Quality of MR thermometry during palliative MR-guided high-intensity focused ultrasound (MR-HIFU) treatment of bone metastases

Table 2 Occurrence rates and hampering rates of the MRT artifacts in % of the total number of datasets per treatment

Treatment number	Location	Lesion type	Time-varying field inhomogeneities				Arterial ghosting		Patient motion
			Respiratory		Non-Respiratory				Muscle contraction		Body movement
1^a,d	Femur	Osteolytic	0	0	0	0	100	0	15	0	0	0
2^a,d	Femur	Osteolytic	0	0	100	0	100	0	14	0	0	0
3^a	Sacrum	Osteolytic	100	100	100	0	0	0	43	29	0	0
4^a	Pubic bone	Mixed	82	64	100	82	100	82	91	73	0	0
5^b	Pubic bone	Osteolytic	69	38	100	0	100	0	6.3	6.3	13	13
6^b,e	Sacrum	Mixed	100	100	100	0	100	0	38	31	54	54
7^b	Shoulder	Osteoblastic	100	100	97	9.7	100	3.2	39	35	35	35
8^c	Rib	Mixed	100	100	100	0	100	20	10	10	0	0
9^b,e,f	Sacrum	Mixed	100	100	100	0	83	0	17	17	39	39
10^c,f	Pubic bone	Osteolytic	100	100	100	33	100	0	3.7	3.7	3.7	3.7
11^c	Pubic bone	Osteolytic	70	65	100	22	96	35	22	17	13	13
12^c	Rib	Mixed	100	100	100	100	100	67	53	47	33	33
13^c	Rib	Osteolytic	100	100	100	56	100	0	11	11	0	0
Total			85	81	94	23	95	14	25	21	17	17

The occurrence rates are shown in normal font, the hampering rates in italic font.
^aPerformed under PSA type A (fentanyl and midazolam).
^bPerformed under PSA type B (propofol and opioid analgesic).
^cPerformed under PSA type C (propofol and esketamine).
^dSame patient, retreated after 2 weeks, metal internal fixation material in the target region.
^eSame patient, retreated after 4.5 months.
^fHigher resolution MRT scans used.

ISSN: 2050-5736