There is an irrebuttable presumption that a miner is totally
disabled due to pneumoconiosis, that a miner's death was due to
pneumoconiosis or that a miner was totally disabled due to
pneumoconiosis at the time of death, if such miner is suffering or
suffered from a chronic dust disease of the lung which:
(a) When diagnosed by chest X-ray (see Sec. 718.202 concerning the
standards for X-rays and the effect of interpretations of X-rays by
physicians) yields one or more large opacities (greater than 1
centimeter in diameter) and would be classified in Category A, B, or C
in:
(1) The ILO-U/C International Classification of Radiographs of the
Pneumoconioses, 1971, or subsequent revisions thereto; or
(2) The International Classification of the Radiographs of the
Pneumoconioses of the International Labour Office, Extended
Classification (1968) (which may be referred to as the ``ILO
Classification (1968)''); or
(3) The Classification of the Pneumoconioses of the Union
Internationale Contra Cancer/Cincinnati (1968) (which may be referred
to as the ``UICC/Cincinnati (1968) Classification''); or
(b) When diagnosed by biopsy or autopsy, yields massive lesions in
the lung; or
(c) When diagnosed by means other than those specified in
paragraphs (a) and (b) of this section, would be a condition which
could reasonably be expected to yield the results described in
paragraph (a) or (b) of this section had diagnosis been made as therein
described: Provided, however, That any diagnosis made under this
paragraph shall accord with acceptable medical procedures.