X-ray intensifying screens with mixed morophology phosphors

A medical X-ray evaluation apparatus comprising:

• a photographic film element in cooperation with an X-ray intensifying screen comprising a phosphor-binder layer coated on a support, said phosphor-binder layer comprising a binder and a phosphor dispersed therein, said phosphor having the monoclinic M' structure and selected from the group consisting of:
• (a) YNb.sub.x Ta.sub.1-x O.sub.4, where x is 0 to about 0.15;
• (b) LuNb.sub.x Ta.sub.1-x O.sub.4, where x is 0 to about 0.2;
• (c) Y.sub.1-y Tm.sub.y TaO.sub.4, where y is 0 to about 0.03;
• (d) a solid solution of (a) and (b);
• (e) a solid solution of (a) and (c);
• (f) Y.sub.1-y Tb.sub.y TaO.sub.4, where y is about 0.001 to about 0.15;
• Lu.sub.1-y Tb.sub.y TaO.sub.4, where y is about 0.001 to about 0.15;
• (h) Gd.sub.1-y Tb.sub.y TaO.sub.4, where y is about 0.001 to about 0.15;
• (i) a solid solution of at least two of (f), (g) and (h);
• (j) any of (a) to (i) wherein up to 45 mole percent of the yttrium, lutetium or gadolinium is replaced by lanthanum;
• (k) any of (a) to (i) wherein up to 15 mole percent the yttrium, lutetium or gadolinium is replaced by ytterbium;
• and
• (l) any of (a), (b), (c), (d) and (e) wherein up to 15 mole percent of the yttrium or lutetium is replaced by gadolinium;
• wherein about 5-80% of said phosphor has a tabular morphology with an average aspect ratio of at least 2:1 and the remainder of said phosphor has a polyhedral morphology.