Intervertebral instability of the lumbar spine is thought to be a possible pathomechanical mechanism underlying low back pain and sciatica and is often an important factor in determining surgical indication for spinal fusion and decompression. Instability of the lumbar spine, however, remains a controversial and poorly understood topic. At present, much controversy exists regarding the proper definition of the condition, the best diagnostic methods, and the most efficacious treatment approaches. Clinical presentation is not specific, and the relationship between radiologic evidence of instability and its symptoms is controversial. Because of its simplicity, low expense, and pervasive availability, functional flexion-extension radiography is the most thoroughly studied and the most widely used method in the imaging diagnosis of lumbar intervertebral instability. In this article, we provide an overview of the current concepts of vertebral instability, focusing on degenerative lumbar intervertebral instability, and review the different imaging modalities most indicated in diagnosing vertebral instability.

Spondylolysis is an osseous defect of the pars interarticularis, thought to be a developmental or acquired stress fracture secondary to chronic low-grade trauma. It is encountered most frequently in adolescents, most commonly involving the lower lumbar spine, with particularly high prevalence among athletes involved in certain sports or activities. Spondylolysis can be asymptomatic or can be a cause of spine instability, back pain, and radiculopathy. The biomechanics and pathophysiology of spondylolysis are complex and debated. Imaging is utilized to detect spondylolysis, distinguish acute and active lesions from chronic inactive non-union, help establish prognosis, guide treatment, and to assess bony healing. Radiography with satisfactory technical quality can often demonstrate a pars defect. Multislice CT with multiplanar reformats is the most accurate modality for detecting the bony defect and may also be used for assessment of osseous healing; however, as with radiographs, it is not sensitive for detection of the early edematous stress response without a fracture line and exposes the patient to ionizing radiation. Magnetic resonance (MR) imaging should be used as the primary investigation for adolescents with back pain and suspected stress reactions of the lumbar pars interarticularis. Several imaging pitfalls render MR imaging less sensitive than CT for directly visualizing the pars defects (regional degenerative changes and sclerosis). Nevertheless, the presence of bone marrow edema on fluid-sensitive images is an important early finding that may suggest stress response without a visible fracture line. Moreover, MR is the imaging modality of choice for identifying associated nerve root compression. Single-photon emission computed tomography (SPECT) use is limited by a high rate of false-positive and false-negative results and by considerable ionizing radiation exposure. In this article, we provide a review of the current concepts regarding spondylolysis, its epidemiology, pathogenesis, and general treatment guidelines, as well as a detailed review and discussion of the imaging principles for the diagnosis and follow-up of this condition.

Vertebral hemangiomas (VHs) are a frequent and often incidental finding on computed tomography (CT) and magnetic resonance (MR) imaging of the spine. When their imaging appearance is "typical" (coarsened vertical trabeculae on radiographic and CT images, hyperintensity on T1- and T2-weighted MR images), the radiological diagnosis is straightforward. Nonetheless, VHs might also display an "atypical" appearance on MR imaging because of their histological features (amount of fat, vessels, and interstitial edema). Although the majority of VHs are asymptomatic and quiescent lesions, they can exhibit active behaviors, including growing quickly, 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). These "atypical" and "aggressive" VHs are a radiological challenge since they can mimic primary bony malignancies or metastases. CT plays a central role in the workup of atypical VHs, being the most appropriate imaging modality to highlight the polka-dot appearance that is representative of them. When aggressive VHs are suspected, both CT and MR are needed. MR is the best imaging modality to characterize the epidural and/or soft-tissue component, helping in the differential diagnosis. Angiography is a useful imaging adjunct for evaluating and even treating aggressive VHs. The primary objectives of this review article are to summarize the clinical, pathological, and imaging features of VHs, as well as the treatment options, and to provide a practical guide for the differential diagnosis, focusing on the rationale assessment of the findings from radiography, CT, and MR imaging.

Although in our series there is not a significant difference in LR rates by the parameter of age, the new USC/VNPI is still a simple and reliable scoring system for therapeutic management of DCIS. We did not find any statistically significant advantage in groups treated with the addition of RT. Obtaining wide surgical margins appears to be the strongest prognostic factor for local recurrence, regardless of other pathological factors or the addition of adjuvant radiation therapy. However, only prospective randomized studies can precisely predict the risk of LR of conservatively treated DCIS. The clinical significance of Sentinel Lymph Nodes micrometastases Immuno-Histo-Chemistry-detected found in DCIS patients remains uncertain. However, we hypothesize that the anatomical disruption after preoperative biopsy procedures increases the likelihood of epithelial cell displacement and the frequency of IHC-positive Sentinel Lymph Nodes, both of which are directly proportional to the degree of manipulation.

In our experience, ASCP was a safe technique for thoracic aorta surgery allowing complex aortic repairs to be performed with good results in terms of hospital mortality and neurologic outcomes. The fact that there was no difference between the two groups suggests that moderate systemic hypothermia (26 degrees C) appears to be a safe and sufficient tool for brain protection. Moreover, the well known hypothermia-related side effects may be avoided.

The purpose of this review article is to summarize the epidemiology, pertinent anatomy, mechanisms of injury, and classification systems of occipital condylar fractures (OCFs), as well as their clinical presentation and screening, the importance of computed tomography (CT) for detection, and current treatment options. The authors emphasize the rate of occurrence of OCFs, which may be detected in as many as 16% of patients with craniocervical injury. Clinical presentation is not specific, and OCF is not readily diagnosed at physical examination. Failure to diagnose may result in substantial morbidity, and thus accurate diagnosis is mandatory for both therapeutic and medicolegal implications. The diagnosis is most likely to be made with CT. Thin-section CT technique is the method of choice to evaluate the traumatized craniocervical junction. OCFs should be suspected in all patients sustaining high-energy blunt trauma to the head and/or upper cervical spine, resulting from axial loading, lateral bending and/or rotation, and/or direct blow. Besides a CT study assessing potential intracranial injuries, these patients require CT of the craniocervical junction. Radiologists should be aware of the types of OCFs and associated injuries.

SummaryTreating complex aortic arch disease with proximal and distal aortic segment involvement is challenging. In recent years, different surgical and endovascular techniques have been applied in a single or multiple-stage approach with the aim to cure and simplify these conditions. The first procedure available for this purpose was the conventional elephant trunk technique. Its recent evolution is the frozen elephant trunk, which treats the descending thoracic aorta using the antegrade release of a self-expandable stent graft. In the following review article, we analyse the advantages and drawbacks of both techniques from clinical and practical perspectives.

The ankylosed spine is prone to fracture even after minor trauma due to its changed biomechanical properties. The two central features of ankylosing spondylitis (AS) that promote the pathological remodeling of the spine are inflammation and new bone formation. AS is also associated with osteoporosis that is attributed to an uncoupling of the bone formation and bone resorption processes. Therefore, bone resorption occurs and promotes weakening of the spine as well as increased risk of vertebral fractures which can be hugely different in terms of clinical relevance. Even in the presence of symptomatic clinical vertebral fractures, the diagnosis can be overruled by attributing the pain to disease activity. Furthermore, given the highly abnormal structure of the spine, vertebral fracture diagnosis can be difficult on the basis of radiography alone. CT can show the fractures in detail. Magnetic resonance imaging is considered the method of choice for the imaging of spinal cord injuries, and a reasonable option for exclusion of occult fractures undetected by CT. Since it is equally important for radiologists and clinicians to have a common knowledge base rather than a compartmentalized view, the aim of this review article was to provide the required clinical knowledge that radiologists need to know and the relevant radiological semiotics that clinicians require in diagnosing clinically significant injury to the ankylosed spine.