Bone scintigraphy as a guide to the diagnosis of osteoid osteoma.

This report describes one case in which bone scintigraphy was helpful in establishing the diagnosis of osteoid osteoma and presents three other cases in which increased accumulation of 99mmTc-EHDP was found at the side of the osteoid osteoma. The study contributes to the observation by others that the osteoid osteoma occurs as a scintigraphic 'hotspot'. It is concluded that the diagnostic delay of the osteoid osteoma can be shortened when bone scintigraphy is performed more often and at an earlier stage in patients with unexplained bone pain or with a clinical history that leads to the suspicion of the presence of an osteoid osteoma.     

Imaging of osteoid osteoma with dynamic gadolinium-enhanced MR imaging

PURPOSE: To compare dynamic gadolinium-enhanced T1-weighted magnetic resonance (MR) imaging with nonenhanced T1-weighted and T2-weighted MR imaging and thin-section computed tomography (CT) for the demonstration of osteoid osteomas. MATERIALS AND METHODS: The images of 11 patients with pathologically proven osteoid osteomas who underwent nonenhanced MR imaging, dynamic gadolinium-enhanced MR imaging, and CT were retrospectively reviewed. Images obtained with all three techniques were scored for conspicuity of the osteoid osteoma relative to the surrounding bone. Time-enhancement curves were generated from signal intensity measurements of these lesions and the adjacent bone marrow. The mean imaging scores of the four techniques were compared, and the statistical significance was calculated by using a linear model with terms for method and patient. Pairwise comparisons were made by using the Tukey-Kramer adjustment for multiple comparisons. RESULTS: Compared with CT, dynamic gadolinium-enhanced MR imaging demonstrated the osteoid osteoma equally well in eight of 11 patients and with better conspicuity in three of 11 patients, although this difference was not statistically significant (P =.69). The dynamic gadolinium-enhanced MR images demonstrated the osteoid osteomas significantly better than the nonenhanced T1-weighted (P <.001) and T2-weighted (P <.001) MR images. On the dynamic gadolinium-enhanced MR images, nine (82%) of 11 patients had peak enhancement of the osteoid osteoma in the arterial phase with early partial washout, compared with slower, progressive enhancement of the adjacent marrow. This resulted in greatest lesion to marrow contrast material enhancement in the arterial phase. One osteoid osteoma had peak enhancement in the venous phase, and one showed progressive enhancement through all phases to 150 seconds. CONCLUSION: Osteoid osteomas can be imaged with greater conspicuity by using dynamic gadolinium-enhanced instead of nonenhanced MR imaging and with conspicuity equal to or better than that obtained with thin-section CT.     

The diagnostic accuracy of MR imaging in osteoid osteoma

OBJECTIVE: To analyse the MR imaging appearances of a large series of osteoid osteomas, to assess the ability of MR imaging to detect the tumour, and to identify potential reasons for misdiagnosis. DESIGN AND PATIENTS: The MR imaging findings of 43 patients with osteoid osteoma were reviewed retrospectively and then compared with other imaging modalities to assess the accuracy of MR localisation and interpretation. RESULTS: The potential for a missed diagnosis was 35% based solely on the MR investigations. This included six tumours which were not seen and nine which were poorly visualised. The major determinants of the diagnostic accuracy of MR imaging were the MR technique, skeletal location, and preliminary radiographic appearances. There was a wide spectrum of MR signal appearances of the lesion. The tumour was identified in 65% of sequences performed in the axial plane. The nidus was present in only one slice of the optimal sequence in 27 patients. Reactive bone changes were present in 33 and soft tissue changes in 37 patients. CONCLUSION: Reliance on MR imaging alone may lead to misdiagnosis. As the osteoid osteoma may be difficult to identify and the MR features easily misinterpreted, optimisation of MR technique is crucial in reducing the risk of missing the diagnosis. Unexplained areas of bone marrow oedema in particular require further imaging (scintigraphy and CT) to exclude an osteoid osteoma.     

Percutaneous Laser Photocoagulation of Osteoid Osteomas

Osteoid osteoma is a painful benign bone tumor. The curative treatment of this tumor consists of complete surgical or percutaneous excision of the nidus with immediate and dramatic relief of symptoms. Interstitial laser photocoagulation (ILP) is a low-invasive percutaneous technique of thermal destruction (coagulation) of deep-seated tumors elsewhere in the body, using low-power laser energy. The aim of ILP is the local destruction of osteoid osteoma without bone weakening. Twenty-two patients with osteoid osteoma were treated with percutaneous ILP of the nidus under computed tomography guidance. The laser energy was provided by a high-power semiconductor diode laser (805 nm) with a 400-&mgr;m optical fiber. Complete pain relief was obtained in 21 patients. Percutaneous ILP of osteoid osteoma seems to be a promising, simple, precise, and minimally invasive technique as an alternative to traditional surgical and percutaneous ablations.     

Osteoid osteoma simulating osteomyelitis: Differentiation with Tc-99m HIG scintigraphy

We present a case of osteoid osteoma with a history of mild pain, local swelling and point tenderness on the right lower leg. The diagnosis of osteoid osteoma was difficult due to the atypical clinical history and misleading radiological and bone scan findings. When it is difficult to differentiate an osteoid osteoma from osteomyelitis using CT, MRI or bone scan; HIG scintigraphy can be used to exclude an infection.     

骨样骨瘤的影像学诊断

目的分析骨样骨瘤的X线、CT及MRI表现,探讨其影像学特征。方法搜集经临床及病理证实的骨样骨瘤23例,男19例,女4例。所有病例均行X线检查,其中同时行CT检查者19例,行MR检查者7例,3种检查都进行者6例。分析骨样骨瘤的X线、CT和MRI表现,及其对瘤巢和瘤巢周围改变的显示能力,总结其特征性的影像学表现。结果23例病灶均显示一直径0.2～2.1cm大小不等的圆形或椭圆形瘤巢,边界清楚,边缘骨质不同程度硬化,骨膜反应,骨髓腔及软组织水肿或关节腔积液。24例X线平片17例显示瘤巢,19例行CT检查者均清晰显示瘤巢,7例行MR检查者5例可显示瘤巢,2例需结合X线及CT检查方能肯定诊断。X线、CT及MR对瘤巢的显示率分别为73.9%(17/23)、100%(19/19)及71.4%(5/7)。结论瘤巢是骨样骨瘤的特征性表现,CT检查是诊断骨样骨瘤最准确的方法,X线检查是诊断骨样骨瘤的重要方法,MR检查对显示瘤巢周围骨髓、软组织及关节腔情况非常敏感,仅凭X线或MR的表现易造成误诊、漏诊。     

骨样骨瘤的影像学诊断

目的 分析骨样骨瘤的X线、CT和MRI表现。方法 搜集经手术病理证实的骨样骨瘤48例，其中男33例，女15例。所有病例均行X线检查，其中同时行CT检查者32例，行MR检查者10例，3种检查方法都进行者8例。分析骨样骨瘤在X线、CT和MRI上的表现及其对瘤巢和瘤巢周围改变的显示能力。结果 48例病灶均表现为一圆形或卵圆形的透亮区，直径为0．4～1．7cm，平均9．7cm，其周围有不同程度的骨质硬化。10例行MR检查者均可见瘤巢周围的软组织、骨髓水肿或关节腔积液。48例X线平片仅37例显示瘤巢，32例行CT检查者均清楚显示瘤巢，X线和CT对瘤巢显示率分别为77％(37／48)和100％(32／32)。10例MR检查者均可作出正确诊断，其中8例能直接判断出瘤巢，另2例需对照平片或CT才能肯定。结论 瘤巢是确诊骨样骨瘤的关键，X线平片仍然是诊断骨样骨瘤的重要检查方法，CT是显示瘤巢的最佳方法，MRI能敏感地显示瘤巢周围骨髓内及软组织的炎性水肿，但可能造成误诊，结合平片或CT可作出准确诊断。     

Osteoid osteoma: operative confirmation of complete removal by bone scintigraphy

The high sensitivity of bone scintigraphy in detecting osteoid osteoma throughout the skeleton has been documented. Recently, radioactive surgical specimens of osteoid osteomas were studied with microradiography, autoradiography, and well-counter scintimetry and were shown to concentrate most of the radionuclide within the nidus of the lesion. These techniques also proved helpful to surgeons in achieving cure with conservative bone excision. We present two cases of osteoid osteoma, one of them recurrent, in which the patients were injected with bone-seeking agent just prior to surgery. The excised specimens were immediately imaged and the entire nidus was seen, confirming the complete removal of the lesion. This simple and rapid procedure is suggested whenever difficulty is anticipated in removal of an osteoid osteoma.     

骨样骨瘤的X线和CT表现

目的 :分析骨样骨瘤的X线和CT表现。方法 :搜集经手术病理证实的骨样骨瘤 2 3例。所有病例均行X线和CT检查 ,分析影像表现特征及其对瘤巢及瘤巢周围改变的显示能力。结果 :2 3例病灶均表现为一圆形或卵圆形的透亮区 ,直径 0 .4～ 1.7cm ,平均 0 .98cm ,其周围有不同程度的骨质硬化。X线和CT对瘤巢显示率分别为 78.3 %( 18/2 3 )和 10 0 %( 2 3 /2 3 )。结论 :瘤巢是确诊骨样骨瘤的关键 ,X线平片是诊断骨样骨瘤的重要检查方法 ,CT是显示瘤巢的最佳方法。     

Osteoid osteoma mimicking chronic arthritis. Diagnosis by bone scintigraphy

The case of a patient with osteoid osteoma of the heel is presented. The patient was misdiagnosed and treated for four years as having arthritis. Osteoid osteoma was diagnosed by 99mTc-MDP bone scan that was performed for the evaluation of the arthritis. Plain radiography and magnetic resonance imaging (MRI) were negative for signs of arthritis. However, MRI when reevaluated after positive bone scintigraphy, was found positive for osteoid osteoma. This case underscores the value of bone scintigraphy for the diagnosis of osteoid osteoma.     

Discrete synchronous multifocal osteoid osteoma of the humerus

 A 24-year-old patient is described who had a 4-year history of pain in the right upper arm, with distinct night pain, that responded to salicylates. From the findings on conventional radiography, bone scintigraphy and MRI a multifocal osteoid osteoma was suspected, with one focus in the cancellous region of the greater tuberosity and a second cortical focus at the proximal humeral diaphysis. The resection ’’en bloc’’ of both tumors and histological examination confirmed the diagnosis. The patient was painfree after the curative resection of the two osteoid osteomas. Osteoid osteoma is a frequently found benign bone tumor, accounting for approximately 11% of cases. In rare cases a multicentric occurrence has been described. A possible occurrence of more than one osteoid osteoma in a single bone, not verified histologically, has been reported only three times in the literature. In patients with scintigraphic and radiographic findings of two foci, discrete synchronous multifocal osteoid osteomas should be suspected.     

Experience of neuroprotective air injection during radiofrequency ablation (RFA) of spinal osteoid osteoma

Purpose

To assess the usefulness of epidural air injection during the RFA treatment of spinal osteoid osteoma.

Methods

A retrospective review of 17 patients who underwent RFA for spinal osteoid osteoma between September 2006 and May 2017 was performed. All the procedures were performed by a single radiologist. We reviewed the perioperative CT studies to assess the distribution of air relative to the osteoid osteoma. The clinical outcome of each patient group was evaluated during routine follow-up.

Results

Seventeen patients were treated for spinal OO (male:female 13:4; mean age was 16, ranging from 4 to 42). The nidus size ranged from 5.8 to 17.2 mm (mean 11.2). In nine cases epidural air injection was performed. In three cases the neuroprotective air was deemed satisfactory with a clear layer of air between the osteoid osteoma and the dural sac being visualised. In six patients adherence between the cortical bone immediately adjacent to the osteoid osteoma and the dural sac in contact was observed.In 15 patients the procedure was successful in terms of pain relief. No neural damage or other complication was reported in either group.

Conclusion

RFA is a safe treatment for spinal osteoid osteoma. Neuroprotective air injection does not appear to be necessary when performing the treatment in the spine.

Key Points

? Seventeen patients with spinal OO were treated with RFA, nine with air injection and eight without. Clinically successful treatment was achieved in 15 patients, with 2 subsequently undergoing surgery ? In 6/9 cases the injected air failed to achieve separation between the osteoid osteoma and the thecal sac because of inflammatory adhesion ? No complications were observed, regardless of whether neuroprotective air was instilled. Neuroprotective air injection appears unnecessary when treating spinal OO

     

Osteoid osteoma: MR imaging revisited

To assess and compare with computed tomography (CT) the performance of magnetic resonance (MR) imaging in the detection of osteoid osteoma, and determine the features of this lesion on MR imaging. The prospective MR imaging and CT diagnosis of osteoid osteoma was determined from original radiology reports. MR images were assessed retrospectively with regard to the location and signal intensity of the nidus and surrounding bone marrow and soft tissue edema. These findings were correlated with the age of the patient, duration of symptoms, and drug therapy. Ten patients with histologically proven osteoid osteoma who underwent MR imaging were reviewed. All 10 lesions were correctly diagnosed at the time of MR imaging. None of the lesions was intracortical. Nine lesions were intra-articular. Two out of five patients with extracortical lesions had false negative CT preceding the MR study. Signal intensity of the nidus, marrow, and soft tissue edema on MR imaging were variable. Perinidal edema was most pronounced in younger patients and had no apparent relation to drug therapy. MR imaging reliably demonstrates the nidus of an osteoid osteoma, which has a variable appearance related to its position relative to the cortex of the bone. A predominance of cancellous osteoid osteomas are encountered in patients referred for MR imaging. Marrow edema in the vicinity of the lesion improves the conspicuity of the nidus. CT may fail to diagnose osteoid osteoma when the nidus is in a cancellous location, due to the lack of perinidal density alteration.     

Subperiosteal osteoid osteoma of the talus

We report three patients with subperiosteal osteoid osteoma of the talus. All showed an erosion of the dorsal surface of the talus with medullary bone sclerosis. Adjacent paraosseous soft tissue calcification was seen in two lesions. Computed tomography demonstrated the nidus of the osteoid osteoma in two cases.     

骨样骨瘤的影像诊断

目的探讨骨样骨瘤的X线、CT与MR表现。方法搜集我院2006—2007年经手术病理证实的骨样骨瘤20例,其中男性12例,女性8例,年龄11~37岁,平均年龄24岁。所有病例均行X线检查,其中行CT检查者6例,行MR检查者8例。分析上述3种影像检查对骨样骨瘤瘤巢的显示率。结果在常规X线检查中20例病灶均表现为一圆形或卵圆形的透亮区,直径>5~16 mm,周围可见不同程度的骨质硬化;其中16例可以看到瘤巢,显示率为80%;6例经CT薄层扫描均可清楚显示瘤巢,显示率为100%;8例行MR检查,其中6例可显示瘤巢,并可见瘤巢周围的软组织肿胀,瘤巢显示率为75%。结论瘤巢是确诊骨样骨瘤的关键。常规X线是诊断骨样骨瘤的首先检查方法,CT是显示瘤巢最可靠的方法,MR显示瘤巢不如CT敏感,但却可以清楚的显示瘤巢周围的软组织肿胀情况。     

Scintigraphic patterns in osteoid osteoma and spondylolysis

A retrospective review was performed of radionuclide bone scans and radiographs of 54 children with diagnoses of spondylolysis or osteoid osteoma/osteoblastoma. The findings indicate that skeletal scintigraphy shows imaging patterns that can be used to help distinguish these two conditions. Most cases of spondylolysis and all cases of osteoid osteoma or osteoblastoma demonstrated focally increased activity on the delayed skeletal scintigrams. Evaluation of the bone scan images obtained during the immediate postinjection period revealed intense activity with osteoid osteoma and osteoblastoma, but minimal or no abnormal activity in cases of spondylolysis. In addition, spondylolysis was the only condition that produced bilateral abnormalities in the pars interarticularis region in these children.     

骨样骨瘤的影像诊断

目的评价平片、CT,MRI对骨样骨瘤的诊断价值.方法18例骨样骨瘤均摄平片,其中16例经CT检查,4例行MRI检查;分析骨样骨瘤的平片、CT,MBI影像学表现.结果骨样骨瘤典型表现为瘤巢及周围反应性骨质硬化,且随病变部位不同而有所差异.诊断准确性平片为92.9%,CT为100%,MRI为83.3%.结论平片是诊断骨样骨瘤的基本手段,CT为最可靠方法,MRI需结合平片、CT进行诊断.     

Osteoid osteoma--ten-years' experience in therapy

AIM: To review ten-years experience in diagnostics and operative treatment of osteoid osteoma. METHODS: A total of 15 patients were retrospectively analyzed in this study. Clinical diagnosis was based on medical check-up, aspirin test, and conventional laboratory and radiographic examinations. CAT scan radionuclide bone scan, and magnetic resonance were performed in certain cases. All the patients were operatively treated by local resection of the tumor-infested bone. The resected part of the bone was intraoperatively checked by X-ray. The aim of this examination was to verify nidus in the resected bone. Afterwards, the resected bone with nidus was histologically analyzed. RESULTS: Osteoid osteoma was histologically verified in 86.6% of cases. Other forms of bone tumors were verified in 13.3%. In the early postoperative period patients were without previous discomforts. Future treatment consisted of regular medical check-up of all the patients. In order to verify the final results, in February 2002 another medical check-up was performed for 11 patients, upon their consent. All of the patients with verified osteoid osteoma were without discomforts. Medical findings were regular in each case. Conventional radiography showed a solid bone remodelling in place of resected bone. CONCLUSION: Osteoid osteoma is a benign bone tumor with typical clinical and radiographic findings. Operative treatment represents a method of choice and demands accurate preoperative localization of the lesion, with the help of computer-assisted tomography.     

Percutaneous Biopsy and Radiofrequency Ablation of Osteoid Osteoma with Excess Reactive New Bone Formation and Cortical Thickening Using a Battery-Powered Drill for Access: A Technical Note

Purpose

To report our experience with the use of a battery-powered drill in biopsy and radiofrequency ablation of osteoid osteoma with excess reactive new bone formation. The battery-powered drill enables obtaining the sample while drilling.

Materials and Methods

During the last 18 months, 14 patients suffering from painful osteoid osteoma with excess reactive new bone formation underwent CT-guided biopsy and radiofrequency ablation. In order to assess and sample the nidus of the osteoid osteoma, a battery-powered drill was used. Biopsy was performed in all cases. Then, coaxially, a radiofrequency electrode was inserted and ablation was performed with osteoid osteoma protocol. Procedure time (i.e., drilling including local anesthesia), amount of scans, technical and clinical success, and the results of biopsy are reported.

Results

Access to the nidus through the excess reactive new bone formation was feasible in all cases. Median procedure time was 50.5 min. Histologic verification of osteoid osteoma was performed in all cases. Radiofrequency electrode was coaxially inserted within the nidus and ablation was successfully performed in all lesions. Median amount CT scans, performed to control correct positioning of the drill and precise electrode placement within the nidus was 11. There were no complications or material failure reported in our study.

Conclusions

The use of battery-powered drill facilitates access to the osteoid osteoma nidus in cases where excess reactive new bone formation is present. Biopsy needle can be used for channel creation during the access offering at the same time the possibility to extract bone samples.

     

99Tc^m-MDP骨显像评估脊柱骨样骨瘤及成骨细胞瘤射频消融效果

目的探讨99Tcm-亚甲基二磷酸盐骨显像对脊柱骨样骨瘤和成骨细胞瘤射频消融疗效评估的价值。资料与方法回顾性收集行射频消融的7例脊柱骨样骨瘤及成骨细胞瘤患者的影像学及临床资料,分析骨显像、CT表现与患者症状、随访结果的关系。结果7例患者(其中骨样骨瘤4例,成骨细胞瘤3例)接受8次射频消融。治疗后2例无疼痛复发,第3、6个月骨显像呈轻度浓聚,其中1例第3个月CT示病变缩小,第12个月消失。3例第4~5个月疼痛复发,骨显像呈轻度浓聚1例,显著浓聚2例,同期CT示病变较治疗前均无变化,继续随访患者疼痛消失。2例射频消融后仍有间断轻度疼痛,第9、12个月骨显像均呈显著浓聚,同期CT示病变缩小1例,增大1例,患者后续分别行手术和再次射频消融。结论骨显像能够早期判断骨样骨瘤和成骨细胞瘤射频消融后病变的活性。骨显像轻度浓聚预示病变治愈,显著浓聚提示病变尚存活性,需继续随访。