METHOD OF DIAGNOSING PANCREATIC ADENOCARCINOMA AND METASTASES IN ITS PARENCHYMA Russian patent published in 2019 - IPC A61B5/55 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to magnetic resonance imaging, abdominal surgery and gastroenterology, and can be used for diagnosing pancreatic (PG) adenocarcinoma and metastases in its parenchyma. Magnetic resonance examination of abdominal organs in T2- and DWI-weighted sequences with calculation of ADC for positioning of pancreas, visualization of general anatomy, determination of direction of pancreatic and common bile ducts. Transpancreatic T2-weighted sequence is performed, sections of which are laid through the pancreas parallel to the Wirsung duct location. For this purpose oblique T2-weighted image with TE in range of 80–90, TR – 9400-9500 is used, matrix resolution is not lower than 320×192. Note here that slice thickness should be 3–4 mm while spacing is set to 0 mm between cuts. Function of triggering data collection on coinciding respiratory triggering or respiratory standstill is used. Number of cuts must be sufficient for imaging the entire pancreas. T2-weighted image of the PG with a duct system is obtained. Presence of PG tumour is detected, which violates the permeability of the duct system with its suprastenotic expansion of the caudal tumour, or metastases in its parenchyma and their mutual arrangement with the duct system. Then, isovoxel DWI-sequence with b 0 and b 1000 is laid in a similar manner in parallel to the Wirsung duct, which reduces the number of artefacts and averaged data in postprocessing on the boundaries of the tissue media in the planes perpendicular to the sections of interest. Then, a summation – FUSION – image of a PG with a tumour or metastases in its parenchyma is obtained, using the ADC of the isovoxel DWI-sequence with b 0 and b 1000 and the transpancreatic T2-sequence. In the presence of hyperintense MP-signal in DWI, limiting diffusion to 0.0008–0.0014 mm²/s in a tumour, iso-hypertensive MP-signal in transpancreatic T2-sequence with violation of permeability of duct system of PG is diagnosed with adenocarcinoma of PG or metastasis in its parenchyma. If observing the MP-picture of PG adenocarcinoma or metastases in its parenchyma to improve visualization of the boundary of the tumour process, parenchyma and duct system of the gland can be used laying a cross-pancreatic T2-weighted sequence, the plane of which perpendicularly crosses the location of Wirsung duct. For this purpose oblique T2-weighted image with TE 80–90, TR 9400-9500 is used, matrix resolution is not lower than 320×192 with cut-off distance of 0 mm. That is followed by a summation – FUSION – image of a PG with a tumour or metastases using an ADC of a isovoxel DWI-sequence with b 0 and b 1000 and a cross-pancreatic T2-weighted sequence.

EFFECT: method provides higher information value and accuracy of differential diagnostics of pancreatic tumour processes, metastases in its parenchyma and condition of its duct system.

1 cl, 12 dwg, 3 ex