Differentiating Atypical Hemangiomas and Metastatic Vertebral Lesions: The Role of T1-Weighted Dynamic Contrast-Enhanced MRI

Vertebral hemangiomas: a review on diagnosis and management

BACKGROUND

Vertebral hemangiomas (VHs) are the most common benign tumors of the spinal column and are often encountered incidentally during routine spinal imaging.

METHODS

A retrospective review of the inpatient and outpatient hospital records at our institution was performed for the diagnosis of VHs from January 2005 to September 2023. Search filters included "vertebral hemangioma," "back pain," "weakness," "radiculopathy," and "focal neurological deficits." Radiographic evaluation of these patients included plain X-rays, CT, and MRI. Following confirmation of a diagnosis of VH, these images were used to generate the figures used in this manuscript. Moreover, an extensive literature search was conducted using PubMed for the literature review portion of the manuscript.

RESULT

VHs are benign vascular proliferations that cause remodeling of bony trabeculae in the vertebral body of the spinal column. Horizontal trabeculae deteriorate leading to thickening of vertical trabeculae which causes a striated appearance on sagittal magnetic resonance imaging (MRI) and computed tomography (CT), "Corduroy sign," and a punctuated appearance on axial imaging, "Polka dot sign." These findings are seen in "typical vertebral hemangiomas" due to a low vascular-to-fat ratio of the lesion. Contrarily, atypical vertebral hemangiomas may or may not demonstrate the "Corduroy" or "Polka-dot" signs due to lower amounts of fat and a higher vascular component. Atypical vertebral hemangiomas often mimic other neoplastic pathologies, making diagnosis challenging. Although most VHs are asymptomatic, aggressive vertebral hemangiomas can present with neurologic sequelae such as myelopathy and radiculopathy due to nerve root and/or spinal cord compression. Asymptomatic vertebral hemangiomas do not require therapy, and there are many treatment options for vertebral hemangiomas causing pain, radiculopathy, and/or myelopathy. Surgery (corpectomy, laminectomy), percutaneous techniques (vertebroplasty, sclerotherapy, embolization), and radiotherapy can be used in combination or isolation as appropriate. Specific treatment options depend on the lesion's size/location and the extent of neural element compression. There is no consensus on the optimal treatment plan for symptomatic vertebral hemangioma patients, although management algorithms have been proposed.

CONCLUSION

While typical vertebral hemangioma diagnosis is relatively straightforward, the differential diagnosis is broad for atypical and aggressive lesions. There is an ongoing debate as to the best approach for managing symptomatic cases, however, surgical resection is often considered first line treatment for patients with neurologic deficit.

Dynamic Contrast Enhanced MR Perfusion and Diffusion-Weighted Imaging of Marrow-Replacing Disorders of the Spine: A Comprehensive Review

Significant advancements in cancer treatment have led to improved survival rates for patients, particularly in the context of spinal metastases. However, early detection and monitoring of treatment response remain crucial for optimizing patient outcomes. Although conventional imaging methods such as bone scan, PET, MR imaging, and computed tomography are commonly used for diagnosing and monitoring treatment, they present challenges in differential diagnoses and treatment response monitoring. This review article provides a comprehensive overview of the principles, applications, and practical uses of dynamic contrast-enhanced MR imaging and diffusion-weighted imaging in the assessment and monitoring of marrow-replacing disorders of the spine.

Perfusion Imaging of the Musculoskeletal System

Perfusion imaging is the aspect of functional imaging, which is most applicable to the musculoskeletal system. In this review, the anatomy and physiology of bone perfusion is briefly outlined as are the methods of acquiring perfusion data on MR imaging. The current clinical indications of perfusion related to the assessment of soft tissue and bone tumors, synovitis, osteoarthritis, avascular necrosis, Keinbock's disease, diabetic foot, osteochondritis dissecans, and Paget's disease of bone are reviewed. Challenges and opportunities related to perfusion imaging of the musculoskeletal system are also briefly addressed.

T1-Weighted, Dynamic Contrast-Enhanced MR Perfusion Imaging Can Differentiate between Treatment Success and Failure in Spine Metastases Undergoing Radiation Therapy

BACKGROUND AND PURPOSE

Current imaging techniques have difficulty differentiating treatment success and failure in spinal metastases undergoing radiation therapy. This study investigated the correlation between changes in dynamic contrast-enhanced MR imaging perfusion parameters and clinical outcomes following radiation therapy for spinal metastases. We hypothesized that perfusion parameters will outperform traditional size measurements in discriminating treatment success and failure.

MATERIALS AND METHODS

This retrospective study included 49 patients (mean age, 63 [SD, 13] years; 29 men) with metastatic lesions treated with radiation therapy who underwent dynamic contrast-enhanced MR imaging. The median time between radiation therapy and follow-up dynamic contrast-enhanced MR imaging was 62 days. We divided patients into 2 groups: clinical success (n = 38) and failure (n = 11). Failure was defined as PET recurrence (n = 5), biopsy-proved (n = 1) recurrence, or an increase in tumor size (n = 7), while their absence defined clinical success. A Mann-Whitney U test was performed to assess differences between groups.

RESULTS

The reduction in plasma volume was greater in the success group than in the failure group (-57.3% versus +88.2%, respectively; P < .001). When we assessed the success of treatment, the sensitivity of plasma volume was 91% (10 of 11; 95% CI, 82%-97%) and the specificity was 87% (33 of 38; 95% CI, 73%-94%). The sensitivity of size measurements was 82% (9 of 11; 95% CI, 67%-90%) and the specificity was 47% (18 of 38; 95% CI, 37%-67%).

CONCLUSIONS

The specificity of plasma volume was higher than that of conventional size measurements, suggesting that dynamic contrast-enhanced MR imaging is a powerful tool to discriminate between treatment success and failure.

Surgical management of symptomatic vertebral hemangiomas: a single institution experience and literature review

Vertebral hemangiomas (VHs), formed from a vascular proliferation in bone marrow spaces limited by bone trabeculae, are the most common benign tumors of the spine. While most VHs remain clinically quiescent and often only require surveillance, rarely they may cause symptoms. They may exhibit active behaviors, including rapid proliferation, extending beyond the vertebral body, and invading the paravertebral and/or epidural space with possible compression of the spinal cord and/or nerve roots ("aggressive" VHs). An extensive list of treatment modalities is currently available, but the role of techniques such as embolization, radiotherapy, and vertebroplasty as adjuvants to surgery has not yet been elucidated. There exists a need to succinctly summarize the treatments and associated outcomes to guide VH treatment plans. In this review article, a single institution's experience in the management of symptomatic VHs is summarized along with a review of the available literature on their clinical presentation and management options, followed by a proposal of a management algorithm.

Dynamic Contrast-Enhanced MR Perfusion: Role in Diagnosis and Treatment Follow-Up in Patients with Vertebral Body Tumors

Recent therapeutic advances have led to increased survival times for patients with metastatic disease. Key to survival is early diagnosis and subsequent treatment as well as early detection of treatment failure allowing for therapy modifications. Conventional MR imaging techniques of the spine can be at times suboptimal for identifying viable tumor, as structural changes and imaging characteristics may not differ pretreatment and posttreatment. Advanced imaging techniques such as DCE-MRI can allow earlier and more accurate noninvasive assessment of viable disease by characterizing physiologic changes and tumor microvasculature.

Intense PSMA Uptake in a Vertebral Hemangioma Mimicking a Solitary Bone Metastasis in the Primary Staging of Prostate Cancer via 68Ga-PSMA PET/CT

A 78-year-old man with newly diagnosed high-risk prostate cancer underwent ⁶⁸Ga-PSMA PET/CT for primary staging. This showed a single, very intense PSMA uptake in the vertebral body of Th2, without discrete morphological changes on low-dose CT. Thus, the patient was considered oligometastatic and underwent MRI of the spine for stereotactic radiotherapy planning. MRI demonstrated an atypical hemangioma in Th2. A bone algorithm CT scan confirmed the MRI findings. The treatment was changed, and the patient underwent a prostatectomy with no concomitant therapy. At three and six months after the prostatectomy, the patient had an unmeasurable PSA level, confirming the benign etiology of the lesion.

Quantification of spinal bone marrow fat fraction using three-material decomposition technique on dual-energy CT: A phantom study

BACKGROUND

Two-material decomposition is insufficient to quantify the fat fraction of spinal bone marrow, which is comprised of a mixture of bone minerals, water, and yellow marrow (fat).

PURPOSE

To develop an accurate three-material decomposition-based bone marrow fat fraction ( F F 3 M D $F{F_{3MD}}$ ) quantification technique for dual-energy CT.

METHODS

Bone marrow edema phantoms containing trabecular bone minerals, water, and fat were constructed using fat fractions and bone mineral density values matching those expected in healthy and edematous bone, and scanned on a commercial dual-energy CT. Fat quantified by F F 3 M D $F{F_{3MD}}$ were compared to MRI-based fat fraction ( F F M R I $F{F_{MRI}}$ ) and conventional two-material-decomposition-based fat fraction ( F F 2 M D $F{F_{2MD}}$ ) to evaluate its accuracy and dependency on various bone mineral densities.

RESULTS

F F 3 M D $F{F_{3MD}}$ demonstrated an excellent correlation with F F M R I $F{F_{MRI}}\;$ (r = 0.97, R²  = 0.96) in the phantom, significantly more accurate than FF_2MD when confounding bone minerals are present (50 mg/cm³ : r = 1.02, R²  = 0.95 vs. r = 0.65, R²  = 0.79 (p < 0.01); 100 mg/cm³ : r = 0.81, R²  = 0.47 vs. r = 0.21, R²  = 0.21 (p < 0.05)).

CONCLUSIONS

F F 3 M D $F{F_{3MD}}$ accurately quantified bone marrow fat fraction, when compared with F F M R I $F{F_{MRI}}$ , in the specially constructed bone marrow phantom.

Delay of Aortic Arterial Input Function Time Improves Detection of Malignant Vertebral Body Lesions on Dynamic Contrast-Enhanced MRI Perfusion

Dynamic contrast-enhanced MRI (DCE) is an emerging modality in the study of vertebral body malignancies. DCE-MRI analysis relies on a pharmacokinetic model, which assumes that contrast uptake is simultaneous in the feeding of arteries and tissues of interest. While true in the highly vascularized brain, the perfusion of the spine is delayed. This delay of contrast reaching vertebral body lesions can affect DCE-MRI analyses, leading to misdiagnosis for the presence of active malignancy in the bone marrow. To overcome the limitation of delayed contrast arrival to vertebral body lesions, we shifted the arterial input function (AIF) curve over a series of phases and recalculated the plasma volume values (V_p) for each phase shift. We hypothesized that shifting the AIF tracer curve would better reflect actual contrast perfusion, thereby improving the accuracy of V_p maps in metastases. We evaluated 18 biopsy-proven vertebral body metastases in which standard DCE-MRI analysis failed to demonstrate the expected increase in V_p. We manually delayed the AIF curve for multiple phases, defined as the scan-specific phase temporal resolution, and analyzed DCE-MRI parameters with the new AIF curves. All patients were found to require at least one phase-shift delay in the calculated AIF to better visualize metastatic spinal lesions and improve quantitation of V_p. Average normalized V_p values were 1.78 ± 1.88 for zero phase shifts (P0), 4.72 ± 4.31 for one phase shift (P1), and 5.59 ± 4.41 for two phase shifts (P2). Mann-Whitney U tests obtained p-values = 0.003 between P0 and P1, and 0.0004 between P0 and P2. This study demonstrates that image processing analysis for DCE-MRI in patients with spinal metastases requires a careful review of signal intensity curve, as well as a possible adjustment of the phase of aortic AIF to increase the accuracy of V_p.

Precise differentiation between jugular foramen paragangliomas and metastases: utility of diffusion-weighted and dynamic contrast-enhanced magnetic resonance imaging

PURPOSE

This study tested the utility of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCE-MRI) in differentiating paragangliomas and metastases in the jugular foramen in combination with conventional imaging.

METHODS

Forty-nine consecutive patients with paragangliomas or metastases between January 2015 and April 2022 were included in this retrospective study. All patients had pretreatment DWI and DCE-MRI. Between paragangliomas and metastases, normalized apparent diffusion coefficient (nADCmean) and DCE-MRI parameters were compared along with conventional imaging features (enhancement pattern, presence of flow voids, cystic/necrotic change, and bone erosion). The diagnostic performance was tested using receiver operating characteristic (ROC) analysis.

RESULTS

Thirty-five paragangliomas (5 male; median 49 years) and 14 metastases (9 male; median 61 years) were analyzed. The most common 3 primary cancers included 4 lung cancers, 3 breast cancers, and 3 melanomas. The presence of flow void was significantly different between paragangliomas and metastases (21/35 vs 2/14; P = 0.0047) in conventional imaging features, while fractional plasma volume (Vp) was significantly different between the two tumor types (median 0.46 vs 0.19; P < 0.001) in DWI and DCE-MRI parameters. The areas under the ROC curves (AUCs) of the presence of flow void and Vp were 0.72 and 0.93, respectively. The AUC of the combination of the presence of flow void and Vp was 0.95 and significantly improved compared to that of the presence of flow void (P < 0.001).

CONCLUSION

Adding DCE-MRI to the head and neck protocol can aid in the precise differentiation between jugular foramen paragangliomas and metastases.

Vertebral Hemangiomas: Prevalence, new classification and natural history. magnetic resonance imaging-based retrospective longitudinal study

BACKGROUND AND PURPOSE

To determine the prevalence of vertebral hemangiomas (VHs), establish a new classification of VHs based on their MRI-signal pattern, and study their natural history.

METHODS

MRI of 1000 consecutive patients who underwent at least two MRI with an interval of at least 3 years. Growth rate and change of MRI-signal pattern during the follow-up period were the parameters included in studying the natural history of VHs.

RESULTS

The prevalence of VHs was 41%. VHs were classified as type I-IV with fat-rich VHs (type I), constituted 79% of all VHs. VHs were more common among females 43% versus males 39%, p = .22. The most affected vertebra was L1. Occurrence rates for cervical (1%), thoracic (7%), and lumbar spine (10%) differed significantly (p < .001). The prevalence of VHs increased with age regardless of gender or spinal part involved (p < .001). Only 26% of VHs changed their size and 4% changed their signal during the average follow-up of 7 years. All VHs were slowly growing lesions (average expected growth of <3 mm/10 years). No significant difference between growth rate of VHs type I (0.25 mm/year) and other types of VHs. None of the VHs that were initially reported as "metastases cannot be rule out" showed alarming change in signal or size.

CONCLUSIONS

VH can be classified into four types based on their MRI-signal pattern. Regardless of their type, VHs are slowly growing lesions. The presence of typical morphological pattern should enable radiologists to confidently differentiate them from vertebral metastases.

Skull metastases and osseous venous malformations: The role of diffusion-weighted and dynamic contrast-enhanced MRI

BACKGROUND AND PURPOSE

Skull metastasis (SM) is a common secondary malignancy. We evaluated the diagnostic performance of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (MRI) in differentiating SM from osseous venous malformations and SM of various origins.

METHODS

This study included 31 patients with SM (median age, 64 years; range, 41-87 years; 29 women; 24 and 7 patients with breast and non-small cell lung cancer, respectively) and 16 with osseous venous malformations (median age, 68 years; range, 20-81 years; 10 women) who underwent both DWI and dynamic contrast-enhanced MRI between January 2015 and October 2021. Normalized mean apparent diffusion coefficients (ADCs) and dynamic contrast-enhanced MRI parameters were compared between SM and osseous venous malformations, and between breast cancer and non-small cell lung cancer. Multivariate stepwise logistic regression analyses were performed to identify statistically significant parameters.

RESULTS

Plasma volume and time-to-maximum enhancement were the most statistically significant parameters for differentiating SM from osseous venous malformations, with an area under the receiver operating characteristic curve of 0.962. The normalized mean ADC and peak enhancement values were the most statistically significant parameters for differentiating breast cancer from non-small cell lung cancer, with an area under the curve of 0.924.

CONCLUSIONS

Our results highlight the efficacious diagnostic performance of DWI and dynamic contrast-enhanced MRI in distinguishing SM from osseous venous malformations and differentiating SM of various origins.

Management of Aggressive Vertebral Haemangioma and Assessment of Differentiating Pointers Between Aggressive Vertebral Haemangioma and Metastases - A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

Vertebral haemangioma has been classified into typical and aggressive vertebral haemangioma (AVH). Management options for AVH are many and the clinician has decision dilemma in choosing the right one. Metastases mimic AVH in clinical and radiological presentation. Differentiating pointers between them has not been clearly delineated in literature. Aim of our review is to identify treatment options; to formulate a management algorithm for AVH based on clinical presentation and to identify radiological differentiating pointers between them.

METHODS

Systematic review was conducted according to PRISMA guidelines. We systematically reviewed all available literature from the year 2001 to 2020. Relevant articles were identified as per laid down criteria from the medical databases. After inclusion, first and second authors went through full text of each included article.

RESULTS

Of 139 studies reviewed, eight met our criteria for review of management and three separate studies for radiological differentiating pointers. 99 patients with 88 AVH had undergone treatment. Back pain with myelopathy is the presenting symptom in majority of patients. Patients with backpain - myelopathic symptoms had improved following surgery; patients with back pain alone had improved with either percutaneous vertebroplasty or CT guided alcohol ablation. Dynamic contrast MRI, Diffusion weighted MRI and ratio of signal intensity between T1w and fat suppression T1w MR help the clinician in differentiating them.

CONCLUSION

Management of AVH can be based on the patient's clinical presentation. Patients presenting with AVH and back pain can be managed with either Percutaneous vertebroplasty or CT guided alcohol ablation. Patients presenting with AVH and neurological symptoms could be managed with surgery. Dynamic contrast enhanced MR, Diffusion weighted MR, ratio of signal intensity between T1w and Fat suppression T1w MR imaging could help the clinician in differentiating the two before contemplating biopsy.

GRADE PRACTICE RECOMMENDATION

C.

Multidisciplinary management of spinal metastases: what the radiologist needs to know

The modern management of spinal metastases requires a multidisciplinary approach that includes radiation oncologists, surgeons, medical oncologists, and diagnostic and interventional radiologists. The diagnostic radiologist can play an important role in the multidisciplinary team and help guide assessment of disease and selection of appropriate therapy. The assessment of spine metastases is best performed on MRI, but imaging from other modalities is often needed. We provide a review of the clinical and imaging features that are needed by the multidisciplinary team caring for patients with spine metastases and stress the importance of the spine radiologist taking responsibility for synthesizing imaging features across multiple modalities to provide a report that advances patient care.

Differentiation of Skull Base Chondrosarcomas, Chordomas, and Metastases: Utility of DWI and Dynamic Contrast-Enhanced Perfusion MR Imaging

BACKGROUND AND PURPOSE

Differentiation of skull base tumors, including chondrosarcomas, chordomas, and metastases, on conventional imaging remains a challenge. We aimed to test the utility of DWI and dynamic contrast-enhanced MR imaging for skull base tumors.

MATERIALS AND METHODS

Fifty-nine patients with chondrosarcomas, chordomas, or metastases between January 2015 and October 2021 were included in this retrospective study. Pretreatment normalized mean ADC and dynamic contrast-enhanced MR imaging parameters were calculated. The Kruskal-Wallis H test for all tumor types and the Mann-Whitney U test for each pair of tumors were used.

RESULTS

Fifteen chondrosarcomas (9 men; median age, 62 years), 14 chordomas (6 men; median age, 47 years), and 30 metastases (11 men; median age, 61 years) were included in this study. Fractional plasma volume helped distinguish all 3 tumor types (P = .003, <.001, and <.001, respectively), whereas the normalized mean ADC was useful in distinguishing chondrosarcomas from chordomas and metastases (P < .001 and P < .001, respectively); fractional volume of extracellular space, in distinguishing chondrosarcomas from metastases (P = .02); and forward volume transfer constant, in distinguishing metastases from chondrosarcomas/chondroma (P = .002 and .002, respectively) using the Kruskal-Wallis H test. The diagnostic performances of fractional plasma volume for each pair of tumors showed areas under curve of 0.86-0.99 (95% CI, 0.70-1.0); the forward volume transfer constant differentiated metastases from chondrosarcomas/chordomas with areas under curve of 0.82 and 0.82 (95% CI, 0.67-0.98), respectively; and the normalized mean ADC distinguished chondrosarcomas from chordomas/metastases with areas under curve of 0.96 and 0.95 (95% CI, 0.88-1.0), respectively.

CONCLUSIONS

DWI and dynamic contrast-enhanced MR imaging sequences can be beneficial for differentiating the 3 common skull base tumors.

Imaging of Bone Marrow: From Science to Practice

The study of the bone marrow may pose important challenges, due to its changing features over the life span, metabolic stress, and in cases of disease or treatment. Bone marrow adipocytes serve as storage tissue, but they also have endocrine and paracrine functions, contributing to local and systemic metabolism.Among different techniques, magnetic resonance (MR) has the benefit of imaging bone marrow directly. The use of advanced MR techniques for bone marrow study has rapidly found clinical applications. Beyond the clinical uses, it has opened up pathways to assess and quantify bone marrow components, establishing the groundwork for further study of its implications in physiologic and pathologic conditions.We summarize the features of the bone marrow as an organ, address the different modalities available for its study, with a special focus on MR advanced techniques and their addition to analysis in recent years, and review some of the challenges in interpreting the appearance of bone marrow.

A Cohort Study to Evaluate the Efficacy and Value of CT Perfusion Imaging in Patients with Metastatic Osteosarcoma after Chemotherapy

Objective

A case-control study was conducted to explore the efficacy of cohort study and value of CT perfusion imaging in patients with metastatic osteosarcoma after chemotherapy.

Methods

Eighty patients with metastatic osteosarcoma treated in our hospital from March 2020 to December 2021 were divided into two groups. According to their different treatment methods, the chemotherapy+antiangiogenesis group had 36 cases and the chemotherapy group had 44 cases. All patients were scanned by 64-slice spiral CT before and after treatment. The differences of tumor volume and perfusion parameters before and after treatment were compared, and the correlation between perfusion parameters and tumor microvessel density (MVD) was analyzed. The receiver working curve (ROC curve) was used to evaluate the efficacy of the two groups after chemotherapy.

Results

Blood flow (BF), blood volume (BV), Pallak blood volume (PBV), and time to start (TTS) in the antitumor angiogenesis+chemotherapy group were significantly lower than those before treatment (P < 0.05). Microvessel density was positively correlated with PS, BF, BV, and PBV (P < 0.05). The reduction rate of BV and BF in the remission group after treatment was significantly higher than that in the nonremission group. When the BV and BF decline rates were 47.37% and 21.53% and the areas under the curve were 0.968 and 0.916, respectively, the diagnostic effect was the best. When the decrease rate of BV was 47.48% and the decrease rate of BF was 21.55%, the sensitivity was 94.72% and 89.56% and the specificity was 91.31% and 91.31%.

Conclusion

The reduction rate of BV and BF in CT perfusion imaging is of high value in evaluating the efficacy of radiotherapy and chemotherapy in patients with NSCLC and can provide more objective basis for observing the changes and judging the prognosis of osteosarcoma after treatment.

Imaging for Plasma Cell Dyscrasias: What, When, and How?

Imaging plays a vital role in the diagnosis, response assessment, and follow-up of patients with plasma cell bone disease. The radiologic diagnostic paradigm has thus far evolved with developing technology and availability of better imaging platforms; however, the skewed availability of these imaging modalities in developed vis-à-vis the developing countries along with the lack of uniformity in reporting has led to a consensus on the imaging criteria for diagnosing and response assessment in plasma cell dyscrasia. Therefore, it is imperative for not only the radiologists but also the treating oncologist to be aware of the criteria and appropriate imaging modality to be used in accordance with the clinical question. The review will allow the treating oncologist to answer the following questions on the diagnostic, prognostic, and predictive abilities of various imaging modalities for plasma cell dyscrasia: a) What lesions can look like multiple myeloma (MM) but are not?; b) Does the patient have MM? To diagnose MM in a high-risk SMM patient with clinical suspicion, which modality should be used and why?; c) Is the patient responding to therapy on follow-up imaging once treatment is initiated?; d) To interpret commonly seen complications post-therapy, when is it a disease and when is the expected sequel to treatment? Fractures, red marrow reconversion?; and e) When is the appropriate time to flag a patient for further workup when interpreting MRI spine done for back pain in the elderly? How do we differentiate between commonly seen osteoporosis-related degenerative spine versus marrow infiltrative disorder?

[Spinal neoplasms]

Spinal neoplasms are generally rare disorders but play an important role in the differential diagnosis of space-occupying masses of the spinal axis. Although there are several different classification criteria (histological origin, dignity, positional relationship to the spine), the standard classification of spinal neoplasms based on the relationship to the dura mater into extraspinal, intraspinal extramedullary and intraspinal intramedullary is used. Magnetic resonance imaging is the gold standard for the morphological imaging of spinal neoplasms, followed by computed tomography. In addition to localization and symptoms, the patient's age is essential with respect to the diagnosis of the possible tumor entity.

Utility of spinal angiography and arterial embolization in patients undergoing CT guided alcohol injection of aggressive vertebral hemangiomas

PURPOSE

The purpose of this study is to evaluate the role of spinal angiography and arterial embolization in avoiding spinal cord ischemia in patients undergoing CT-guided alcohol injection of aggressive vertebral hemangiomas.

METHODS

In this retrospective study, patients with vertebral hemangioma who underwent CT-guided direct alcohol injection between January 2007 and October 2018 were identified. Of 28 such patients, 26 had neurological deficits, and 2 had only back pain or radiculopathy. Direct alcohol injection without prior arterial embolization was done in 17 patients. Direct alcohol injection with prior arterial embolization was done in 11 patients. Clinical outcome was assessed immediately after the intervention and at follow-up.

RESULTS

Three patients, who underwent alcohol injection without trans-arterial embolization, had worsening of neurological deficits in the post procedure period due to spinal cord ischemia. No complications related to spinal cord ischemia were noted in the embolization group. There was no significant difference in the outcomes between the two groups if the three patients with complications are excluded (p = 0.34).

CONCLUSION

While CT-guided direct alcohol injection is effective in the management of symptomatic and aggressive vertebral hemangiomas, spinal angiography and trans-arterial embolization of the blood supply to the vertebral body hemangioma, prior to the direct transpedicular alcohol embolization of the lesion, improves the safety of the procedure.

Spinal collision lesions

Collision lesions are rare neoplasms often described in the hepatobiliary system, genitourinary system and adrenal glands. Vertebral haemangiomas (VH) are the most common lesions involving the vertebral bodies. VHs are usually asymptomatic and considered as "Do not touch" lesions. Rarely they can be symptomatic. Imaging findings of typical and atypical haemangiomas, variant forms of haemangioma such as aggressive haemangiomas are well known. Collision lesions involving VHs are extremely rare. This article presents a series of cases with collision lesions of the vertebral body involving VHs.

ADVANCES IN KNOWLEDGE

This Case series demonstrates the various collision lesions in spinal haemangioma.

Differentiation Between Osteoporotic And Neoplastic Vertebral Fractures: State Of The Art And Future Perspectives

Vertebral fractures are a common condition, occurring in the context of osteoporosis and malignancy. These entities affect a group of patients in the same age range; clinical features may be indistinct and symptoms non-existing, and thus present challenges to diagnosis. In this article, we review the use and accuracy of different imaging modalities available to characterize vertebral fracture etiology, from well-established classical techniques, to the role of new and advanced imaging techniques, and the prospective use of artificial intelligence. We also address the role of imaging on treatment. In the context of osteoporosis, the importance of opportunistic diagnosis is highlighted. In the near future, the use of automated computer-aided diagnostic algorithms applied to different imaging techniques may be really useful to aid on diagnosis.

Early response assessment after CyberKnife stereotactic radiosurgery for symptomatic vertebral hemangioma by quantitative parameters from dynamic contrast-enhanced MRI

PURPOSE

The present study aimed to explore the value of DCE-MRI to evaluate the early efficacy of CyberKnife stereotactic radiosurgery in patients with symptomatic vertebral hemangioma (SVH).

METHODS

A retrospective analysis of patients with spinal SVH who underwent CyberKnife stereotactic radiosurgery from January 2017 to August 2019 was performed. All patients underwent DCE-MRI before treatment and three months after treatment. The parameters included volume transfer constant (K^trans), transfer rate constant (K_ep), and extravascular extracellular space volume fraction (V_e).

RESULTS

A total of 11 patients (11 lesions) were included. After treatment, six patients (54.5%) had a partial response, five patients (45.4%) had stable disease, and three patients (27.3%) presented with reossification. K^trans and K_ep decreased significantly in the third month after treatment (p = 0.003 and p = 0.026, respectively). ΔK^trans was -46.23% (range, -87.37 to -23.78%), and ΔK_ep was -36.18% (range, -85.62 to 94.40%). The change in V_e was not statistically significant (p = 0.213), and ΔV_e was -28.01% (range, -58.24 to 54.76%).

CONCLUSION

DCE-MRI parameters K^trans and K_ep change significantly after CyberKnife stereotactic radiosurgery for SVH. Thus, DCE-MRI may be of value in determining the early efficacy of CyberKnife stereotactic radiosurgery.

Differentiating atypical hemangiomas and vertebral metastases: a field-of-view (FOV) and FOCUS intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) study

PURPOSE

Some atypical vertebral hemangiomas (VHs) may mimic metastases on routine MRI and can result in misdiagnosis and ultimately to additional imaging, biopsy and unnecessary costs. The purpose of this study is to assess the utility of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) on account of field-of-view optimized and constrained undistorted single shot (FOCUS) in distinguishing atypical VHs and vertebral metastases.

METHODS

A total of 25 patients with vertebral metastases and 25 patients with atypical VHs were confirmed by clinical follow-up or pathology. IVIM-DWI imaging was performed at different b values (0, 30, 50, 100, 150, 200, 400, 600, 800, 1000 mm²/s). IVIM parameters [the true diffusion coefficient (D), pseudodiffusion coefficient (D*), standard apparent diffusion coefficient (ADC), and perfusion fraction (f)] were calculated and compared between two groups by using Student's t test. A receiver operating characteristic analysis was performed.

RESULTS

Quantitative analysis of standard ADC and D parameters showed significantly lower values in vertebral metastases when compared to atypical hemangiomas [ADC value: (0.70 ± 0.12) × 10^-3 mm²/s vs (1.14 ± 0.28) × 10^-3 mm²/s; D value: (0.47 ± 0.07) × 10^-3 mm²/s vs (0.76 ± 0.14) × 10^-3 mm²/s, all P < 0.01]. The sensitivity and specificity of D value were 93.8% and 92.3%, respectively.

CONCLUSION

The standard ADC value and D value may be used as an indicator to distinguish vertebral metastases from atypical VHs. FOCUS IVIM-derived parameters provide potential value in the quantitatively differentiating vertebral metastases from vertebral atypical hemangiomas.

T1-weighted Dynamic Contrast-enhanced MRI to Differentiate Nonneoplastic and Malignant Vertebral Body Lesions in the Spine

Background Dynamic contrast agent-enhanced (DCE) perfusion MRI may help differentiate between nonneoplastic and malignant lesions in the spine. Purpose To investigate the correlation between fractional plasma volume (V_p), a parameter derived from DCE perfusion MRI, and histopathologic diagnosis for spinal lesions. Materials and Methods In this retrospective study, patients who underwent DCE perfusion MRI and lesion biopsy between May 2015 and May 2018 were included. Inclusion criteria were short time interval (<30 days) between DCE perfusion MRI and biopsy, DCE perfusion MRI performed before biopsy, and DCE perfusion MRI performed at the same spine level as biopsy. Exclusion criteria were prior radiation treatment on vertebrae of interest, poor DCE perfusion MRI quality, nondiagnostic biopsy, and extensive spinal metastasis or prior kyphoplasty. One hundred thirty-four lesions were separated into a nonneoplastic group (n = 51) and a malignant group (n = 83) on the basis of histopathologic analysis. Two investigators manually defined regions of interest in the vertebrae. DCE perfusion MRI parameter V_p was calculated by using the Tofts pharmacokinetic two-compartment model. V_p was quantified, normalized to adjacent normal vertebrae, and compared between the two groups. A Mann-Whitney U test and receiver operating characteristic analysis was performed to verify the difference in V_p between the nonneoplastic and malignant groups. Reproducibility was assessed by calculating the Cohen κ coefficient. Results One hundred patients (mean age, 65 years ± 11 [standard deviation]; 52 men) were evaluated. V_p was lower in nonneoplastic lesions versus malignant lesions (1.6 ± 1.3 vs 4.2 ± 3.0, respectively; P < .001). The sensitivity of V_p was 93% (77 of 83; 95% confidence interval [CI]: 85%, 97%), specificity was 78% (40 of 51; 95% CI: 65%, 89%), and area under the receiver operating characteristic curve was 0.88 (95% CI: 0.82, 0.95). Cohen κ coefficient suggested substantial agreement in both intra- (κ = 0.72) and interreader (κ = 0.70) reproducibility. Conclusion This study indicated that dynamic contrast agent-enhanced perfusion MRI parameter, fractional plasma volume, was able to differentiate between nonneoplastic spinal lesions and malignant lesions. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Haller in this issue.

Differentiation of bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone with multiparametric MRI

PURPOSE

To investigate the diagnostic utilities of imaging parameters derived from T1-weighted imaging (T1WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to differentiate bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone.

MATERIALS AND METHODS

Thirty-six lesions from 36 patients with prostate cancer were analyzed with T1WI, DWI, and DCE-MRI. The lesions were classified in the bone metastases (n = 22) and benign red marrow depositions (n = 14). Lesion-muscle ratio (LMR), apparent diffusion coefficient (ADC), volume transfer constant (K^trans), reflux rate (Kep), and volume fraction of the extravascular extracellular matrix (Ve) values were obtained from the lesions. The imaging parameters of the both groups were compared using the Mann-Whitney U test, receiver operating characteristics (ROC) curves were analyzed. For the ROC curves, area under the curves (AUCs) were compared.

RESULTS

The ADC, K^trans, K_ep, and V_e values of bone metastases were significantly higher than those of benign red marrow depositions (Mann-Whitney U test, p < 0.05). However, there was no significant difference in LMR between the two groups (Mann-Whitney U test, p = 0.360). The AUCs of K^trans_, K_ep, ADC, V_e, and LMR were 0.896, 0.844, 0.812, 0.724, and 0.448, respectively. In the pairwise comparison of ROC curves, the AUCs of K^trans and K_ep was significantly higher than LMR.

CONCLUSIONS

K^trans, K_ep, V_e, and ADC values can be used as imaging tools to differentiate bone metastases from prostate cancer and benign red marrow depositions of the pelvic bone.

Accuracy of diffusion-weighted imaging in discriminating atypical vertebral haemangiomas from malignant masses in patients with vertebral lesions: a cross-sectional study

Purpose

Vertebral haemangiomas are incidental findings in imaging modalities. Atypical haemangiomas are haeman-giomas rich in vascular tissue, and they are found to be hypointense in T1 sequences and hyperintense in T2 sequences, mimicking the findings of metastatic lesions. In the present study we aim to evaluate the ability of diffusion- weighted imaging to differentiate these two groups of vertebral lesions.

Material and methods

In the present cross-sectional study, a total of 23 lesions were included, including 10 haemangiomas and 13 malignant lesions. Diffusion-weighted imaging was used to compare atypical haemangiomas and metastatic lesions. The apparent diffusion co-efficient was determined for each lesion, and then the mean of each group was calculated. The means were then compared. Receiver operating characteristic analysis was used to determine a cut-off ADC value to differentiate these lesions.

Results

The difference between the mean age of the two groups was not significant. The mean ADC value for atypical haemangiomas was 1884 ± 74 × 10^-6 mm²/s and 1008 ± 81 × 10^-6 mm²/s for the malignant lesions. The difference between the two groups was statistically significant (p < 10^-3). ROC curve analysis determined an ADC value of 958 × 10^-6 mm²/s to be able to differentiate between atypical haemangiomas and malignant lesions.

Conclusions

Diffusion-weighted MRI could be used to differentiate between atypical haemangiomas and malignant metastatic lesions.

Vertebral hemangiomas: Diagnosis and management. A single center experience

OBJECTIVE

Vertebral hemangiomas (VH) are common benign lesions involving the spine. Owing to the multiplicity of treatments, the management of VH has not always been consistent. In this retrospective review of a single center experience, indications and options available for the treatment of VH are outlined.

PATIENTS AND METHODS

This is a retrospective review of 71 cases of VH managed at our institution between 2005 and 2019. Sixty of these cases were managed non-operatively, with 11 cases undergoing operative intervention. Of the 11 cases that underwent surgery, there were 2 cervical cases and 9 in the thoracic spine. Ten cases were symptomatic, and 1 incidental. Three patients presented with localized pain, and the remaining 7 had neurological deficit. Decompression with maximal resection of the hemangioma was undertaken in 10 cases, and vertebroplasty in 1.

RESULTS

Of the 60 patients who were managed non-operatively, 13 patients had presented with back/neck pain, with the remaining 47 patients being asymptomatic and diagnosed incidentally. Among the 13 symptomatic patients, all were offered surgical intervention for pain management, but given lack of severity of symptoms, all had opted for conservative approaches of pain control. In the 11 patients who underwent surgery, the preoperative diagnosis of VH was accurate in all but 1 case. There were 2 cervical cases treated with corpectomy. One patient was treated with vertebroplasty, and the remaining 8 with decompression. Radiation was used in 2 cases. Of the 10 patients undergoing decompression, 7 patients had improvement of the neurologic deficit, with resolution of pain in the remaining 3. None of our cases demonstrated deterioration.

CONCLUSION

VH are often discovered incidentally during evaluation of spinal pain. Except in rare cases, the diagnosis of VH is made correctly from the radiographic and MRI studies. Observation for the asymptomatic lesion is appropriate. For VH presenting with deficit or intractable pain, decompressive surgery is recommended. Radiation is appropriate in cases of recurrent VH.

Rapidly Progressive Myelopathy Caused by Aggressive Vertebral Hemangioma

Introduction

Vertebral hemangiomas are the most common benign tumors of the spine, having an incidence of 10-12% in the general population. They are asymptomatic, incidental findings in the vast majority of patients; however, in rare cases, they can expand to cause neural compression. Aggressive lesions of this sort are most commonly found in the thoracic spine, and expansion leads to the subacute development of myelopathy.

Case Report

The authors report a rare case of aggressive vertebral hemangioma at the T1 vertebral body which caused rapidly progressive myelopathy over the course of 7 days. Clinical and radiological findings are shown as well as surgical management of the lesion. The patient regained the ability to ambulate, and there was no evidence of disease recurrence at 2-year follow-up.

Conclusions

Although aggressive vertebral hemangiomas are a rare cause of myelopathy, they must be kept in mind in the differential diagnosis of cord compressive lesions. In this case, contrary to most, the expansion of the hemangioma led to rapid development of neurological decline necessitating urgent surgical intervention.

The Dixon technique for MRI of the bone marrow

Dixon sequences are established as a reliable MRI technique that can be used for problem-solving in the assessment of bone marrow lesions. Unlike other fat suppression methods, Dixon techniques rely on the difference in resonance frequency between fat and water and in a single acquisition, fat only, water only, in-phase and out-of-phase images are acquired. This gives Dixon techniques the unique ability to quantify the amount of fat within a bone lesion, allowing discrimination between marrow-infiltrating and non-marrow-infiltrating lesions such as focal nodular marrow hyperplasia. Dixon can be used with gradient echo and spin echo techniques, both two-dimensional and three-dimensional imaging. Another advantage is its rapid acquisition time, especially when using traditional two-point Dixon gradient echo sequences. Overall, Dixon is a robust fat suppression method that can also be used with intravenous contrast agents. After reviewing the available literature, we would like to advocate the implementation of additional Dixon sequences as a problem-solving tool during the assessment of bone marrow pathology.

Giant vertebral hemangioma masquerading as aggressive tumor: Tc-99m tagged RBC scan can help to solve the diagnostic conundrum!

Hemangiomas are the most common benign lesions involving the spine. Metastasis is the most common malignant condition. The diagnosis of typical hemangiomas on conventional CT and MRI imaging is straightforward. However, when the hemangiomas are very large they may have atypical features making their diagnosis on these conventional imaging modalities inconclusive. In such cases nuclear medicine techniques such as Tc-99m RBC may aid in resolving the diagnostic conundrum. Awareness and use of proper diagnostic modality can prevent unnecessary biopsy. In this case report we try to highlight the added value of Tc-99m RBC scan to conventional imaging techniques in differentiating giant vertebral hemangioma from more aggressive malignant tumors.

Incidentalomas in Spine and Spinal Cord Imaging

Incidentalomas are common in magnetic resonance imaging (MRI) of the spine. These incidental findings (IFs) can be seen involving the spinal cord, nerve root, vertebral body, posterior arch and the extraspinal region. This review article describes the imaging findings, stratifies the IFs similar to the computed tomography (CT) colonography reporting and data system and briefly mentions the current recommendations for further evaluation and management of IFs. Radiologists are the first to detect these lesions, suggest further evaluation and management of IFs. It is therefore mandatory for them to be aware of recommendations in clinical practice in order to avoid increased patient anxiety, excessive healthcare expenditure and inadvertent therapeutic procedures.