| Abstract | Cilj: Utvrditi mogućnost ponovljivosti mjerenja mastoidnog nastavaka na suhoj kosti i MSCT snimkama.
Metode: Mjerenje je provedeno u laboratoriju za forenzičnu i biološku antropologiju Sveučilišta u Splitu dva puta od strane jednog mjeritelja, s vremenskim odmakom od dva dana. Pri mjerenju su se koristile smjernice iz priručnika Standardne metode prema postupcima za prikupljanje podataka za forenzički skeletni materijal 2.0., u kojemu je duljina mastoidnog nastavka definirana kao udaljenost od točke porion (po) (gornja točka na vanjskom slušnom kanalu) do točke mastoidale (ms) (najniža točka na mastoidnom nastavku). Mjeren je desni mastoidni nastavka na trideset lubanja koje su dio osteološke zbirke Sveučilišnog odjela za forenzične znanosti. Mjerenje je provedeno na suhoj kosti uz pomoć pomične mjerke, a mastoidni nastavak na MSCT snimkama, iz virtualne baze Sveučilišta, je mjeren rabeći računalni program Stratovan, Software Verzija 2020.10.13.0859 (Stratovan Corporation, Davis, CA). Ponovljivost mjerenja ispitanja je na temelju tehnike izračuna relativne tehničke pogreške mjerenja (rTEM) zadane ≤ 1,5 %, i koeficijenta pouzdanosti od 0,95.
Rezultati: Nakon provedene statističke analize podataka dobivene su vrijednosti: tehnička pogreška mjerenja (TEM) u rasponu od 1,57-1,97 mm, što je više od dozvoljenih 1,5 mm, relativna tehnička pogreška mjerenja (rTEM) u rasponu od 4,86-6,00 %, koja je neprihvatljiva razina pogreške unutar promatrača jer bi trebala biti ≤ 1,5 %, te koeficijent pouzdanosti (R) u rasponu od 0,59-0,77 koji rezultat nije zadovoljavajući jer se njegova vrijednost kreće od 0 (nije pouzdano) do 1 (potpuna pouzdanost), a u ovo radu je odabran koeficijent pouzdanosti od 0.95.
Zaključci: Mjerenje mastoidnog nastavka iziskuje antropološko iskustvo i dobro predznanje anatomije lubanje, te kontinuirani rad na mjerenju kosturnih ostatak zbog stjecanja vještine. Za mjerenja na MSCT snimkama trebalo bi proći određenu obuku iz radiološke obrade podataka. Ponovljivost mjerenja mastoidnog nastavka uvjetovana je iskustvom i stručnošću mjeritelja jer je isti vrlo složen za analiziranje zbog svoje anatomske strukture. |
| Abstract (english) | Aim: To determine the repeatability of mastoid process measurement on dry bone and MCST scans.
Methods: The measurement was performed by one person, and it was carried out in the laboratory for forensic and biological anthropology of the University of Split, twice, with a time gap of two days. Measurements were made using the guidelines from the Standard Methods for Data Collection Procedures for Forensic Skeletal Material 2.0 manual, in which the length of the mastoid process is defined as the distance from the porion (po) (upper point on the external auditory canal) to the mastoid (ms) (the lowest point on the mastoid process). Measurements of the right mastoid process were performed on thirty skulls from the osteological collection from the University Department of Forensic Sciences. The measurement was made on dry bone with the help of a caliper, and the mastoid process on MSCT images, from the University's virtual database, was measured using Stratovan, Software Version 2020.10.13.0859 (Stratovan Corporation, Davis, CA). The repeatability of the test measurement is based on the calculation technique of the relative technical error of measurement (rTEM) set at ≤ 1.5%, and a reliability coefficient of 0.95.
Results: After the statistical data analysis, the following values were obtained: technical error of measurement (TEM) in the range of 1.57-1.97 mm, which is more than the allowed 1.5 mm, relative technical error of measurement (rTEM) in the range of 4.86-6.00 %, which is an unacceptable level of intra-observer error because it should be ≤ 1.5 %, and a reliability coefficient (R) in the range of 0.59-0.77 which result is not satisfactory because its value ranges are from 0 (not reliable) to 1 (complete reliability), and in this study was chosen the reliability coefficient of 0.95.
Conclusions: Measuring the mastoid process requires anthropological experience and a good previous knowledge of skull anatomy, as well as continuous work on measuring skeletal remains to achieve skills. For measurements on MSCT images, the measurer should undergo certain training in radiological data processing. The repeatability of the measurement of the mastoid process is conditioned by the experience and expertise of the measurer because it is very complex to analyze due to its anatomical structure. |
