone transplant (BT group). The bony temporal deformity was measured with a semiautomatic MATLAB program and patients were compared to sex-and age-matched controls. The deformity was significantly reduced in both groups (P < 0.001). In the S group, it was reduced from a mean ± standard deviation of 3.6 ± 1.9% to 1.0 ± 1.2% and in the BT group, it was reduced from 3.3% ± 1.4% to 1.1% ± 0.8%. The contour deformity in metopic synostosis is present both before and after surgery and should therefore be termed temporal retrusion (TR). This assessment method enables objective comparison of TR before and after surgical correction and is a potential tool to evaluate TR in metopic synostosis. © 2017 by Mutaz B. Habal, MD.
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| 9. |
- Söfteland, Madiha Bhatti, 1977, et al.
(författare)
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The Degree of Surgical Frontal Volume Correction in Metopic Synostosis Determines Long-Term Outcomes
- 2017
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Ingår i: Journal of Craniofacial Surgery. - : Ovid Technologies (Wolters Kluwer Health). - 1049-2275. ; 28:5, s. 1161-1163
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Tidskriftsartikel (refereegranskat)abstract
- Metopic synostosis results in a keel-shaped forehead, reduced frontal intracranial volume (ICV), and lower frontal to total volume ratio. The ratio improves with cranioplasty, but at 3 years of age, the ratio is still not normalized when compared to that in normal children. The aim of the present study was to investigate whether a low frontal to total ICV ratio at 3 years of age was due to relapse or insufficient correction.All children surgically treated for metopic synostosis in combination with a spring at Sahlgrenska University Hospital with subsequent spring extraction between 2002 and 2008 (n=20) were included. A MATLAB program was used to measure frontal and total ICV.Preoperatively, the frontal to total ICV ratio was 9.81.3% (mean +/- standard deviation). At spring removal, 6 months after cranioplasty, the ratio had increased to 11.8 +/- 2.4%. At 3 years of age, the ratio was 11.6 +/- 1.9%. In age-matched normal children, the ratio was 14.4 +/- 1.9% preoperatively, 15.3 +/- 2.2% at time of spring extraction, and 13.4 +/- 1.4% at 3 years of age.Cranioplasty thus improved the frontal to total ICV ratio, but did not normalize it. The ratio did not change from 6 months after the cranioplasty to 3 years of age. These results indicate that a more pronounced frontal volume correction during cranioplasty is necessary to achieve a normalized distribution of ICV in metopic synostosis.
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| 10. |
- Thunholm, Peter, 1959-, et al.
(författare)
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Evaluating the effectiveness of an armoured brigade staff
- 2014
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Ingår i: Assessing command and control effectiveness. - London : Ashgate. - 9781472436948 ; , s. 141-160
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Bokkapitel (refereegranskat)abstract
- The purpose with this chapter is to present a study of the effectiveness of an Armoured Brigade Headquarters (HQ) in some specific respects. Important issues were (1) how is the HQ Staff dimensioned in relation to its tasks, (2) how does the three staff processes work (Planning, Execution and Coordination / Decision) and (3) how well does the HQ’s Standard Operating Procedure (SOP) and Battle Rhythm function in the light of the HQ’s organization and work processes? The study was designed as a survey study and was based on the following four instruments: (1) Military Command Team Effectiveness Instrument (CTEF 2.0; Essence, Vogelaar, Baranski, Berggren, Van Buskirk, Goodwin & Myller, 2008); (2) Measurement of workload according to the Borg scale (Borg, 1998); (3) Subjective assessments of quality of the Brigade HQ’s orders and reports, and (4) verification that the Brigade HQ followed it’s Standard Operating Procedure. Fifty-four staff members of an Armoured Brigade HQ volunteered as participants. In the study, the HQ was challenged with a peace support / peace keeping operation exercise.The overall result regarding the CTEF and quality measurements on orders and reports indicate that the HQ worked well during the entire exercise and that the SOP and Battle Rhythm worked rather well. However, through the CTEF, four problem areas were identified. These areas regarded (1) the level of uncertainty in the mission, (2) the high complexity of the task, (3) the perceived instability of the objectives that were supposed to be attained in the mission environment, and (4) a high level of workload in some staff sections. Three of these areas are not under the control of the Brigade HQ (high level of uncertainty, high task complexity and unstable objectives of the operation). However, the fourth area, workload, could be influenced. Some staff sections seem to be undermanned in the current organization and that problem needs to be handled, by increasing some staff sections or by moving some duties to other sections.
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