Malignant Vertebral Lesions Research Articles

Diffusion-Weighted Imaging and Chemical Shift Imaging to Differentiate Benign and Malignant Vertebral Lesion: A Hospital-Based Cross-Sectional Study.

Objective The aim of this study was to evaluate the role of diffusion-weighted imaging (DWI) and chemical shift imaging (CSI) for the differentiation of benign and malignant vertebral lesions. Methods Patients with vertebral lesions underwent routine magnetic resonance imaging (MRI) along with DWI and CSI. Qualitative analysis of the morphological features was done by routine MRI. Quantitative analysis of apparent diffusion coefficient (ADC) from DWI and fat fraction (FF) from CSI was done and compared between benign and malignant vertebral lesions. Results Seventy-two patients were included. No significant difference was noted in signal intensities of benign and malignant lesions on conventional MRI sequences. Posterior element involvement, paravertebral soft-tissue lesion, and posterior vertebral bulge were common in malignant lesion, whereas epidural/paravertebral collection, absence of posterior vertebral bulge, and multiple compression fractures were common in benign vertebral lesion ( p < 0.001). The mean ADC value was 1.25 ± 0.27 mm 2 /s for benign lesions and 0.9 ± 0.19 mm 2 /s for malignant vertebral lesions ( p ≤ 0.001). The mean value of FF was 12.7 ± 7.49 for the benign group and 4.04 ± 2.6 for the malignant group ( p < 0.001). A receiver operating characteristic (ROC) curve analysis showed that an ADC cutoff of 1.05 × 10 -3 mm 2 /s and an FF cutoff of 6.9 can differentiate benign from malignant vertebral lesions, with the former having 86% sensitivity and 82.8% specificity and the latter having 93% sensitivity and 96.6% specificity. Conclusion The addition of DWI and CSI to routine MRI protocol in patients with vertebral lesions promises to be very helpful in differentiating benign from malignant vertebral lesions when difficulty in qualitative interpretation of conventional MR images arises.

Diffusion-weighted magnetic resonance imaging in differentiation between different vertebral lesions using ADC mapping as a quantitative assessment tool

BackgroundDiffusion-weighted imaging is one of the most useful clinical MRI techniques. Including this technique with other sequences used for routine spine scanning improves sensitivity and the capacity to characterize lesions. This study aims to evaluate the utility of apparent diffusion coefficient obtained from diffusion-weighted MR imaging in differentiating between benign and malignant vertebral lesions according to the optimal cutoff ADC value.ResultsThis study included 30 patients at Ain Shams University hospitals; all of them were subjected to full clinical assessment and magnetic resonance imaging. Patients were classified into 4 groups: inflammatory lesions (12 cases) followed by malignant lesions (7 cases), then benign neoplastic lesions (6 cases), then traumatic lesions (3 cases) and osteoporosis (two cases). Inflammatory lesions revealed restricted diffusion. Benign neoplastic lesions/hemangioma showed low signal at DWIs due to free diffusion, while malignant/metastatic lesions showed restricted diffusion. Traumatic lesions showed restricted diffusion. The osteoporotic lesions showed iso- to hyper-intense signal at DWIs. The mean ADC value of the benign lesions was 1.8 ± 0.43 mm2/s, while metastatic tumors was 0.96 ± 0.5 × 10–3 mm2/s; however, overlapping values may be present.ConclusionsCompared with benign tumors, malignant tumors have lower ADC values; nevertheless, some lesions, such as tuberculosis, have low ADC values that are like those of malignant tumors. Diffusion MRI and ADC values should always be analyzed in conjunction with standard MRI sequences as well as a thorough clinical history and examination.

Dynamic contrast-enhanced magnetic resonance perfusion volumetrics can differentiate tuberculosis of the spine and vertebral malignancy

There is considerable overlap in radiologic features of tubercular and malignant spinal lesions on conventional magnetic resonance imaging (MRI). To evaluate the role of dynamic contrast-enhanced (DCE) MRI perfusion parameters in differentiating vertebral malignancy from spinal tuberculosis. This was a prospective study and we enrolled consecutive patients presenting with a clinical/radiologic evidence of vertebral lesions. DCE-MRI of the spine was performed using 3D volume interpolated breath-hold examination (VIBE) sequence after intravenously injecting 0.1 mmol/kg body weight of gadopentetate dimeglumine. We used Tofts model to calculate DCE parameters that included Ktrans (transfer constant), kep (rate constant), ve (fractional volume of extracellular extravascular space), and iAUC (initial area under the curve). We compared the mean value of each perfusion parameter by type of lesion (tubercular/malignant) at 0.05 significance level and performed receiver operating characteristic curve analysis. We could confirm histologic/cytologic diagnosis in 35 of the 45 patients recruited. Of these, 19 were tubercular and 16 were malignant lesions. The mean (± standard deviation) of kep (min-1) was significantly higher (2.89 ± 3.3) in malignant compared to tubercular lesions (0.81 ± 0.19), whereas ve was significantly lower in malignant (0.27 ± 0.13 mL/g) compared to benign lesions (0.47 ± 0.12 mL/g) at 0.05 significance level. kep cutoff of ≥1.17 min-1 had a sensitivity of 93.8% and specificity of 100% with a diagnostic accuracy of 94.4% in detecting malignant disease. High kep is the single best predictor of malignant vertebral lesions. We recommend kep cutoff value of ≥1.17 min-1 that has high diagnostic accuracy in identifying malignant lesions.

The Role of Chemical Shift Magnetic Resonance Imaging (SCMRI) to Differentiate Benign and Malignant Vertebral Lesions

The Role of Chemical Shift Magnetic Resonance Imaging (SCMRI) to Differentiate Benign and Malignant Vertebral Lesions

Diagnostic Accuracy of Quantitative Imaging Biomarkers in the Differentiation of Benign and Malignant Vertebral Lesions

PurposeTo compare and combine the diagnostic performance of the apparent diffusion coefficient (ADC) derived from diffusion-weighted imaging (DWI) and proton density fat fraction (PDFF) derived from chemical-shift encoding (CSE)-based water-fat magnetic resonance imaging (MRI) for distinguishing benign and malignant vertebral bone marrow lesions (VBML).MethodsA total of 55 consecutive patients with 53 benign (traumatic, inflammatory and primary) and 36 malignant (metastatic and hematologic) previously untreated VBMLs were prospectively enrolled in this IRB-approved study and underwent sagittal DWI (single-shot spin-echo echo-planar with multi-slice short TI inversion recovery fat suppression) and CSE-based MRI (gradient-echo 6‑point modified Dixon) in addition to routine clinical spine MRI at 1.5 T or 3.0 T. Diagnostic reference standard was established according to histopathology or imaging follow-up. The ADC = ADC (0, 800) and PDFF = fat / (water + fat) were calculated voxel-wise and examined for differences between benign and malignant lesions.ResultsThe ADC and PDFF values of malignant lesions were significantly lower compared to benign lesions (mean ADC 861 × 10−6 mm2/s vs. 1323 × 10−6 mm2/s, p < 0.001; mean PDFF 3.1% vs. 28.2%, p < 0.001). The areas under the curve (AUC) and diagnostic accuracies were 0.847 (p < 0.001) and 85.4% (cut-off at 1084.4 × 10−6 mm2/s) for ADC and 0.940 (p < 0.001) and 89.9% for PDFF (cut-off at 7.8%), respectively. The combined use of ADC and PDFF improved the diagnostic accuracy to 96.6% (malignancy if ADC ≤ 1118.2 × 10−6 mm2/s and PDFF ≤ 20.0%, otherwise benign).ConclusionQuantitative evaluation of both ADC and PDFF was useful in differentiating benign VBMLs from malignancy. The combination of ADC and PDFF improved the diagnostic performance and yielded high diagnostic accuracy for the differentiation of benign and malignant VBMLs.

DOES QUANTIFICATION OF DIFFUSION (ADC VALUE) AID IN IDENTIFYING MALIGNANT VERTEBRAL LESIONS? A CROSS SECTIONAL OBSERVATIONAL STUDY.

Background: Characterization of vertebral pathologies as benign or malignant is a frequent dilemma that often requires invasive procedures for diagnosis. Today, imaging is sufcient for diagnosis of most benign vertebral pathologies with further conrmation on response to therapy. With better understanding of diffusion characteristics of tissues, attempt is being made to assess various imaging characteristics to make a denite diagnosis of malignant lesions as well. In this study we quantied apparent diffusion coefcient (ADC) of lesions in an effort to determine whether ADC values are different for benign or malignant vertebral body lesions. Consecutive patients that reported to the department of Radiodiagnosis, during 1st November 2017 to 31st March 2019, were included in the study. In this cross sectional observational study, for 32, that is, 22 benign and ten malignant vertebral lesions, diffusion weighted (DW) MRI sequence was done and ADC values were recorded. Conrmation was done with post treatment follow up or wherever feasible, tissue diagnosis. All malignant cases had histopathology conrmation from the site of primary lesion. Quantitative variables using independent t-test were used for comparison of ADC values between two groups. Results: The difference in mean ADC values of benign and malignant lesions were statistically signicant (P&lt;0.0001). The optimal cutoff of ADC -3 2 value for differentiating benign from malignant vertebral body lesion was 0.950 x 10 mm /s with sensitivity of 80% and specicity of 95.45%. Conclusion:In all cases, DWI/ ADC, along with routine MR sequences, were able to characterize the lesion either as benign or malignant except in two cases of tubercular infection of spine and one each of spindle cell sarcoma &amp; metastasis from cancer lung where there was overlap of ADC values.

T2-weighted Dixon MRI of the spine: A feasibility study of quantitative vertebral bone marrow analysis

PurposeTo compare the measurements of fat fraction (FF) and in-phase vs. opposed-phase ratio between two-dimensional T2-weighted (T2W) spin-echo (SE) Dixon and three-dimensional (3D) T1-weighted (T1W) volume interpolated breath-hold examination (VIBE) Dixon sequences in malignant vertebral lesions and normal vertebral bone marrow. Materials and methodsThirty patients with focal vertebral malignancies (20 men, mean age, 67.3±9.4 [SD] years; age range: 41–84 years) and 30 patients without malignant spinal disease (11 men, mean age, 70.1±12.9 [SD]; age range: 53–93 years) were retrospectively included. Each patient underwent spine MRI at 1.5 Tesla including T2W SE and T1W VIBE 2-point Dixon sequences. Two readers independently performed 3D-volume of interest (VOI) and region of interest (ROI)-based FF and IO-ratio measurements of malignant lesions and normal vertebrae. Student t-test, Pearson correlation (r) test and two-way mixed model intraclass correlation coefficients (ICC) were used to compare measurements. ResultsT2W SE and T1W VIBE mean FF and IO-ratio were significantly smaller in malignancy compared to normal marrow, but there were significant differences of paired measurement mean values between T2W SE and T1W VIBE Dixon parameters in malignant lesions T2W SE VOI FF=9%, T2W SE ROI FF=7%, T2W SE IO-ratio=4% vs. T1W VIBE VOI FF=11%, T1W VIBE ROI FF=9%, T1W VIBE IO-ratio=−2%, and in normal vertebrae T2W SE VOI FF=74%, T2W SE ROI FF=77%, T2W SE IO-ratio=51% vs. T1W VIBE VOI FF=67%, T1W VIBE ROI FF=73%, T1W VIBE IO-ratio=58% (each P comparing the paired T2W TSE and T1W VIBE parameter, respectively<0.001). There was excellent positive correlation between T2W SE and T1W VIBE-FF (r≥0.99) and VOI and ROI FF measurements for each sequence (r≥0.99). Inter-reader agreement was excellent for all measurements (ICC≥0.94 for all). ConclusionCalculation of T2W SE Dixon derived FF is feasible and gave valid results that help discriminate between malignant vertebral lesions and normal vertebral bone marrow.

Diffusion-Weighted Magnetic Resonance Imaging of Spine

척추영상에 사용되는 확산강조영상의 기술적 측면, 양성과 악성 척추체 압박골절의 구분, 다발성골수종이나 전이암의 발견과 감별진단, 그리고 항암화학요법이나 방사선치료 후 반응 평가에 대해 기술하고자 한다.

The Application of Apparent Diffusion Coefficient and Chemical Shift Images in Differentiation of Benign and Malignant Vertebral Lesions

Background: One of the most common clinical problems is the differentiation of vertebral marrow lesions, particularly in the elderly patients. Since clinical staging, treatment strategy, and prognosis in malignant and benign lesions are different, it is very essential to determine the benign and malignant nature of vertebral pathologies. Objectives: The aim of this study was to assess the value of diffusion weighted magnetic resonance imaging and chemical shift in the diagnosis, characterization, and differentiation of benign and malignant vertebral bone marrow lesions and to define the sensitivity and the specificity in differentiating benign and malignant vertebral lesions according to the optimal cut-off Apparent-diffusion-coefficient (ADC) values and signal intensity ratio (SIR). Methods: This study included 39 patients with 86 untreated vertebral lesions that underwent the routine MRI sequences of the spine as well as the two non-routine sequences (DWI and in/opposed phase). The optimal cut-off ADC value and SIR were determined for the differentiation of benign and malignant lesions. We used the biopsy results and clinical follow-up, as the gold standard to classify the vertebral marrow lesions as benign and malignant. Results: Of the examined 39 patients, 67 focal lesions were included that 42 lesions proved to be malignant and 25 lesions diagnosed as benign. The results of this study showed that the ADC values of benign lesions were significantly (P < 0.001) higher than untreated metastatic lesions. SIR values were calculated 1.155 ± 0.183 in malignant lesions, while it was 0.649 ±0.341 in benign lesions. Threshold analysis yield optimal cut-off point that showed ADC min and ADC mean and SIR had high sensitivity, specificity, and accuracy in the discrimination of benign and malignant lesions. Conclusions: Quantitative diffusion weighted and chemical shift MR imaging are effective non-invasive technique in differentiating benign from malignant vertebral bone marrow lesions that provide additional information to the routine MRI sequences.

Proton density fat fraction (PDFF) MRI for differentiation of benign and malignant vertebral lesions.

To investigate whether proton density fat fraction (PDFF) measurements using a six-echo modified Dixon sequence can help to differentiate between benign and malignant vertebral bone marrow lesions. Sixty-six patients were prospectively enrolled in our study. In addition to conventional MRI at 3.0-Tesla including at least sagittal T2-weighted/spectral attenuated inversion recovery and T1-weighted sequences, all patients underwent a sagittal six-echo modified Dixon sequence of the spine. The mean PDFF was calculated using regions of interest and compared between vertebral lesions. A cut-off value of 6.40% in PDFF was determined by receiver operating characteristic curves and used to differentiate between malignant (< 6.40%) and benign (≥ 6.40%) vertebral lesions. There were 77 benign and 44 malignant lesions. The PDFF of malignant lesions was statistically significant lower in comparison with benign lesions (p < 0.001) and normal vertebral bone marrow (p < 0.001). The areas under the curves (AUC) were 0.97 for differentiating benign from malignant lesions (p < 0.001) and 0.95 for differentiating acute vertebral fractures from malignant lesions (p < 0.001). This yielded a diagnostic accuracy of 96% in the differentiation of both benign lesions and acute vertebral fractures from malignancy. PDFF derived from six-echo modified Dixon allows for differentiation between benign and malignant vertebral lesions with a high diagnostic accuracy. • Establishing a diagnosis of indeterminate vertebral lesions is a common clinical problem • Benign bone marrow processes may mimic the signal alterations observed in malignancy • PDFF differentiates between benign and malignant lesions with a high diagnostic accuracy • PDFF of non-neoplastic vertebral lesions is significantly higher than that of malignancy • PDFF from six-echo modified Dixon may help avoid potentially harmful bone biopsy.

Predictive Models in Differentiating Vertebral Lesions Using Multiparametric MRI.

Conventional MR imaging has high sensitivity but limited specificity in differentiating various vertebral lesions. We aimed to assess the ability of multiparametric MR imaging in differentiating spinal vertebral lesions and to develop statistical models for predicting the probability of malignant vertebral lesions. One hundred twenty-six consecutive patients underwent multiparametric MRI (conventional MR imaging, diffusion-weighted MR imaging, and in-phase/opposed-phase imaging) for vertebral lesions. Vertebral lesions were divided into 3 subgroups: infectious, noninfectious benign, and malignant. The cutoffs for apparent diffusion coefficient (expressed as 10-3 mm2/s) and signal intensity ratio values were calculated, and 3 predictive models were established for differentiating these subgroups. Of the lesions of the 126 patients, 62 were infectious, 22 were noninfectious benign, and 42 were malignant. The mean ADC was 1.23 ± 0.16 for infectious, 1.41 ± 0.31 for noninfectious benign, and 1.01 ± 0.22 mm2/s for malignant lesions. The mean signal intensity ratio was 0.80 ± 0.13 for infectious, 0.75 ± 0.19 for noninfectious benign, and 0.98 ± 0.11 for the malignant group. The combination of ADC and signal intensity ratio showed strong discriminatory ability to differentiate lesion type. We found an area under the curve of 0.92 for the predictive model in differentiating infectious from malignant lesions and an area under the curve of 0.91 for the predictive model in differentiating noninfectious benign from malignant lesions. On the basis of the mean ADC and signal intensity ratio, we established automated statistical models that would be helpful in differentiating vertebral lesions. Our study shows that multiparametric MRI differentiates various vertebral lesions, and we established prediction models for the same.

Multicenter clinical and imaging evaluation of targeted radiofrequency ablation (t-RFA) and cement augmentation of neoplastic vertebral lesions

BackgroundTreatment of spinal metastatic lesions by radiofrequency ablation (RFA) before cementation can potentially help in local tumor control and pain relief. This is often limited by access and tumor location....

Reconstruction of Vertebral Body After Radiofrequency Ablation and Augmentation in Dorsolumbar Metastatic Vertebral Fracture: Analysis of Clinical and Radiological Outcome in a Clinical Series of 18 Patients.

Painful spinal metastases usually occur in malignant neoplastic disease. Treatment for bone metastases has been largely conservative, and it includes the use of high doses of analgesics, radiotherapy, chemotherapy, hormone therapy, and bisphosphonates; however, results are sometimes transient and ineffective. In the presence of neurological involvement a surgical strategy should be considered. Recently, percutaneous procedures such as radiofrequency ablation, vertebroplasty, and kyphoplasty have been introduced as palliative techniques to treat painful vertebral metastases [3, 11, 25]. In our study we combined the use of radiofrequency ablation with vertebroplasty in the treatment of dorsolumbar metastatic vertebral fractures in order to examine the relationship between restoration of the vertebral structure and decrease in pain. From January 2014 to March 2015 we retrospectively analyzed 18 patients with malignant vertebral lesions who underwent radiofrequency ablation with vertebroplasty followed by cementoplasty, with posterior transpedicle fixation on levels near the lesions. The parameters examined were: demographics, pain relief, and the distribution of polymethylmethacrylate (PMMA) determined by the mean Saliou filling score; all complications were recorded. The mean age of the patients was 55.72 years (range 34-69); average operative time was 60.4 min (range, 51-72). The average pain index score (visual analog score; VAS) decreased significantly from 8.05 at baseline to 3.0 (p < 0.05) after 6 months. The Saliou filling score revealed a distribution of PMMA in the vertebral body that was satisfactory (12-18) in eight patients, mediocre (6-12) in seven patients, and inadequate (0-6) in the remaining three patients. In two vertebrae, minimal asymptomatic cement leakage occurred in the lateral recess without neurological damage. No pulmonary embolism and no visceral or neural damage was recorded. Radiofrequency ablation combined with vertebroplasty seems to achieve rapid and lasting improvement in clinical symptoms in patients with malignant vertebral lesions. There was wide diffusion of PMMA in the vertebral body, with a mean cement volume of 4.5 ml.

Accuracy of magnetic resonance imaging in differentiating between benign and malignant vertebral lesions: Role of Diffusion-weighted imaging, in-phase/opposed-phase imaging and apparent diffusion coefficient

ObjectiveTo determine the ability of MRI to distinguish between benign and malignant vertebral lesions. Materials and methodsWe included 85 patients and studied a total of 213 vertebrae (both pathologic and normal). For each vertebra, we determined whether the lesion was hypointense in T1-weighted sequences and whether it was hyperintense in STIR and in diffusion-weighted sequences. We calculated the in-phase/out-of-phase quotient and the apparent diffusion coefficient for each vertebra. We combined parameters from T1-weighted, diffusion-weighted, and STIR sequences to devise a formula to distinguish benign from malignant lesions. ResultsThe group comprised 60 (70.6%) women and 25 (29.4%) men with a mean age of 67±13.5 years (range, 33–90 y). Of the 85 patients, 26 (30.6%) had a known primary tumor. When the lesion was hypointense on T1-weighted sequences, hyperintense on STIR and diffusion-weighted sequences, and had a signal intensity quotient greater than 0.8, the sensitivity was 97.2%, the specificity was 90%, and the diagnostic accuracy was 91.2%. If the patient had a known primary tumor, these values increased to 97.2%, 99.4%, and 99%, respectively. ConclusionBenign lesions can be distinguished from malignant lesions if we combine the information from T1-weighted, STIR, and diffusion-weighted sequences together with the in-phase/out-of-phase quotient of the lesion detected in the vertebral body on MRI.

Evaluation of benign and malignant vertebral lesions with diffusion weighted magnetic resonance imaging and apparent diffusion coefficient measurements

Aim of the workThe aim of this study was to assess the utility of apparent diffusion coefficient obtained in diffusion-weighted MR imaging for the differentiation between benign and malignant vertebral lesions, and to determine the sensitivity and the specificity in differentiating benign and malignant vertebral lesions according to the optimal cutoff ADC value. Patients and methodsIn 50 patients, 96 vertebral lesions were included and underwent DW MR Imaging. The mean ADC values of normal and abnormal vertebrae were calculated. The optimal cutoff ADC value was determined for the differentiation of benign and malignant lesions. The results were correlated with histopathological and surgical findings. ResultsThe mean ADC value of benign lesions was significantly higher than that of malignant ones (P<0.05). There was an overlap between the mean ADC values of malignant and tuberculous lesions. According to the optimal cutoff value of 1.21×10−3mm2/s, determined for the differentiation of benign and malignant vertebral lesions, sensitivity was 95.12%, specificity 92.73%, positive predictive value 90.70%, and negative predictive value 96.23%. ConclusionVertebral lesions were differentiated as benign or malignant with high sensitivity and specificity with the aid of ADC values calculated from maps obtained by DWI.

1:45 PM, Abstract No. 32 - The anti-tumor effect of polymethylmethacrylate cement on vertebral tumor of rabbit after percutaneous vertebroplasty

Percutaneous vertebroplasty (PVP) has been commonly used for the treatment of vertebral compression fractures secondary to metastasis and has been shown to achieve excellent pain relief immediately after the PVP. However, the mechanism by which PVP treats vertebral lesions remains controversial, and it is speculated that mechanical and/or anti-tumor effects of polymethylmethacrylate (PMMA) cement might be responsible for the pain relief. The purpose of this study is to investigate the anti-tumor effect of bone cement on vertebral tumor in-vivo after PVP. Twenty New Zealand white rabbits with lumbar vertebral tumor, established by percutaneous puncturing transplant of VX2 carcinoma, were randomly and equally divided into the study group and the control group with 10 rabbits in each group. PVP with injection of 0.3 ml PMMA cement was carried out on the rabbits of the study group while the procedure with injection of 0.3 ml physiological saline was employed with the rabbits of the control group. PET/CT was performed on all the rabbits before the PVP. The stand uptake value (SUV) of each vertebral tumor was then measured. Five rabbits were randomly selected at 1d and 4d after the cement or saline injection respectively in each group. PET/CT was performed again on each rabbit. The animals were then executed and the tissues of the tumors were collected for pathological examination. Before PVP, the difference in SUV of the vertebral tumors between the two groups was of no statistical significance. In the study group, the SUV of the vertebral tumor was dropped markedly after the PMMA cement injecting. However, there is no significant difference in the SUV of the vertebral tumors between the pre- and post-procedure in the control group. Pathological results showed that there were typical nuclei concentration, nuclei dissolution and necrosis of tumor cells near the cement, on the contrary, this was not observed in the control group. PMMA cement has a significant anti-tumor effect on the vertebral tumor in-vivo after the PVP, and this could be at least one of the mechanisms by which PVP treats malignant vertebral lesions.

Precisión de la resonancia magnética en la diferenciación entre lesión vertebral maligna y benigna: papel de las secuencias de difusión, del cociente fuera de fase/en fase y de los valores del coeficiente de difusión aparente

ObjectiveTo determine the ability of MRI to distinguish between benign and malignant vertebral lesions. Material and methodsWe included 85 patients and studied a total of 213 vertebrae (both pathologic and normal). For each vertebra, we determined whether the lesion was hypointense in T1-weighted sequences and whether it was hyperintense in STIR and in diffusion-weighted sequences. We calculated the in-phase/out-of-phase quotient and the apparent diffusion coefficient for each vertebra. We combined parameters from T1-weighted, diffusion-weighted, and STIR sequences to devise a formula to distinguish benign from malignant lesions. ResultsThe group comprised 60 (70.6%) women and 25 (29.4%) men with a mean age of 67±13.5 years (range, 33-90 y). Of the 85 patients, 26 (30.6%) had a known primary tumor. When the lesion was hypointense on T1-weighted sequences, hyperintense on STIR and diffusion-weighted sequences, and had a signal intensity quotient greater than 0.8, the sensitivity was 97.2%, the specificity was 90%, and the diagnostic accuracy was 91.2%. If the patient had a known primary tumor, these values increased to 97.2%, 99.4%, and 99%, respectively. ConclusionBenign lesions can be distinguished from malignant lesions if we combine the information from T1-weighted, STIR, and diffusion-weighted sequences together with the in-phase/out-of-phase quotient of the lesion detected in the vertebral body on MRI.

The role of magnetic resonance imaging and positron emission tomography-computed tomography combined in differentiating benign from malignant lesions contributing to vertebral compression fractures

Background:Obtaining tissue confirmation of the underlying pathology is the gold standard for establishing the etiology of nontraumatic vertebral compression fractures. However, newer investigative modalities such as the magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) combined potentially offer the ability to distinguish between benign and malignant lesions, thereby circumventing the need for invasive tissue diagnostic/biopsy procedures.Methods:Twenty-four patients with nontraumatic, spontaneous vertebral compression fractures were prospectively studied. After clinical evaluation, all patients underwent MRI (with/without contrast) focusing on the spinal lesion, followed by whole-body PET-CT. This was followed by fine needle aspiration cytology (FNAC) of the lesion to confirm the diagnosis. The sensitivity and specificity of MRI and PET-CT studies were calculated for benign vs. malignant lesions.Results:The sensitivity/specificity of MRI for benign lesions were 78.57%/90%, while the sensitivity/specificity values of PET-CT for benign disease were 92.8%/90% respectively. Alternatively, the sensitivity/specificity of MRI for malignant lesions were 90%/78.57%, while the sensitivity/specificity of PET-CT for malignant disease were 90%/92.8%, respectively. Furthermore, the sensitivity for diagnosing malignant lesions utilizing both studies together was 100%, but the algorithm was not specific. Additionally, the specificity for MRI and PET-CT combined was 100% for benign lesions. PET-CT also helped in monitoring responses to empirical antitubercular treatment (ATT) therapy. Of interest, FNAC was inconclusive in four cases in which PET-CT findings helped further in either obtaining a tissue diagnosis from another location or institution of empirical therapy in suspected cases of tuberculosis.Conclusions:The specificity for MRI and PET-CT combined was 100% for benign lesions. Unfortunately, the specificity for MRI and PET-CT combined was not 100% for malignant vertebral lesions, though it was sensitive. The PET-CT scan was an extremely useful tool when FNAC from the affected site proved inconclusive. It gave additional information regarding the overall extent of disease, while identifying other locations amenable to FNAC. Furthermore, in countries where tuberculosis is endemic, the empirical response to ATT therapy could be monitored utilizing PET-CT.

Quantitative Analysis of the Diffusion-Weighted Steady-State Free Precession Signal in Vertebral Bone Marrow Lesions

: Diffusion-weighted steady-state free precession (DW-SSFP) sequences have shown great potential for the differential diagnosis of benign osteoporotic and malignant neoplastic vertebral compression fractures, which appear hypo- to isointense or hyperintense in DW-SSFP magnetic resonance imaging, respectively. In contrast to other diffusion weighting sequences, the DW-SSFP signal depends not only on the apparent diffusion coefficient (ADC), but also on the tissue relaxation times and sequence parameters. The purpose of the present study was to provide a detailed analysis of the DW-SSFP signal in benign and malignant vertebral lesions (VLs) and in vertebral bone marrow (VBM) to understand the observed signal alterations and their dependence on tissue and sequence parameters. : Magnetic resonance imaging was performed in 40 patients with benign (n = 20) or malignant (n = 20) VLs to determine the fat fraction and tissue parameters (ADC, T1, T2, T2*) for both the water and fat signal. With these values, the DW-SSFP signal was simulated and compared with the measured signals for different diffusion gradients by determining the signal intensity ratio between the SSFP signals of the lesions and of normal-appearing VBM for both malignant and benign VLs. : The simulated DW-SSFP contrast agreed well with the measured contrast and provided a very good differentiation between benign osteoporotic and malignant VLs. ADCs were significantly different in both lesion types (malignant 1.36 vs. osteoporotic 1.77 × 10 mm/s); however, the observed contrast differences were caused predominantly by an opposed-phase readout in combination with significantly different T2* values (malignant 22 vs. osteoporotic 14 ms) and fat fractions (malignant 3.9% vs. osteoporotic 12%) in the lesions as well as significantly different fat fractions in normal-appearing VBM (malignant 42% vs. osteoporotic 52%) of both patient groups. : Although the ADCs of the evaluated malignant and benign VLs showed highly significant differences, the influence of diffusion on the DW-SSFP signal contrast is relatively low compared with other tissue parameters due to the very complex signal mechanism of the SSFP sequence. Thus, the observed DW-SSFP signal contrast of different VLs (hypo-/isointense vs. hyperintense signal) is rather fat- and T2*-weighted than diffusion-weighted. The intermediate diffusion weighting of the applied SSFP sequence, however, helps to shift the different contrasts into a signal range that is easily visually accessible.

Value of opposed-phase gradient-echo technique in distinguishing between benign and malignant vertebral lesions

Our objective was to evaluate the possible role of opposed-phase gradient-echo (GRE) sequence in predicting the nature of vertebral lesions supposing that in the case of malignancy fat is completely replaced while in the case of benign lesion fat is still present. Eighty-six patients with vertebral lesions underwent MR examination at 0.5 T. The MR protocol included a T1-weighted spin-echo (SE) and an opposed-phase GRE using the same parameters (TR=280-320 ms, flip angle=90 degrees, slice thickness=3.5-4 mm, matrix=256x160-192, field of view=34-36 cm, no. of excitations=2-4) except for TE (10 ms in SE vs 7 ms in GRE) to obtain opposed-phased images. Qualitative (nature of lesion, detectability, degree of signal intensity (SI), marrow pattern) and quantitative (SI on opposed-phase GRE minus SI on T1-weighted SE minus SI ratio=SI on out-of-phase GRE images divided by SI on T1-weighted SE images) analysis were performed. The SI ratio values were analysed using Mann-Whitney rank-sum test and receiver operating characteristics (ROC) curve. Lesions resulted to be malignant in 45 and benign in 41 patients (23 biopsies, 20 MR follow-ups, 43 clinical and other imaging follow-ups). Based on visual inspection of opposed-phased images, visual SI was evaluated high in 38 (34 malignant, 34 benign), mild in 28 (9 malignant, 19 benign) and low in 20 (2 malignant, 18 benign) patients. Based on region-of-interest measurements, SI ratio values range was 0.36-6.2 (mean value=1.68+/-0.82) for malignant and 0.07-1.54 (mean value=0.77+/-0.44) for benign lesions. A cut-off value of 1.2 gave a sensitivity, specificity, accuracy, negative predictive value and positive predictive value, respectively, of 88.8, 80.49, 84.88, 86.4 and 83.33%. The ROC analysis of the SI ratio showed an area under ROC curve of 0.92 and a statistically significant difference between the two groups of lesions was observed ( p<0.01). The GRE opposed-phase sequence can help to predict the nature of a vertebral lesion. This fast and widely available technique together with morphological criteria can improve the accuracy of MRI.