Assessing agreement between preclinical magnetic resonance imaging and histology: An evaluation of their image qualities and quantitative results

One consequence of demographic change is the increasing demand for biocompatible materials for use in implants and prostheses. This is accompanied by a growing number of experimental animals because the interactions between new biomaterials and its host tissue have to be investigated. To evaluate novel materials and engineered tissues the use of nondestructive imaging modalities have been identified as a strategic priority. This provides the opportunity for studying interactions repeatedly with individual animals, along with the advantages of reduced biological variability and decreased number of laboratory animals. However, histological techniques are still the golden standard in preclinical biomaterial research. The present article demonstrates a detailed method comparison between histology and magnetic resonance imaging. This includes the presentation of their image qualities as well as the detailed statistical analysis for assessing agreement between quantitative measures. Exemplarily, the bony ingrowth of tissue engineered bone substitutes for treatment of a cleft-like maxillary bone defect has been evaluated. By using a graphical concordance analysis the mean difference between MRI results and histomorphometrical measures has been examined. The analysis revealed a slightly but significant bias in the case of the bone volume ðbiasHisto MRI: Bonevolume = 2: 40 %, p < 0: 005) and a clearly significant deviation for the remaining defect width ðbiasHisto MRI: Defectwidth = 6: 73 %, p 0: 005Þ: But the study although showed a considerable effect of the analyzed section position to the quantitative result. It could be proven, that the bias of the data sets was less originated due to the imaging modalities, but mainly on the evaluation of different slice positions. The article demonstrated that method comparisons not always need the use of an independent animal study, additionally

Towards e-health literacy on depression for adolescents: Information sought versus information gained

Half of all mental health disorders start occurring by the age of 14, with depression being the fourth most common disorder among adolescents worldwide. The prevalence of depression among German adolescents has nearly doubled in recent years. When it comes to mental health information sources, the internet has become a common medium for adolescents. Hence, to raise awareness of depression among this group, their specific expectations for online information and services must be met. Due to a lack of mixed-methods studies, this study therefore compares adolescents' expectations of online information and support services about depression (Study I), and information provided on the internet (Study II). Based on a literature review, qualitative interviews with adolescents were conducted (N=34). Moreover, the multi-platform online communication of nine German non-profit organizations (NPOs) that aim to improve information and care for people suffering from depression was analyzed using quantitative content analysis (N=1,435). Comparing the information gained from both studies, results indicate that expectations for fact-based communication were met by the NPOs frequently providing information on depression and requested experience reports were often communicated. However, discrepancies are apparent in the use of communication channels and videos, and the particular importance of personalization is evident

Assessing agreement between preclinical magnetic resonance imaging and histology: An evaluation of their image qualities and quantitative results

<div><p>One consequence of demographic change is the increasing demand for biocompatible materials for use in implants and prostheses. This is accompanied by a growing number of experimental animals because the interactions between new biomaterials and its host tissue have to be investigated. To evaluate novel materials and engineered tissues the use of non-destructive imaging modalities have been identified as a strategic priority. This provides the opportunity for studying interactions repeatedly with individual animals, along with the advantages of reduced biological variability and decreased number of laboratory animals. However, histological techniques are still the golden standard in preclinical biomaterial research. The present article demonstrates a detailed method comparison between histology and magnetic resonance imaging. This includes the presentation of their image qualities as well as the detailed statistical analysis for assessing agreement between quantitative measures. Exemplarily, the bony ingrowth of tissue engineered bone substitutes for treatment of a cleft-like maxillary bone defect has been evaluated. By using a graphical concordance analysis the mean difference between MRI results and histomorphometrical measures has been examined. The analysis revealed a slightly but significant bias in the case of the bone volume and a clearly significant deviation for the remaining defect width But the study although showed a considerable effect of the analyzed section position to the quantitative result. It could be proven, that the bias of the data sets was less originated due to the imaging modalities, but mainly on the evaluation of different slice positions. The article demonstrated that method comparisons not always need the use of an independent animal study, additionally.</p></div

Quantitative results of the bone volume (BV) within the artificial defect.

<p>For comparison, the results of quantitative MRI and histomorphometry of the selected animals for method comparison (cf. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.t001" target="_blank">Table 1</a>) were presented with the measured <i>BV</i> value of all animals investigated in the study of <i>Korn et al</i>. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.ref014" target="_blank">14</a>]. The results were displayed as mean ± 95% CI. Statistical significance is indicated by *p< 0.05 and **p<0.01.</p

Experimental design, all of the rats were assigned randomly to the experimental groups.

<p>Experimental design, all of the rats were assigned randomly to the experimental groups.</p

Measured parameters used for the concordance analysis.

<p>Here, a MRI slice image of a control was shown exemplarily. A detailed description of the tissue structures is given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.g003" target="_blank">Fig 3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.t003" target="_blank">Table 3</a>. To determine the overall newly formed bone (<i>BV</i>), the bone tissue area at the left and the right side of the artificial defect was measured. The remaining defect width (<i>rDW</i>) is marked with the red arrow. The scale bar represents 1.0 mm.</p

Augmenting the artificial, cylindrical, cleft-like defect with tissue engineered bone grafts.

<p>Augmenting the artificial, cylindrical, cleft-like defect with tissue engineered bone grafts.</p

Detectable anatomical tissue structures of coronal slice images [26,27].

<p>Detectable anatomical tissue structures of coronal slice images [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.ref026" target="_blank">26</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.ref027" target="_blank">27</a>].</p

Multimodal representation of the artificial defect area.

<p>The same specimen of group 2 was chosen as displayed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.g004" target="_blank">Fig 4</a>. The right column shows image magnifications of the newly formed bone tips. The scale bars represent 1.0 mm and 0.2 mm, respectively. (A & A₁) Stained histologic sections. (B & B₁) Fluorescence micrographs, the sequential polyfluorochrome labeling with Alizarine red and Calcein green highlighted the newly formed woven bone. (C & C₁) Corresponding MRI images of the defect area. (A+B, A₁+B₁, B+C, B₁+C₁) If the stained sections or MRI images are superimposed with the Fluorescence micrographs, the recent mineralized bone tissue is clearly visible.</p

Coronal section of the maxilla and the skull with MRI and histology.

<p>The tissue structures are labeled and summarized in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0179249#pone.0179249.t003" target="_blank">Table 3</a>. One tissue sample of an animal from the control group is shown, exemplarily. The scale bars represent 1.0 mm. (A₁) MRI, picture detail of the artificial defect. This view was used for image analysis. (A₂) MRI, magnified view of the newly formed bone at the margins of the defect. (B) Histological image, Masson-Goldner trichrome stain. (B₁) Magnified view of the newly formed bone. (A₁+B) & (A₂+B₁) Superimposed MRI slice images with histological images. (C) Sketch of the front viewing direction of the coronal slices.</p