Implementation of a high-resolution, high-contrast magnetic resonance imaging protocol with extended delayed phases for peritoneal mesothelioma.

Background: Imaging of peritoneal malignancies using conventional cross-sectional imaging is challenging, but accurate assessment of peritoneal disease burden could guide better selection for definitive surgery. Here we demonstrate feasibility of high-resolution, high-contrast magnetic resonance imaging (MRI) of peritoneal mesothelioma and explore optimal timing for delayed post-contrast imaging. Methods: Prospective data from inpatients with malignant peritoneal mesothelioma (MPM), imaged with a novel MRI protocol, were analyzed. The new sequences augmenting the clinical protocol were (I) pre-contrast coronal high-resolution T2-weighted single-shot fast spin echo (COR hr T2w SSH FSE) of abdomen and pelvis; and (II) post-contrast coronal high-resolution three-dimensional (3D) T1-weighted modified Dixon (COR hr T1w mDIXON) of abdomen, acquired at five delay times, up to 20 min after administration of a double dose of contrast agent. Quantitative analysis of contrast enhancement was performed using linear regression applied to normalized signal in lesion regions of interest (ROIs). Qualitative analysis was performed by three blinded radiologists. Results: MRI exams from 14 participants (age: mean ± standard deviation, 60±12 years; 71% male) were analyzed. The rate of lesion contrast enhancement was strongly correlated with tumor grade (cumulative nuclear score) (r=-0.65, P<0.02), with 'early' delayed phase (12 min post-contrast) and 'late' delayed phase (19 min post-contrast) performing better for higher grade and lower grade tumors, respectively, in agreement with qualitative scoring of image contrast. Conclusions: High-resolution, high-contrast MRI with extended post-contrast imaging is a viable modality for imaging peritoneal mesothelioma. Multiple, extended (up to 20 min post-contrast) delayed phases are necessary for optimal imaging of peritoneal mesothelioma, depending on the grade of disease.

Self-supervised multicontrast super-resolution for diffusion-weighted prostate MRI.

PURPOSE: This study addresses the challenge of low resolution and signal-to-noise ratio (SNR) in diffusion-weighted images (DWI), which are pivotal for cancer detection. Traditional methods increase SNR at high b-values through multiple acquisitions, but this results in diminished image resolution due to motion-induced variations. Our research aims to enhance spatial resolution by exploiting the global structure within multicontrast DWI scans and millimetric motion between acquisitions. METHODS: We introduce a novel approach employing a "Perturbation Network" to learn subvoxel-size motions between scans, trained jointly with an implicit neural representation (INR) network. INR encodes the DWI as a continuous volumetric function, treating voxel intensities of low-resolution acquisitions as discrete samples. By evaluating this function with a finer grid, our model predicts higher-resolution signal intensities for intermediate voxel locations. The Perturbation Network's motion-correction efficacy was validated through experiments on biological phantoms and in vivo prostate scans. RESULTS: Quantitative analyses revealed significantly higher structural similarity measures of super-resolution images to ground truth high-resolution images compared to high-order interpolation (p < $$ < $$ 0.005). In blind qualitative experiments, 96 . 1 % $$ 96.1\% $$ of super-resolution images were assessed to have superior diagnostic quality compared to interpolated images. CONCLUSION: High-resolution details in DWI can be obtained without the need for high-resolution training data. One notable advantage of the proposed method is that it does not require a super-resolution training set. This is important in clinical practice because the proposed method can easily be adapted to images with different scanner settings or body parts, whereas the supervised methods do not offer such an option.

Morphological features of the stomach of Malayan pangolin, Manis javanica.

The morphology of the stomach of Malayan pangolin, Manis javanica was studied at macroscopic, light microscopic, and scanning electron microscopic levels. The stomach of M. javanica was C-shaped with short lesser curvature. At the oesophageal junction, the inner smooth muscle was thickened in the greater curvature side. The entire stomach was lined by a thick cornified stratified squamous epithelium, except at the duct orifices of glands and in the pyloric gland region. The wall of the fundus was thin and devoid of glands. The gastric glands consisted of mucous, oxyntic, and pyloric glands. The mucous glands were observed in the lesser curvature (Mg-L), in the greater curvature (Mg-G), and in the pyloric canal (Mg-C) respectively. The oxyntic glands were organized into gland mass, making an oval mound elevated to the gastric lumen, in the middle of the greater curvature. The oxyntic gland mass has a single common duct with opening directed to the pyloric side. This duct was surrounded by mucus gland (Mg-G). The pyloric glands were located caudal to the pylorus. There was no sphincter at the pyloric-duodenal junction. Large mucosal protuberance, the torus pyloricus was observed in the side of the lesser curvature of the pyloric canal. In the lumen of pyloric canal region, numerous spines and small pebbles were observed. The muscle layers in the wall of this region were considerably thickened. The present results on the stomach of M. javanica are thought to be closely related to the toothless and eating habits of this animal species.

Immunohistochemical study on the distribution and relative frequency of endocrine cells in the stomach of the Malayan Pangolin, Manis javanica.

The distribution and relative frequency of six kinds of endocrine cells in the stomach of the Malayan pangolin, Manis javanica were studied immunohistochemically using the avidin-biotin-peroxidase complex method. The stomach of the pangolin has three regions of mucous gland, one oxyntic gland and one pyloric gland. Cells immunoreactive for chromogranin, serotonin, somatostatin, BPP and glucagon were detected in all of the gastric glands, while gastrin-immunoreactive cells were found in the entire gastric gland except for the oxyntic gland. The distribution pattern of endocrine cells in the mucous gland and pyloric gland was mainly from the middle to apical portions of the glands. The endocrine cells were rare or not detected in the basal portion of all of the mucous glands and pyloric gland, but they were also found in the basal portion of the oxyntic gland. The distribution pattern of the endocrine cells in the mucous and pyloric glands suggested that this position facilitates a quick response to the luminal ingesta. The wide distribution of gastrin-immunoreactive cells in all of the mucous glands and pyloric gland was the most remarkable finding. This distribution suggests a major function of gastrin-immunoreactive cells for the digestive process in the Malayan pangolin stomach.

Morphology of the dorsal lingual papillae in the lesser mouse deer, Tragulus javanicus.

The dorsal lingual papillae of the lesser mouse deer were studied morphologically using light and scanning electron microscopy. Four types of papillae, filiform, fungiform, vallate and foliate, were observed. Filiform papillae consisted of larger main papillae with smaller secondary papillae on their anterolateral aspects. Secondary papillae were well distributed over the anterior two-thirds of the tongue, but were very rare or absent in the posterior third. Fungiform papillae were distributed among the filiform papillae, being larger and more abundant on the tip of the tongue. Vallate papillae were round-flat or long-flat, surrounded by a prominent circular groove and a thin annular pad. An important finding was the presence of distinct and prominent foliate papillae on the posterolateral sides of the tongue. Keratinisation of the covering stratified squamous epithelium was relatively weak. Taste buds were observed in the epithelium of the fungiform, vallate and foliate papillae. The lingual papillae of the lesser mouse deer showed some characteristics that differed from those reported for domestic ruminants. These may be related to the feeding habits and the type of food eaten by this species.