Christopher Dowd, MD's Publications

Effective Use of ALK Inhibitors in EML4::ALK-Positive Lymphatic Malformations.

Clarifying the clinical landscape of pediatric spinal arteriovenous shunts: an institutional experience and individual patient-data meta-analysis.

Evolving indications for pediatric neurointerventional radiology: A single institutional 25-year experience in infants less than one year of age and a brief historical review.

Incidence of fibrosing colonopathy with pancreatic enzyme replacement therapy in patients with cystic fibrosis.

Dual-agent percutaneous sclerotherapy technique for macrocystic lymphatic malformations.

Endovascular Therapy for Intracranial Giant Cell Arteritis : Systematic Review, Technical Considerations and the Effect of Intra-arterial Calcium Channel Blockers.

Intraoperative Angiogram Using C-Arm Fluoroscopy and Direct Common Carotid Artery Puncture During Surgical Treatment of Paraclinoid Aneurysms.

Percutaneous sclerotherapy for head and neck lymphatic malformations in neonates and infants ≤12 months of age.

Pharyngo-tympano-stapedial middle meningeal artery variant supply to a falcotentorial dural arteriovenous fistula.

Super-selective cavernous sinus and inferior petrosal sinus sampling for Cushing syndrome: Technique and interpretation.

Transradial Approach for Thoracolumbar Spinal Angiography and Tumor Embolization: Feasibility and Technical Considerations.

Cerebral angiography: Techniques and practice.

Combined Use of X-ray Angiography and Intraprocedural MRI Enables Tissue-based Decision Making Regarding Revascularization during Acute Ischemic Stroke Intervention.

Delayed-Onset Cranial Nerve Palsy After Transvenous Embolization of Indirect Carotid Cavernous Fistulas.

Dural Arteriovenous Fistulas of the Foramen Magnum Region: Clinical Features and Angioarchitectural Phenotypes.

Endovascular Biopsy of Vertebrobasilar Aneurysm in Patient With Polyarteritis Nodosa.

Endovascular treatment strategy, technique, and outcomes for dural arteriovenous fistulas of the marginal sinus region.

Intracranial hemorrhage due to central venous occlusion from hemodialysis access: A case report.

Neurological manifestations of polyarteritis nodosa: a tour of the neuroaxis by case series.

Patient and family experience of telehealth care delivery as part of the CF chronic care model early in the COVID-19 pandemic.

Radial artery access anatomy: considerations for neuroendovascular procedures.

Radial artery access for neuroendovascular procedures: safety review and complications.

Remote monitoring in telehealth care delivery across the U.S. cystic fibrosis care network.

Reply.

Robotics for neuroendovascular intervention: Background and primer.

Safety and efficacy results of the Flow Redirection Endoluminal Device (FRED) stent system in the treatment of intracranial aneurysms: US pivotal trial.

Segmental overgrowth and aneurysms due to mosaic PDGFRB p.(Tyr562Cys).

Vascular anomalies: Classification and management.

Brain Arteriovenous Malformation Recurrence After Apparent Microsurgical Cure: Increased Risk in Children Who Present With Arteriovenous Malformation Rupture.

Concurrent presentation of brain arteriovenous malformation, peripheral arteriovenous malformation, and cerebellar astrocytoma: Case report.

Determining the Suitability of Registries for Embedding Clinical Trials in the United States: A Project of the Clinical Trials Transformation Initiative.

Five-year results of randomized bioactive versus bare metal coils in the treatment of intracranial aneurysms: the Matrix and Platinum Science (MAPS) Trial.

Impact of Aortic Arch Anatomy on Technical Performance and Clinical Outcomes in Patients with Acute Ischemic Stroke.

Interrater Reliability in the Measurement of Flow Characteristics on Color-Coded Quantitative DSA of Brain AVMs.

Intrasaccular flow disruption (WEB) of a large wide-necked basilar apex aneurysm using PulseRider-assistance.

Recent Administration of Iodinated Contrast Renders Core Infarct Estimation Inaccurate Using RAPID Software.

Long-Term Outcomes of Endovascular Treatment of Indirect Carotid Cavernous Fistulae: Superior Efficacy, Safety, and Durability of Transvenous Coiling Over Other Techniques.

Relationship of clinical presentation and angiographic findings in patients with indirect cavernous carotid fistulae.

The effect of preoperative embolization and flow dynamics on resection of brain arteriovenous malformations.

Biopharmaceutical Industry Approaches to Facility Segregation for Viral Safety: An Effort from the Consortium on Adventitious Agent Contamination in Biomanufacturing.

Estimation of intra-arterial chemotherapy distribution to the retina in pediatric retinoblastoma patients using quantitative digital subtraction angiography.

Flanking the fenestration: circumferential limb-to-limb stent-assisted coiling of a basilar artery fenestration aneurysm.

Improved procedural safety following protocol changes for selective ophthalmic arterial infusion of chemotherapy for treatment of ocular retinoblastoma.

Normalization of Congenital Venous Stasis Retinopathy Following Sclerotherapy of a Macrocystic Lymphatic Malformation.

Revisiting classic MRI findings of venous malformations: Changes in protocols may lead to potential misdiagnosis.

Endovascular Biopsy: In Vivo Cerebral Aneurysm Endothelial Cell Sampling and Gene Expression Analysis.

Flanking the fenestration: circumferential limb-to-limb stent-assisted coiling of a basilar artery fenestration aneurysm.

Improving mechanical thrombectomy time metrics in the angiography suite: Stroke cart, parallel workflows, and conscious sedation.

Pial Artery Supply as an Anatomic Risk Factor for Ischemic Stroke in the Treatment of Intracranial Dural Arteriovenous Fistulas.

Technical factors affecting outcomes following endovascular treatment of posterior circulation atherosclerotic lesions.

Effects on vessel measurement accuracy and subsequent occlusion after calcium channel blocker infusion during treatment of cerebral aneurysms with the Pipeline embolization device.

Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

Pediatric intracranial dural arteriovenous fistulas: age-related differences in clinical features, angioarchitecture, and treatment outcomes.

The Cystic Fibrosis Foundation Patient Registry. Design and Methods of a National Observational Disease Registry.

Association between Venous Angioarchitectural Features of Sporadic Brain Arteriovenous Malformations and Intracranial Hemorrhage.

Atypical MRI features in soft-tissue arteriovenous malformation: a novel imaging appearance with radiologic-pathologic correlation.

Endovascular biopsy: Strategy for analyzing gene expression profiles of individual endothelial cells obtained from human vessels✩.

Endovascular biopsy: Technical feasibility of novel endothelial cell harvesting devices assessed in a rabbit aneurysm model.

Extent of collateralization predicting symptomatic cerebral vasospasm among pediatric patients: correlations among angiography, transcranial Doppler ultrasonography, and clinical findings.

Lesion location, stability, and pretreatment management: factors affecting outcomes of endovascular treatment for vertebrobasilar atherosclerosis.

MRI phenotypes of localized intravascular coagulopathy in venous malformations.

Onyx embolization of an intraosseous pseudoaneurysm of the middle meningeal artery in a patient with meningiomatosis, McCune-Albright syndrome, and gray platelet syndrome.

Progressive versus Nonprogressive Intracranial Dural Arteriovenous Fistulas: Characteristics and Outcomes.

Spontaneous retroclival hematoma: a case series.

Superselective Intra-Arterial Ethanol Sclerotherapy of Feeding Artery and Nidal Aneurysms in Ruptured Cerebral Arteriovenous Malformations.

Volume-staged radiosurgery for large arteriovenous malformations: an evolving paradigm.

Aspirin therapy in venous malformation: a retrospective cohort study of benefits, side effects, and patient experiences.

Bioactive versus bare platinum coils in the treatment of intracranial aneurysms: the MAPS (Matrix and Platinum Science) trial.

Cavernous and inferior petrosal sinus sampling and dynamic magnetic resonance imaging in the preoperative evaluation of Cushing's disease.

Cerebral arterial fenestrations.

Contrast staining on CT after DSA in ischemic stroke patients progresses to infarction and rarely hemorrhages.

Endothelial cell high-enrichment from endovascular biopsy sample by laser capture microdissection and fluorescence activated cell sorting.

Influence of patient age on angioarchitecture of brain arteriovenous malformations.

Lesion stability characteristics outperform degree of stenosis in predicting outcomes following stenting for symptomatic intracranial atherosclerosis.

Radiation dose reduction in intra-arterial chemotherapy infusion for intraocular retinoblastoma.

Radiological and clinical features of vein of Galen malformations.

Symptom differences and pretreatment asymptomatic interval affect outcomes of stenting for intracranial atherosclerotic disease.

Cerebral arteriopathy associated with Arg179His ACTA2 mutation.

Current trends in endovascular management of traumatic cerebrovascular injury.

Early versus later presentations of venous malformations: where and why?

Endovascular biopsy: evaluating the feasibility of harvesting endothelial cells using detachable coils.

Safety of retained microcatheters: an evaluation of radiofrequency heating in endovascular microcatheters with nitinol, tungsten, and polyetheretherketone braiding at 1.5 T and 3 T.

Stent-assisted coiling versus coiling alone in unruptured intracranial aneurysms in the matrix and platinum science trial: safety, efficacy, and mid-term outcomes.

Density of thrombus on admission CT predicts revascularization efficacy in large vessel occlusion acute ischemic stroke.

Mechanical embolectomy for treatment of large vessel acute ischemic stroke in children.

Pediatric intracranial nongalenic pial arteriovenous fistulas: clinical features, angioarchitecture, and outcomes.

Serial angiographic appearance of segmental arterial mediolysis manifesting as vertebral, internal mammary and intra-abdominal visceral artery aneurysms in a patient presenting with subarachnoid hemorrhage and review of the literature.

Spinal dural arteriovenous fistulas and intrathecal venous drainage: correlation between digital subtraction angiography, magnetic resonance imaging, and clinical findings.

Brain arteriovenous malformation multiplicity predicts the diagnosis of hereditary hemorrhagic telangiectasia: quantitative assessment.

Embolization of skull base meningiomas and feeding vessels arising from the internal carotid circulation.

Intraosseous CSF fistula in a patient with Gorham disease resulting in intracranial hypotension.

Pediatric intracranial aneurysms: new and enlarging aneurysms after index aneurysm treatment or observation.

Supernova hemorrhage: obliterative hemorrhage of brain arteriovenous malformations following γ knife radiosurgery.

Transvenous embolization of a pediatric pial arteriovenous fistula.

Zygomatico-orbital intra-arterial melphalan infusion for intraocular retinoblastoma.

Cervical and intracranial arterial anomalies in 70 patients with PHACE syndrome.

Endovascular treatment of medically refractory cerebral vasospasm following aneurysmal subarachnoid hemorrhage.

Increasing parvovirus filter throughput of monoclonal antibodies using ion exchange membrane adsorptive pre-filtration.

Long-term outcome in the repair of spinal cord perimedullary arteriovenous fistulas.

Masseteric venous malformations: diagnosis, treatment, and outcomes.

MR imaging of partially thrombosed cerebral aneurysms: characteristics and evolution.

Overloading ion-exchange membranes as a purification step for monoclonal antibodies.

Intracranial aneurysms in childhood: 27-year single-institution experience.

Multiple intracranial aneurysms and moyamoya disease associated with microcephalic osteodysplastic primordial dwarfism type II: surgical considerations.

Neonatal giant pial arteriovenous malformation: genesis or rapid enlargement in the third trimester.

Treatment of arteriovenous malformation of the mandible with resection and immediate reconstruction.

Combined microsurgical and endovascular management of complex intracranial aneurysms.

Comprehensive management of symptomatic and aggressive vertebral hemangiomas.

Evidence of inflammatory cell involvement in brain arteriovenous malformations.

Spinal dural arteriovenous fistulae: clinical features and long-term results.

Assessment of vasculature of meningiomas and the effects of embolization with intra-arterial MR perfusion imaging: a feasibility study.

Association between lumbar epidural injection and development of acute paraparesis in patients with spinal dural arteriovenous fistulas.

Estimation of fusiform intracranial aneurysm growth by serial magnetic resonance imaging.

Predictors of rehemorrhage after treatment of ruptured intracranial aneurysms: the Cerebral Aneurysm Rerupture After Treatment (CARAT) study.

The effects of diffuseness and deep perforating artery supply on outcomes after microsurgical resection of brain arteriovenous malformations.

Current treatment strategies and outcomes in the management of symptomatic vertebral hemangiomas.

Intraorbital arteriovenous fistulae of the ophthalmic veins treated by transvenous endovascular occlusion: technical case report.

Carotid stent delivery in an XMR suite: immediate assessment of the physiologic impact of extracranial revascularization.

Initial clinical experience with a new self-expanding nitinol stent for the treatment of intracranial cerebral aneurysms: the Cordis Enterprise stent.

Interobserver variability in grading of brain arteriovenous malformations using the Spetzler-Martin system.

Long-term outcome of endovascular stenting for symptomatic basilar artery stenosis.

Neurosurgery at the crossroads: integrated multidisciplinary management of 449 patients with brain arteriovenous malformations.

Cardiac injury after subarachnoid hemorrhage is independent of the type of aneurysm therapy.

Cavernous and inferior petrosal sinus sampling in the evaluation of ACTH-dependent Cushing's syndrome.

Clinical characteristics and management of vascular anomalies: findings of a multidisciplinary vascular anomalies clinic.

Continuous bleeding from a basilar terminus aneurysm imaged with CT angiography and conventional angiography.

Embolization for the treatment of idiopathic posterior epistaxis.

Intraarterial thrombolysis trials in acute ischemic stroke.

Neurotoxicity of intra-arterial papaverine preserved with chlorobutanol used for the treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage.

The relationship of coexisting extranidal aneurysms to intracranial hemorrhage in patients harboring brain arteriovenous malformations.

Abnormal expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in brain arteriovenous malformations.

Combined microsurgical and endovascular management of complex intracranial aneurysms.

Endovascular strategies for carotid cavernous and intracerebral dural arteriovenous fistulas.

Endovascular treatment for dural arteriovenous fistulae of the superior petrosal sinus.

Facial hemangioma and cerebral corticovascular dysplasia: a syndrome associated with epilepsy.

Guglielmi detachable coil extraction: suction generated by pusher-wire withdrawal after coil detachment within an intracranial aneurysm.

Meningiomas: the role of preoperative angiography and embolization.

Neurodevelopmental outcome after endovascular treatment of vein of Galen malformations.

Parallel venous channel as the recipient pouch in transverse/sigmoid sinus dural fistulae.

Rapidly reversible dementia.

Accuracy of selective venous sampling for intact parathyroid hormone in difficult patients with recurrent or persistent hyperparathyroidism.

Angioplasty for intracranial symptomatic vertebrobasilar ischemia.

Bow hunter stroke caused by cervical disc herniation. Case report.

Characteristics of brain arteriovenous malformations with coexisting aneurysms: a comparison of two referral centers.

Dural carotid cavernous fistula: definitive endovascular management and long-term follow-up.

Percutaneous vertebroplasty: an emerging therapy for vertebral compression fractures.

The learning curve for coil embolization of unruptured intracranial aneurysms.

Vascular myelopathies-vascular malformations of the spinal cord: presentation and endovascular surgical management.

Dural arteriovenous fistula associated with prothrombin gene mutation.

Embolization of non-ruptured aneurysms.

Endovascular treatment of a ruptured dual aperture cavernous aneurysm.

Reporting terminology for brain arteriovenous malformation clinical and radiographic features for use in clinical trials.

The many faces of PHACE syndrome.

Balloon tracheal occlusion for congenital diaphragmatic hernia: experimental studies.

Balloon-assist technique for endovascular coil embolization of geometrically difficult intracranial aneurysms.

Carotid artery cavernous fistulas.

Carotid artery stent placement for atherosclerotic disease: rationale, technique, and current status.

Cerebral hyperperfusion syndrome after percutaneous transluminal stenting of the craniocervical arteries.

Endovascular and surgical treatment of unruptured cerebral aneurysms: comparison of risks.

Endovascular management of extracranial carotid artery dissection achieved using stent angioplasty.

Endovascular stenting for carotid artery stenosis: preliminary experience using the shape-memory- alloy-recoverable-technology (SMART) stent.

Endovascular treatment of a ruptured intracranial dissecting vertebral aneurysm in a kickboxer.

Endovascular treatment of cerebral artery aneurysms during pregnancy: report of three cases.

Endovascular treatment of noncarotid extracranial cerebrovascular disease.

Endovascular treatment of ruptured posterior circulation cerebral aneurysms. Clinical and angiographic outcomes.

Hemorrhagic complications in vein of Galen malformations.

Patient presentation, angiographic features, and treatment of strangulation-induced bilateral dissection of the cervical internal carotid artery. Report of three cases.

Primary stenting for high-grade basilar artery stenosis.

Role of angiography in the evaluation of patients with pulsatile tinnitus.

Stent angioplasty for cervical carotid artery stenosis in high-risk symptomatic NASCET-ineligible patients.

Stent-supported coil embolization: the treatment of fusiform and wide-neck aneurysms and pseudoaneurysms.

Subclavian arteritis and pseudoaneurysm formation secondary to stent infection.

Treatment of dural arteriovenous malformations and fistulas.

Acquired pial arteriovenous fistula following cerebral vein thrombosis.

Application of a rheolytic thrombectomy device in the treatment of dural sinus thrombosis: a new technique.

Beating aneurysm sign: angiographic evidence of ruptured aneurysm tamponade by intracranial hemorrhage. Case illustration.

Clinical use of stents for carotid artery disease.

Embolization of the meningohypophyseal trunk as a cause of diabetes insipidus.

Endovascular recanalization with balloon angioplasty and stenting of an occluded occipital sinus for treatment of intracranial venous hypertension: technical case report.

Endovascular stenting of an acutely thrombosed basilar artery: technical case report and review of the literature.

Five year results of LINAC radiosurgery for arteriovenous malformations: outcome for large AVMS.

Intraventricular contrast medium leakage during ethanol embolization of an arteriovenous malformation.

Rescue treatment of acute parent vessel thrombosis with glycoprotein IIb/IIIa inhibitor during GDC coil embolization.

Simultaneous subarachnoid hemorrhage and carotid cavernous fistula after rupture of a paraclinoid aneurysm during balloon-assisted coil embolization.

Spinal dural arteriovenous fistula with an associated feeding artery aneurysm: case report.

Tandem intracranial stent deployment for treatment of an iatrogenic, flow-limiting, basilar artery dissection: technical case report.

Transverse/sigmoid sinus dural arteriovenous fistulas presenting as pulsatile tinnitus.

Treatment of an intracranial aneurysm using a new three-dimensional-shape Guglielmi detachable coil: technical case report.

Treatment of posterior circulation ischemia with extracranial percutaneous balloon angioplasty and stent placement.

Causes and management of aneurysmal hemorrhage occurring during embolization with Guglielmi detachable coils.

Congenital cardiac anomalies with vein of Galen malformations in infants.

Diagnosis and treatment of dural arteriovenous fistulas.

Embolization of neurosurgical lesions involving the ophthalmic artery.

Endovascular treatment of mural-type vein of Galen malformations.

Endovascular treatment of pseudoaneurysms with electrolytically detachable coils.

Percutaneous stenting for symptomatic stenosis of aberrant right subclavian artery.

Preliminary experience with an electrolytically detachable fibered coil.

The effect of oestrogen on the development of arteriovenous fistulae induced by venous hypertension in rats.

Cavernous internal carotid artery aneurysms treated with electrolytically detachable coils.

Diagnosis of a posterior fossa dural arteriovenous fistula in a neonate by cranial ultrasonography.

Dural arteriovenous fistulas of the marginal sinus.

Intravascular stent and endovascular coil placement for a ruptured fusiform aneurysm of the basilar artery. Case report and review of the literature.

Endovascular surgical approach to intracranial vascular diseases.

Endovascular therapy for the carotid artery.

Endovascular treatment of basilar tip aneurysms using electrolytically detachable coils.

Reduced caliber of the internal carotid artery: a normal finding with ipsilateral absence or hypoplasia of the A1 segment.

The role of angiogenic factor bFGF in the development of dural AVFs.

Transluminal angioplasty for arteriosclerotic disease of the distal vertebral and basilar arteries.

Venous angiography is needed to interpret inferior petrosal sinus and cavernous sinus sampling data for lateralizing adrenocorticotropin-secreting adenomas.

Endovascular management of biopsy-related posterior inferior cerebellar artery pseudoaneurysm.

Interventional neurovascular techniques in the treatment of stroke--state-of-the-art therapy.

Percutaneous transluminal angioplasty of subclavian stenosis from neurofibromatosis.

Spinal dural arteriovenous fistulas supplied by branches of the internal iliac arteries.

Treatment of massive posterior epistaxis by detachable coil embolization of a cavernous internal carotid artery aneurysm.

Development of acquired arteriovenous fistulas in rats due to venous hypertension.

Direct-puncture coil embolization of maxillofacial high-flow vascular malformations.

Endovascular platinum coil embolization of incompletely surgically clipped cerebral aneurysms.

Flow-directed use of electrolytically detachable platinum embolization coils.

Interventional neurovascular techniques for cerebral revascularization in the treatment of stroke.

Intracranial aneurysms. Evolution and future role of endovascular techniques.

Localization procedures in patients with persistent or recurrent hyperparathyroidism.

Posterior fossa venous angiomas with drainage through the brain stem.

The efficacy of endosaccular aneurysm occlusion in alleviating neurological deficits produced by mass effect.

Thrombolytic therapy in acute stroke.

Treatment of a high-flow arteriovenous malformation by direct puncture and coil embolization.

Treatment of dural sinus thrombosis by urokinase infusion.

Cerebral percutaneous transluminal angioplasty.

Endovascular treatment of vertebral artery dissections and pseudoaneurysms.

Grading venous restrictive disease in patients with dural arteriovenous fistulas of the transverse/sigmoid sinus.

Hemangiomas and vascular malformations of the head and neck: MR characterization.

Microcatheter retrieval device for intravascular foreign body removal.

Transarterial embolization of vertebral hemangioma.

Transluminal angioplasty for atherosclerotic disease of the vertebral and basilar arteries.

Treatment of giant intradural (perimedullary) arteriovenous fistulas.

Intractable complex partial seizure: correlation of magnetic resonance imaging with pathology and electroencephalography.

Intravascular balloon dilatation therapy for intracranial arterial vasospasm: patient selection, technique, and clinical results.

A variant of arteriovenous fistulas within the wall of dural sinuses. Results of combined surgical and endovascular therapy.

Direct endovascular thrombolytic therapy for dural sinus thrombosis.

Interventional neurovascular treatment of a giant intracranial aneurysm using platinum microcoils.

Interventional radiologic adjuncts in cerebrovascular surgery.

Intracranial aneurysms: interventional neurovascular treatment with detachable balloons--results in 215 cases.

Magnetic resonance imaging of intractable complex partial seizures: pathologic and electroencephalographic correlation.

Management of vascular perforations that occur during neurointerventional procedures.

Multiple dural arteriovenous fistulas of the cranium and spine.

Particulate embolization of the anterior choroidal artery in the treatment of cerebral arteriovenous malformations.

Transarterial platinum coil embolization of carotid-cavernous fistulas.

Aneurysms of the petrous portion of the internal carotid artery: results of treatment with endovascular or surgical occlusion.

Cryptic vascular malformations of the spinal cord: diagnosis by magnetic resonance imaging and outcome of surgery.

Dural arteriovenous fistulas involving the inferior petrosal sinus: angiographic findings in six patients.

Dural arteriovenous fistulas supplied by ethmoidal arteries.

Endovascular coil embolization of unusual posterior inferior cerebellar artery aneurysms.

Endovascular detachable balloon embolization therapy of cavernous carotid artery aneurysms: results in 87 cases.

Transfemoral venous embolization of vein of Galen malformations.

Treatment of carotid-cavernous fistulas associated with Ehlers-Danlos syndrome.

Treatment of intracranial aneurysms with preservation of the parent vessel: results of percutaneous balloon embolization in 84 patients.

Endovascular treatment of scalp arteriovenous fistulas associated with a large varix.

Transarterial occlusion of solitary intracerebral arteriovenous fistulas.

Transluminal angioplasty for treatment of intracranial arterial vasospasm.

Transluminal angioplasty of intracerebral vessels for cerebral arterial spasm: reversal of neurological deficits after delayed treatment.

Venography and venous pressure monitoring in dural sinus meningiomas.

A new porcine bioprosthesis: design rationale and early clinical experience.

MR imaging of brain contusions: a comparative study with CT.

Thrombosed dialysis grafts: efficacy of intrathrombic deposition of concentrated urokinase, clot maceration, and angioplasty.

Vertebral-body collapse in focal and diffuse disease: patterns of pathologic processes.