Readout Matrix Size
Fit complete ADC dwell intervals into a supplied readout window and retain the unused tail rather than rounding an infeasible fractional matrix size.
Description
A readout window may contain only a whole number of dwell intervals.
A readout window may contain only a whole number of dwell intervals. Rounding down avoids counting a partial acquisition interval.
The tool returns completeSamples (complete samples); usedReadoutMs (used readout ms); unusedWindowMs (unused window ms). Input measurements and model parameters are supplied by the caller; the tool computes the stated summary rather than acquiring those measurements.
When to use Readout Matrix Size
Use Readout Matrix Size when you already have availableReadoutMs, dwellMicroseconds and want completeSamples, usedReadoutMs, unusedWindowMs. This is useful for checking a supplied calculation, documenting a measurement convention, or comparing observations prepared on the same basis.
How to use Readout Matrix Size and understand its results
- Enter availableReadoutMs, dwellMicroseconds using the field table below. Match the units, ordering and data boundaries described in the calculation.
- Run the tool after checking the stated bounds and matching paired observations or categories. A malformed request gives a tool error rather than a usable measurement.
- Read completeSamples, usedReadoutMs, unusedWindowMs. Use the calculation and interpretation below to distinguish amounts, ratios, signs and decision flags where applicable.
- Review the supplied parameters and assumptions before using the result in a report or comparing it with another observation.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| availableReadoutMs | Available readout ms | number | Required |
| dwellMicroseconds | Dwell microseconds | number | Required |
Require positive inputs and at least one complete sample. Return used duration and nonnegative unused window under floating-point arithmetic.
samples = floor(1000×availableMs/dwellMicroseconds) The symbols refer to the supplied quantities or generated values described above; unit conversions and comparison boundaries follow the stated implementation.
{
"input": {
"availableReadoutMs": 2.565,
"dwellMicroseconds": 10
},
"output": {
"completeSamples": 256,
"usedReadoutMs": 2.56,
"unusedWindowMs": 0.004999999999999893
}
}Limitations and assumptions
This budgets N dwell intervals, not the N−1 span between sample centers. Gradient settling and ramp sampling are external.
Numerical inputs must be finite. The tool checks its declared input shape and calculation constraints; those checks do not verify the quality, calibration or representativeness of the supplied observations.
Alternative or Complementary methods
Readout Time: Distinguish N full ADC dwells from the (N−1)-dwell first-to-last timestamp span; gradient ramps are not included. Echo Spacing: Budget echo-center spacing from explicitly nonoverlapping readout, turnaround and settling intervals; waveform overlaps require a different timing model.
Methodological background: RAD229: MRI signal and sequence lecture notes.1
References
-
RAD229: MRI signal and sequence lecture notes — Brian Hargreaves and colleagues, Stanford University
Similar or alternative tools
- Readout Time
Distinguish N full ADC dwells from the (N−1)-dwell first-to-last timestamp span; gradient ramps are not included.
- Echo Spacing
Budget echo-center spacing from explicitly nonoverlapping readout, turnaround and settling intervals; waveform overlaps require a different timing model.