Accuracy of CT Attenuation Measurement for Differentiating Treated Osteoblastic Metastases From Enostoses

2020

J Med Imag Rad Onc

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Introduction Bone biopsies are often used to direct antibiotic choice in patients with suspected osteomyelitis. The aim of this study was to identify the best predictors of positive bone biopsy cultures. Methods A retrospective review of 845 patients who underwent computed tomography (CT)‐guided non‐spine bone biopsies at a tertiary academic healthcare institution. Thirty‐seven patients (4.4%) had biopsies performed for suspected osteomyelitis. Laboratory markers, as well as imaging features, were measured. t‐Tests and Fisher’s exact tests were used to compare clinical and demographic variables between patients with positive bone cultures and patients with negative bone cultures. Multivariable logistic regression was used to identify the best predictors of bone culture positivity. Results All patients had negative blood cultures; however, only eight patients (21.6%) had positive bone cultures, with Staphyloccocus the most common organism. Multivariable logistic regression analysis showed that an open wound (OR = 14.00, 95% CI (1.74, 112.4), p = 0.013) and any fluid aspirated at the time of biopsy (OR = 10.50, 95% CI (1.21, 91.01), p = 0.033) were the best predictors of bone culture positivity. The area under the curve (AUC) for this multivariable model was 0.784 with sensitivity and specificity of 0.778 and 0.778, respectively. Interestingly, and contrary to popular belief, open wounds with exposed bone did not always yield positive bone cultures, and when cultures were positive, were not polymicrobial. Conclusions Aspiration of fluid at the time of biopsy and the presence of an open wound are the best predictors of positive bone cultures.

Section: Discussioncontrasting

confidence: 56%

Predictors of positive bone cultures from CT‐guided bone biopsies performed for suspected osteomyelitis

Lee

2020

J Med Imag Rad Onc

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“…A prior paper showed that a threshold mean CT attenuation of 885 HU had an accuracy of 91.7% and 81.7% to differentiate enostoses from untreated and treated osteoblastic metastases, respectively. 12 This analysis was restricted to only osteoblastic lesions, whereas our analysis considered all bone lesions that were suspicious enough to be biopsied. Our study evaluated whether the CT attenuation of a bone lesion was predictive of whether it was malignant or not, which was a slightly different question.…”

Section: Discussionmentioning

confidence: 99%

“…1 , 2 , 3 , 4 , 5 While advances in imaging techniques have allowed for the detection of bone lesions on staging studies, bone biopsies are still required for confirmation of malignancy, and to provide tissue for additional histopathological studies. 6 , 7 , 8 , 9 , 10 , 11 Systemic treatment changes the imaging appearance of malignant bone lesions on CT 12 and MRI. 13 After systemic treatment, some osteoblastic lesions show increased CT attenuation and others show decreased CT attenuation.…”

Section: Introductionmentioning

confidence: 99%

“… 13 After systemic treatment, some osteoblastic lesions show increased CT attenuation and others show decreased CT attenuation. 12 Systemic treatment results in increased signal drop‐out in out‐of‐phase chemical‐shift imaging MRI (CSI‐MRI) sequences. 13 CT studies used for staging/surveillance also cannot differentiate a treated lesion from a viable untreated lesion.…”

Section: Introductionmentioning

confidence: 99%

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Utility of absolute apparent diffusion coefficient and chemical‐shift imaging versus CT attenuation for predicting malignancy from percutaneous bone biopsies

J of Medical Radiation Sci

Ashok

2021

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Introduction: Bone lesions are sometimes detected on computed tomography studies, and biopsies are performed to evaluate whether these are malignant. The aim of the study is to evaluate whether chemical-shift imaging (CSI) and diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI) are more informative than the CT attenuation for predicting malignancy. Methods: Retrospective analysis of 86 patients who underwent both diagnostic CT, CSI MRI and DWI MRI within 6 weeks prior to bone biopsy at a tertiary care academic institution between 01/01/2010 and 03/01/2020. The CT attenuation, signal intensity on in-phase sequences (SIIP), signal intensity on out-of-phase sequences (SIOP), signal intensity ratio (SIR = SIOP/SIIP) and the apparent diffusion coefficient (ADC) of the lesions over the region of the biopsy tract were measured. Results: A threshold CT attenuation of 157 Hounsfield Units (HU) had a sensitivity of 47.7%, specificity of 83.3% and area under the curve (AUC) of 0.59. A threshold ADC of 793 9 10 À6 mm 2 /s had a sensitivity of 75.8%, specificity of 85.7% and AUC of 0.83 to predict whether a bone biopsy would detect malignancy. A threshold SIR of 0.949 had a sensitivity of 77.8%, specificity of 77.8% and AUC of 0.81 to predict whether a bone biopsy would detect malignancy. ADC (P = 0.029) and SIR (P = 0.009) were significantly better than CT attenuation. There was no predictive difference between SIR and ADC (P = 0.742). Conclusions: The CT attenuation of a lesion is a poor predictor of malignancy in bone lesions. CSI and DWI are significantly better for predicting malignancy.

“…The data presented show that enostoses appear similar on PET/CT to CT and may show 18 F-FDG uptake on PET above background. Although osteoblastic metastatic lesions may have a similar appearance, bone islands can be identified with high sensitivity and specificity by their higher attenuation value on CT[36]. On MRI, osteoblastic metastases may also show a halo of surrounding bone marrow edema, which may help distinguish these lesions from bone islands[28].…”

Section: Discussionmentioning

confidence: 99%

Positron emission tomography/computed tomography imaging appearance of benign and classic “do not touch” osseous lesions

Elangovan

2019

WJR

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BACKGROUND Classic “do not touch” and benign osseous lesions are sometimes detected on 18 -F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) studies. These lesions are often referred for biopsy because the physician interpreting the PET/CT may not be familiar with the spectrum of 18 F-FDG uptake patterns that these lesions display. AIM To show that “do not touch” and benign osseous lesions can have increased 18 F-FDG uptake above blood-pool on PET/CT; therefore, the CT appearance of these lesions should dictate management rather than the standardized uptake values (SUV). METHODS This retrospective study evaluated 287 independent patients with 287 classic “do not touch” (benign cystic lesions, insufficiency fractures, bone islands, bone infarcts) or benign osseous lesions (hemangiomas, enchondromas, osteochondromas, fibrous dysplasia, Paget’s disease, osteomyelitis) who underwent 18 F-FDG positron emission tomography/computed tomography (PET/CT) at a tertiary academic healthcare institution between 01/01/2006 and 12/1/2018. The maximum and mean SUV, and the ratio of the maximum SUV to mean blood pool were calculated. Pearson’s correlations between lesion size and maximum SUV were calculated. RESULTS The ranges of the maximum SUV were as follows: For hemangiomas (0.95-2.99), bone infarcts (0.37-3.44), bone islands (0.26-3.29), enchondromas (0.46-2.69), fibrous dysplasia (0.78-18.63), osteochondromas (1.11-2.56), Paget’s disease of bone (0.93-5.65), insufficiency fractures (1.06-12.97) and for osteomyelitis (2.57-12.64). The range of the maximum SUV was lowest for osteochondromas (maximum SUV 2.56) and was highest for fibrous dysplasia (maximum SUV of 18.63). There was at least one lesion that demonstrated greater 18 F-FDG avidity than the blood pool amongst each lesion type, with the highest maximum SUV ranging from 9.34 times blood pool mean (osteomyelitis) to 1.42 times blood pool mean (hemangiomas). There was no correlation between the maximum SUV and the lesion size except for enchondromas. Larger enchondromas had higher maximum SUV ( r = 0.36, P = 0.02). CONCLUSION The classic “do not touch” lesions and classic benign lesions can be 18 F-FDG avid. The CT appearance of these lesions should dictate clinical management rather than the maximum SUV.