Medication-related osteonecrosis of the jaw: the radiologist's role.

In recent decades, the dreaded adverse effect of bisphosphonates, osteonecrosis of the jaw, has been widely reported and described in detail. Osteonecrosis of the jaw consists of the destruction of part of the maxilla as a consequence of these antiresorptive drugs. In recent years, new drugs that can also cause osteonecrosis of the jaw (e.g., some monoclonal antibodies or antiangiogenic drugs) have come on the market. For this reason, the term "bisphosphonate-related osteonecrosis of the jaw" has been replaced with "medication-related osteonecrosis of the jaw (MRONJ). This review aims to describe the radiologic characteristics of MRONJ that, although nonspecific, radiologists need to recognize in the appropriate clinical context.

Correlation between the main clinical, imaging, and arthroscopy findings in patients with temporomandibular disorders.

The purpose of this work was to prospectively correlate the most characteristic clinical symptoms of temporomandibular disorders, such as pain and limitation of mouth opening, with the findings of magnetic resonance imaging (disc position, degenerative changes, and effusion) and arthroscopy findings (roofing, synovitis, chondromalacia, adhesions, and perforations). These examinations were performed in 298 patients diagnosed with internal derangement refractory to conservative treatment. The mean age of the patients was 38.59 years; 92.6% were female. The t-test and one-way analysis of variance (ANOVA) were used to correlate the findings. Significant relationships were found between pain and disc displacement without reduction (P = 0.033) and effusion (P = 0.003) on MRI, coinciding with correlations between pain and roofing of 0-25% (P = 0.016) and synovitis (P = 0.001) on arthroscopy. A significant relationship was also observed between mouth opening limitation and the presence of osteoarthrosis (P = 0.018) on MRI, and between mouth opening limitation and synovitis (P = 0.022), chondromalacia (P = 0.002), and adhesions (P < 0.001) on arthroscopy. All of these findings were observed in patients with a poor initial clinical situation, which highlights the considerable potential of correlating these data with imaging and arthroscopy findings.

Brain CT requests from emergency department: Reality.

OBJECTIVES: To evaluate the most common reasons for requesting brain CT studies from the emergency department and to calculate the prevalence of urgent acute pathology on this population group. MATERIAL AND METHODS: We reviewed brain CT studies requested from the emergency department during October and November 2018. We recorded the following variables: age, sex, reason for requesting the study, CT findings, use of contrast agents and reasons for using them, and, in patients who had undergone previous head CT studies, whether the findings had changed. SPSS was used for statistical analyses. RESULTS: A total of 507 urgent brain CT studies were done (41.4% in men, 58.6% in women; mean age, 65.4±20 years). The most common reason for requesting the study was head trauma (40.5%); only 15.6% of these studies showed acute posttraumatic intracranial lesions. The second most common reason was focal neurologic symptoms (16%); only 16% of these studies showed recent ischemic infarcts or acute bleeding. No pathological findings were reported in 43.2% of the studies. The most common abnormal finding was ischemic lesions in small vessels (20%). Space-occupying lesions (both benign and malignant) were found in 3.9% of all patients. CONCLUSIONS: Most brain CT studies requested from the emergency department showed no findings that would modify the management of the patient. Overuse of urgent brain CT increases the radiology department's workload and exposes patients to radiation unnecessarily.

Strengths, weaknesses, opportunities, and threat analysis of dual-energy CT in head and neck imaging.

Technological development of dual-energy computed tomography (DECT) can play an important role in head and neck area. Multiple innovative applications have evolved, optimizing images, achieving metallic artifact reduction, differentiating materials with better primary tumor delineation, thyroid cartilage and bone invasion. Furthermore, quantification algorithms allow measuring iodine concentration, reflecting the blood supply of a lesion indirectly. DECT enables acquiring images with lower radiation doses and iodine intravenous contrast load to obtain the same CT values.. However, DECT uses ionizing radiation, which does not occur with MRI, and requires long post-processing times. Artifacts on iodine maps may be a potential source of pseudolesions. Besides, photon-counting CT scanners are a promising technique that may displace some DECT advantages. A review analyzing the current status of DECT applied to head and neck imaging from the scope of strengths, weaknesses, opportunities, and threatsanalysis would be very interesting to facilitate a realistic, fact-based, data-driven look of this technique.

Ultralow-dose CT of the petrous bone using iterative reconstruction technique, tin filter and high resolution detectors allows an adequate assessment of the petrous bone structures.

OBJECTIVES: To assess image quality and radiation dose in computed tomography (CT) studies of the petrous bone done with a scanner using a tin filter, high-resolution detectors, and iterative reconstruction, and to compare versus in studies done with another scanner without a tin filter using filtered back projection reconstruction. MATERIAL AND METHODS: Thirty two patients (group 1) were acquired with an ultra-low dose CT (32-MDCT, 130kV, tin filter and iterative reconstruction). Images and radiation doses were compared to 36 patients (group 2) acquired in a 16-MDCT (120kV and filtered back-projection). Muscle density, bone density, and background noise were measured. Signal-to-noise ratio (SNR) was calculated. To assess image quality, two independent radiologists subjectively evaluated the visualization of the different structures of the middle and inner ear (0=not visualized, 3=perfectly identified and delimited). Interobserver agreement was calculated. Effective dose at different anatomical levels with the dose-length product was recorded. RESULTS: In the quantitative analysis, there were no significant differences in image noise between the two groups. In the qualitative analysis, a similar or slightly lower subjective score was obtained in the delimitation of different structures of the ossicular chain and cochlea in the 32-MDCT, compared to 16-MDCT, with statistically significant differences. Mean effective dose (±standard deviation) was 0.16±0.04mSv for the 32-MDCT and 1.25±0.30mSv for the 16-MDCT. CONCLUSIONS: The use of scanners with tin filters, high-resolution detectors, and iterative reconstruction allows to obtain images with adequate quality for the evaluation of the petrous bone structures with ultralow doses of radiation (0.16±0.04mSv).

[Valuation of automatized ASPECTS as an artificial intelligence tool in daily clinical]. / Valoración del ASPECTS automatizado como herramienta de inteligencia artificial en la práctica clínica diaria.

AIMS: To evaluate an automated ASPECTS (ASPECTS-a) software against two radiologists' reading of CT scans requested from the Emergency Department. Describe the most frequent failures of the ASPECTS-a. MATERIAL AND METHODS: All the cranial CT Scans requested by the Emergency Department in one month were collected. The following data were recorded: age, sex, the reason for requesting the study, and imaging findings. A program was used that provides an ASPECTS score automatically. Subsequently, 2 radiologists independently reviewed all of the studies and provided the visual ASPECTS (ASPECTS-v). In case of discrepancy, a new reading was made by consensus. RESULTS: A total of 295 brain CT scans (45.1% male) with a mean age of 65 ± 20.0 years were included. 91.8% were interpreted as ASPECTS-v 10 in both cerebral hemispheres by both readers. ASPECTS-a scored 45% with ASPECTS 10 in both cerebral hemispheres. In 152 (51.5%) the ASPECTS-a and the ASPECTS-v did not coincide. The causes of the discrepancy were mainly due to segmentation errors (usually due to asymmetric atrophies). Most of the segmentation errors were located in the head of the caudate nucleus, observed in 60 studies. CONCLUSIONS: ASPECTS-a is a powerful and helpful tool, but human supervision is always necessary, particularly in groups of patients with pre-existing brain changes.

TITLE: Valoración del ASPECTS automatizado como herramienta de inteligencia artificial en la práctica clínica diaria.Objetivos. Evaluar un software del Alberta Stroke Program Early CT Score (ASPECTS) automatizado (ASPECTS-a) frente a la lectura de dos radiólogos en las tomografías computarizadas (TC) solicitadas desde el servicio de urgencias. Describir los fallos más frecuentes del ASPECTS-a. Material y métodos. Se recogieron las TC cerebrales solicitadas por el servicio de urgencias en el período de un mes. Se registraron los siguientes datos: edad, sexo, motivo de solicitud del estudio y hallazgos en la prueba de imagen. Se utilizó un programa que proporciona una puntuación del ASPECTS automáticamente. Posteriormente, dos radiólogos examinaron de forma independiente todos los estudios y realizaron un ASPECTS visual (ASPECTS-v). En caso de discrepancia, se hizo una nueva lectura en consenso. Se compararon los resultados del ASPECTS-a con el ASPECTS-v. Resultados. Se realizaron un total de 295 TC cerebrales urgentes con una edad media de 65 ± 20 años. El 91,8% lo interpretaron los dos lectores como ASPECTS 10 en ambos hemisferios cerebrales. El ASPECTS-a puntuó el 45% con ASPECTS 10 en ambos hemisferios cerebrales. En 152 (51,5%), el ASPECTS-a y el ASPECTS-v no coincidieron. Las causas de la discrepancia fueron fundamentalmente por errores en la segmentación (generalmente por atrofias asimétricas). La mayor parte de los errores en la segmentación se localizaban en la cabeza del núcleo caudado, lo que se observó en 60 estudios. Conclusiones. El ASPECTS-a es una herramienta potente y de gran ayuda, pero siempre es necesaria una supervisión humana, particularmente en grupos de pacientes con cambios cerebrales preexistentes.

Brain CT requests from emergency department: reality. / Tomografía computarizada cerebral solicitada desde Urgencias: la realidad.

OBJECTIVES: To evaluate the most common reasons for requesting brain CT studies from the emergency department and to calculate the prevalence of urgent acute pathology on this population group. MATERIAL AND METHODS: We reviewed brain CT studies requested from the emergency department during October and November 2018. We recorded the following variables: age, sex, reason for requesting the study, CT findings, use of contrast agents and reasons for using them, and, in patients who had undergone previous head CT studies, whether the findings had changed. SPSS was used for statistical analyses. RESULTS: A total of 507 urgent brain CT studies were done (41.4% in men, 58.6% in women; mean age, 65.4±20 years). The most common reason for requesting the study was head trauma (40.5%); only 15.6% of these studies showed acute posttraumatic intracranial lesions. The second most common reason was focal neurologic symptoms (16%); only 16% of these studies showed recent ischemic infarcts or acute bleeding. No pathological findings were reported in 43.2% of the studies. The most common abnormal finding was small vessel disease (20%). Space-occupying lesions (both benign and malignant) were found in 3.9% of all patients. CONCLUSIONS: Most brain CT studies requested from the emergency department showed no findings that would modify the management of the patient. Overuse of urgent brain CT increases the radiology department's workload and exposes patients to radiation unnecessarily.

Ultralow-dose CT of the petrous bone using iterative reconstruction technique, tin filter and high resolution detectors allows an adequate assessment of the petrous bone structures. / La tomografía computarizada de peñascos con dosis ultrabaja, utilizando filtro de estaño, detectores de alta resolución y reconstrucción iterativa, permite una adecuada valoración de las estructuras del peñasco.

OBJECTIVES: To assess image quality and radiation dose in computed tomography (CT) studies of the petrous bone done with a scanner using a tin filter, high-resolution detectors, and iterative reconstruction, and to compare versus in studies done with another scanner without a tin filter using filtered back projection reconstruction. MATERIAL AND METHODS: Thirty two patients (group 1) were acquired with an ultra-low dose CT (32-MDCT, 130 kV, tin filter and iterative reconstruction). Images and radiation doses were compared to 36 patients (group 2) acquired in a 16-MDCT (120 kV and filtered back-projection). Muscle density, bone density, and background noise were measured. Signal-to-noise ratio (SNR) was calculated. To assess image quality, two independent radiologists subjectively evaluated the visualization of the different structures of the middle and inner ear (0 = not visualized, 3 = perfectly identified and delimited). Interobserver agreement was calculated. Effective dose at different anatomical levels with the dose-length product was recorded. RESULTS: In the quantitative analysis, there were no significant differences in image noise between the two groups. In the qualitative analysis, a similar or slightly lower subjective score was obtained in the delimitation of different structures of the ossicular chain and cochlea in the 32-MDCT, compared to 16-MDCT, with statistically significant differences. Mean effective dose (± standard deviation) was 0.16 ± 0.04 mSv for the 32-MDCT and 1.25 ± 0.30 mSv for the 16-MDCT. CONCLUSIONS: The use of scanners with tin filters, high-resolution detectors, and iterative reconstruction allows to obtain images with adequate quality for the evaluation of the petrous bone structures with ultralow doses of radiation (0.16±0.04 mSv).

Should susceptibility-weighted imaging be included in the basic protocol for magnetic resonance imaging of the brain? / ¿Se debe incluir la secuencia de susceptibilidad magnética en el protocolo de resonancia magnética cerebral básico?

OBJECTIVE: To analyze the clinical impact of routine acquisition of susceptibility-weighted imaging (SWI) in magnetic resonance imaging (MRI) studies of the brain. MATERIAL AND METHODS: This prospective observational study included all patients undergoing brain MRI including SWI during a 6-month period. Patients were divided into two groups based on the clinical information provided: Group 1 comprised patients in whom SWI acquisition formed part of the brain MRI protocol, and Group comprised patients who underwent SWI without these sequences being included in the protocol. We recorded patients' age, sex, and risk factors (hypertension, history of brain trauma or intracranial vascular malformations). We analyzed the SWI findings, whether these findings were visible on the other sequences, and whether identifying these findings resulted in substantial changes to the radiological report. RESULTS: There were 62 patients in Group 1 and 79 in Group 2. The groups were similar in age and risk factors. SWI findings resulted in substantial changes to the radiological report in 34% of the patients in Group 1 and in 14% of those in Group 2; this difference was statistically significant. CONCLUSION: SWI can help radiologists detect findings not seen on conventional brain MRI that sometimes result in substantial changes to the radiological report.

Inner ear MRI: is it always useful to manage intravenous contrast? / Resonancia magnética de conducto auditivo interno: ¿es siempre útil administrar contraste intravenoso?

OBJECTIVE: To evaluate the added value of administering intravenous contrast (IVC) routinely to the MRI of patients with audiovestibular symptoms in the assessment of a neuroradiologist and a resident. MATERIALS AND METHODS: Retrospective study including patients who had an inner ear MRI for two months. Two radiologists reviewed independently and blinded the images. A first assessment was made analyzing just the sequences acquired without contrast and then a second evaluation of all the sequences, including post-contrast T1 sequences. The interobserver correlation and the correlation between MRI findings and the reason for requesting the study were calculated. RESULTS: 40 patients were included. The range age was 36-80 years. The most frequent reason for request the MRI was hearing loss (52.5%). Neuroradiologist without IVC found 82.5% of extraotic pathology and 17.5% of otic pathology, highlighting the neurinoma of the VIII pair (7.5%); ossifying labyrinthitis, retrofenestrated otosclerosis and cholesteatoma. After IVC administration, findings were similar. The resident identified otic pathology in 5% in baseline sequences and 20% using CIV. The interobserver correlation using IVC was excellent (0.97), but weak without IVC (0.52). There was a correlation between the reasons for request the MRI and the findings in the ears, both in protocols without IVC (p = 0.004) and in protocols with IVC (p = 0.002). CONCLUSION: Inner ear MRI without contrast gives relevant information to assess audiovestibular symptoms. The use of IVC increases the degree of confidence in a novel radiologist, while in the expert its use is less relevant. A protocol should be proposed in which gadolinium is used in selected patients.

Segmental arterial mediolysis. / Mediolisis arterial segmentaria.

This article reports the case of a 51-year-old woman in whom brain MRI to follow up multiple sclerosis incidentally discovered an intramural hematoma in the extracranial internal carotid artery. MR angiography of the supra-aortic trunks and CT angiography of the aorta showed arterial dilations, aneurysms, dissections, and intramural hematomas in the internal carotid arteries, vertebral arteries, and arteries in the splanchnic territory. These findings raised suspicion of segmental arterial mediolysis. After 6 months of treatment with antiplatelet drugs, the arterial involvement resolved. Segmental arterial mediolysis is an uncommon disease; low clinical suspicion and radiologists' lack of knowledge about this entity mean that it can go undetected or be confused with other vasculitides. This report describes the most relevant pathophysiological findings and correlates them with the imaging findings.

Advanced magnetic resonance imaging techniques for tumors of the head and neck. / Técnicas avanzadas de resonancia magnética en patología tumoral de cabeza y cuello.

Magnetic resonance imaging has become a fundamental tool for the evaluation of head and neck tumors. The anatomic details that magnetic resonance images provide are fundamental for diagnosing, characterizing, and staging both primary tumors and lymph node metastases. In addition to technical improvements in anatomic sequences, such as Dixon techniques to improve fat suppression, other sequences being developed, such as diffusion and perfusion, provide molecular, biological, and physiological information about the tumor and are yielding imaging biomarkers that can help in determining the tumor's biology at the time of diagnosis and in the follow-up of the disease. Magnetic resonance imaging also provides very useful information about the response to treatment.

The utility of dual-energy CT for metal artifact reduction from intracranial clipping and coiling. / Utilidad de la tomografía computarizada de energía dual en la reducción del artefacto metálico generado por clips y coils intracraneales.

OBJECTIVE: To assess the ability of dual-energy CT (DECT) to reduce metal-related artifacts in patients with clips and coils in head CT angiography, and to analyze the differences in this reduction between both type of devices. MATERIALS AND METHODS: Thirteen patients (6 clips, 7 coils) were selected and retrospectively analized. Virtual monoenergetic images (MEI) with photon energies from 40 to 150 keV were obtained. Noise was measured at the area of maximum artifact. Subjective evaluation of streak artifact was performed by two radiologists independently. Differences between noise values in all groups were tested by using the ANOVA test. Mann-Whitney U test was used to compare the differences between clips and coils. Cohens κ statistic was used to determine interobserver agreement. RESULTS: The lowest noise value was observed at high energy levels (p<0,05). Noise was higher in the coil group than in the clip group (p<0.001). Interobserver agreement was good (κ=0.72). CONCLUSIONS: TCED with MEI helps to minimize the artifact from clips ands coils in patients who undergo head CT angiography. The reduction of the artifact is greater in patients with surgical clipping than in patients with endovascular coiling.

Diplopia secondary to orbital fracture in adults. / Diplopía secundaria a fractura orbitaria en adultos.

OBJECTIVE: To evaluate the incidence and evolution of diplopia as a complication of orbital fractures in adults. PATIENTS AND METHODS: A review was conducted on medical records of all consecutive adults with orbital fracture referred between January 2014 and December 2015. An analysis was made of the incidence of diplopia secondary to fracture in the acute phase and its evolution. A descriptive study was performed on the variables related to patients, fractures, and fracture and diplopia treatment. RESULTS: The study included 39patients with a mean age of 48years (17-85). Of all the patients, 17 (43.6%) presented with diplopia in the acute phase. Differences were found between the groups with and without diplopia in relation to muscle entrapment diagnosed by orbital computed tomography, duction limitation, and fracture surgery ≤1week (P=.02, P=.00, P=.04, respectively). Out of the 17patients with diplopia, 12 had a mean follow-up of 18weeks (1-72), and in 10 (83.3%) diplopia was resolved in a mean time of 10weeks (1-72). There were spontaneous resolution in 4 (33.3%) patients, and resolution after fracture surgery in 4 (57%) of the 7 that underwent surgery. In 4cases (33.3%) prisms were prescribed, and 2 (16.6%) required strabismus surgery. CONCLUSIONS: Diplopia secondary to orbital fracture in adults is frequent, but it is resolved in most cases spontaneously or after fracture surgery. A few patients will require prisms and/or strabismus surgery.

The postsurgical spine. / La columna poscirugía.

Failed back surgery syndrome is the persistence or reappearance of pain after surgery on the spine. This term encompasses both mechanical and nonmechanical causes. Imaging techniques are essential in postoperative follow-up and in the evaluation of potential complications responsible for failed back surgery syndrome. This review aims to familiarize radiologists with normal postoperative changes and to help them identify the pathological imaging findings that reflect failed back surgery syndrome. To interpret the imaging findings, it is necessary to know the type of surgery performed in each case and the time elapsed since the intervention. In techniques used to fuse the vertebrae, it is essential to evaluate the degree of bone fusion, the material used (both its position and its integrity), the bone over which it lies, the interface between the implant and bone, and the vertebral segments that are adjacent to metal implants. In decompressive techniques it is important to know what changes can be expected after the intervention and to be able to distinguish them from peridural fibrosis and the recurrence of a hernia. It is also crucial to know the imaging findings for postoperative infections. Other complications are also reviewed, including arachnoiditis, postoperative fluid collections, and changes in the soft tissues adjacent to the surgical site.

[Dual energy CT angiography of the carotid arteries: quality, bone subtraction, and radiation dosage using tube voltage 80/140 kV versus 100/140 kV]. / Energía dual y angioTC de carótidas: calidad, eliminación de hueso y dosis de radiación de 80/140 kV frente a 100/140 kV.

OBJECTIVE: To study the differences in vascular image quality, bone subtraction, and dose of radiation of dual energy CT angiography of the supraaortic trunks using different tube voltages. MATERIAL AND METHODS: We reviewed the CT angiograms of the supraaortic trunks in 46 patients acquired with a 128-slice dual source CT scanner using two voltage protocols (80/140 kV and 100/140 kV). The "head bone removal" tool was used for postprocessing. We divided the arteries into 15 segments. In each segment, we evaluated the image quality of the vessels and the effectiveness of bone removal in multiplanar reconstructions (MPR) and in maximum intensity projections (MIP) with each protocol, analyzing the trabecular and cortical bones separately. We also evaluated the dose of radiation received. RESULTS: Of the 46 patients, 13 were studied using 80/140 kV and 33 with 100/140 kV. There were no significant differences between the two groups in age or sex. Image quality in four segments was better in the group examined with 100/140 kV. Cortical bone removal in MPR and MIP and trabecular bone removal in MIP were also better in the group examined with 100/140 kV. The dose of radiation received was significantly higher in the group examined with 100/140 kV (1.16 mSv with 80/140 kV vs. 1.59 mSv with 100/140 kV). CONCLUSION: Using 100/140 kV increases the dose of radiation but improves the quality of the study of arterial segments and bone subtraction.

[Primary non-Hodgkin large B-cell lymphoma of bladder. Report of a case]. / Linfoma no hodgkin B de célula grande primario de vejiga. Presentación de un caso.

INTRODUCTION: primary genitourinary lymphomas are uncommon. Among them, bladder lymphomas are extremely unusual tumors, with clinico-radiological features similar to urothelial carcinomas of bladder. Histopathological, immunohistochemical and molecular studies are compulsory for the diagnosis. We report a case of this tumor. CLINICAL CASE: An 80-year-old woman was admitted to our hospital with hematuria. Abdominal ultrasound and cystoscopy revealed an infiltrating bladder tumor involving the right lateral wall. After transuretral biopsy, a diagnosis of non-Hodgkin large B-cell lymphoma was made. Neither clinical symptoms nor radiological findings showed disseminated disease, indicating that the tumor was localized in the bladder. After chemotherapy, the patient is disease-free after 9 months follow-up. COMMENT: if a bladder tumor with uncommon histopathological features is found, lymphoma should be excluded, because chemotherapy avoids cystectomy.