Volumetric OCT Image Data Processing

A non-transitory, computer-readable storage medium storing computer program instructions which, when executed by a processor, cause the processor to execute a method of processing C-scan data comprising a sequence of B-scans of an imaging target, which has been acquired by an optical coherence tomography, OCT, imaging system scanning along corresponding scan lines that extend across the imaging target, and trace scan data, which has been acquired by the OCT imaging system performing a scan along a trace scan line which crosses the scan lines, to generate correction data for compensating for axial displacements between B-scans in the sequence of B-scans caused by a relative motion of the OCT imaging system and the imaging target that varies a distance therebetween during acquisition of the B-scans by the OCT imaging system, and to further generate a reliability indicator which indicates a reliability of the generated correction data, the method comprising:

• generating the correction data by determining, for each B-scan of at least some of the B-scans in the sequence, a respective indicator of an axial shift between respective representations of a common ocular feature in the B-scan and trace scan data;
• and
• generating the reliability indicator by:
• calculating, using the indicators determined for pairs of B-scans in the at least some of the B-scans, respective values of a metric which are indicative of respective speeds or respective accelerations of the imaging target relative to the OCT imaging system when the pairs of B-scans were acquired;
• determining if at least a predetermined number of the calculated values of the metric exceed a threshold value;
• in a case where at least the predetermined number of calculated values of the metric are determined to exceed the threshold value, setting the reliability indictor to indicate that the correction data is unreliable;
• and
• in a case where at least the predetermined number of calculated values of the metric are determined to not exceed the threshold value, setting the reliability indictor to indicate that the correction data is reliable.

A data processing apparatus arranged to process C-scan data comprising a sequence of B-scans of an imaging target, which has been acquired by an optical coherence tomography, OCT, imaging system scanning along corresponding scan lines that extend across the imaging target, and trace scan data, which has been acquired by the OCT imaging system performing a scan along a trace scan line which crosses the scan lines, to generate correction data for compensating for axial displacements between B-scans in the sequence of B-scans caused by a relative motion of the OCT imaging system and the imaging target that varies a distance therebetween during acquisition of the B-scans by the OCT imaging system, and to further generate a reliability indicator which indicates a reliability of the generated correction data, the apparatus comprising:

• a correction data generator module arranged to generate the correction data by determining, for each B-scan of at least some of the B-scans in the sequence, a respective indicator of an axial shift between respective representations of a common ocular feature in the B-scan and the trace scan data;
• and
• a reliability indicator generator module arranged to generate the reliability indicator by:
• calculating, using the indicators determined for pairs of B-scans in the at least some of the B-scans, respective values of a metric which are indicative of respective speeds or respective accelerations of the imaging target relative to the OCT imaging system when the pairs of B-scans were acquired;
• determining if at least a predetermined number of the calculated values of the metric exceed a threshold value;
• in a case where at least the predetermined number of calculated values of the metric are determined to exceed the threshold value, setting the reliability indictor to indicate that the correction data is unreliable;
• and
• in a case where at least the predetermined number of calculated values of the metric are determined to not exceed the threshold value, setting the reliability indictor to indicate that the correction data is reliable.

A data processing apparatus arranged to process C-scan data comprising a sequence of B-scans of an imaging target, which has been acquired by an optical coherence tomography, OCT, imaging system scanning along corresponding scan lines that extend across the imaging target, and trace scan data, which has been acquired by the OCT imaging system performing a scan along a trace scan line which crosses the scan lines, to generate correction data for compensating for axial displacements between B-scans in the sequence of B-scans caused by a relative motion of the OCT imaging system and the imaging target that varies a distance therebetween during acquisition of the B-scans by the OCT imaging system, and to further generate a reliability indicator which indicates a reliability of the generated correction data, the data processing apparatus comprising:

• a storage device storing a computer program comprising instructions;
• and
• a computer processor arranged to execute the instructions to:
• generate the correction data by determining, for each B-scan of at least some of the B-scans in the sequence, a respective indicator of an axial shift between respective representations of a common ocular feature in the B-scan and the trace scan data;
• and
• generate the reliability indicator by:
• calculating, using the indicators determined for pairs of B-scans in the at least some of the B-scans, respective values of a metric which are indicative of respective speeds or respective accelerations of the imaging target relative to the OCT imaging system when the pairs of B-scans were acquired;
• determining if at least a predetermined number of the calculated values of the metric exceed a threshold value;
• in a case where at least the predetermined number of calculated values of the metric are determined to exceed the threshold value, setting the reliability indictor to indicate that the correction data is unreliable;
• and
• in a case where at least the predetermined number of calculated values of the metric are determined to not exceed the threshold value, setting the reliability indictor to indicate that the correction data is reliable.