Type:
Educational Exhibit
Keywords:
Forensic / Necropsy studies, CT, Diagnostic procedure, Forensics, Trauma
Authors:
Y. Kawasumi, Y. Hosokai, A. Usui, M. Sato, Y. Takane, H. Saito, T. Ishibashi, M. Funayama; Sendai/JP
DOI:
10.1594/ecr2011/C-1846
Imaging findings OR Procedure details
MDCT Scanning protocol
- Aquilion 8 MDCT,
Toshiba,
Japan
- 120 kVp
- Head: conventional scan,
4.0-mm slice thickness
- Whole body: helical scan,
2.0-mm slice thickness
All cases underwent a conventional autopsy soon after CT.
After receiving the autopsy reports from forensic pathologists,
the CT images were reviewed and the correlations between CT findings and autopsy results were discussed.
Reconstructed 3D surface images can depict a ligature mark.
The orientation of this ligature mark is the key to identifying differences between typical hanging,
atypical hanging,
and ligature strangulation.
A fracture of the hyoid bone and thyroid cartilage are additional clues to distinguish these forms of hanging and strangulation.
However,
when the deviation of a bone fragment is moderate,
it is difficult to detect the fracture even on CT.
For such a case,
MR imaging may be effective.
Hanging
Typical Hanging
The remains are found in suspension.
The ligature mark is bilaterally symmetric and upward slope towards the back of the neck (Fig.
1: autopsy,
Fig. 2: CT).
The anterior portion of the ligature mark is located between the hyoid bone and the prominence of the thyroid cartilage in the majority of cases (Fig.
3: autopsy,
Fig. 4: CT).
The great horn of the hyoid bone and the superior horn of the thyroid cartilage are pressed against the vertebral body,
and frequently fracture in cases of typical hanging.
A fracture of the superior horn of the thyroid cartilage (Fig.
5: autopsy,
Fig.
6: CT) is more common in elderly people,
because the thyroid cartilage becomes calcified with age.
A deviation of the hyoid bone is also present in some cases (Fig.
7).
Atypical Hanging
All cases that do not correspond to typical hangings are defined as atypical hanging.
In such cases,
the ligature mark is usually asymmetric or unilateral (Fig.
8: autopsy,
Fig. 9: CT).
Fracture of the hyoid bone and thyroid cartilage is dependent on the site of constriction (Fig.
10: autopsy,
Fig.
11: CT).
Ligature strangulation
Generally,
a ligature mark is located horizontally (Fig.
12: autopsy,
Fig.
13: CT).
The appearance of the ligature mark changes depending on the type of ligature: e.g.,
the ligature mark can be double or three-fold and hard ligature frequently creates friction abrasion (Fig.
12).
The level of constriction is typically below the hyoid bone; hyoid bone fracture and deviation are uncommon.
In comparison,
thyroid cartilage fracture,
particularly of the superior horn,
is occasionally present (Fig.
14: autopsy,
Fig.
15: CT).