Computed tomography of suspected scaphoid fractures

PURPOSE: Computed tomography (CT) can be used to triage suspected scaphoid fractures. This study assessed intraobserver and interobserver reliability and positive and negative predictive values of CT for the diagnosis of a nondisplaced scaphoid fracture. METHODS: Eight observers evaluated CT scans from 30 patients (13 with nondisplaced scaphoid fractures, 17 with no scaphoid fractures) for the presence or absence of a fracture. Five observers evaluated the scans a second time. Statistical analyses included intraobserver and interobserver reliability and diagnostic characteristics. RESULTS: Computed tomography had substantial intraobserver and interobserver reliability for the diagnosis of a nondisplaced scaphoid fracture. The average sensitivity, specificity, and accuracy of CT for a nondisplaced scaphoid fracture were 89%, 91%, and 90% for the first round and 97%, 85%, and 88% for the second round of observations, respectively. Based on an estimated prevalence of 5% true fractures among patients with suspected scaphoid fractures, the average positive predictive value for the detection of radiographically occult scaphoid fractures with tomography of the wrist was 0.28. The average negative predictive value was 0.99. CONCLUSIONS: Computed tomography should be used with caution for triage of nondisplaced scaphoid fractures because false-positive results occur, perhaps from misinterpretation of vascular foraminae or other normal lines in the scaphoid. Given the relative infrequency of true fractures among patients with suspected scaphoid fractures, CT is better for ruling out a fracture than for ruling one in.     

Computed tomography in diagnosis of pelvic lipomatosis

Pelvic lipomatosis is a rare condition which may be associated with obstructive uropathy. The radiologic features may be simulated by pelvic malignancy and, in the past, surgery has often had to be performed for confirmation of the diagnosis. A case is described in which computed tomography (CT) provided definite proof that the pelvic organ displacement was due to excessive fat. It is considered that CT may obviate the need for further workup or surgery in these patients unless exploration is required for the relief of ureteric obstruction.     

Computed tomography and ultrasound in diagnosis of pelvic lipomatosis

Computed tomography (CT) and ultrasound are emerging as useful diagnostic adjuvants in the confirmation of pelvic lipomatosis. A case of pelvic lipomatosis studied by CT and sonography is presented. These two techniques offer greater precision in the demonstration of fatty tissue density within the true pelvis. The findings appear characteristic and unique. CT and ultrasound confirmation of pelvic lipomatosis provide added confidence in an accurate clinical diagnosis and may obviate the need for diagnostic surgical exploration.     

Computed tomography in spinal dysraphism.

Computed tomography of the spine has been used to evaluate patients with spinal dysraphism. With this technique, the nature of soft-tissue masses can often be correctly diagnosed and the underlying bony anomalies clarified.     

Computed tomography of orbital medial wall fractures

Increasing experience with computed tomographic evaluation of head trauma reveals this radiologic modality to be superior to conventional polytomography in the assessment of certain areas of maxillofacial injury. A comparison of hypocycloidal polytomography and computed tomography in nine patients with fractures of the medial wall of the orbit reveals CT to be superior in localization of the fracture site, delineation of displaced bone fragments, and recognition of herniation of intraorbital contents into the ethmoid labyrinth. Information regarding damage to the nasolacrimal duct and associated intraorbital abnormalities such as the presence and location of hemorrhage and foreign bodies is also available from the CT scan.     

Computed tomography in diagnosis of pelvic lipomatosis.

Pelvic lipomatosis is a disease characterized by abnormal deposition of mature adipose tissue within the confines of the pelvis surrounding the bladder, prostate, and rectosigmoid. The presenting symptoms are vague and nonspecific, and it has typical radiologic features. Computed tomography is extremely useful in the differential diagnosis because of its ability to differentiate fatty infiltration from other conditions which can cause elevation and compression of the urinary bladder and sigmoid colon. Computed tomographic confirmation of the presence of fat surrounding the bladder and rectum eliminates the need for surgical biopsy, unless indicated for other reasons. The course of this disease is usually benign and indolent, however a close follow-up is mandatory to rule out those cases in which ureteral obstruction may develop requiring surgical relief of the obstruction. When cystitis glandularis is found in association with pelvic lipomatosis, periodic cystoscopic examinations are recommended because of the potential risk of malignant transformation.     

Computerized axial tomography of pelvic ring fractures

The radiographs of all patients admitted to the Naval Hospital, Oakland with the diagnosis of pelvic trauma from 1981 through 1985 were reviewed. Thirty-one patients sustained single or double vertical ring fractures. Fifteen of these patients underwent both plain radiography and Computerized Axial Tomographic (CAT) scans in the evaluation of their pelvic injuries. The CAT scans of these pelvic injuries aided in detecting occult sacroiliac disruptions, determining the extent of posterior ring comminution, evaluating possible extension of the pelvic fractures into the acetabulum, assessing pelvic ring stability, and demonstrating soft-tissue injuries within the pelvis. Six pelvic injuries were diagnosed as single vertical breaks in the pelvic ring and nine were diagnosed as double vertical breaks in the pelvic ring by plain radiographs. CAT scanning demonstrated occult posterior ring disruptions in four patients which led to the reclassification of their injuries to double vertical fractures. CAT scanning also demonstrated significant degrees of sacral comminution in five patients which altered surgical treatment plans in all five patients. Two fractures were classified as unstable based on marked sacral comminution demonstrated on CAT scan. Extension of the pelvic ring fractures into the acetabulum was suggested on plain radiographs in three patients and was excluded by review of the CAT scans in these patients. Significant intrapelvic hematomas were demonstrated in three patients and urine extravasation into the hip joint from a bladder laceration was seen in one patient with the CAT scan.(ABSTRACT TRUNCATED AT 250 WORDS)     

Computed tomography image-guided surgery in complex acetabular fractures

Eleven complex acetabular fractures in 10 patients were treated by open reduction with internal fixation incorporating computed tomography image guided software intraoperatively. Each of the implants placed under image guidance was found to be accurate and without penetration of the pelvis or joint space. The setup time for the system was minimal. Accuracy in the range of 1 mm was found when registration was precise (eight cases) and was in the range of 3.5 mm when registration was only approximate (three cases). Added benefits included reduced intraoperative fluoroscopic time, less need for more extensive dissection, and obviation of additional surgical approaches in some cases. Compared with a series of similar fractures treated before this image guided series, the reduction in operative time was significant. For patients with complex anterior and posterior combined fractures, the average operation times with and without application of three-dimensional imaging technique were, respectively, 5 hours 15 minutes and 6 hours 14 minutes, revealing 16% less operative time for those who had surgery using image guidance. In the single column fracture group, the operation time for those with three-dimensional imaging application, was 2 hours 58 minutes and for those with traditional surgery, 3 hours 42 minutes, indicating 20% less operative time for those with imaging modality. Intraoperative computed tomography guided imagery was found to be an accurate and suitable method for use in the operative treatment of complex acetabular fractures with substantial displacement.     

CT在Pilon骨折术前评估中的意义

目的探讨CT对胫骨远端Pilon骨折术前评估的意义。方法总结了2000年1月～2005年6月具有完整X线片及CT随访资料的Pilon骨折52例,术前评估结合X线片和关节面CT平扫对骨折进行分型,并描绘骨折线的走行,测量骨折角,分析关节骨块的解剖特点。根据软组织条件、骨折类型、骨折线走行、骨折角、关节骨块位置设计个性化的治疗方案。石膏固定5例,闭合复位经皮螺钉固定加石膏外固定5例,微创钢板接骨术(MIPPO)技术钢板固定治疗17例,外固定结合有限内固定16例,切开复位内固定治疗9例。结果术后平均随访17.2个月。CT改变了9例Rüedi-Allgwer分型,21例发现了新的骨折块。CT平扫中主要骨折线呈冠状面走行的占61.5%,呈矢状面走行的占34.6%,对这两类骨折采用了不同的入路和内固定方式。用Mazur方法评估术后功能:优30例,良13例,可8例,差1例,总优良率82.7%,Ⅲ型的优良率为57.1%,CT显示有冲床死骨的优良率仅为44.4%。结论结合CT对Pilon骨折分型更准确;Ⅲ型骨折只要软组织条件允许,应切开复位关节面骨折;依据主要骨折线的走行和骨块的位置选择切口和内固定方式;对冲床死骨需直视下复位,但此类病例预后较差。     

Computed tomography and magnetic resonance imaging in spinal hydatidosis

Computed tomography and magnetic resonance imaging in patients with spinal hydatidosis provide comprehensive evaluation of the actual extent of the disease. Paravertebral uncalcified cysts, hardly recognizable by conventional radiologic examinations, are clearly shown by both methods. Initial involvement of the spongy bone is evident in computed tomography scans, in contrast to what usually appears to be normal in plain films or tomograms. Occurrence of cysts within the spinal canal is revealed by both types of computed scans, with magnetic resonance imaging being able to provide further information on the involvement of the spinal cord.     

Computed tomography to assess pelvic lysis after total hip replacement

To assess the accuracy of a computer-assisted computed tomography image analysis program in determining the location and volume of periacetabular osteolysis, we designed an osteolysis model by implanting bilateral total hip replacements in human pelvic cadavers and creating osteolytic lesions of varying sizes. The volumes of 48 defects were measured physically, and axial computed tomography scans were obtained. The computed tomography images were processed with streak artifact reduction and segmentation algorithms. The location and volume of lesions were determined from these images. Eighty-one percent (39 lesions) were identified correctly from the computed tomography scans. Detection was location-dependent. More lesions were detected in the ilium (100%) and at the rim (89%) than in the ischium (78%) or the pubis (50%). Computed tomography overestimated lesion volume by a mean of 0.5 +/- 2.3 cm. The volumetric error was unrelated to lesion location but was dependent on lesion size. As lesion size increased above 10 cm, the mean percentage error decreased to 1.8%. Computed tomography image analysis can be used more accurately than plain radiographs to investigate the effectiveness of treatment and the natural history of pelvic osteolysis.     

Computed tomography in the management of spinal cord arteriovenous malformations

This is a report of two cases of intramedullary arteriovenous malformations (AVMs) where computed tomography (CT) was used as a complementary diagnostic investigation. CT scan features in these two cases are briefly discussed.     

CT硬膜外造影对腰椎管狭窄症的诊断价值

目的：探讨硬膜外造影后CT(CT-E)对腰椎管狭窄症的诊断价值及影像特征。方法：对27例腰椎管狭窄症患者行腰椎X线平片及单纯CT检查后再行CT-E检查。CT—E扫描椎体下1／3、椎间隙、椎体上缘平面，结合单纯CT及手术所见行对比分析。结果：CT-E诊断中央管狭窄3例，中央管伴侧隐窝狭窄2例，侧隐窝狭窄16例，神经根管狭窄4例，椎问孔狭窄2例。与于术所见吻合25例，诊断准确率达93％；单纯CT与手术所见吻合23例．诊断准确率为85％。结论：CT—E对腰椎管狭窄症更具有定性、定位诊断作用，可为有限化手术提供依据。     

Long-term outcome in patients with combined spinal and pelvic fractures

The outcome of 30 patients with combined spinal and pelvic fractures (C group) was retrospectively investigated and compared with matched group of similar number of isolated spinal fractures (S group) and isolated pelvic fractures (P Group), admitted to our institution between Jan 1998 and May 2002, following a high-energy trauma. After a mean follow-up of 57 months their outcomes were studied using EuroQol questionnaire and return to work status. The EQ-5D scores for patients in the S group were 0.71 (SD 0.29) compared to 0.60 (SD 0.14) for patients in the P group and 0.63 (SD 0.23) for patients in the C group. The EQ-VAS scores were similarly favourable towards patients in the S group. Seventy percent of patients in the S group returned to their previous level of employment after a mean duration of 5.3 months compared to 55% in the P group and 57% in the C group after a mean duration of 9.4 months and 12.8 months, respectively. Patients with isolated spinal fractures had an overall satisfactory outcome compared with patients in the other 2 groups. However, no difference was noted while analysing the outcomes in the later 2 groups (p<0.05), suggesting that the pelvic fracture contributes to the poor outcome, and the presence of a spinal fracture does not influence the long-term outcome. However, problems related to associated injuries and motor neurological deficits have profound confounding effect on the outcome in all 3 groups.     

The value of computerized tomography in fractures of the pelvic ring

Summary Thirty four fractures of the pelvic ring were examined by computerized tomography and the findings compared with those obtained with conventional radiography. CT scanning enabled precise delineation of the fracture sites in the posterior ring. A new classification is proposed which defines five patterns of fracture of the posterior ring. Computerized tomography is a valuable aid in planning operation in these injuries.

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Résumé 34 fractures non-consécutives de l'anneau pelvien sont examinées en tomométrie axiale computérisée. Les images sont confrontées à celles de la radiologie conventionnelle. Ceci permet une définition précise des lésions au niveau de l'anneau postérieur. Une nouvelle classification de ces fractures est proposée en cinq types de lésions de l'anneau postérieur. L'utilisation de la tomométrie axiale computérisée dans la planification préopératoire est soulignée.

     

Bone atrophy after plate fixation. Computed tomography of femoral shaft fractures

Twelve patients with previous femoral shaft fracture treated by rigid plate fixation were examined by computed tomography (CT) scanning 1 or 2 days after plate removal. In the previously plated segment an average reduction in cortical density of 11 per cent was found, and the reduction was most pronounced in the cortex directly beneath the plate. No reduction in cortical thickness of the plated bone occurred. Proximal and distal to the site of the plate, and in the ipsilateral tibial shaft, a slight reduction in cortical density and thickness averaging 2-3 per cent was found.     

Bone atrophy after plate fixation: Computed tomography of femoral shaft fractures

Twelve patients with previous femoral shaft fracture treated by rigid plate fixation were examined by computed tomography (CT) scanning 1 or 2 days after plate removal. In the previously plated segment an average reduction in cortical density of 11 per cent was found, and the reduction was most pronounced in the cortex directly beneath the plate. No reduction in cortical thickness of the plated bone occurred. Proximal and distal to the site of the plate, and in the ipsilateral tibial shaft, a slight reduction in cortical density and thickness averaging 2-3 per cent was found.