Defined positions of the ultrasound head. A, Right lateral wall. B, Left lateral wall. C, Nasal dorsum.
Lateral view of the nose (A) and ultrasound image (B) in a patient with a fractured nasal dorsum. Arrow indicates fracture.
Occipitomental view of the nose (A) and ultrasound image (B) in a patient with a fractured lateral nasal wall. Arrow indicates fracture.
Thiede O, Krömer J, Rudack C, Stoll W, Osada N, Schmäl F. Comparison of Ultrasonography and Conventional Radiography in the Diagnosis of Nasal Fractures. Arch Otolaryngol Head Neck Surg. 2005;131(5):434-439. doi:10.1001/archotol.131.5.434
To compare the diagnostic findings of ultrasonography and radiography in nasal fractures.
Design and Main Outcome Measures
In this prospective study, 63 patients (23 female and 40 male; mean age, 26.8 years) with clinical signs of a nasal bone fracture were investigated. All patients underwent radiography (lateral view of the nose plus occipitomental view) and ultrasonography (10-MHz ultrasound scanner) of the nasal dorsum and the lateral nasal walls and a clinical examination by 2 consultants. Thirty-six patients underwent nasal fracture reduction. Two radiographs and 3 ultrasound images of each patient were analyzed by 2 experienced readers at different times. After assessing the nasal dorsum and lateral nasal walls in radiographs and ultrasound images, they decided whether the nose was fractured or not or whether the results were uncertain. The results were analyzed by various statistical testing methods (for sensitivity, specificity, positive and negative predictive value, and accuracy).
Assessment of the lateral nasal walls revealed that ultrasonography was statistically superior (P = .04) to radiography. In contrast, assessment of the nasal dorsum showed radiography to be statistically superior (P = .01) to ultrasonography. Assessment of the nasal pyramid revealed no statistical difference between radiography and ultrasonography (P = .91).
In assessment of the nasal pyramid, ultrasonography can be considered an alternative to radiography, with equivalent diagnostic performance.
Nasal fractures are the most commonly observed fractures in the trauma setting.1 A uniform classification of these fractures has not been established, but there have been some attempts to classify them.2 The nasal pyramid is a complex structure consisting of the 2 nasal bones and the 2 frontal processus of the maxillary bone. A nasal fracture can involve any part of the nasal pyramid. The lateral nasal walls (caudal part of the nasal bones and parts of the frontal processus) and the nasal dorsum (cranial part of the nasal bones), as well as the nasal septum, generally require the most attention when assessing a fracture of the nasal pyramid.
If there are no further injuries, such as hematomas or expanded fractures of the nasal septum, within 7 days after trauma the patient undergoes reduction of the nasal fracture under local anesthesia or, in cases of noncompliance, under general anesthesia.3 Afterward, the nose is fixed with a plaster cast. Some authors recommend nasal packs to stabilize the bone fragments, especially in the case of a depressed fracture.3
In addition to the clinical examination (crepitation, deviation from the midline, and dislocated fracture), the nasal bone fracture is often diagnosed by radiography. The radiographs usually comprise a lateral image of the nasal bone focused on the nasal dorsum and an occipitomental radiograph from which the lateral nasal walls can be assessed. The need for radiography has been questioned by some authors,4 who find it an inappropriate means of assessing a nasal fracture. However, adequate imaging of a nasal fracture is often required because of legal consequences resulting from nasal fracture etiology.
An alternative to radiography is ultrasonography, a common and easy method involving no additional radiation exposure. The value of ultrasonography as a diagnostic tool for the detection of “bone” fractures (eg, in congenital hip dislocation, fractures of the radial or clavicular bone, or fractures of the ribs or skull) has been proven in various studies.5- 8
To our knowledge, only 4 studies9- 12 have dealt with the diagnosis of nasal fractures by ultrasound imaging. Danter et al10 used a special 20-MHz ultrasound head of an ultrasound device to investigate nasal fractures in 18 patients. The ultrasonographic results were compared with the clinical diagnosis (sensitivity, 83%; and specificity, 50%) and with radiography findings (sensitivity, 94%; and specificity, 83%). The authors did not distinguish between the nasal dorsum and the lateral nasal walls. Furthermore, a comparison of the radiographic findings with the clinical diagnosis was not performed. Kwon et al11 performed ultrasonography on 45 patients who were suspected to have a nasal fracture. Ten of those patients also underwent a computed tomographic scan. The authors found that the ultrasound diagnosis showed a positive correlation with the findings on computed tomographic scanning. Beck et al9 examined 21 patients using 5-MHz and 7.5-MHz ultrasound heads. These authors demonstrated that all fractures diagnosed by radiography also could be detected by ultrasonography. However, they did not compare the ultrasonographic and radiographic results with the clinical diagnosis.
The aim of the present single-blinded study (2 independent readers [F.S. and C.R.]) was to analyze the correlation of ultrasonography and radiography results with the clinical and the intraoperative findings in a representative number of patients. Furthermore, we analyzed whether the 2 diagnostic methods showed different results based on different fracture locations.
Sixty-three patients (23 female and 40 male; mean age, 26.8 years) with clinical signs of a nasal fracture were enrolled in this prospective study. The study was carried out between January 2003 and November 2003 in accord with ethical standards established in an appropriate version of the 1964 Declaration of Helsinki.
Following clinical examination, a first-line imaging set of conventional radiographs (lateral view and occipitomental [or Waters] view of the nasal bones) was taken in every subject. The radiologic management of patients was performed according to the guidelines of the German Society of Otorhinolaryngology, Head and Neck Surgery. The lateral view of the nose delineates fractures of the nasal dorsum, where the 2 nasal bones are connected. The Waters view is used to detect fractures of the lateral nasal walls. Furthermore, an ultrasound examination in defined positions (Figure 1) was performed by 2 experienced otorhinolaryngologists (O.T. and J.-H.K.) using a 10-MHz ultrasound head (EUP-L34T, 3 × 1.4 cm; Hitachi Medical Corp, Tokyo, Japan) of a commonly used ultrasound device (EUB-525RS, Hitachi Medical Corp). On the basis of these diagnostic findings (clinical examination, radiography, and ultrasonography), a decision was made on whether there was a nasal fracture, and the treatment was then determined.
In 36 patients, repositioning of the fractured nasal bone was performed under local or general anesthesia. In most cases, nasal reduction was performed by digital pressure and an elevator. The surgeons were asked to document all details about the nasal repositioning, especially the fracture location, occurrence of crepitation, and type of stabilization (plaster cast or other). Furthermore, they were to document whether the fracture had been stably repositioned.
After data collection for all 63 patients, 2 otorhinolaryngologists (F.S. and C.R.) who had more than 10 years’ clinical experience analyzed the radiographs (lateral view and occipitomental view of the nasal bones) and ultrasound images (right and left lateral nasal walls and nasal dorsum) at different times without being aware of the patients’ history (single-blinded study). The sequence in which the diagnostic methods (ultrasonography and radiography) were analyzed was randomized. For each diagnostic method and for each fracture location (nasal dorsum and lateral nasal walls), the reader noted whether there was a fracture, no fracture, or an uncertain result. The reader then stated whether the nasal pyramid was or was not broken or whether the result was uncertain.
The ultrasonographic and radiographic results were compared with the diagnosis made in the outpatient clinic. The diagnosis was based on results from the clinical examination, radiographs, ultrasound images, and, in cases in which reduction of the nasal bone was performed, intraoperative findings. The findings were rated as “correct” if the radiography or the ultrasonography result matched the clinical diagnosis. If they failed to match, they were rated as “incorrect.” When assessment of the nose by radiography or ultrasonography was uncertain, the cases were rated as “uncertain,” irrespective of whether the nose was broken. In addition, the radiographic and ultrasonographic assessments of the 2 readers were compared.
The statistical program used was Statistical Product and Service Solutions 11.0 for Windows (SPSS Inc, Chicago, Ill). The χ2 test and the κ test were used (namely, to compare the results between the 2 diagnostic tools [radiography and ultrasonography] and between the 2 readers). The results of the κ test were interpreted as follows: κ values ranging from 0.21 to 0.40 indicated fair correspondence; 0.41 to 0.60, moderate correspondence; 0.61 to 0.80, good correspondence; and 0.81 to 1.00, very good correspondence. P<.05 was considered a significant difference. Furthermore, the sensitivity, specificity, positive and negative predictive value, and accuracy were calculated.
A nasal fracture was diagnosed in 42 (67%) of 63 patients. In all 42 patients, a fracture of at least 1 lateral nasal wall was found. In 40 patients, a fracture line of the nasal dorsum was diagnosed. In 19 patients, the broken nose was caused by punches, and the second leading cause was falls, as seen in 15 patients. Thirty-six (86%) of 42 patients with a broken nose underwent reduction of the nasal fracture. Six patients refused reduction, or the fracture lines were only minimally dislocated, so that the patients were aware of virtually no nasal deformity that could be improved by reduction. Reduction of the nasal fractures was performed under local anesthesia in 26 patients. In 4 patients, the nose deviated so much or these 4 patients were so noncompliant that reduction was possible only under general anesthesia. Because of a fracture of the nasal septum in 5 patients, the nasal septum and the nasal fracture also had to be reconstructed. One of these patients also had a septum hematoma. Reduction of the lateral nasal walls was possible in all but 1 patient. In 3 patients, the nasal dorsum could not be reduced, but the lateral nasal wall was depressed and could be reduced. In 26 patients, reduction of the nasal fractures was stable. In 9 patients, reduction of the nasal fractures was not stable, so the nostrils were packed with absorbent cotton for 3 days to stabilize the nasal pyramid. In all 36 patients, the nose was fixed with a plaster cast.
Two radiographs and 3 ultrasound images of each of the 63 patients were analyzed by 2 different readers (F.S. and C.R.). Figure 2 shows an example of a fractured nasal dorsum, and Figure 3 shows an example of a fractured lateral nasal wall. As no significant differences were found between the results of the 2 readers and because the κ test showed a good correspondence in most comparisons between the readers’ findings (Table 1), the data of both readers were pooled for further analysis.
The descriptive statistical analysis (sensitivity, specificity, positive and negative predictive value, and accuracy) of the comparison between the clinical and surgical diagnosis and the radiographic and ultrasonographic assessment of the nasal dorsum showed comparable or higher values for the radiographic examination (Table 2). In contrast, the comparison of the lateral nasal walls revealed that ultrasonography was superior to radiography. In the final comparison of the nasal pyramid, for most values, the ultrasonographic sensitivity, specificity, positive and negative predictive value, and accuracy were superior to the radiographic results.
The χ2 test showed radiography to be significantly superior to ultrasonography in assessment of the nasal dorsum, while ultrasonography was significantly superior to radiography in assessment of the lateral nasal walls. In the final assessment of the nasal pyramid, there was no significant difference between the findings of the ultrasonographic examination and the radiographic examination (Table 3).
In contrast to the study by Danter et al,10 who used a special 20-MHz ultrasound head and a 7.5-MHz ultrasound head in 8 patients with nasal fractures, all patients in the present study were examined with a 10-MHz ultrasound head. Although the uncommon 20-MHz ultrasound head has a better surface resolution, Danter at al10 demonstrated that all nasal fractures that were detectable with a 20-MHz ultrasound head could also be detected with a 7.5-MHz ultrasound head in all 8 patients. For this reason, and because the 10-MHz ultrasound head is the most commonly used ultrasound device in the examination of the head and neck in daily routine, the 10-MHz head was used in the present study.
The size of the ultrasound head used in this study was 3 × 1.4 cm. This proved to be a disadvantage in the examination of children with a small nose, whereas it enabled the nasal dorsum and the lateral nasal wall to be visualized in one image in adult patients. This was advantageous in the retrospective analysis of nasal trauma and especially in cases with potential legal consequences, in which good documentation of the fracture is important. If the nasal dorsum is swollen or if trauma has led to an irregular surface of the nose, a water-filled rubber glove may be helpful in optimizing performance of the ultrasound examination. However, this was not necessary in any of the present patients.
Ultrasonography is a dynamic procedure that allows the reader to make the diagnosis from an unlimited number of pictures. This made it much easier for the 2 investigators performing the ultrasound examination to decide whether there was a nasal fracture than for the 2 readers whose decisions were based on 3 ultrasound images only. This suggests that results of an ultrasound examination are better when the procedure is performed by the same person reading the results.
In this study, assessment of the nasal dorsum by radiography reached a sensitivity of 82% and a specificity of 69%. For the lateral nasal walls, a sensitivity of 52% and a specificity of 49% were achieved. The final assessment of the nasal pyramid by radiography reached a sensitivity of 80% and a specificity of 38%. These data parallel results reported in the literature.13
Assessment based on ultrasound images yielded a sensitivity of 49% and a specificity of 69% with respect to the nasal bone. The analysis of the lateral nasal walls showed a sensitivity of 70% and a specificity of 70%. The final assessment of the nasal pyramid by ultrasonography reached a sensitivity of 77% and a specificity of 57%. These figures are lower than those reported by Kwon et al,11 who located the nasal fracture in all patients using ultrasonography.
In the study by Danter et al,10 assessment of the nasal fracture yielded a sensitivity of 83% if the clinical diagnosis was used as the reference and a sensitivity of 94% if the radiography results were considered. These data are similar to the results reported in this study.
The present study revealed a significant advantage of radiography with respect to the nasal dorsum. In particular, a slightly dislocated fracture of the nasal bone was difficult to assess by ultrasonography. These results are in contrast to those of Kwon et al,11 who found that radiographic assessment of the nasal bone yielded a sensitivity of only 60% to 70%, whereas analysis of the nasal bone by ultrasonography yielded a sensitivity of 100%.
By contrast, in the present study, assessment of the lateral nasal wall was significantly better when based on ultrasound examination than on the occipitomental radiograph. Specifically, the swelling of soft tissue led to difficulties in analyzing the radiograph, while this problem did not occur in the ultrasound examination except in rare cases of open bone fracture. In the final assessment of the nasal pyramid, no significant statistical differences were found.
The examination of nasal bone fractures by ultrasonography is a common method involving no radiation exposure. Compared with the radiographic occipitomental view, ultrasonography is a more adequate diagnostic tool for assessment of lateral nasal wall fractures. In contrast, nasal dorsum fractures were represented much more clearly in the lateral radiographic view of the nose. In the final assessment of the nasal pyramid, radiography and ultrasonography were considered equivalent methods, although ultrasonography showed slight advantages in the descriptive statistical analysis. Therefore, ultrasonography can be considered an alternative to radiography, with equivalent diagnostic performance in assessing nasal pyramid fractures.
Correspondence: Oliver Thiede, MD, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital, Kardinal von Galen Ring 10, D-48129 Münster, Germany (firstname.lastname@example.org).
Submitted for Publication: September 2, 2004; final revision received January 19, 2005; accepted February 2, 2005.