隐性骨折的MRI分析

目的 探讨隐性骨折的MRI诊断价值。方法 16例急性外伤患者均行X线平片检查及MRI检查,3例同时行CT检查,受伤部位分别为股骨髁3例,胫骨近端8例,胸腰段椎体5例。结果 本组16例X线平片均未见骨折征像;11例（11／16）股骨髁及胫骨近端受伤病例中3例（3／16）T1WI见骨皮质下线状信信号带改变,8例（8／16）显示由关节面下向骨干走行的不规则条状、紊乱低信号改变;在T2WI上对应于T1WI低信号区仍表现为相应形状的低信号,且在低信号周围可见高信号水肿改变;T1脂肪抑制序列扫描显示水肿带信号明显增强、增宽。2例股骨髁和1例胫骨近端病例同时行CT检查,示周围软组织肿胀,未见确切骨折征像。5例（5／16）胸腰段椎体MR T1WI、T2WI示椎体中央有水平方向走行的线状低信号带,在T2WI低信号周围可见高信号水肿。结论 MRI能够早期确诊隐性骨折,若患者临床症状、体征不能除外隐性骨折,X线检查后行MRI应为最佳的检查手段。     

MR imaging: its role in detecting occult fractures

Magnetic resonance (MR) studies were performed on 30 consecutive patients who continued to be symptomatic despite negative or inconclusive findings on radiographs and other imaging studies including radionuclide bone scans, computed tomography, and/or polytomography. There were 9 men and 21 women, 20–92 years old (mean age 63 years) whose MR studies were done 3–72 h after frank trauma in 22 cases and in another 8 after 1–4 weeks of increasing pain subsequently attributed to trauma or unaccustomed effort. MR studies were performed using 0.5-T (Phillips) or 1.5-T (Phillips, GE) superconductive magnets. Results indicated that: (1) MR images allowed identification of acute fractures in an emergency room setting, as well as subtle subacute or chronic fractures in the context of strong clinical suspicions despite negative or inconclusive radiographs and other subsequently indecisive imaging studies. (2) MR imaging is the most sensitive way of documenting the earliest changes in traumatized osseous and soft tissue structures simultaneously.     

Survey of the initial management and imaging protocols for occult scaphoid fractures in UK hospitals

Objective

The aim of this research was to survey how occult fractures of the scaphoid bone are both imaged and managed initially.

Materials and methods

A total of 832 questionnaires were sent via e-mail to active associate members of the British Orthopaedic Association. Included was a series of questions regarding the timing of initial and subsequent orthopaedic review of this group of patients and the use of serial radiographs and second-line imaging techniques.

Results

Nearly half of the UK’s acute NHS trusts were represented (45%). The response rate was 16% (130 out of 832). Only 16% of respondents were aware of a local imaging protocol for the investigation of suspected fractures of the scaphoid. Ninety-four percent of respondents performed a second radiograph at first fracture clinic review. Fifty-eight percent used magnetic resonance imaging (MRI) as a second-line investigation; with computed tomography scan and radionuclide isotope bone scan being performed by 26% and 16% respondents, respectively.

Conclusions

The survey revealed a wide variation in the management of occult fractures of the scaphoid. MRI has been shown to be both sensitive and specific in diagnosing occult carpal bone fractures. There is a need to standardise the management of these injuries to ensure early diagnosis and limit unnecessary wrist immobilisation.     

Panoramic versus conventional radiography of scaphoid fractures

OBJECTIVE: The objective of this study was to compare the diagnostic value of panoramic and conventional radiography in the detection of fractures of the carpal scaphoid bone. MATERIALS AND METHODS: Panoramic (orthopantomographic) and conventional radiographs of 90 patients with acute or chronic wrist trauma were reviewed retrospectively. Images were analyzed and reviewed independently by four observers: two radiologists and two traumatologists. The kappa statistic was used to calculate intraand interobserver agreement and the correlation between the two imaging techniques. RESULTS: Panoramic radiography of the wrist was superior to conventional radiography in ruling out scaphoid fractures (74%, 20/27) in patients with suspicious findings on conventional radiography; revealed more cases of scaphoid fractures (21.4%, 12/56); and revealed more cases of delayed union (n = 2), nonunion (n = 3), and union (n = 3). Agreement values were higher, with better inter- and intraobserver agreement, for the panoramic examinations than for the conventional radiographic examinations. CONCLUSION: The panoramic examination of the wrist is a useful technique for the diagnosis and follow-up of scaphoid fractures. Its use is recommended as a complement to conventional radiography in cases with inconclusive findings.     

MRI demonstration of radiographically occult fractures: what have we been missing?

During the course of MRI examinations of the knee for possible internal derangement, the hip for avascular necrosis, and the shoulder for rotator cuff tears, we have encountered many examples of unsuspected fractures of the tibial plateau, femoral condyles, pelvis, hip and proximal humerus. These fractures were either radiographically inapparent or demonstrated very subtle abnormalities that were missed on prospective interpretation. In addition, a large number of patients have been found to demonstrate evidence of intraosseous trabecular disruption, or edema and hemorrhage of medullary bone, or stress type injuries, all of which are radiographically occult. The clinical significance of these osseous abnormalities varies and is dependent upon the degree of injury. It is believed that an awareness of these osseous abnormalities will improve the accuracy of MRI interpretation, will heighten an appreciation of the subtle radiographic abnormalities that may be present, and will improve patient evaluation and management.     

Magnetic resonance imaging of suspected scaphoid fractures using a low field dedicated extremity MR system

AIM: To determine whether magnetic resonance imaging (MRI) using a dedicated extremity system could be utilized for the routine assessment of patients with a clinically suspected scaphoid fracture, and to determine the most cost-effective timing of MRI for these patients. MATERIALS AND METHODS: MRI of the wrist using a 0.2T extremity MR system was performed in two groups of patients. Fifty-six patients were examined within 4 days of injury and 53 with persistent symptoms at 10 days to 6 weeks following injury. A scaphoid series of radiographs was negative in both groups. RESULTS: The early MR group had seven scaphoid, six radial and four other fractures. Management was altered in 89%. The late MR group had 14 scaphoid, nine radial and three other fractures. Management was altered in 69%. A cost model showed that overall costs are less with early rather than late scanning. CONCLUSION: MRI of the wrist when scaphoid fracture is suspected can be undertaken in all patients with negative radiographs and could be performed in most departments with an MRI machine. There are significant patient benefits and overall costs would change little from conventional practice.     

The role of MR imaging in scaphoid disorders

The scaphoid bone of the wrist is one of the most commonly fractured bones in the body. Due to its importance in the biomechanics and functionality of the wrist, it is important to depict and characterize the type of injury. Plain radiographs and scintigraphy may fail to disclose the type and severity of the injury. In patients with normal initial plain radiographs, MR imaging can discriminate occult fractures from bone bruises and may also demonstrate ligamentous disruption. MR imaging can also discriminate the proximal pole viability versus avascular necrosis secondary to previous fracture, which is important for treatment planning. Treatment of non-united fractures with vascularized grafts can be evaluated with contrast-enhanced MR imaging. Idiopathic osteonecrosis or Preiser’s disease was originally described after trauma. The non-traumatic disorders of the scaphoid include post-traumatic osteoarthritis, inflammatory bone marrow edema in patients with rheumatoid arthritis, and osteomyelitis. MR imaging is helpful in all the above disorders to demonstrate early bone marrow edema, cartilage degeneration and associated subchondral marrow changes. The most commonly found tumors in the scaphoid are usually benign and include enchondroma, osteoblastoma and osteoid osteoma. MR imaging is not mandatory for the initial diagnosis, which should be based on plain X-ray findings.     

Unenhanced steady state free precession versus traditional MR imaging for congenital heart disease

Purpose

To assess potential benefits of three dimensional (3D) steady state free precession (SSFP) magnetic resonance sequence for congenital heart disease (CHD).

Materials and methods

Twenty consecutive patients with CHD (male:female ratio,14:6, mean age, 27.5 ± 8.5 years) underwent both 3D SSFP and traditional MR imaging (TMRI) [including two dimensional (2D) SSFP and contrast enhanced magnetic resonance angiography (CEMRA)]. Image quality and diagnosis were compared, and Bland–Altman analysis was used to evaluate consistency of 3D SSFP and CEMRA for diameter measurements.

Results

A total of 35 intra and 81 extra cardiac anomalies were identified in all patients. The image quality of 3D SSFP and TMRI for either intra or extra cardiac anomalies of all patients scored ≥3, which allowed an establishment of diagnosis for all cases. The diagnostic sensitivity, specificity, and accuracy of 3D SSFP for the detection of intra cardiac anomalies were all 100%, whereas for extra cardiac anomalies they were 93.8%, 93.8%, 100%, respectively. Mean differences (3D SSFP minus CEMRA) for aorta and pulmonary arteries were 0.5 ± 1.2 mm and 0.0 ± 1.7 mm, respectively, showing good consistency of 3D SSFP and CEMRA for diameter measurements.

Conclusion

3D SSFP MRI can be an alternative image modality to TMRI for patients with congenital heart disease, especially for those who have renal insufficiency, breath-hold difficulty or who are allergic to contrast agent. It can also provide powerful complementary information for patients who undergo TMRI, especially at ventriculoarterial connection site.     

The added value of cross-sectional imaging in the detection of additional radiographically occult fractures in the setting of a Chopart fracture

Purpose

Radiography has a low sensitivity for the detection of fractures related to the talonavicular and calcaneocuboid articulations, also known as Chopart fractures. The purpose of this study is to determine the sensitivity of radiographs for detecting additional foot and ankle fractures related to Chopart fracture using CT or MRI as the reference standard.

Method

We performed an IRB-approved, retrospective review of radiology reports between 2010 and 2014. Inclusion criteria were (1) diagnosis of a Chopart fracture and (2) at least one radiograph and subsequent cross-sectional imaging (CT or MR). CT or MRI was considered the diagnostic reference standard. Results were stratified by the energy of trauma and by type of radiograph performed (weight-bearing (WB) versus non-WB).

Results

One hundred eight patients met the inclusion criteria. The calcaneocuboid articulation was the most commonly involved type of Chopart fracture, seen in 75% of cases (81/108). Chopart fractures were detected on the initial radiographs in 67.6% of cases (73/108). Additional fractures of the ankle and midfoot were diagnosed in 34.2% of cases (37/108), with 56.7% (21/37) of these cases having at least one additional fracture seen on CT or MRI that was not seen on the initial radiographs, with fractures of the midfoot most often missed. In 56.7% (17/30) patients whose radiographs detected Chopart fractures, at least one additional fracture was missed; 30% of them demonstrated intra-articular extension and 56.7% were considered displaced. High-energy trauma was related to higher incidence of additional fractures. There was no significant difference in the sensitivity of radiographs to detect additional fractures between high versus low-energy trauma (p?=?0.3) and WB versus non-WB radiographs (p?=?0.5). Most patients were treated nonoperatively (56.5%, 61/108), with surgical intervention more frequent in patients with a high energy of trauma (51.7% versus 33.3%, p?=?0.05).

Conclusion

In the setting of a Chopart fracture, CT or MRI can add significant value in the detection of additional ankle or midfoot fractures, irrespective of the energy of trauma. Since additional fractures can have important management implications, CT or MRI should be considered as part of the standard workup for all midfoot fractures.

     

质子脂肪抑制序列在四肢隐性骨折中的诊断价值

目的探讨质子脂肪抑制序列(PDFASAT)在四肢隐性骨折中的诊断价值。方法31例四肢关节外伤患者在伤后45d内均行X线平片及多序列高场强(1．5T)MR检查，检查序列包括快速SE T1WI、T2WI，PDF ASAT等。受伤部位为膝关节21例，髋关节6例，肘关节1例，肩关节2例，踝关节1例。结果31例X线平片均未见明显骨折征象。MR检查发现：21例(21／31)膝关节受伤病例中腓骨近端隐性骨折10例，胫骨近端4例，股骨髁7例；6例(6／31)髋关节受伤病例中粗隆问隐性骨折2例，股骨颈隐性骨折2例，髋臼隐性骨折2例；1例(1／31)肘关节受伤病例显示肱骨远端隐性骨折；2例(2／31)肩关节受伤病例显示肱骨近端隐性骨折；1例(1／31)踝关节受伤病例显示腓骨远端隐性骨折；MR信号主要表现为T1WI、T1WI呈细线状、条带状低信号影，PDFASAT呈更清晰锐利的细线状、条带状高信号影，PDFASAT序列更易认识辨别。结论MRI能发现早期至慢性期隐性骨折的存在，如临床强烈提示骨折可能而X线检查阴性者，MR检查的PDFASAT序列是明确诊断的最佳序列。     

多层螺旋CT与磁共振成像在细微及隐匿性骨折诊断中的应用

目的探讨多层螺旋CT(MSCT)与磁共振成像(MRI)在细微及隐匿性骨折中的诊断价值。方法对69例车祸伤后,常规X线、普通CT检查阴性,但怀疑有骨折或临床症状明显者行MSCT和MRI检查。结果 MSCT检查发现52例细微骨折,其中鼻骨骨折8例,颅底骨折9例,脊柱骨折6例,肋骨骨折10例、骨关节骨折19例;另17例MSCT检查未见骨折征象,再行MRI检查并诊断为隐匿性骨折,其中脊柱骨折5例,骨关节骨折12例。结论 MSCT检查能发现常规X线与普通CT未能发现的细微骨折,对特殊部位,如颅底、肋骨骨折诊断有明显优势,对骨折的类型、骨折线涉及范围有较准确的诊断;而MRI检查可显示不能被MSCT所发现的骨挫伤及隐匿性骨折。MSCT与MRI联合应用,可为骨折患者的临床治疗及交通事故的医疗鉴定提供可靠的依据。     

Diagnostic accuracy of an abbreviated MRI protocol for detecting radiographically occult hip and pelvis fractures in the elderly

Skeletal Radiology - To determine the diagnostic accuracy of an abbreviated, two-sequence MRI protocol using limited pulse sequences for the detection of radiographically occult hip and pelvis...     

MR imaging of orbital blow-out fractures

We report on a case of orbital blow-out fractures involving the medial and inferior walls. In this case conventional multiplanar 8 mm thick sections with magnetic resonance (MR) imaging proved to be more helpful than 1.5 mm axial thin sections with CT in demonstrating the extent of orbital floor herniation of fat. Entrapment of muscle was excluded. Oblique sagittal views were most helpful in evaluating the orbital floor, since the full course of the inferior rectus muscle is seen. Additionally, the optic nerve is seen along its entire length. Masking of intraorbital contents by isodense hemorrhage on CT studies apparently is not a problem with MR imaging if hemorrhage is small or nonacute.     

MR imaging of supra-acetabular insufficiency fractures

 Objective. Diagnosis of insufficiency fractures in the pelvis is difficult, especially in patients with prior malignancy, irradiation, steroid therapy or osteoporosis. This report shows the MR imaging appearance of supra-acetabular insufficiency fractures and how they can be differentiated from metastatic disease. Design and patients. Twelve patients (four men, eight women, average age 72.8 years) at risk for pelvic insufficiency fractures and who had pelvic or hip pain were studied with MR imaging. Indications were possible recurrent tumor or previous radiation to the pelvis (7 patients); osteoporosis from steroid use in rheumatoid arthritis (two patients); to exclude osteonecrosis of the hip (two patients); or to rule out a hip fracture (one patient). Results. A characteristic linear region of low signal intensity on both T1- and T2-weighted sequences was found in the supra-acetabular region paralleling the superior acetabulum in a curvilinear arc in 92% (11/12) of cases, and oblique in origin in 8% (1/11). Diffuse bands of high signal on T2-weighted images indicated surrounding edema. In two cases, MR findings obviated biopsy. One patient underwent a biopsy prior to the imaging studies being reviewed. All patients were treated conservatively and did well. Discussion. Attention to insufficiency fractures has previously focused on characteristic locations in the sacrum and pubic bones. Supra-acetabular insufficiency fractures also occur and are difficult to diagnose without a high degree of suspicion. MR imaging is a useful tool for diagnosing supra-acetabular insufficiency fractures. The characteristic MR imag-ing appearance of these fractures can preclude additional diagnostic studies and therapy in most instances.     

Technique for diagnosis of scaphoid fractures

Fracture of the scaphoid bone accounts for 60 percent of all carpal injuries. Early diagnosis of a scaphoid fracture is extremely important. Missing the fracture may lead to disability due to potential avascular necrosis or non-union of the fragments. The presence of a scaphoid fracture may be determined with greater certainty by using a multiple angle scaphoid series detailed by the author.