Multimodality Imaging of Foreign Bodies: New Insights into Old Challenges.

Traumatic wounds and lacerations are a common reason for patients to present to emergency departments, with retained foreign bodies (FBs) accounting for 7%-15% of cases, particularly those involving the extremities. These retained materials result in a granulomatous tissue response known as an FB reaction, a pathologic attempt to isolate the FB from the host. The most common FB materials are glass, metal, and wood, but other compositions can also be found, such as plastic and animal-derived materials. Clinical history, physical examination, and wound exploration are essential in investigation of retained material but are not sufficient to exclude an FB, and additional investigation is required. Imaging evaluation is a useful tool to help depict and locate an FB, assess possible complications, and guide removal. Conventional radiography, the first-line method in this scenario, is a widely available low-cost depiction method that has good sensitivity for depicting FBs. If the retained material is not depicted at conventional radiography, US can be performed. US is highly sensitive in depicting both radiolucent and radiopaque FBs in superficial locations. For deeper objects, CT may be necessary. MRI is the best imaging modality to delineate local soft-tissue and osseous complications. Retained FBs can result in early and delayed complications, with infection being the most frequent complication. To avoid preventable morbidities related to FBs, radiologists should be familiar with imaging findings and provide essential information to help the attending physician treat each patient. Online supplemental material is available for this article. ©RSNA, 2020.

Whole-Body Imaging of Multiple Myeloma: Diagnostic Criteria.

Multiple myeloma (MM) is a clonal plasma cell proliferative disorder characterized by primary infiltration of bone marrow and excessive production of abnormal immunoglobulin. This disease is the second most common hematologic malignancy (after lymphoma), and its spectrum of characteristic features are widely known by the acronym CRAB (hypercalcemia, renal impairment, anemia, and bone lesions). Traditionally, the diagnosis and treatment of MM have been triggered by clear end-organ damage. However, owing to recently introduced treatment options that can extend patient survival and the increasing recognition of biomarkers that can be used to identify patients at high risk of progression to active disease, the diagnostic criteria have been revised. Bone disease is one of the most prominent features of MM, and imaging has an important role in diagnosis and follow-up, with each whole-body imaging modality having different indications in distinct disease situations. Skeletal survey has been the standard imaging procedure used during the past decade, but it should no longer be used unless it is the only option. Whole-body low-dose CT is a reasonable and cost-effective initial imaging approach. Whole-body MRI is the most sensitive technique for detecting bone involvement and assessing painful complications. PET/CT is the best tool for evaluating treatment response. The importance of radiologists has increased in this scenario. Therefore, to properly assist hematologists and improve the care of patients with MM, it is essential that radiologists know the updated diagnostic criteria for MM, indications for and limitations of each imaging option, and recommendations for follow-up. Online supplemental material is available for this article. ©RSNA, 2019.

Ligaments of the posterior and lateral talar processes: MRI and MR arthrography of the ankle and posterior subtalar joint with anatomic and histologic correlation.

OBJECTIVE: MRI and combined ankle and posterior subtalar MR arthrography in cadavers were used to evaluate the ligaments of the posterior and lateral talar processes. Subsequent anatomic and histologic correlation was performed. MATERIALS AND METHODS: Ten cadaveric ankles were used. Routine radiography and MRI were initially performed. Ankle and posterior subtalar MR arthrography, followed by anatomic and histologic analysis, was then performed to allow better assessment of the ligaments of the lateral and posterior talar process. RESULTS: In all subjects, MR arthrography provided superior delineation of the articular and periarticular structures, as well as the ligaments. The lateral talocalcaneal and medial talocalcaneal ligaments were best seen in the axial and coronal planes, respectively. The axial plane was best for visualizing the fibulotalocalcaneal ligament, and the sagittal plane was best for evaluating the posterior talocalcaneal ligament. The anterior and posterior talofibular ligaments and the posterior tibiotalar ligament (superficial and deep portions) were best seen in the axial plane. Histologic analysis was correlated to anatomic sectioning and showed the attachment sites of these ligaments. CONCLUSION: Combined ankle and posterior subtalar MR arthrography enhances visualization of the ligaments attaching to the posterior and lateral talar processes, including the posterior, lateral, and medial talocalcaneal and fibulotalocalcaneal ligaments.

Prepatellar quadriceps continuation: MRI of cadavers with gross anatomic and histologic correlation.

OBJECTIVE: The "prepatellar quadriceps continuation" is the appropriate designation for the deepest soft-tissue layer that lies anterior to the patella, related to the deep rectus femoris tendinous fibers. The purpose of this study was to define and investigate the prepatellar quadriceps continuation and its relationship with the patella in cadavers using MRI and gross anatomic and histologic analyses. MATERIALS AND METHODS: MRI of 12 fresh-frozen knee specimens was performed using T1-weighted sequences in the axial and sagittal planes. Specimens were then sectioned in 3-mm-thick slices to correspond precisely with the MR images. Histologic analysis was performed in two specimens. The MR images were compared with findings seen on anatomic sectioning and histology. In addition, the layered organization of the patellar tendon was analyzed in 29 embalmed knee specimens obtained from human cadavers of both sexes. RESULTS: The normal prepatellar quadriceps continuation was seen as a band of low signal intensity in the MR images. This structure could not be differentiated easily from the low signal intensity of the patellar cortical bone. The sagittal plane was the most optimal plane for visualization of the attachment site of this continuation to the patella. Gross anatomic dissections revealed that at the proximal pole of the patella, the quadriceps tendon was formed by the rectus femoris and vastus intermedius muscles. The entire quadriceps tendon had an average thickness of 8.54 mm in this region. The thickness of the quadriceps tendon fibers extending over the anterior patellar surface measured, on average, 0.68 mm, and the average thickness of those fibers inserting into the proximal patellar pole was 7.87 mm. Histologic analysis showed that the attachment site of the prepatellar quadriceps continuation was formed by the distal extension of the deep longitudinal fibers of the rectus femoris tendon. At the border zone between the tendons and the patella, the tendinous fibers gradually were transformed into fibrocartilage. This so-called chondroapophyseal type of attachment was found to cover the entire anterior surface of the patella. The average thickness of the fibrocartilage at the insertion of the quadriceps tendon, patellar tendon, and prepatellar quadriceps continuation measured 0.136, 0.023, and 0.004 mm, respectively. CONCLUSION: The prepatellar quadriceps continuation is formed by fibers of the rectus femoris tendon and connects the quadriceps and patellar tendons. All tendons are attached through formation of a chondroapophyseal zone and are therefore transformed into a seam of fibrocartilage. Based on these anatomic features, separation of the prepatellar quadriceps continuation from the patella in the absence of more extensive abnormalities of the quadriceps mechanism is plausible.

Triceps brachii tendon: anatomic-MR imaging study in cadavers with histologic correlation.

OBJECTIVE: The purpose of this cadaveric study was to describe the normal MR anatomy of the triceps brachii tendon (TBT) insertion, to correlate the findings with those seen in anatomic sections and histopathologic analysis, and to review triceps tendon injuries. MATERIALS AND METHODS: Twelve cadaveric elbows were used according to institution guidelines. T1-weighted spin-echo MR images were acquired in three planes. Findings on MR imaging were correlated with those derived from anatomic and histologic study. RESULTS: On MR images, the TBT had a bipartite appearance as it inserted on olecranon in all specimens. The insertion of the medial head was deeper than that of the long and lateral heads and was mainly muscular at its insertion, with a small amount of the tendon blending with the muscle distally, necessitating histologic analysis to determine if there was tendon blending with the muscle at the site of insertion and if the medial head inserted together with the common tendon or as a single unit. At histopathologic analysis, the three heads of the triceps tendon had a common insertion on the olecranon. The bipartite aspect of the tendon that was identified in the MR images was not seen by histologic study, indicating that there was a union of the medial and common tendons just before they inserted into bone. CONCLUSION: TBT has a bipartite appearance on MR images and inserts on olecranon as a single unit.

Ligamentos dos processos talares posterior e lateral: ressonância magnética e artro-ressonância magnética do tornozelo e da articulação subtalar posterior com correlação anatômica e histológica / Ligaments of the posterior and lateral talar processes: MR imaging and MR arthrography of the ankle and posterior subtalar joint with anatomic and histologic correlation

INTRODUÇÃO: A ressonância magnética (RM) e artro-ressonância magnética (artro-RM) vêm sendo rotineiramente empregadas para o estudo das estruturas ligamentares do tornozelo. Os processos talares posterior e lateral constituem locais de várias inserções ligamentares, sendo algumas praticamente desconhecidas e não demonstradas por métodos de imagem. OBJETIVOS: Demonstrar o papel da artro-RM combinada do tornozelo e da articulação subtalar posterior para avaliação dos ligamentos dos processos posterior e lateral do tálus, caracterizar o melhor plano de imagem por RM para análise ligamentar, e correlacionar os aspectos por imagem com aqueles provenientes da análise anatômica e histológica. MÉTODOS: Radiografia e imagem por RM foram inicialmente realizadas em dez tornozelos de cadáveres. Artro-RM do tornozelo e da articulação subtalar posterior seguidas de análise anátomo-histológica foram então realizadas para permitir uma melhor avaliação dos ligamentos dos processos posterior e lateral do tálus. RESULTADOS: Em todos os espécimes, a artro-RM permitiu uma melhor caracterização das estruturas ligamentares. Os ligamentos talocalcâneo lateral e medial foram melhor avaliados nos planos axial e coronal, respectivamente. O plano axial foi o melhor para visualizar o ligamento fibulotalocalcâneo, e o plano sagital foi o melhor para a avaliação do ligamento talocalcâneo posterior. Os ligamentos talofibular anterior e posterior, e o ligamento tibiotalar posterior (porções superficial e profunda) foram melhor demonstrados no plano axial. A correlação anátomo-histológica mostrou os locais das inserções ligamentares...

INTRODUCTION: MR imaging and MR arthrography have been routinely used in the ankle ligaments study. The posterior and lateral talar processes are sites of many ligaments insertions, some of which are practically unknown and not shown in imaging methods. OBJECTIVES: To demonstrate the role for combined ankle and posterior subtalar MR arthrography in the assessment of the ligaments of the posterior and lateral talar processes, to establish the best MR imaging plane to analyze the ligaments, and correlate the imaging aspects with those delineated through anatomic inspection and histologic analysis. METHODS: Routine radiography and MR imaging were initially performed in ten cadaveric ankles. Ankle and posterior subtalar MR arthrography, followed by anatomic and histologic analysis, was then performed to allow better assessment of the ligaments of the lateral and posterior talar processes. RESULTS: In all specimens, MR arthrography provided better delineation of the ligaments structures. The lateral talocalcaneal and medial talocalcaneal ligaments were best seen in the axial and coronal planes, respectively. The axial plane was best to visualize the fibulotalocalcaneal ligament, and the sagittal MR plane was best for evaluating the posterior talocalcaneal ligament. The anterior and posterior talofibular ligaments, and posterior tibiotalar ligament (superficial and deep portions) were best demonstrated in the axial plane. Histologic analysis was correlated to anatomic sectioning and showed the attachment sites of these ligaments. CONCLUSION: Combined ankle and posterior subtalar MR arthrography allowed the characterization of the ligaments attaching to the posterior and lateral talar processes, including the posterior, lateral and medial talocalcaneal and fibulotalocalcaneal ligaments. Anatomic correlation with MR and MR arthrography showed the best plane to analyze these ligaments. Histologic study confirmed the insertions of these ligaments.

Communication between the proximal tibiofibular joint and knee via the subpopliteal recess: MR arthrography with histologic correlation and stratigraphic dissection.

OBJECTIVE: The anatomy and functional importance of the proximal tibiofibular joint (TFJ) have rarely been emphasized. Specifically, the detailed anatomic basis and MRI findings of the communication between the proximal TFJ and the knee have not been defined in the literature. To investigate such communication, anatomic and histologic correlation with MRI findings in frozen specimens and dissections of embalmed specimens was used in the study. MATERIALS AND METHODS: Twelve frozen knees were studied on MR arthrography. MR images of each specimen were compared with anatomic slices and histologic sample analysis. Dissection of an additional 28 embalmed specimens was performed to further investigate communication and the anatomy of the proximal TFJ. RESULTS: Communication between the proximal TFJ and the knee was observed in 27.5% of all anatomic specimens. It occurred via the subpopliteal recess and was related to a defect in the posterior ligament of the fibular head in all specimens. Evidence of an injury was apparent on MR images and was proven on histologic examination in 9% of the anatomic specimens that had such communication. CONCLUSION: The frequency of the communication between the proximal TFJ and knee via the subpopliteal recess related to a defect in the posterior ligament of the fibular head was found to be 27.5%. Evidence of an injury was present in 9% of anatomic specimens that had such communication. Injury to the posterior ligament of the fibular head and instability of the proximal TFJ may accompany a variety of knee injuries. Knowledge of the detailed anatomic appearance and MRI characteristics of the structures related to the proximal TFJ is key to identifying injuries to these structures.

Complex distal insertions of the tibialis posterior tendon: detailed anatomic and MR imaging investigation in cadavers.

PURPOSE: The purpose of this report was to demonstrate the normal complex insertional anatomy of the tibialis posterior tendon (TPT) in cadavers using magnetic resonance (MR) imaging with anatomic and histologic correlation. MATERIAL AND METHODS: Ten cadaveric ankles were used according to institutional guidelines. MR T1-weighted spin echo imaging was performed to demonstrate aspects of the complex anatomic distal insertions of the TPT in cadaveric specimens. Findings on MR imaging were correlated with those derived from anatomic and histologic study. RESULTS: Generally, the TPT revealed a low signal in all MR images, except near the level of the medial malleolus, where the TPT suddenly changed direction and "magic angle" artifact could be observed. In five out of ten specimens (50%), a type I accessory navicular bone was found in the TPT. In all cases with a type I accessory navicular bone, the TPT had an altered signal in this area. Axial and coronal planes on MR imaging were the best in identifying the distal insertions of the TPT. A normal division of the TPT was observed just proximal to the insertion into the navicular bone in five specimens (100%) occurring at a maximum proximal distance from its attachment to the navicular bone of approximately 1.5 to 2 cm. In the other five specimens, in which a type I accessory navicular bone was present, the TPT directly inserted into the accessory bone and a slip less than 1.5 mm in thickness could be observed attaching to the medial aspect of the navicular bone (100%). Anatomic inspection confirmed the sites of the distal insertions of the components of the TPT. CONCLUSION: MR imaging enabled detailed analysis of the complex distal insertions of the TPT as well as a better understanding of those features of its insertion that can simulate a lesion.

Diagnóstico de malformação arteriovenosa uterina por meio da ultra-sonografia com doppler colorido e achados à angiorressonância magnética: relato de caso / Diagnosis of uterine arteriovenous malformation by Doppler ultrasonography and magnetic angioresonance findings: a case report

As malformações arteriovenosas do útero são entidades raras. Sua forma de apresentação clínica é muito diversa, devendo o ginecologista e o imaginologista estar atentos para esta possibilidade diagnóstica, para estabelecer o tratamento de forma precisa e rápida. O presente artigo visa mostrar um caso de malformação arteriovenosa uterina adquirida após doença trofoblástica gestacional, cujo diagnóstico foi bem estabelecido por meio da ultra-sonografia com Doppler colorido e correlação com angiorressonância magnética.