On (b)(6) 2017, the customer sent sample anonymized images to synpative rep.Older images appeared correct (jpeg lossless).The problematic ones come from this year and are jpeg 2000 compressed.The customer found there are no data luts (look up tables) encoded into the images.All images have window center ((b)(4)) and window width ((b)(4)) values set to 2047 and 4096 respectively.The probe tool revealed the following values: black pixels have values of 0.0 (as expected), white/grey pixels have values that range from: 1 to ~250 on study #1 (problematic image), 1 to ~3800 on study #2 ("good" image) the customer determined the window center/width values are in an appropriate range for the "good" images (i.E.Study 2 and 3), but are completely out of range for the "bad" image (study 1).The customer also noted: "clearcanvas's analysis is incorrect as the images have data beyond 256.The customer concluded there is a bug decompressing jpeg 2000 lossless images and so their probe analysis is incorrect" (note: data beyond 256" is referring to pixel depth).At the time, further analysis from synaptive found the following: the bits stored ((b)(4)) value is set to 12-bit in the dicom header; however, it appears the jpeg 2000 compressed pixel data is actually 16-bit; when the tag value is edited to 16, the image appears correct (i.E.Not dark) on load.Therefore, the dicom data is incongruent.A workaround was provided to the customer at the time: correct the dicom header to reflect the pixel data correctly.This should be fixed at the image source.Otherwise, manually change the bits stored ((b)(4)) value to 16.On 04-feb-2020, a software defect was discovered on while investigating an issue regarding a research device.This led to a retrospective analysis of feedback tickets.The research device uses the same jpeg 2000 codec as the device described in this report.While the likelihood of potential serious health consequences is remote, the use of the defective software associated could result in misdiagnosis, potentially causing significant indirect harm necessitating medical intervention that is serious but temporary.This defect is only encountered in select scenarios, where a modality produces images that are compressed using jpeg 2000, and the image pixel data is less than 16-bit, and the "bitness" of the compressed data stream does not match that of the image pixel data.The outcome of the above is a loss of precision in the decompressed pixel data, which causes the symptoms that were reported by the customer.The root cause is that a software defect found in the device that is encountered when it is used with non-dicom compliant jpeg 2000 compressed images.The software improperly uses the dicom bit depth (i.E.The bits stored tag) to decompress the compressed pixel data stream for display, instead of the bit depth that is encoded in the compressed pixel data stream itself.In non-dicom compliant images where the dicom and compressed pixel data stream bit depths do not match, the software outputs an image with some loss of precision in the decompressed pixel data.In these scenarios, the modality producing the image is itself also not compliant to dicom ps3.5 8.2.4.Note: the customer has two device licenses, (b)(4) the complaint describes issues encountered while using one device but did not disclose which device was being used.As the complaint is regarding one device, a single mdr will be reported.Mdr reports: 3012075008-2020-00001, 3012075008-2020-00003 and 3012075008-2020-00004 have the same root cause.A capa has been opened and recall initiated to address the issue in affected devices.
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