Answer to the question from page 117.

Prawidłowa odpowiedź: D.

Correct answer: D.

There were several causes of a false positive result in this case:

pain localized in this region – the physician focused on it;

due to the slim stature of the patient, the structures of the retroperitoneal space were located just below the abdominal wall and their accessibility was impressive;

lack of knowledge concerning the anatomy of the iliopsoas muscles;

lack of knowledge concerning the examining methods of these muscles.

According to my own observations, the lack of knowledge concerning the anatomy and US examining methods of the iliopsoas muscles is common among ultrasonographers. Therefore, such failures will continue to happen despite numerous pertinent publications(. In obese patients with a large amount of gas in the intestines, the lower segment of the psoas major muscle (as this muscle is of concern here) is frequently inaccessible in the examination. In order to visualize this region, one might apply pressure on the transducer or repeat the exam upon the administration of gas-reducing agents. In case of doubts, two sides of the abdomen should be compared, which constitutes a simple and effective method. Figs. 2 and 3 present such a case in both sides of the pelvis. On fig. 2, only the belly of the psoas major muscle (M) is visible from the right (R) and left (L) side (muscle section at the higher level). This muscle's tendon (arrows pointed downwards) is presented from the right and left side on fig. 3 (muscle section at the lower level). The arrows pointed upwards, however, indicate the ventral aspect of the iliac wings. This element is also visible on figs. 1 and 2. So as to make sure that the described structure is the psoas major muscle, its transverse section may be made, i.e. the transducer may be positioned obliquely in relation to the spine and outwards (fig. 4). The arrows in the lower part of the figure show the belly of this muscle where one may trace its fibrillary structure. The arrows in the upper part of the figure indicate the lateral group of abdominal wall muscles.

Fig. 2

Fig. 3

Fig. 1

Fig. 4

Regarding the differentiation between the lesions in the iliac fossa, it is worth mentioning, as cited in Verschelden et al.(, that normal belly of the psoas major muscle may mimic intestinal intussusception, particularly in children. Pathological lesions localized in this muscle constitute a completely different problem but should also be taken into account(.