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Background An artificial intelligence model that assesses primary bone tumors on radiographs may assist in the diagnostic workflow. Purpose To develop a multitask deep learning (DL) model for simultaneous bounding box placement, segmentation, and classification of primary bone tumors on radiographs. Materials and Methods This retrospective study analyzed bone tumors on radiographs acquired prior to treatment and obtained from patient data from January 2000 to June 2020. Benign or malignant bone tumors were diagnosed in all patients by using the histopathologic findings as the reference standard. By using split-sample validation, 70% of the patients were assigned to the training set, 15% were assigned to the validation set, and 15% were assigned to the test set. The final performance was evaluated on an external test set by using geographic validation, with accuracy, sensitivity, specificity, and 95% CIs being used for classification, the intersection over union (IoU) being used for bounding box placements, and the Dice score being used for segmentations. Results Radiographs from 934 patients (mean age, 33 years ± 19 [standard deviation]; 419 women) were evaluated in the internal data set, which included 667 benign bone tumors and 267 malignant bone tumors. Six hundred fifty-four patients were in the training set, 140 were in the validation set, and 140 were in the test set. One hundred eleven patients were in the external test set. The multitask DL model achieved 80.2% (89 of 111; 95% CI: 72.8, 87.6) accuracy, 62.9% (22 of 35; 95% CI: 47, 79) sensitivity, and 88.2% (67 of 76; CI: 81, 96) specificity in the classification of bone tumors as malignant or benign. The model achieved an IoU of 0.52 ± 0.34 for bounding box placements and a mean Dice score of 0.60 ± 0.37 for segmentations. The model accuracy was higher than that of two radiologic residents (71.2% and 64.9%

Background Current measurements of multiple myeloma disease burden are suboptimal. Daratumumab is a monoclonal antibody that targets CD38, an antigen expressed on nearly all myeloma cells. Purpose To demonstrate preclinical and first-in-human application of an antibody composed of the native daratumumab labeled with the positron-emitting radionuclide zirconium 89 (89Zr) through the chelator deferoxamine (DFO), or 89Zr-DFO-daratumumab, for immunologic PET imaging of multiple myeloma. Materials and Methods 89Zr-DFO-daratumumab was synthesized by conjugating 89Zr to daratumumab with DFO. A murine xenograft model using CD38-positive OPM2 multiple myeloma cells was used to evaluate CD38-specificity of 89Zr-DFO-daratumumab. Following successful preclinical imaging, a prospective phase I study of 10 patients with multiple myeloma was performed. Study participants received 74 MBq (2 mCi) of intravenous 89Zr-DFO-daratumumab. Each participant underwent four PET/CT scans over the next 8 days, as well as blood chemistry and whole-body counts, to determine safety, tracer biodistribution, pharmacokinetics, and radiation dosimetry. Because 89Zr has a half-life of 78 hours, only a single administration of tracer was needed to obtain all four PET/CT scans. Results 89Zr-DFO-daratumumab was synthesized with radiochemical purity greater than 99%. In the murine model, substantial bone marrow uptake was seen in OPM2 mice but not in healthy mice, consistent with CD38-targeted imaging of OPM2 multiple myeloma cells. In humans, 89Zr-DFO-daratumumab was safe and demonstrated acceptable dosimetry. 89Zr-DFO-daratumumab uptake was visualized at PET in sites of osseous myeloma. Conclusion These data demonstrate successful CD38-targeted immunologic PET imaging of multiple myeloma in a murine model and in humans. © RSNA, 2020 Online supplemental material is available for this article.

Purpose To evaluate the use of susceptibility-weighted MRI for the differentiation of predominantly osteoblastic and osteolytic spine metastases. Materials and Methods For this prospective study, 53 study participants (mean age, 54.5 years ± 14.3 [range, 22-88 years]; 27 men with a mean age of 55.3 years ± 12.7 [range, 22-72 years] and 26 women with a mean age of 53.8 years ± 15.7 [range, 23-88 years]) with clinically suspected spine metastases underwent imaging with standard MRI sequences, susceptibility-weighted MRI, and CT. Sensitivities and specificities of MRI sequences for the detection of predominantly osteoblastic and osteolytic metastases were determined by using CT as the reference standard. The metastases-to-vertebral body signal intensity ratio (MVR) was calculated to compare modalities. Phantom measurements were obtained to correlate bone densities between MRI sequences and CT. Results A total of 64 metastases (38 predominantly osteoblastic, 26 predominantly osteolytic) were detected. Susceptibility-weighted MRI achieved a sensitivity of 100% (38 of 38) and specificity of 96% (25 of 26) for predominantly osteoblastic metastases and a sensitivity of 96% (25 of 26) and specificity of 100% (38 of 38) for predominantly osteolytic metastases. Standard MRI sequences achieved a sensitivity of 89% (34 of 38) and specificity of 73% (19 of 26) for predominantly osteoblastic metastases and a sensitivity of 73% (19 of 26) and specificity of 92% (35 of 38) for predominantly osteolytic metastases. MVR measurements obtained with susceptibility-weighted MRI demonstrated a strong correlation with those obtained with CT (R2 = 0.75), whereas those obtained with T1-weighted MRI, T2-weighted MRI, and turbo inversion-recovery magnitude MRI showed a weak to moderate correlation (R2 = 0.00, R2 = 0.35, and R2 = 0.39, respectively). Susceptibility-weighted MRI showed a strong correlation with CT with regard to metastases size (R2 = 0.91). In phantom measurements, susceptibility-weighted MRI enabled the reliable differentiation of different degrees of mineralization (R2 = 0.92 compared with CT). Conclusion Susceptibility-weighted MRI enables the reliable differentiation between predominantly osteoblastic and osteolytic spine metastases with a higher accuracy than standard MRI sequences. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Schweitzer in this issue.

Background It is important to diagnose sclerotic bone lesions in order to determine treatment strategy. Purpose To evaluate the diagnostic performance of a CT radiomics-based machine learning model for differentiating bone islands and osteoblastic bone metastases. Materials and Methods In this retrospective study, patients who underwent contrast-enhanced abdominal CT and were diagnosed with a bone island or osteoblastic metastasis between 2015 to 2019 at either of two different institutions were included: institution 1 for the training set and institution 2 for the external test set. Radiomics features were extracted. The random forest (RF) model was built using 10 selected features, and subsequent 10-fold cross-validation was performed. In the test phase, the RF model was tested with an external test set. Three radiologists reviewed the CT images for the test set. The sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) were calculated for the models and each of the three radiologists. The AUCs of the radiomics model and radiologists were compared. Results A total of 177 patients (89 with a bone island and 88 with metastasis; mean age, 66 years ± 12 [standard deviation]; 111 men) were in the training set, and 64 (23 with a bone island and 41 with metastasis; mean age, 69 years ± 14; 59 men) were in the test set. Radiomics features (n = 1218) were extracted. The average AUC of the RF model from 10-fold cross-validation was 0.89 (sensitivity, 85% [75 of 88 patients]; specificity, 82% [73 of 89 patients]; and accuracy, 84% [148 of 177 patients]). In the test set, the AUC of the trained RF model was 0.96 (sensitivity, 80% [33 of 41 patients]; specificity, 96% [22 of 23 patients]; and accuracy, 86% [55 of 64 patients]). The AUCs for the three readers were 0.95 (95% CI: 0.90, 1.00), 0.96 (95% CI: 0.90, 1.00), and 0.88 (95% CI: 0.80, 0.96). The AUC of radiomics model was higher than that of only reader 3 (0.96 vs 0.88, respectively; P = .03). Conclusion A CT radiomics-based random forest model was proven useful for differentiating bone islands from osteoblastic metastases and showed better diagnostic performance compared with an inexperienced radiologist. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Vannier in this issue.

Purpose To assess for nanopore formation in bone marrow cells after irreversible electroporation (IRE) and to evaluate the antitumoral effect of IRE, used alone or in combination with doxorubicin (DOX)-loaded superparamagnetic iron oxide (SPIO) nanoparticles (SPIO-DOX), in a VX2 rabbit tibial tumor model. Materials and Methods All experiments were approved by the institutional animal care and use committee. Five porcine vertebral bodies in one pig underwent intervention (IRE electrode placement without ablation [n = 1], nanoparticle injection only [n = 1], and nanoparticle injection followed by IRE [n = 3]). The animal was euthanized and the vertebrae were harvested and evaluated with scanning electron microscopy. Twelve rabbit VX2 tibial tumors were treated, three with IRE, three with SPIO-DOX, and six with SPIO-DOX plus IRE; five rabbit VX2 tibial tumors were untreated (control group). Dynamic T2*-weighted 4.7-T magnetic resonance (MR) images were obtained 9 days after inoculation and 2 hours and 5 days after treatment. Antitumor effect was expressed as the tumor growth ratio at T2*-weighted MR imaging and percentage necrosis at histologic examination. Mixed-effects linear models were used to analyze the data. Results Scanning electron microscopy demonstrated nanopores in bone marrow cells only after IRE (P , .01). Average volume of total tumor before treatment (503.1 mm3 ± 204.6) was not significantly different from those after treatment (P = .7). SPIO-DOX was identified as a reduction in signal intensity within the tumor on T2*-weighted images for up to 5 days after treatment and was related to the presence of iron. Average tumor growth ratios were 103.0% ± 75.8 with control treatment, 154.3% ± 79.7 with SPIO-DOX, 77% ± 30.8 with IRE, and -38.5% ± 24.8 with a combination of SPIO-DOX and IRE (P = .02). The percentage residual viable tumor in bone was significantly less for combination therapy compared with control (P = .02), SPIO-DOX (P , .001), and IRE (P = .03) treatment. The percentage residual viable tumor in soft tissue was significantly less with IRE (P = .005) and SPIO-DOX plus IRE (P = .005) than with SPIO-DOX. Conclusion IRE can induce nanopore formation in bone marrow cells. Tibial VX2 tumors treated with a combination of SPIO-DOX and IRE demonstrate enhanced antitumor effect as compared with individual treatments alone. © RSNA, 2017 Online supplemental material is available for this article.

Purpose To determine the improvement of radiologist efficiency and performance in the detection of bone metastases at serial follow-up computed tomography (CT) by using a temporal subtraction (TS) technique based on an advanced nonrigid image registration algorithm. Materials and Methods This retrospective study was approved by the institutional review board, and informed consent was waived. CT image pairs (previous and current scans of the torso) in 60 patients with cancer (primary lesion location: prostate, n = 14; breast, n = 16; lung, n = 20; liver, n = 10) were included. These consisted of 30 positive cases with a total of 65 bone metastases depicted only on current images and confirmed by two radiologists who had access to additional imaging examinations and clinical courses and 30 matched negative control cases (no bone metastases). Previous CT images were semiautomatically registered to current CT images by the algorithm, and TS images were created. Seven radiologists independently interpreted CT image pairs to identify newly developed bone metastases without and with TS images with an interval of at least 30 days. Jackknife free-response receiver operating characteristics (JAFROC) analysis was conducted to assess observer performance. Reading time was recorded, and usefulness was evaluated with subjective scores of 1-5, with 5 being extremely useful and 1 being useless. Significance of these values was tested with the Wilcoxon signed-rank test. Results The subtraction images depicted various types of bone metastases (osteolytic, n = 28; osteoblastic, n = 26; mixed osteolytic and blastic, n = 11) as temporal changes. The average reading time was significantly reduced (384.3 vs 286.8 seconds; Wilcoxon signed rank test, P = .028). The average figure-of-merit value increased from 0.758 to 0.835; however, this difference was not significant (JAFROC analysis, P = .092). The subjective usefulness survey response showed a median score of 5 for use of the technique (range, 3-5). Conclusion TS images obtained from serial CT scans using nonrigid registration successfully depicted newly developed bone metastases and showed promise for their efficient detection. © RSNA, 2017 Online supplemental material is available for this article.

Purpose To determine the usefulness of whole-body diffusion-weighted imaging (DWI) to assess the response of bone metastases to treatment in patients with metastatic castration-resistant prostate cancer (mCRPC). Materials and Methods A phase II prospective clinical trial of the poly-(adenosine diphosphate-ribose) polymerase inhibitor olaparib in mCRPC included a prospective magnetic resonance (MR) imaging substudy; the study was approved by the institutional research board, and written informed consent was obtained. Whole-body DWI was performed at baseline and after 12 weeks of olaparib administration by using 1.5-T MR imaging. Areas of abnormal signal intensity on DWI images in keeping with bone metastases were delineated to derive total diffusion volume (tDV); five target lesions were also evaluated. Associations of changes in volume of bone metastases and median apparent diffusion coefficient (ADC) with response to treatment were assessed by using the Mann-Whitney test and logistic regression; correlation with prostate-specific antigen level and circulating tumor cell count were assessed by using Spearman correlation (r). Results Twenty-one patients were included. All six responders to olaparib showed a decrease in tDV, while no decrease was observed in all nonresponders; this difference between responders and nonresponders was significant (P = .001). Increases in median ADC were associated with increased odds of response (odds ratio, 1.08; 95% confidence interval [CI]: 1.00, 1.15; P = .04). A positive association was detected between changes in tDV and best percentage change in prostate-specific antigen level and circulating tumor cell count (r = 0.63 [95% CI: 0.27, 0.83] and r = 0.77 [95% CI: 0.51, 0.90], respectively). When assessing five target lesions, decreases in volume were associated with response (odds ratio for volume increase, 0.89; 95% CI: 0.80, 0.99; P = .037). Conclusion This pilot study showed that decreases in volume and increases in median ADC of bone metastases assessed with whole-body DWI can potentially be used as indicators of response to olaparib in mCRPC. Online supplemental material is available for this article.

Purpose To determine the correlation between the volume of bone metastasis as assessed with diffusion-weighted (DW) imaging and established prognostic factors in metastatic castration-resistant prostate cancer (mCRPC) and the association with overall survival (OS). Materials and Methods This retrospective study was approved by the institutional review board; informed consent was obtained from all patients. The authors analyzed whole-body DW images obtained between June 2010 and February 2013 in 53 patients with mCRPC at the time of starting a new line of anticancer therapy. Bone metastases were identified and delineated on whole-body DW images in 43 eligible patients. Total tumor diffusion volume (tDV) was correlated with the bone scan index (BSI) and other prognostic factors by using the Pearson correlation coefficient (r). Survival analysis was performed with Kaplan-Meier analysis and Cox regression. Results The median tDV was 503.1 mL (range, 5.6-2242 mL), and the median OS was 12.9 months (95% confidence interval [CI]: 8.7, 16.1 months). There was a significant correlation between tDV and established prognostic factors, including hemoglobin level (r = -0.521, P < .001), prostate-specific antigen level (r = 0.556, P < .001), lactate dehydrogenase level (r = 0.534, P < .001), alkaline phosphatase level (r = 0.572, P < .001), circulating tumor cell count (r = 0.613, P = .004), and BSI (r = 0.565, P = .001). A higher tDV also showed a significant association with poorer OS (hazard ratio, 1.74; 95% CI: 1.02, 2.96; P = .035). Conclusion Metastatic bone disease from mCRPC can be evaluated and quantified with whole-body DW imaging. Whole-body DW imaging-generated tDV showed correlation with established prognostic biomarkers and is associated with OS in mCRPC. (©) RSNA, 2016 Online supplemental material is available for this article.

Purpose To develop and assess the diagnostic performance of a three-dimensional (3D) whole-body T1-weighted magnetic resonance (MR) imaging pulse sequence at 3.0 T for bone and node staging in patients with prostate cancer. Materials and Methods This prospective study was approved by the institutional ethics committee; informed consent was obtained from all patients. Thirty patients with prostate cancer at high risk for metastases underwent whole-body 3D T1-weighted imaging in addition to the routine MR imaging protocol for node and/or bone metastasis screening, which included coronal two-dimensional (2D) whole-body T1-weighted MR imaging, sagittal proton-density fat-saturated (PDFS) imaging of the spine, and whole-body diffusion-weighted MR imaging. Two observers read the 2D and 3D images separately in a blinded manner for bone and node screening. Images were read in random order. The consensus review of MR images and the findings at prospective clinical and MR imaging follow-up at 6 months were used as the standard of reference. The interobserver agreement and diagnostic performance of each sequence were assessed on per-patient and per-lesion bases. Results The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were significantly higher with whole-body 3D T1-weighted imaging than with whole-body 2D T1-weighted imaging regardless of the reference region (bone or fat) and lesion location (bone or node) (P < .003 for all). For node metastasis, diagnostic performance (area under the receiver operating characteristic curve) was higher for whole-body 3D T1-weighted imaging (per-patient analysis; observer 1: P < .001 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P = .006 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging; observer 2: P = .006 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P = .006 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging), as was sensitivity (per-lesion analysis; observer 1: P < .001 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P < .001 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging; observer 2: P < .001 for 2D T1-weighted imaging vs 3D T1-weighted imaging, P < .001 for 2D T1-weighted imaging + PDFS imaging vs 3D T1-weighted imaging). Conclusion Whole-body MR imaging is feasible with a 3D T1-weighted sequence and provides better SNR and CNR compared with 2D sequences, with a diagnostic performance that is as good or better for the detection of bone metastases and better for the detection of lymph node metastases.

Purpose To demonstrate that magnetic resonance (MR) imaging-guided high-intensity focused ultrasound (HIFU) is a safe, effective, and durable treatment option for the management of osteoid osteoma in children and young adults. Materials and Methods This prospective study was institutional review board approved and is registered with clinicaltrials.gov (identification number NCT02302651). Written informed consent was obtained from patients or their parents. Patients who had both clinical and radiologic findings that were diagnostic for nonvertebral osteoid osteoma and no contraindications to MR imaging-guided HIFU were enrolled between June 2010 and June 2013. The feasibility, safety, and clinical effectiveness of MR imaging-guided HIFU were considered primary outcomes; tumor control at imaging was considered a secondary outcome. Analyses were conducted on a per-protocol basis. Results Forty-five of the 50 recruited patients underwent MR imaging-guided HIFU. All patients were discharged without treatment-related complications. The median visual analog scale (VAS) pain score (scale, 0-10) decreased from 8 before treatment to 0 at 1-week and 1- , 6- , 12- , 24- , and 36-month follow-up. Similarly, median VAS scores for the degree to which pain interfered with sleep and physical and daily activities decreased to 0 within the 1st month after treatment and remained stable at subsequent follow-up. Overall, 39 (87%) of the 45 patients achieved and maintained a VAS score of 0 during the 3-year observation period. Quality of life, as assessed by using Functional Assessment of Cancer Therapy-Bone Pain (FACT-BP) scores (scale, 0-60 points), improved, with the median FACT-BP score of 28 (points) before treatment increasing to a median score of 55 at 1-week follow-up and 60 at 6-month and subsequent follow-ups. At (final) 36-month follow-up, MR imaging depicted an absence of residual nidus vascularity in 32 (76%) of the 42 patients who were treated with MR imaging-guided HIFU only. Conclusion The durable clinical efficacy and safety of MR imaging-guided HIFU were demonstrated. These features are evidence of the potential of MR imaging-guided HIFU to be part of a routine strategy for the treatment of osteoid osteoma.

Purpose To compare dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging parameters between metastatic bone lesions with and without the epidermal growth factor receptor (EGFR) mutation in consecutive patients with primary non-small cell lung cancer (NSCLC). Materials and Methods This study was approved by the institutional review board. Forty-seven patients with NSCLC and a confirmed EGFR mutation status (27 patients were positive and 26 were negative for EGFR mutation), who underwent DCE MR imaging for bone metastases between November 2012 and March 2016, were included in this study. Two radiologists independently analyzed the volume transfer constant (K

To compare the diagnostic performance of fluorine 18 ((18)F) fluoride positron emission tomography (PET)/computed tomography (CT) with that of conventional imaging (CT and magnetic resonance [MR] imaging) in evaluating the osseous involvement in meningioma.The study was approved by the ethics committee and institutional review board and was conducted according to the Declarations of Helsinki and Tokyo. Written informed consent was obtained from all patients. A retrospective comparative study between (18)F-fluoride PET/CT and conventional imaging was conducted to detect osseous involvement in patients with a verified diagnosis of meningioma. Osseous involvement was verified by using definitive surgery (including drilling or careful sampling of the skull in all patients). The diagnostic performance, determined by calculating the sensitivity, specificity, positive predictive value ( PPV positive predictive value ), negative predictive value ( NPV negative predictive value ), and accuracy, was assessed.Data sets from a total of 78 patients with proven meningioma were compared. Osseous involvement was histopathologically confirmed in 25 patients (32%). The sensitivity, specificity, PPV positive predictive value , NPV negative predictive value , and accuracy were 92.0%, 86.8%, 76.7%, 95.8%, and 88.5% for (18)F-fluoride PET/CT and 64.0%, 83.0%, 64.0%, 83.0%, and 76.9% for conventional imaging, respectively. The receiver operating characteristic ( ROC receiver operating characteristic ) analysis revealed that the area under the ROC receiver operating characteristic curve ( Az area under the ROC curve ) value of (18)F-fluoride PET/CT was significantly greater than that of conventional imaging (0.965 ± 0.02 [standard error] vs 0.703 ± 0.066 [standard error], P.0001).An approach using (18)F-fluoride PET/CT improves preoperative detection of osseous involvement. In those without abnormal (18)F-fluoride uptake within the skull, the patient may proceed directly to conventional surgery. However, a positive finding of osseous involvement at (18)F-fluoride PET/CT should prompt confirmation by drilling or sampling of bone.

To compare the features of bone metastases at computed tomography (CT) to tracer uptake at fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and fluorine 18 16β-fluoro-5-dihydrotestosterone (FDHT) PET and to determine associations between these imaging features and overall survival in men with castration-resistant prostate cancer.This is a retrospective study of 38 patients with castration-resistant prostate cancer. Two readers independently evaluated CT, FDG PET, and FDHT PET features of bone metastases. Associations between imaging findings and overall survival were determined by using univariate Cox proportional hazards regression.In 38 patients, reader 1 detected 881 lesions and reader 2 detected 867 lesions. Attenuation coefficients at CT correlated inversely with FDG (reader 1: r = -0.3007; P.001; reader 2: r = -0.3147; P.001) and FDHT (reader 1: r = -0.2680; P = .001; reader 2: r = -0.3656; P.001) uptake. The number of lesions on CT scans was significantly associated with overall survival (reader 1: hazard ratio [HR], 1.025; P = .05; reader 2: HR, 1.021; P = .04). The numbers of lesions on FDG and FDHT PET scans were significantly associated with overall survival for reader 1 (HR, 1.051-1.109; P.001) and reader 2 (HR, 1.026-1.082; P ≤ .009). Patients with higher FDHT uptake (lesion with the highest maximum standardized uptake value) had significantly shorter overall survival (reader 1: HR, 1.078; P = .02; reader 2: HR, 1.092; P = .02). FDG uptake intensity was not associated with overall survival (reader 1, P = .65; reader 2, P = .38).In patients with castration-resistant prostate cancer, numbers of bone lesions on CT, FDG PET, and FDHT PET scans and the intensity of FDHT uptake are significantly associated with overall survival.

To identify the correlation of pre- and postablation imaging features with pain relief, pain intensity, and patient mood after radiofrequency (RF) ablation of solitary painful osseous metastases.This prospective, multicenter group trial was approved by each institutional review board. Participants were enrolled between November 1, 2001, and April 6, 2006. Written informed consent was obtained from all subjects, and patient confidentiality protocols were followed in compliance with HIPAA. Computed tomography (CT)-guided RF ablation and contrast material-enhanced 1-month follow-up CT and/or magnetic resonance imaging were performed in 49 subjects (24 men, 25 women; age range, 34-83 years) with a confirmed malignant solitary bone lesion of maximum dimension of 8 cm or smaller that was causing intractable pain. Pain intensity and patient mood were measured before and after RF ablation. Tumor imaging features were recorded. Unadjusted and adjusted linear mixed-effects models, with a random intercept for each subject, were used to model patient mood, pain relief, and pain intensity scores at three times after ablation as a function of each tumor characteristic.Decreased postablation tumor pain correlated with preablation tumor volume (P = .02) and pathologic fracture (P = .01), while pain relief correlated with pathologic fracture (P = .03) and percentage of bone-tumor interface (BTI) ablated (P = .02). Conversely, presence of an irregular rim after ablation (P = .02) and rim thickness (P = .01) correlated with increased pain. There was no evidence in this study that RF ablation of larger tumor percentage or larger volume leads to better pain relief or decreased pain (P.05).Existing pathologic fracture and smaller tumor size appear to be predictive parameters of success when selecting patients for palliative RF ablation of painful solitary osseous metastases. Successful palliation also appears to be related to the percentage of BTI ablated.

To prospectively investigate and monitor the response to antiandrogen treatment of bone metastases in patients with prostate cancer by using diffusion-weighted (DW) magnetic resonance (MR) imaging with the apparent diffusion coefficient (ADC) and functional diffusion maps (DMs).This study had institutional review board approval; informed consent was obtained from all patients. Nine treatment-naive men (mean age, 73 years; range, 66-86 years) with 20 pelvic bone metastases were included. Imaging was performed before antiandrogen treatment and at 1, 2, and 3 months afterward. Imaging included a DW MR imaging sequence with five b factors (0-800 sec/mm²). Serum prostate-specific antigen (PSA) levels and mean ADCs of each metastasis were measured over time and analyzed by using the general linear model. Pairwise comparisons (paired-samples t tests) of PSA levels and ADCs before and after therapy were performed with the significance level set at P.017 (Bonferroni correction). To determine the relationship between serum PSA level and the averaged mean ADCs in each patient, the two parameters were correlated across time. In addition, an analysis with functional DMs was performed to evaluate ADC response to treatment on a per-voxel basis.Serum PSA levels decreased by more than 90% during therapy. The mean ADCs of metastases were increased significantly at 1 (P.001), 2 (P = .002), and 3 (P = .011) months after therapy compared with pretreatment values. Heterogeneous response was revealed at functional DM analysis. After 1 month of therapy, 47.3% of all analyzed tumor voxels showed significantly increased ADCs, while 46.5% were unchanged and 6.2% exhibited decreased ADCs in comparison to the pretreatment values. At 3 months after therapy, the proportion of voxels showing ADC decrease was higher (13.7%) than that at 1 month.DW MR imaging allows monitoring of antiandrogen therapy in bone metastases. PSA level decrease corresponded well with an increase in mean tumor ADC. Heterogeneity of tumor response to therapy was demonstrated by functional DM analysis.

To evaluate the long-term follow-up results of ultrasonographically (US)-guided high-intensity focused ultrasound ablation in patients with primary bone malignancy.The study was approved by the ethics committee. Each patient or parent (if patient was younger than 18 years), signed an informed consent form before being selected and treated. From December 1997 to November 2004, 80 patients with a primary bone malignancy-60 with stage IIb disease and 20 with stage III disease (Enneking staging system)-were treated with US-guided high-intensity focused ultrasound ablation. High-intensity focused ultrasound ablation combined with chemotherapy was performed in 62 patients with osteosarcoma, one patient with periosteal osteosarcoma, and three patients with Ewing sarcoma. The remaining 14 patients had chondrosarcoma, giant cell bone cancer, periosteal sarcoma, or an unknown malignancy and were treated with high-intensity focused ultrasound ablation only. Magnetic resonance (MR) imaging or computed tomography (CT), and single photon emission computed tomography (SPECT) were used to assess tumor response. Cumulative survival rates were calculated by using the Kaplan-Meier method. Adverse effects were recorded.High-intensity focused ultrasound ablation guided by real-time US was performed. Follow-up images demonstrated completely ablated malignant bone tumors in 69 patients and greater than 50% tumor ablation in the remaining 11 patients. Overall survival rates at 1, 2, 3, 4, and 5 years were 89.8%, 72.3%, 60.5%, 50.5%, and 50.5%, respectively. Survival rates at 1, 2, 3, 4, and 5 years were 93.3%, 82.4%, 75.0%, 63.7%, and 63.7%, respectively, in the patients with stage IIb cancer and 79.2%, 42.2%, 21.1%, 15.8%, and 15.8%, respectively, in those with stage III disease. Among the patients with stage IIb disease, long-term survival rates were substantially improved in the 30 patients who received the full treatment-that is, complete high-intensity focused ultrasound and full cycles of chemotherapy-compared with the survival rates for the 24 patients who did not finish the chemotherapy cycles and the six patients who underwent partial ablation only. Only five (7%) of the 69 patients who underwent complete ablation had local cancer recurrence during the follow-up period. Forty adverse events were recorded, with 14 patients requiring surgical intervention.US-guided high-intensity focused ultrasound ablation of malignant bone tumors is feasible and effective and eventually may be a component of limb-sparing techniques for patients with these cancers.

To determine if sclerotic bone lesions evident at body computed tomography (CT) are of value as a diagnostic criterion of tuberous sclerosis complex (TSC) and in the differentiation of TSC with lymphangioleiomyomatosis (LAM) from sporadic LAM.Informed consent was signed by all patients in this HIPAA-compliant study approved by the institutional review board. Retrospective analysis was performed of the body CT studies of 472 patients: 365 with sporadic LAM, 82 with TSC/LAM, and 25 with TSC. The images were reviewed by using a picture archiving and communication system workstation with bone settings (window width, 1500 HU; window level, 300 HU) and fit-to-screen option. CT image characteristics assessed included shape, size, and distribution of sclerotic bone lesions with subsequent calculation of differences in the frequency of these lesions.Most commonly the sclerotic bone lesions were round, measured 0.3 cm (range, 0.2-3.2), and were distributed throughout the spine. The frequencies differed among the three patient groups Four or more sclerotic bone lesions were detected in all 25 (100%) of those with TSC, with a sensitivity of .89 (72 of 82) and specificity of .97 (355 of 367) in the differentiation of sporadic LAM from TSC/LAM (P.01).The number of sclerotic bone lesions at body CT is of potential value in the diagnosis of TSC and in the differentiation of patients with sporadic LAM from those with TSC/LAM. (c) RSNA, 2010.

To demonstrate that radiofrequency (RF) ablation can be used safely and effectively to treat selected cases of chondroblastoma.Approval was obtained from institutional review boards, research was in compliance with HIPAA protocol. The need to obtain informed consent was waived for retrospective review of patient records. The records of patients with biopsy-proved chondroblastoma who were treated with RF ablation at two academic centers from July 1995 to July 2007 were reviewed. RF ablation was performed with a single-tip electrode by using computed tomography for guidance. Lesion characteristics were determined from imaging studies obtained at the time of the procedure. Symptoms were assessed before and 1 day after the procedure. Longer-term follow-up was obtained from medical records.Thirteen male and four female patients were treated (mean age, 17.3 years). The lesions were located in the proximal humerus (n = 7), proximal tibia (n = 4), proximal femur (n = 3), and distal femur (n = 3). The mean volume of the lesions was 2.46 mL. All patients reported relief of symptoms on postprocedure day 1. Three patients were lost to follow-up. Of the 14 patients for whom longer-term (mean, 41.3 months; range, 4-134 months) follow-up was available, 12 had complete relief of symptoms with no need for medications and full return to all activities. The patient who had the largest lesion of the study required surgical intervention because of collapse of the articular surface in the treatment area. Residual viable tumor was found at surgery. Another patient experienced mechanical problems that were thought to be unrelated to the RF ablation and was rendered pain-free after subsequent surgical treatment.Percutaneous RF ablation is an alternative to surgery for treatment of selected chondroblastomas. Larger lesions beneath weight-bearing surfaces should be approached with caution due to an increased risk of articular collapse and recurrence.

To assess lesion-related and technical factors that affect diagnostic yield in image-guided core-needle biopsy (CNB) of bone and soft-tissue lesions.Institutional review board approval and verbal informed consent were obtained for a HIPAA-compliant prospective study of 151 consecutive CNBs of bone (n = 88) and soft-tissue (n = 63) lesions. Each CNB specimen was reported separately in the final pathology report. Diagnostic yield (total number of biopsies that yield a diagnosis divided by total number of biopsies) was calculated for all lesions and subgroups on the basis of lesion composition (lytic, sclerotic, soft tissue), lesion size (or = 2,2 to 5, or5 cm), biopsy needle gauge, image guidance modality, number of specimens obtained, and specimen length (5, 5-10, or10 mm). The minimum number of specimens required to obtain a diagnosis was determined on the basis of the specimen number at which the diagnostic yield reached a plateau. Chi(2) And Wilcoxon rank-sum tests were performed in bivariate analyses to evaluate associations between each factor and diagnostic yield. Significant factors were evaluated with multivariate logistic regression.Diagnostic yield was 77% for all lesions. Yield was 87% for lytic bone lesions and 57% for sclerotic bone lesions (P = .002). Diagnostic yield increased with larger lesions (54% for lesionsor = 2 cm, 75% for lesions2 to 5 cm, and 86% for lesions5 cm [P = .006]). There was no difference in diagnostic yield for bone versus soft-tissue lesions or according to needle gauge or image guidance modality. Diagnostic yield was 77% for bone lesions and 76% for soft-tissue lesions (P = .88). Yield was 83%, 72%, 77%, and 83% for biopsies performed with 14-, 15-, 16-, and 18-gauge needles, respectively (P = .57). Yield was 77% with computed tomographic guidance and 78% with ultrasonographic guidance (P = .99). Diagnostic yield increased with number of specimens obtained and with longer specimen length; it reached a plateau at three specimens for bone lesions and four specimens for soft-tissue lesions.Diagnostic yield is higher in lytic than in sclerotic bone lesions, in larger lesions, and for longer specimens. Obtaining a minimum of three specimens in bone lesions and four specimens in soft-tissue lesions optimizes diagnostic yield.

The approach to the radiographic diagnosis of bone tumors consists of analyzing the lesion in an organized fashion, with attention to the specific radiographic features of tumor location, margins, and zone of transition; periosteal reaction; mineralization; size and number of lesions; and presence of a soft-tissue component. Patient age is also an important clinical factor in the diagnosis of bone tumors, because various lesions have predilections for specific age groups.

To retrospectively compare the diagnostic accuracy of positron emission tomography (PET)/computed tomography (CT), PET, conventional imaging, and combined PET/CT and conventional imaging for tumor staging of bone and soft-tissue sarcomas, by using histologic or follow-up imaging findings as the reference standard.Institutional review board approval was received for this HIPAA-compliant study; informed consent was obtained. Integrated PET/CT was performed in 117 patients (69 male patients, 48 female patients; mean age, 42 years +/- 21 [standard deviation]; range, 9-86 years). Conventional imaging consisted of magnetic resonance imaging of the primary site, chest radiography, whole-body contrast material-enhanced CT, and bone scintigraphy. A total of four reviewers assessed all images. Overall and T staging were evaluated in 69 (59%) patients who underwent surgical removal of the primary tumors and had pathologically proved results. N and M staging were evaluated in all patients, and their reference methods were based on histologic findings (n = 101) and follow-up CT findings (n = 16).Interpretations based on combined PET/CT and conventional imaging findings correctly staged tumors in 60 (87%) of 69 patients, overstaged tumors in eight (12%) patients, and understaged tumors in one (1%) patient. Overall staging accuracy of combined PET/CT and conventional imaging was significantly higher than that at PET (P.0001). Combined PET/CT and conventional imaging resulted in correct N staging in 114 (97%) of 117 patients and M staging in 109 (93%) of 117 patients. Combined PET/CT and conventional imaging helped reduce overstaging in three (4%) patients and helped change tumor diagnosis from unresectable to resectable in two (2%) patients compared with PET/CT.The combination of PET/CT and conventional imaging is accurate in preoperative staging of bone and soft-tissue sarcoma.

Institutional review board approval and written informed consent were obtained. Patients with newly diagnosed prostate cancer and patients suspected of having recurrent prostate cancer were prospectively evaluated with fluorine 18 fluorocholine (FCH) combined in-line positron emission tomography (PET) and computed tomography (CT). In 19 patients (mean age, 67 years +/- 8; range, 57-85 years), standardized uptake values of FCH in 17 different tissues were determined by using volumes of interest. In nine patients evaluated at initial staging, histologic findings of the resected prostate were compared to FCH uptake. Only small variations of physiologic tracer accumulation were measured in all organs but the kidneys. Differentiation of benign hyperplasia from cancerous prostate lesions was not possible with FCH PET/CT. However, in patients with recurrent prostate cancer, FCH PET/CT is a promising imaging modality for detecting local recurrence and lymph node metastases.

To retrospectively identify risk factors that may impede a favorable clinical outcome after thermocoagulation for osteoid osteoma.Informed consent (permission for the procedure and permission to use patient data for analysis) was obtained from all patients who met study criteria, and institutional review board did not require approval. Analysis included age, sex, size and location of osteoid osteoma, presence of calcified nidus, number of needle positions used for coagulation, coagulation time, accuracy of needle position, learning curve of radiologist, and previous treatment in 95 consecutive patients with osteoid osteoma treated with thermocoagulation. With chi(2) analysis, Fisher exact test, or unpaired Student t test and logistic regression analysis, 23 unsuccessfully treated patients were compared with 72 successfully (pain-free) treated patients.Parameters associated with decreased risk for treatment failure were advanced age (mean age, 24 years in treatment success group vs 20 years in treatment failure group) and increased number of needle positions during thermocoagulation. Estimated odds ratios were, respectively, 0.93 (95% confidence interval: 0.88, 0.99) and 0.10 (95% confidence interval: 0.02, 0.41). Patients with a lesion of 10 mm or larger seemed at risk for treatment failure (odds ratio = 2.68), but the 95% confidence interval of 0.84 to 8.52 included the 1.00 value. Needle position was inaccurate in nine of 23 patients with treatment failure; only one needle position was used in eight of these nine patients. Lesion location, calcification, sex, coagulation time, radiologist's learning curve, and previous treatment were not risk factors.Multiple needle positions reduce the risk of treatment failure in all patients and should especially, but not exclusively, be used in large (or =10-mm) lesions or lesions that are difficult to engage to reduce the risk for unsuccessful treatment.

To compare the results of whole-body magnetic resonance (MR) imaging with staging based on computed tomographic (CT), dedicated MR imaging, and nuclear scintigraphic results as standard of reference.Fifty-one patients with known malignant tumors were included in the study. Patients were placed on a rolling table platform capable of moving the patient rapidly through the isocenter of the magnet bore. The thorax and the abdomen were imaged by using fast breath-hold T2-weighted sequences in the transverse plane. After intravenous administration of a paramagnetic contrast agent, three-dimensional gradient-echo data sets were collected in five stations and covered the body from the skull to the knees. Location and size of cerebral, pulmonary, hepatic, and osseous metastases were documented by two experienced radiologists. Whole-body MR imaging findings were compared with results obtained at skeletal scintigraphy, CT, and dedicated MR imaging.The mean examination time for whole-body MR imaging was 14.5 minutes. All cerebral, pulmonary, and hepatic metastases greater than 6 mm in diameter could be identified with whole-body MR imaging. Small pulmonary metastases were missed with MR imaging, which did not change therapeutic strategies, but MR imaging depicted a single hepatic metastasis that was missed with CT. Skeletal scintigraphy depicted osseous metastases in 21 patients, whereas whole-body MR imaging revealed osseous metastases in 24 patients. The additional osseous metastases seen with MR imaging were confirmed at follow-up examinations but did not result in a change in therapy. Whole-body MR imaging performed on a per-patient basis revealed sensitivity and specificity values of 100%.Whole-body MR imaging for the evaluation of metastases compared well with the reference techniques for cerebral, pulmonary, and hepatic lesions. Whole-body MR imaging was more sensitive in the detection of hepatic and osseous metastases than were the reference techniques.

To review the imaging appearance of periosteal osteosarcoma, with pathologic comparison.Data for 40 pathologically confirmed periosteal osteosarcomas were retrospectively reviewed. Patient demographic data were recorded, and radiographs (n = 40), bone scintigrams (n = 10), angiograms (n = 2), and computed tomographic (CT) (n = 11) and magnetic resonance (MR) (n = 12) images were evaluated for lesion location and size, cortical changes, marrow involvement, and intrinsic characteristics by two musculoskeletal radiologists, with agreement by consensus. Pathology reports were reviewed for presence and predominance of histologic components (fibrous, chondroid, and osteoid), tumor grade, and marrow involvement.There were 25 male (62%) and 15 female (38%) patients with an age range of 10-37 years (average age, 20 years). The most frequent lesion locations were the diaphysis of the tibia (16 patients) or of the femur (15 patients). Radiographs showed a broad-based soft-tissue mass that was attached to the cortex (all patients) and showed cortical thickening (33 patients), cortical scalloping/erosion (37 patients), and/or perpendicular periosteal reaction (38 patients) extending into the soft-tissue mass. Soft-tissue masses were well defined in 91%-100% of cases and surrounded a median of 50%-55% of the cortex. Lesions commonly showed low attenuation at CT (10 patients) and high signal intensity on T2-weighted MR images (10 patients), reflecting the high water content of these largely chondroblastic lesions. Focal areas of adjacent marrow replacement were common at MR imaging (nine patients) but represented reactive changes unless they were in direct continuity with the overlying soft-tissue mass (this was rare, occurring in only one patient, and represented marrow invasion). Review of pathology reports revealed that all lesions contained chondroid tissue, which predominated in 34 patients.The radiologic appearance of periosteal osteosarcoma is a broad-based surface soft-tissue mass causing extrinsic erosion of thickened underlying diaphyseal cortex and perpendicular periosteal reaction extending into the soft-tissue component. Reactive marrow changes are commonly seen at MR imaging, but true marrow invasion is rare.

To determine if in vivo detection of choline by using hydrogen 1 (1H) magnetic resonance (MR) spectroscopy with dynamic contrast material-enhanced MR imaging can help differentiate between benign and malignant musculoskeletal tumors.MR imaging was performed in 36 consecutive patients with bone and soft-tissue tumors larger than 1.5 cm in diameter. Examinations were performed at 1.5 T with a surface coil appropriate for the location of the lesions. Single-voxel 1H MR spectroscopy was performed by using a point-resolved spectroscopic sequence with echo times of 40, 135, and 270 msec. The volume of interest within lesions was positioned on the areas of early enhancement (8 seconds after arterial enhancement) according to the findings of dynamic contrast-enhanced MR imaging with subtraction. The criterion for determining whether choline was present in a lesion was a clearly identifiable peak at 3.2 ppm in at least two of the three spectra acquired at echo times. MR spectroscopic results and histopathologic findings were determined in blinded fashion and compared with kappa statistics. P.001 was considered to indicate a significant difference.Choline was detected in 18 of 19 patients with malignant tumors and in three of 17 patients with benign lesions. The three benign lesions included one perineurioma, one giant cell tumor, and one abscess. Choline was not detected in 14 patients with benign lesions nor in one patient with a densely ossifying low-grade parosteal osteosarcoma. In vivo 1H MR spectroscopy characterized bone and soft-tissue tumors, resulting in a sensitivity of 95%, specificity of 82%, and accuracy of 89% (P.001).Choline can be reliably detected in large malignant bone and soft-tissue tumors by using a multiecho point-resolved spectroscopic protocol. 1H MR spectroscopy can help differentiate malignant from benign musculoskeletal tumors by revealing the presence or absence of water-soluble choline metabolites.

To describe the imaging characteristics of a large series of telangiectatic osteosarcomas with pathologic findings for comparison.The authors retrospectively reviewed 40 pathologically confirmed telangiectatic osteosarcomas. Patient demographics and images from radiography (n = 36), bone scintigraphy (n = 17), angiography (n = 4), computed tomography (CT) (n = 25), and magnetic resonance (MR) imaging (n = 27) were evaluated by three authors in consensus for lesion location, size, and intrinsic characteristics. There were 27 men (68%) and 13 women (32%) in the study, with an age range of 4-83 years (mean age, 24 years).Lesions frequently affected the femur, tibia, and humerus. Radiographs showed geographic bone lysis, a wide zone of transition, and matrix mineralization. CT demonstrated low attenuation, MR demonstrated high signal intensity on T2-weighted images, and both demonstrated hemorrhage, which simulated the appearance of aneurysmal bone cyst. Viable sarcomatous tissue surrounding hemorrhagic and/or necrotic regions was best seen at contrast material-enhanced CT and MR imaging, with thick peripheral, septal, and nodular enhancement in all cases. Subtle matrix mineralization in this viable tissue was best seen at CT. An associated soft-tissue mass was also seen in 19 of 25 cases (76%) at CT and in 24 of 27 cases (89%) at MR imaging.CT and MR imaging findings of telangiectatic osteosarcoma often include thick nodular tissue (and matrix mineralization at CT) in a largely hemorrhagic and/or necrotic osseous lesion with an associated soft-tissue mass, which allows distinction from aneurysmal bone cyst.

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.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.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.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.

To determine the safety and efficacy of radio-frequency (RF) ablation for pain reduction, quality of life improvement, and analgesics use reduction in patients with skeletal metastases.Over 10 months, 12 adult patients with a single painful osteolytic metastasis in whom radiation therapy or chemotherapy had failed and who reported severe pain (pain scoreor = 4 [scale of 0-10]) over a 24-hour period were treated with percutaneous imaging-guided RF ablation with a multi-tined electrode while under general anesthesia. Patient pain was measured with a Brief Pain Inventory 1 day after the procedure, every week for 1 month, and thereafter every other week (total follow-up, 6 months). Patient analgesics use was also recorded at these follow-up intervals. Follow-up contrast material-enhanced computed tomography was performed 1 week after the procedure. Complications were monitored. Analysis of the primary end point was undertaken with paired comparison procedures.Lesion size was 1-11 cm. Before RF ablation, mean worst pain score in a 24-hour period in 12 patients was 8.0 (range, 6-10). At 4 weeks after treatment, mean worst pain decreased to 3.1 (P =.001). Mean pain before treatment was 6.5 and decreased to 1.8 (P.001) 4 weeks after treatment. Mean pain interference in general activity decreased from 6.6 to 2.7 (P =.002) 4 weeks after treatment. Eight of 10 patients using analgesics reported reduced use at some time after RF ablation. No serious complications were observed.RF ablation of painful osteolytic metastases is safe, and the relief of pain is substantial.

To determine the diagnostic accuracy of image-guided percutaneous biopsy in 110 primary bone tumors of varying internal compositions.One hundred ten consecutive patients with primary bone tumors underwent biopsy with computed tomography (CT) or fluoroscopy. Ninety-one patients underwent surgical follow-up and 19 received medical treatment and underwent subsequent imaging studies. Final analysis of bone biopsy results included tumor type, malignancy, final tumor grade, biopsy complications, and effect on eventual treatment outcome.Seventy-seven tumors were malignant and 33 were benign. Most common tumors at biopsy were osteosarcoma (n = 20), lymphoma (n = 18), chondrosarcoma (n = 16), and giant cell tumor (n = 16). Correct final diagnosis was attained in 97 (88%) patients. Sixty-three lesions were solid nonsclerotic; 26, sclerotic; and 21, lytic with cystic centers containing internal areas of fluid, hemorrhage, or necrosis. In six of 21 lesions with a predominant cystic internal composition, problems occurred in determining a final diagnosis. In 13 patients, definite correct diagnosis was not obtained with initial percutaneous bone biopsy. Of these patients, benign bone tumors were better defined with surgical specimens in seven, a diagnosis of malignancy was changed to that of another malignancy in four, and the diagnosis was changed from benign to malignant in two. Nine patients underwent open surgical biopsy. Seven of the difficult cases were of cystic tumors with hemorrhagic fluid levels visible at CT or magnetic resonance imaging. The only complication was a small hematoma.Percutaneous biopsy of primary bone tumors is safe and accurate for diagnosis and grade of specific tumor. In cases with nondiagnostic biopsy, open-procedure biopsy is likely to be associated with similar diagnostic difficulties.

To assess the use of combined color Doppler ultrasonography (US), power Doppler US, and spectral wave analysis (SWA) in differentiating malignant and benign musculoskeletal tumors.Seventy-nine musculoskeletal tumors (34 malignant, 45 benign) were examined with color and power Doppler US and SWA. Two radiologists independently assessed US images and SWA findings. Echotexture and vessel characteristics such as stenoses, occlusions, loops, shunts, trifurcations, vascular pattern, and resistive index were evaluated. All tumors were subject to US-guided or open biopsy for histologic correlation.Combined color and power Doppler US and SWA revealed four major (stenosis, occlusion, trifurcation, vascular pattern) and three minor (shunt, self loop, resistive index) vessel characteristics, which proved helpful in differentiating benign from malignant lesions. Echotexture showed moderate sensitivity (82% [28 of 34 tumors]) and low specificity (38% [17 of 45 tumors]). When comparing several combinations of vessel characteristics, a combination of any two major characteristics demonstrated the best results (sensitivity, 94% [33 of 39 tumors]; specificity, 93% [three of 45 tumors]). Combining more than two characteristics resulted in lower sensitivity.Combined color and power Doppler US and SWA may enable assessment of vascular architecture and altered flow of musculoskeletal tumors. Vascular architecture analysis enables differentiation of benign and malignant lesions and evaluation of musculoskeletal tumors.

To compare the accuracies of computed tomography (CT), magnetic resonance (MR) imaging, and bone scintigraphy in staging disease in patients with neuroblastoma.Ninety-six children with newly diagnosed neuroblastoma were enrolled in a multicenter prospective cohort study. CT, MR, and bone scintigraphy were used to evaluate tumor stage. Sensitivity and specificity values and receiver operating characteristic (ROC) curve analyses were used to compare the accuracy of CT, MR, and scintigraphy for tumor staging.Eighty-eight patients were eligible for staging analysis, and 45 patients who underwent surgery at initial diagnosis were eligible for analysis of local tumor extent. CT and MR had sensitivities of 43% and 83%, respectively (P.01), and specificities of 97% and 88%, respectively (P.05), for detection of stage 4 disease. Areas under the ROC curves for CT and MR were 0.81 and 0.85, respectively (P =.06); that for scintigraphy was 0.83. Addition of scintigraphy to both CT and MR increased the areas under the ROC curves to 0.90 and 0.88, respectively. Accuracy of CT and MR for staging disease confined to the chest or abdomen (stages 1, 2, and 3) was poor.MR alone and CT and MR combined with bone scintigraphy enable the accurate detection of stage 4 disease. Both CT and MR perform poorly for local tumor staging.

To assess the morphologic changes of osteoid osteomas on computed tomographic (CT) scans in association with pain duration.Institutional review board approval was obtained. Informed consent was waived. From January 2008 to December 2012, 235 patients were treated with interstitial laser ablation at the Hôpital Lariboisière. Ninety-six patients with histopathologically proven osteoid osteomas, complete clinical files, and CT data were studied retrospectively. The following variables were assessed: age, sex, bone location, bone segment, location of the osteoid osteoma in relation to the native cortex, nidus area, nidus calcification area and attenuation at CT, and nidus mineralization ratio (percentage of the calcification area over the total nidus area). Analysis of variance, Kaplan-Meier method, and Cox multivariate regression model were used for statistical analyses.The study sample consisted of 96 patients, 68 of whom were male (71%) and 28 of whom were female (29%) (ratio of male to female patients, 2.4:1). Mean age ± standard deviation was 22.2 years ± 10.4 (range, 4-54 years; median, 18.5 years). The patients' age and nidus mineralization ratio increased significantly with pain duration (hazard ratio, 0.975 [P = .031] and 0.193 [P = .007], respectively). No significant association was found between pain duration and other variables, including the nidus area. In long bones, diaphyseal osteoid osteomas were significantly less mineralized than those in other locations (P = .009).The nidus mineralization ratio of osteoid osteomas increases significantly with pain duration and may be a marker of tumor age. Diaphyseal osteoid osteomas demonstrate a lower ratio of nidus mineralization. At the onset of symptoms, older patients experience pain for a longer period before treatment.

To retrospectively assess the use of a combination of cancellous bone reconstructions (CBR) and multiplanar reconstructions (MPRs) for the detection of bone metastases at thoracoabdominal computed tomography (CT) compared with the use of MPRs alone.The study was approved by the local institutional review board. Included were 156 consecutive patients with confirmed cancer who underwent a whole-body positron emission tomography (PET)/CT examination for clinical purposes (93 male and 63 female patients; mean age ± standard deviation, 59.8 years ± 14.9; range, 11-85 years). Only the CT images were processed with the CBR algorithm, which segments the bones and removes the cortical layer from the images. The PET images served as part of the reference standard. Images from 15 patients were used as a training set. Four radiologists independently evaluated images of half of the remaining 141 patients by using CBRs and MPRs together, and the other half by using MPRs only. Radiologists were blinded to patient names, and patient order was randomized. Results for detection rates and reporting time were recorded and compared with a standard of reference for each patient that was created by one senior radiologist and one nuclear medicine specialist by using all available CT and PET data, CBRs, and follow-up examinations. General estimation equations were used for statistical analysis.There were 349 lesions found in 103 patients, with 203 classified as malignant. Each patient was assessed by two readers per method, leading to a total of 698 lesions. The detection rate for all bone lesions was 35% (247 of 698) for MPRs and 74% (520 of 698) when CBRs and MPRs were used together, which was significantly higher (P.001). The average reading time decreased from 85 to 43 seconds (P.001) when both reconstructions were used.Advanced visualization of cancellous bone significantly increased the detection of bone metastases and reduced the time for interpretation.

Chondroblastomas are benign cartilaginous lesions; however, intervention is necessary to stop progression and alleviate pain. The authors evaluated three patients in whom minimally invasive percutaneous radio-frequency heat ablation was used to treat pathologically proven chondroblastoma to determine whether this treatment demonstrated long-term success. The authors found that this approach may be an effective alternative to surgical intervention in some cases.

To determine the relative frequency, incidence, and locations of metastases of hepatocellular carcinoma (HCC), correlate extrahepatic metastatic disease with intrahepatic tumor staging, and determine the computed tomographic (CT) manifestations of HCC metastases.CT findings in 403 consecutive patients with HCC at our institution since 1992 were reviewed retrospectively. One hundred forty-eight patients with extrahepatic metastatic HCC were identified, and the locations, sizes, and attenuation and enhancement characteristics of the lesions were recorded.A majority (128 [86%] of 148) of patients with extrahepatic HCC foci had either intrahepatic stage IVA tumor (112 [76%] patients) or an intrahepatic stage III tumor (16 [11%] patients) at the occurrence of metastases. The most frequent site of the first detectable metastasis was the lung (58 [39%] patients). Tabulation of all extrahepatic metastatic sites showed the most common to be the lung in 81 (55%) patients, the abdominal lymph nodes in 60 (41%) patients, and the bone in 41 (28%) patients.The lung, abdominal lymph nodes, and bone are the most common sites of extrahepatic metastatic HCC. Most extrahepatic HCC occurs in patients with advanced intrahepatic tumor stage (stage IVA). Incidental extrahepatic lesions at CT in patients with stage I or II intrahepatic HCC are unlikely to represent metastatic HCC.

To differentiate between benign and malignant cartilaginous tumors with fast contrast material-enhanced magnetic resonance (MR) imaging.In 37 patients, fast contrast-enhanced MR images were obtained in eight enchondromas, 11 osteochondromas, and 18 chondrosarcomas. Start of enhancement-early, within 10 seconds after arterial enhancement; delayed, between 10 seconds and 2 minutes; late, after 5 minutes on spin-echo images-and progression of enhancement were represented with three types of time-signal intensity curves. Findings were correlated with the surgical specimen in 27 cases, curettage material in three cases, and biopsy combined with long-term follow-up findings in seven cases.Start of enhancement and the combination of start and progression of enhancement correlated significantly (P.001) with benign and malignant tumors. Early enhancement was seen in chondrosarcoma, not seen in enchondroma, and seen in osteochondroma only when growth plates were unfused. The sensitivity was 89%, specificity 84%, positive predictive value 84%, and negative predictive value 89%. Differentiation of malignancy from benignity on the basis of early and exponential enhancement was possible with a sensitivity of 61%, specificity 95%, positive predictive value 92%, and negative predictive value 72%.Preliminary results show that in the adult population fast contrast-enhanced MR imaging may assist in differentiation between benign and malignant cartilaginous tumors.

PURPOSE: To analyze the effectiveness of core-needle biopsy for evaluation of possible primary musculoskeletal neoplasms, which often are evaluated with open biopsy. MATERIALS AND METHODS: Core-needle biopsy was performed at a tertiary care institution in 141 patients suspected of having a mesenchymal neoplasm. In 85 patients, the lesion was in soft tissue; in 56 patients, the lesion was in bone. Eighty-nine patients had a malignant lesion, and 52 had a benign lesion. Twenty-eight patients had undergone previous surgery. RESULTS: In 105 (74%) patients, core-needle biopsy results were concordant with results from specimens subsequently obtained at surgery with respect to tumor histologic features and grade, or they provided sufficient diagnostic information to obviate surgery. In 36 (26%) patients, inaccurate core-needle biopsy results were obtained: In nine, results were imprecise about exact histologic features; in three, results were correct about histologic features but incorrect about tumor grade. In 25 (18%) patients, open biopsy was performed after core-needle biopsy. The accuracy and rate of performance of open biopsy for soft-tissue lesions were not significantly different from those for bone lesions. CONCLUSION: Percutaneous core-needle biopsy can be an effective alternative to open biopsy in the evaluation of possible mesenchymal neoplasms of either bone or soft tissue. Needle biopsy of such lesions, however, is best performed as part of a multidisciplinary team approach to tumor management.

To estimate the incidence of occult metastases to the brain and skeleton in patients suspected of having non-small cell lung cancer (NSCLC) (stage higher than T1Nomo) with surgically resectable disease, to assess the accuracy of screening magnetic resonance (MR) imaging and radionuclide bone scanning for help in identifying occult metastases, and to determine the effectiveness of a high dose of MR contrast material.Twenty-nine patients suspected of having NSCLC localized to the lung or to the lung and regional nodes underwent preoperative MR imaging with contrast material enhancement and radionuclide bone scanning for detection of brain or skeletal metastases. Patients were followed up for 12 months to determine the incidence of clinical metastatic disease.Eight (28%) patients had occult metastatic disease to the brain or skeleton. Brain metastases were identified on MR images in five of six patients. Bone metastases were identified on MR images in four of five patients and on bone scans in three of five patients. MR imaging was no more accurate than bone scanning for skeletal evaluation. A high dose of MR contrast material allowed detection of more metastases and of small lesions.Contrast-enhanced MR imaging of the brain is indicated for the exclusion of brain metastases in patients with clinically operable known or possible NSCLC and a large (3-cm) lung mass. Skeletal imaging may be indicated if an isolated brain metastasis is detected.