Double unit conversion corrupts time data when values are already in milliseconds (Help needed)

[Devguru-codes]

Location

package/src/pyaslreport/modalities/asl/processor.py:264-266

Description

_convert_units_to_milliseconds unconditionally multiplies time fields by 1000. If a BIDS JSON was generated manually or from a scanner that outputs values in milliseconds (e.g., PostLabelingDelay: 1800), it silently double-converts them to 1,800,000 without any heuristic safeguards.

Reproduction (on main branch)

Script

from pyaslreport.modalities.asl.processor import ASLProcessor
proc = object.__new__(ASLProcessor)

session = {"PostLabelingDelay": 1800, "EchoTime": 15}
proc._convert_units_to_milliseconds(session)
# Result: PLD=1800000, EchoTime=15000 (both double-converted)

Processor / API Normalized Response (main branch)

Input payload with values already in milliseconds:

{
  "PostLabelingDelay": 1800,
  "EchoTime": 15,
  "RepetitionTime": 4000.0,
  "MagneticFieldStrength": 3.0,
  "Manufacturer": "Generic"
}

Output after processor normalization (bug present):

{
  "PostLabelingDelay": 1800000,
  "EchoTime": 15000,
  "RepetitionTimePreparation": 4000000.0,
  "MagneticFieldStrength": 3.0,
  "Manufacturer": "Generic"
}

Automated Results on main branch

#	Test	Status	Detail
1	Seconds input (1.8s -> 1800ms)	PASS
2	Already-ms input (1800 stays 1800)	FAIL	PLD=1800000, ET=15000
3	List already-ms ([1800,2000,2200] stays same)	FAIL	[1800000, 2000000, 2200000]
4	List seconds input ([1.8,2.0,2.2] -> [1800,2000,2200])	PASS

Summary: PASSED=2 FAILED=2

Suggested Fix

Add a heuristic guard: if a scalar time value is > 10, or any element in a list is > 10, it is assumed to already be in milliseconds and the conversion is skipped. This threshold is safe because typical ASL time values in seconds are all < 10 (EchoTime ~0.01-0.03s, PLD ~1-3s, RepetitionTime ~3-6s).

I will wait for your response on this one. If you think this solution is not viable then lets come up with a better solution. Then, I implement it.