ACR Appropriateness Criteria® Low Back Pain: 2021 Update.

In the United States, acute low back pain, with or without radiculopathy, is the leading cause of years lived with disability and the third ranking cause of disability-adjusted life-years. Uncomplicated acute low back pain and/or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies. Imaging is considered in those patients who have had up to 6 weeks of medical management and physical therapy that resulted in little or no improvement in their back pain. It is also considered for those patients presenting with red flags, raising suspicion for a serious underlying condition, such as cauda equina syndrome, malignancy, fracture, or infection. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Plexopathy: 2021 Update.

Plexopathy may be caused by diverse pathologies, including trauma, nerve entrapment, neoplasm, inflammation, infection, autoimmune disease, hereditary disease, and idiopathic etiologies. For patients presenting with brachial or lumbosacral plexopathy, dedicated plexus MRI is the most appropriate initial imaging modality for all clinical scenarios and can identify processes both intrinsic and extrinsic to the nerves. Other imaging tests may be appropriate for initial imaging depending on the clinical scenario. This document addresses initial imaging strategies for brachial and lumbosacral plexopathy in the following clinical situations: nontraumatic plexopathy with no known malignancy, traumatic plexopathy (not perinatal), and plexopathy occurring in the context of a known malignancy or posttreatment syndrome. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Suspected Spine Infection.

Spine infection is both a clinical and diagnostic imaging challenge due to its relatively indolent and nonspecific clinical presentation. The diagnosis of spine infection is based upon a combination of clinical suspicion, imaging evaluation and, when possible, microbiologic confirmation performed from blood cultures or image-guided percutaneous or open spine biopsy. With respect to the imaging evaluation of suspected spine infection, MRI without and with contrast of the affected spine segment is the initial diagnostic test of choice. As noncontrast MRI of the spine is often used in the evaluation of back or neck pain not responding to conservative medical management, it may show findings that are suggestive of infection, hence this procedure may also be considered in the evaluation of suspected spine infection. Nuclear medicine studies, including skeletal scintigraphy, gallium scan, and FDG-PET/CT, may be helpful in equivocal or select cases. Similarly, radiography and CT may be appropriate for assessing overall spinal stability, spine alignment, osseous integrity and, when present, the status of spine instrumentation or spine implants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Preparing for the Unexpected: A Review of Incidental Extraspinal Findings on Computed Tomography/Magnetic Resonance Imaging of the Spine.

Potentially clinically important incidental/unexpected extraspinal findings occur with sufficient frequency in cross-sectional imaging of the spine to warrant the radiologist's careful consideration, regardless of whether the interpreter is a neuroradiologist, a musculoskeletal radiologist, an emergency radiologist, or a generalist. Awareness of the commonly encountered incidentalomas and the anatomy contained within the field of view of cervical, thoracic, and lumbar spine cross-sectional imaging examinations, respectively, assists radiologists in their efficient and accurate analysis. This article familiarizes radiologists with some of the potential relevant extraspinal findings that may be encountered, and recommends an extraspinal search pattern for each spinal segment.

ACR Appropriateness Criteria® Myelopathy: 2021 Update.

Myelopathy is a clinical diagnosis with localization of the neurological findings to the spinal cord, rather than the brain or the peripheral nervous system, and then to a particular segment of the spinal cord. Myelopathy can be the result of primary intrinsic disorders of the spinal cord or from secondary conditions, which result in extrinsic compression of the spinal cord. While the causes of myelopathy may be multiple, the acuity of presentation and symptom onset frame a practical approach to the differential diagnosis. Imaging plays a crucial role in the evaluation of myelopathy with MRI the preferred modality. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Postsurgical Spine: Techniques, Expected Imaging Findings, and Complications.

Postsurgical spine imaging actually commences with the preoperative and perioperative imaging examinations that are performed before and during the patient's surgical procedure, respectively. It is in this context that postsurgical spine imaging examinations are best evaluated with a better appreciation of the changes, sometimes dramatic, that can occur following spine surgery. Careful follow-up is the rule in spine surgery, and these patients will have multiple imaging examinations over time. Some studies are performed immediately due to possible complications or exacerbation of pain symptoms, whereas others are used to assess the status of a fusion procedure. In any case it is prudent to always be aware of the overlap between the "normal" or expected imaging findings in the postoperative spine and potential pathologic processes that are developing at the postsurgical site. Additionally, a basic understanding of common spine surgical techniques and approaches is paramount toward rendering a thoughtful analysis. In this chapter, the authors discuss these imaging findings in the setting of the most commonly performed spine surgeries and emphasize the importance of active communication between the radiologist and spine surgeon.

Myelography: From Lipid-Based to Gadolinium-Based Contrast Agents.

Myelographic contrast media of various types have been used over the past 100 years. Many of the early contrast agents had significant toxicities. Gas myelography was tried, but the contrast between gas and soft tissue is poor. Pantopaque, an oil-based iodinated medium was successfully used for decades, but was not compatible with computed tomography (CT) scanning because it was viscous, insoluble, and caused streak artifact. The development of water-soluble agents allowed even distribution in the subarachnoid space and excellent depiction of spinal anatomy on post-myelographic CT scanning. Although invasive, myelography will remain a useful tool for the foreseeable future.

Use and evaluation of a semi-permeable mesh implant in vertebral augmentation for the treatment of painful osteoporotic vertebral compression fractures.

OBJECTIVE: To assess the efficacy of a semi-permeable mesh implant in the treatment of painful thoracic and lumbar osteoporotic vertebral compression fractures. METHODS: Patients with painful thoracic and lumbar osteoporotic vertebral compression fractures which were refractory to conventional medical management and less than 3 months of age were considered possible candidates for this vertebral augmentation technique. Data recorded for the procedure included patient age, gender, fracture level and morphology, mesh implant size, amount of cement injected, cement extravasation, complications, and pre- and post-procedure numeric pain scores and Oswestry Disability Index (ODI) scores. RESULTS: 17 patients were included in this retrospective study; 12 women and 5 men, with an average age of 78.6 years. Each patient had one level treated with the mesh implant; 4 thoracic levels and 13 lumbar levels. The 10×15 mm implant was used in 13 treated vertebrae, including the two thoracic vertebrae; the 10×20 mm implant was used to treat 3 lumbar vertebrae, and one 10×25 mm implant was used to treat an L1 vertebra. An average of 2.4 mL of acrylic bone cement was injected, and there was fluoroscopic evidence of a small amount of cement leakage in one case. No patient related complications were seen and there were no device failures. All patients, followed-up to at least 3 weeks, showed significant pain relief. The average pretreatment numeric pain score of 9 and ODI of 50 decreased to an average post-treatment score of 0.6 and 12, respectively (p<0.001). CONCLUSIONS: Vertebral augmentation with a semi-permeable mesh stent implant can be used to effectively and safely treat osteoporotic vertebral compression fractures within the lower thoracic and lumbar spine.

Postoperative spine imaging in cancer patients.

Primary or metastatic spine tumors can present with pain and/or neurologic compromise depending on their location within the spinal axis. Metastases and multiple myeloma comprise most of these lesions. Management of spinal tumors includes surgical decompression with stabilization (neo), adjuvant chemotherapy and radiation therapy, curettage, bone grafting, bone marrow replacement, and palliative treatment with vertebral augmentation. Pre- and postoperative imaging plays a critical role in the diagnosis and management of patients with spinal tumors. This article reviews postoperative imaging of the spine, including imaging protocols, immediate and long-term routine imaging findings, and emergent findings in symptomatic patients.

Radiologic evaluation and management of postoperative spine paraspinal fluid collections.

Postoperative paraspinal fluid collections can present a management dilemma to both radiologists and surgeons. Although many of these collections present as incidental findings and are unrelated to the presenting signs and symptoms that led to the imaging study, certain collections in the context of the appropriate clinical scenario may require additional evaluation and even emergent intervention. This article reviews those collections that are most frequently encountered and suggests management strategies that may assist in the evaluation and management of the patient.

Improved outcomes with direct percutaneous CT guided lumbar synovial cyst treatment: advanced approaches and techniques.

PURPOSE: To determine if lumbar synovial cyst rupture in symptomatic patients results in improved clinical outcome when using direct tandem and/or coaxial percutaneous CT guided techniques. MATERIALS AND METHODS: 20 patients with unilateral lower extremity radiculopathy and/or low back pain underwent CT guided percutaneous treatment for their symptomatic lumbar synovial cysts. Cysts were identified with the use of a low osmolar non-ionic contrast agent via facet joint injection or through direct injection. Cyst rupture, using a direct tandem and/or coaxial technique, was attempted in all patients using an 18 gauge guide needle and a 22 gauge insert needle. Following attempted cyst aspiration, cyst rupture was performed using 1-3 mL of a mixture of methylprednisolone (2 mL, 80 mg) and bupivacaine (3 mL, 0.5%). All patients were followed-up in clinic for a minimum of 6 months after their procedures and up to a maximum of 24 months. RESULTS: 11 patients were male and nine were female, with an average age of 65.6 years. 17 patients presented with severe unilateral lower extremity radiculopathy and three patients were experiencing low back pain. One of the patients had two synovial cysts, and therefore a total of 21 lumbar synovial cysts were treated in this group of patients. Direct cyst puncture was achieved using a tandem technique in nine patients, a coaxial interlaminar approach in seven patients, a coaxial transforaminal approach in two patients, and a coaxial trans-facet approach in three patients. Cyst rupture was documented in all cases, as evidenced by CT confirmation of cyst decompression and contrast agent extravasation into the epidural space. The mean surveillance period in these patients was 18 months. Six patients experienced their usual radicular pain within 2 months of their treatment. Four of these patients were re-treated for recurrent smaller cysts. These patients have not had a recurrence at 24 months of follow up. Two of these six patients elected to undergo open surgical decompression without symptomatic improvement. No treatment related complications were observed in this group of patients. CONCLUSIONS: Direct tandem and/or coaxial percutaneous CT guided techniques for rupture and treatment of symptomatic lumbar synovial cysts reduces recurrence rates and therefore helps avoid more invasive open surgical procedures in this group of patients.

Brain imaging findings in symptomatic patients after allogeneic haematopoietic stem cell transplantation: correlation with clinical outcome.

OBJECTIVE: To investigate the risk factors for, and the incidence of, structural abnormalities on brain imaging in allogeneic haematopoietic stem cell transplant (HSCT) patients, and correlate these findings with survival. METHODS: We retrospectively reviewed all brain computed tomography (CT) and/or magnetic resonance imaging (MRI) studies obtained during the first post-HSCT year from 2004 thru 2007 in allogeneic HSCT recipients. RESULTS: A total of 128 patients had brain imaging in the first post-HSCT year. Forty one of these 128 patients (32 %) had structural abnormalities on brain imaging: cerebrovascular complications (n = 10), central nervous system (CNS) infection (n = 9), subdural fluid collection (n = 6), CNS recurrence of haematological malignancy (n = 11), and drug toxicity abnormalities (n = 5). The only significant risk factor for structural imaging abnormality was younger patient age (P = 0.01). MRI was significantly more likely than CT to provide specific imaging diagnosis of cerebral lesions (P = 0.001). HSCT patients with cerebrovascular complications have poor survival (P < 0.05). However, overall survival was not significantly worse for the 41 patients with the structural imaging abnormalities as compared to the 87 patients who had brain imaging but no structural abnormalities. CONCLUSIONS: There was no survival difference in patients whose brain imaging was normal or abnormal. However, there was poor outcome in patients with cerebrovascular complications after HSCT. KEY POINTS : • Brain imaging frequently demonstrates neurological complications following haematopoietic stem cell transplantation. • Younger HSCT patients are more likely to exhibit abnormal brain imaging findings. • HSCT recipients with cerebrovascular complications have the worst survival. • However brain imaging results are weak indicators of overall survival after HSCT.

Interventional assessment of the lumbar disk: provocation lumbar diskography and functional anesthetic diskography.

The diagnosis of diskogenic low back pain (LBP) can be elusive. Physical examination of the lumbar disk is limited and imaging offers few objective clues. While invasive, lumbar diskography is a method available to examine or "provoke" the disk directly and determine if LBP is coming from a disk and which disk(s) is responsible for the pain. Once identified, features of the abnormal disk can be evaluated, including the disk's response to intradiskal local anesthetic and disk architecture as observed on diskography imaging and postdiskogram computed tomography. Response to anesthetic can be correlated with imaging features potentially impacting treatment but can also stand alone as an independent objective marker of diskogenic LBP. Here we review the indications for lumbar diskography and the basic lumbar diskogram procedure. We also review the alternative more advanced technique for studying the anesthetic and mechanical features of the disk, functional anesthetic diskography.

Sacroplasty.

Sacral vertebroplasty, or sacroplasty, entails the percutaneous insertion of 1 or more bone needles into the sacral ala and, less commonly, the sacral vertebra with fluoroscopic and/or computed tomographic guidance. Acrylic bone cement is then injected under imaging guidance to treat the lesion and stabilize the sacrum. Sacroplasty is indicated for the treatment of painful sacral insufficiency fractures and painful sacral masses, both of which destabilize the sacrum. In properly selected patients, sacroplasty is an extremely efficacious procedure with a low-risk profile when performed with meticulous imaging guidance and a thorough appreciation of the complex sacral anatomy. Complete pain relief is observed in the overwhelming majority of patients that are treated for sacral insufficiency fractures. While the success rate is lower in patients with painful sacral neoplastic lesions, many of these patients experience a reduction in analgesic use and a return to ambulation.

Noncardiac implantable pacemakers and stimulators: current role and radiographic appearance.

OBJECTIVE: The purpose of this pictorial essay is to familiarize radiologists with the clinical functioning, proper anatomic positioning, appearance on radiographs and CT scans, potential complications, and MRI safety issues of several implantable noncardiac pacemaker and stimulator devices. CONCLUSIONS: The use of noncardiac pacemakers and stimulators is rapidly increasing because of the utility of these devices in the management of surgically and medically refractory conditions. Unlike cardiac pacemakers, electrical stimulators are MRI compatible under certain circumstances.

Computed tomography evaluation of spondylolysis and spondylolisthesis in asymptomatic patients.

STUDY DESIGN: A retrospective radiographic study involving analysis of abdominal and pelvic computed tomography (CT) scans obtained on patients presenting with clinical conditions other than back pain. OBJECTIVE: To determine the incidence of spondylolysis and spondylolisthesis in patients requiring inpatient or emergency department CT evaluation for unrelated abdominal and pelvic conditions. SUMMARY OF BACKGROUND DATA: Spondylolysis and spondylolisthesis are part of a disease process that is thought to be resultant from biomechanical stresses related to bipedal locomotion. The incidence is estimated to be 3% to 10% in the general population. Many of these cases occur without associated symptoms. To our knowledge, there is a relative paucity of data on the use of CT to evaluate the prevalence of these 2 entities in patients seeking medical attention for unrelated conditions. METHODS: Five hundred ten consecutive abdominal and pelvic multi-detector CT scans obtained on a single scanner (Philips MX8000; Eindhoven, The Netherlands) were reviewed. These patients presented with such complaints as abdominal pain and fever, or were imaged as part of their inpatient evaluation for conditions unrelated to lumbar spine pathology. A board certified radiologist and a radiology resident retrospectively evaluated CT scans for lumbar spondylolysis, spondylolisthesis, and associated degenerative changes. A neuroradiologist confirmed all positive cases. RESULTS: Of the 510 cases examined, there were 29 cases of spondylolysis at L5, corresponding to a prevalence of 5.7%. Twenty-three of the cases demonstrated bilateral spondylolysis and 6 unilateral. Sixteen of the 23 cases of bilateral spondylolysis also had spondylolisthesis, 13 of which were grade I, and 3 of which were grade II. In patients 45 years old and younger who did not have spondylolysis or spondylolisthesis, we observed a 32.2% incidence of sclerosis involving the L5 lumbar pedicles. CONCLUSIONS: This study demonstrates a 5.7% prevalence of spondylolysis and a 3.1% prevalence of spondylolisthesis in patients undergoing CT scans of the abdomen and pelvis for unrelated reasons, corresponding to the rate of spondylolysis and spondylolisthesis detected in prospective plain radiographic studies. We observed a 1.2% incidence of unilateral spondylolysis, and approximately 67% of these demonstrated contralateral sclerosis. It is suggested in the literature that sclerosis of the contralateral pedicle seen in cases of unilateral spondylolysis may be a compensatory response to mechanical stresses on an unstable lumbar vertebral body.

Indications for CT in patients receiving anticoagulation after head trauma.

BACKGROUND AND PURPOSE: Head CT is frequently ordered for trauma patients who are receiving anticoagulation. However, whether patients with a Glasgow Coma Scale (GCS) score of 15 and normal findings on neurologic examination require CT is still debated. The purpose of our study was to assess the use of cranial CT in patients receiving anticoagulants after head trauma and to establish clinical criteria to identify those in this group who do not need emergency CT. METHODS: We retrospectively reviewed patients receiving heparin or coumadin who had head trauma and who subsequently underwent cranial CT at a level I trauma center within a 4-year period. Patients were evaluated for mechanism of injury, clinical signs and symptoms of head injury, and type and reason for anticoagulation. Prothrombin time, international normalized ratio, partial thromboplastin time, GCS score, age, and head CT results were recorded for each patient. RESULTS: A total of 89 patients fulfilled the enrollment criteria. Among them, 82 had no evidence of intracranial injury on CT. Seven patients had evidence of intracranial hemorrhage. Patients without hemorrhage had no significant focal neurologic deficits and presented with an average GCS score of 14.8. Patients with intracranial hemorrhage tended to have focal neurologic deficits and presented with an average GCS score of 12.0. CONCLUSION: Patients with head injury, normal GCS scores, and no focal neurologic deficits and who are receiving the anticoagulants heparin or coumadin may not necessarily require emergency CT.

Radiation safety during spine interventions.

Image-guided spine interventions are being performed by radiologists and other physicians with increased frequency. This article assesses the use of several techniques and devices that can mitigate radiation exposure during interventional procedures. Measurements were obtained on a humanoid phantom with use of various shielding methods. Significant radiation dose reductions as great as 98.7% can be achieved with use of a combination of stationary and mobile lead barriers and operator position. The application of basic radiation physics in combination with prudent radiographic technique can significantly reduce radiation exposure to the operator and other personnel during spine interventions.