A novel approach for automatic segmentation of prostate and its lesion regions on magnetic resonance imaging

ObjectiveTo develop an accurate and automatic segmentation model based on convolution neural network to segment the prostate and its lesion regions.MethodsOf all 180 subjects, 122 healthy individuals and 58 patients with prostate cancer were included. For each subject, all slices of the prostate were comprised in the DWIs. A novel DCNN is proposed to automatically segment the prostate and its lesion regions. This model is inspired by the U-Net model with the encoding-decoding path as the backbone, importing dense block, attention mechanism techniques, and group norm-Atrous Spatial Pyramidal Pooling. Data augmentation was used to avoid overfitting in training. In the experimental phase, the data set was randomly divided into a training (70%), testing set (30%). four-fold cross-validation methods were used to obtain results for each metric.ResultsThe proposed model achieved in terms of Iou, Dice score, accuracy, sensitivity, 95% Hausdorff Distance, 86.82%,93.90%, 94.11%, 93.8%,7.84 for the prostate, 79.2%, 89.51%, 88.43%,89.31%,8.39 for lesion region in segmentation. Compared to the state-of-the-art models, FCN, U-Net, U-Net++, and ResU-Net, the segmentation model achieved more promising results.ConclusionThe proposed model yielded excellent performance in accurate and automatic segmentation of the prostate and lesion regions, revealing that the novel deep convolutional neural network could be used in clinical disease treatment and diagnosis

Bland-Altman plots showing inter-observer variability of measurements.

<p>(A) Upper: for R2* values, (B) middle: for phase values, and (C) lower: for FA values. CN: caudate nucleus; ALIC: anterior limb of the internal capsule; PLIC: posterior limb of the internal capsule; L: left; R: right.</p

The R2* values (1/sec) in the four WM regions in eight periods (Mean ± SD, n = 56).

<p>Note: Infants were divided into eight groups according to the postmenstrual age (PMA).</p><p>M: male; ALIC: anterior limb of the internal capsule; PLIC: posterior limb of the internal capsule; GCC: genu of the corpus callosum; SCC: splenium of the corpus callosum.</p

R2* and phase values vs. iron concentration calculated by equations in CN, PUT and GP.

<p>(A) Upper: R2* vs. iron concentration, and (B) lower: phase vs. iron concentration. Pearson correlation analysis showed a strongly positive correlation between the R2* values and the iron concentrations (<i>P</i><0.001). r is the coefficient of correlation. As for phase values, no correlations with the iron concentrations were found (<i>P</i>>0.05). CN: caudate nucleus; PUT: putamen; GP: globus pallidus.</p

Regional phase value vs. postmenstrual age in the white matter regions.

<p>Pearson correlation analysis showed a positive correlation between the phase values and postmenstrual age in ALIC and PLIC (<i>P</i><0.001). r is the coefficient of correlation. As for phase values in GCC and SCC, no correlations with postmenstrual age were found (<i>P</i>>0.05). ALIC: anterior limb of the internal capsule; PLIC: posterior limb of the internal capsule; GCC: genu of the corpus callosum; SCC: splenium of the corpus callosum.</p

Regional R2* value vs. postmenstrual age in deep gray nuclei.

<p>Pearson correlation analysis showed a positive correlation between the R2* values and postmenstrual age in gray nuclei (<i>P</i><0.001). r is the coefficient of correlation. CN: caudate nucleus; PUT: putamen; GP: globus pallidus; THA: thalamus; RN: red nucleus; SN: substantia nigra.</p

The R2* values (1/sec) in the six deep gray nuclei in eight periods (Mean ± SD, n = 56).

<p>Note: Infants were divided into eight groups according to the postmenstrual age (PMA).</p><p>M: male; CN: caudate nucleus; PUT: putamen; GP: globus pallidus, THA: thalamus; RN: red nucleus; SN: substantia nigra.</p

Regional R2* value vs. postmenstrual age in the white matter regions.

<p>Pearson correlation analysis showed a positive correlation between the R2* values and postmenstrual age in the white matter regions (<i>P</i><0.001). r is the coefficient of correlation. ALIC: anterior limb of the internal capsule; PLIC: posterior limb of the internal capsule; GCC: genu of the corpus callosum; SCC: splenium of the corpus callosum.</p

Regional phase value vs. postmenstrual age in deep gray nuclei.

<p>Pearson correlation analysis showed no significant correlation between the phase values and postmenstrual age in gray nuclei (<i>P</i>>0.05). The <i>P</i> values of the linear correlation in different regions are shown. CN: caudate nucleus; PUT: putamen; GP: globus pallidus; THA: thalamus; RN: red nucleus; SN: substantia nigra.</p