Cone-Beam CT of the Extremities in Clinical Practice.

Cone-beam CT (CBCT) is a promising tool with increasing applications in musculoskeletal imaging due to its ability to provide thin-section CT images of the appendicular skeleton and introduce weight bearing, which accounts for loading forces that typically interact with and affect this anatomy. CBCT devices include an x-ray source directly opposite a digital silicon detector panel that performs a single rotation around an object of interest, obtaining thin-section images. Currently, the majority of research has been focused on the utility of CBCT with foot and ankle pathologic abnormalities, due to the complex architectural arrangement of the tarsal bones and weight-bearing nature of the lower extremities. Associated software can provide a variety of options for image reconstruction, including metal artifact reduction, three-dimensional biometric measurements, and digitally reconstructed radiographs. Advancements in this technology have allowed imaging of the knee, hip, hand, and elbow. As more data are published, it is becoming evident that CBCT provides many additional benefits, including fast imaging time, low radiation dose, lower cost, and small equipment footprint. These benefits allow placement of CBCT units outside of the traditional radiology department, including the orthopedic clinic setting. These technologic developments have motivated clinicians to define the scope of CBCT for diagnostics, surgical planning, and longitudinal imaging. As efforts are made to create standardized protocol and measurements, the current understanding and surgical approach for various orthopedic pathologic conditions will continue to shift, with the hope of improving outcomes. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Volumetric Analysis of a Novel Chimeric Gracilis and Profunda Artery Perforator Flap.

BACKGROUND: The presence of a chimeric gracilis and profunda artery perforator (PAP) flap with a common arterial pedicle has been demonstrated on computed tomography angiography in up to 59% of patients and confirmed in a cadaveric model. Already utilized for head and neck reconstruction by Heredero et al, this novel flap could provide more volume than either flap alone which is advantageous, particularly in patients with sizable defects. The purpose of this study was to determine the average tissue volume that can be utilized from this chimeric flap. METHODS: CT Angiogram imaging studies exhibiting chimeric flap anatomy were reviewed over a 7-year period at a single institution utilizing Visage Version 7.1, a radiology picture archiving and communication system. This software was used to trace the flap pedicles and to capture estimated soft tissue volumes of each respective flap. RESULTS: A total of 31 patients, consisting of 52 lower extremity gracilis and PAP chimeric flaps, underwent tissue volume analysis. The average total volume of soft tissue supplied by the gracilis flap was found to be 70.21 cm3 (standard deviation [SD] = 26.99). The average volume of the PAP flap was 31.73 cm3 (SD = 26.12). The average total volume captured by the chimeric gracilis and PAP flap was 101.94 cm3 (SD = 62.40). CONCLUSION: The potential soft tissue volume that can be harvested from a chimeric gracilis and PAP flap is significantly greater than solitary gracilis or PAP flaps. This chimeric flap may serve as a viable and advantageous reconstructive option for patients requiring large volume soft tissue coverage, particularly if other sizable options are not available.

Carbon-fiber-reinforced polyetheretherketone orthopedic implants in musculoskeletal and spinal tumors: imaging and clinical features.

Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK) orthopedic implants are gaining popularity in oncologic applications as they offer many potential advantages over traditional metallic implants. From an imaging perspective, this instrumentation allows for improved evaluation of adjacent anatomic structures during radiography, computed tomography (CT), and magnetic resonance imaging (MRI). This results in improved postoperative surveillance imaging quality as well as easier visualization of anatomy for potential image-guided percutaneous interventions (e.g., pain palliation injections, or ablative procedures for local disease control). CFR-PEEK devices are also advantageous in radiation oncology treatment due to their decreased imaging artifact during treatment planning imaging and decreased dose perturbation during radiotherapy delivery. As manufacturing processes for CFR-PEEK materials continue to evolve and improve, potential orthopedic applications in the spine and appendicular skeleton increase. An understanding of the unique properties of CFR-PEEK devices and their impact on imaging is valuable to radiologists delivering care to orthopedic oncology patients in both the diagnostic and interventional settings. This multidisciplinary review aims to provide a comprehensive insight into the radiologic, surgical, and radiation oncology impact of these innovative devices.

Improving Turnaround Time in a Hospital-based CT Division with the Kaizen Method.

The Kaizen method is an approach to lean process improvement that is based on the idea that small ongoing positive changes can lead to major improvements in efficiency and reduction of waste. The hospital-based CT division at Mayo Clinic Arizona had been receiving numerous concerns of delays in the performance of examinations from inpatients, outpatients, and patients presenting to the emergency department. These concerns, along with a planned hospital expansion, provided the impetus to perform a process improvement project with the goal of reducing inpatient, emergency department, and outpatient turnaround times by 20%. Kaizen process improvement was chosen because of the emphasis on reduction of waste, standardization, and empowerment of frontline staff. The project was led by a process improvement coach who was trained in lean process improvement and A3 thinking. At the end of a weeklong Kaizen event, inpatient turnaround time decreased by 54%, emergency department turnaround time decreased by 29%, and outpatient turnaround time decreased by 45%. These results were achieved and sustained by establishing standardized work, developing frontline problem solvers, instituting visual management, aligning with relevant metrics, emphasizing patient and staff satisfaction, and reducing lead time and non-value-added work. When done properly, a Kaizen event can be an effective tool for process improvement in the health care setting. Online supplemental material is available for this article. ©RSNA, 2022.

Kaizen Process Improvement in Radiology: Primer for Creating a Culture of Continuous Quality Improvement.

Kaizen process improvement is an element of lean production that is an approach to creating continuous improvement. Kaizen is based on the idea that small ongoing positive changes in workflow and elimination of waste can yield major improvements over time. A focused Kaizen event, or rapid process improvement event, can lead to sustainable process improvement in health care settings that are resistant to change. This approach has been proven to be successful in health care. These events are led by a trained facilitator and coach who provides appropriate team education and engagement. To ensure success, the team must embrace the Kaizen culture, which emphasizes the development of a "learning organization" that is focused on relentless pursuit of perfection. The culture empowers all staff to improve the work they perform, with an emphasis on the process and not the individual. Respect for individual people is key in Kaizen. In radiology, this method has been successful in empowering frontline staff to improve their individual workflows. A 5-day Kaizen event has been successful in increasing on-time starts, decreasing lead time, increasing patient and staff satisfaction, and ensuring sustainability. Sustainable success can occur when the team stays true to lean principles, engages leaders, and empowers team members with the use of timely data to drive decision making. Online supplemental material is available for this article. ©RSNA, 2022.

Calcific Tendinosis Reduces Diagnostic Performance of Magnetic Resonance Imaging in the Detection of Rotator Cuff Tears.

OBJECTIVE: This study aimed to investigate the effect of calcific tendinosis on the diagnosis of rotator cuff tears (RCTs) on magnetic resonance imaging (MRI) and magnetic resonance arthrography (MRA). MATERIALS AND METHODS: Calcific tendinosis was confirmed radiographically. Two musculoskeletal radiologists then retrospectively and independently reviewed the MRI/MRA examinations, with surgery or arthroscopy performed within 90 days of the MRI. Rotator cuffs were categorized as no tear, partial-thickness tear, and full-thickness tear. Partial-thickness tear/full-thickness tear groups were combined for analysis. RESULTS: Forty-eight MRI (mean age, 63.4 years; range, 37-83 years; female-to-male ratio, 29:19) and 7 MRA (mean age, 49.2 years; range, 25-60 years; female-to-male ratio, 4:3) patients were included. Reader 1 and reader 2 sensitivity/specificity values for RCTs on MRI were 95%/50% and 89%/30%, and the values on MRA were 100%/67% and 100%/100%, respectively. Overall agreement was present in 87% (48 of 55; κ = 0.55 [95% confidence interval, 0.26-0.85]). CONCLUSIONS: Magnetic resonance imaging has decreased specificity in diagnosing RCTs when calcific tendinosis is present. Magnetic resonance arthrography performed better in this population and could be considered.

Society of Skeletal Radiology- white paper. Guidelines for the diagnostic management of incidental solitary bone lesions on CT and MRI in adults: bone reporting and data system (Bone-RADS).

The purpose of this article is to present algorithms for the diagnostic management of solitary bone lesions incidentally encountered on computed tomography (CT) and magnetic resonance (MRI) in adults. Based on review of the current literature and expert opinion, the Practice Guidelines and Technical Standards Committee of the Society of Skeletal Radiology (SSR) proposes a bone reporting and data system (Bone-RADS) for incidentally encountered solitary bone lesions on CT and MRI with four possible diagnostic management recommendations (Bone-RADS1, leave alone; Bone-RADS2, perform different imaging modality; Bone-RADS3, perform follow-up imaging; Bone-RADS4, biopsy and/or oncologic referral). Two algorithms for CT based on lesion density (lucent or sclerotic/mixed) and two for MRI allow the user to arrive at a specific Bone-RADS management recommendation. Representative cases are provided to illustrate the usability of the algorithms.

The Chimeric Gracilis and Profunda Artery Perforator Flap: Characterizing This Novel Flap Configuration with Angiography and a Cadaveric Model.

BACKGROUND: A chimerically configured gracilis and profunda artery perforator (PAP) flap is highly prevalent based on recent computed tomography (CT)-imaging data. The purpose of this study is to further characterize the vascular anatomy of this novel flap configuration and determine the feasibility of flap dissection. METHODS: To characterize flap arterial anatomy, lower extremity CT angiograms performed from 2011 to 2018 were retrospectively reviewed. To characterize venous anatomy and determine the feasibility of flap harvest, the lower extremities of cadavers were evaluated. RESULTS: A total of 974 lower extremity CT angiograms and 32 cadavers were included for the assessment. Of the 974 CT angiograms, majority (966, 99%) were bilateral studies, yielding a total of 1,940 lower extremities (right-lower-extremity = 970 and left-lower-extremity = 970) for radiographic evaluation. On CT angiography, a chimerically configured gracilis and PAP flap was found in 51% of patients (n = 494/974). By laterality, chimeric anatomy was present in 26% of right lower extremities (n = 254/970) and 25% of left lower extremities (n = 240/970); bilateral chimeric anatomy was found in 12% (n = 112/966) of patients. Average length of the common arterial pedicle feeding both gracilis and PAP flap perforasomes was 31.1 ± 16.5 mm (range = 2.0-95.0 mm) with an average diameter of 2.8 ± 0.7 mm (range = 1.3-8.8 mm).A total of 15 cadavers exhibited chimeric anatomy with intact, conjoined arteries and veins allowing for anatomical tracing from the profunda femoris to the distal branches within the tissues of the medial thigh. Dissection and isolation of the common pedicle and distal vessels was feasible with minimal disruption of adjacent tissues. Chimeric flap venous anatomy was favorable, with vena commitante adjacent to the common pedicle in all specimens. CONCLUSION: Dissection of a chimeric medial thigh flap consisting of both gracilis and PAP flap tissues is feasible in a cadaveric model. The vascular anatomy of this potential flap appears suitable for future utilization in a clinical setting.

Desmoplastic Fibroblastoma: An Uncommon Tumor With a Relatively Characteristic MRI Appearance.

OBJECTIVE. We undertook this study to determine the radiologic features of desmo-plastic fibroblastoma. MATERIALS AND METHODS. We reviewed available radiologic images for 29 pathologically confirmed desmoplastic fibroblastomas, including images from MRI, radiography, ultrasound (US), and CT. RESULTS. The patient population included 14 women and 15 men (mean age, 60 years; range, 23-96 years). Typically, lesions were oval or lobulated and relatively small (mean, 5.6 cm). In 14 of the 22 cases that included patient histories, lesions had grown slowly, with two eventually causing pain. The remaining eight were discovered incidentally. All lesions involved or were below the deep fascia. Lesions were well-defined and associated with muscle (45%), deep fascia (28%), joint (21%), or tendon (7%). MR images were available in 26 cases; 14 included unenhanced and contrast-enhanced studies. On MRI imaging all lesions were well-defined and adjacent to dense connective tissue. On T1-weighted images, lesions showed varying amounts of low and intermediate signal intensity similar to that of tendon and skeletal muscle, respectively. On fluid-sensitive images, lesions were more heterogeneous, generally showing a wider spectrum of decreased to intermediate signal intensity. On contrast-enhanced MR images, enhancement was characteristically peripheral and septal with patchy areas of homogeneity. In the 10 cases with radiographs, images showed negative findings or a nonmineralized mass. The 10 available ultrasound studies showed mixed echogenicity. In eight patients, unenhanced CT showed lesions having attenuation similar to that of skeletal muscle. CONCLUSION. Desmoplastic fibroblastoma is an uncommon neoplasm with a relatively characteristic MRI appearance.

Iatrogenic humeral anatomic neck fracture after intraosseous vascular access.

Intraosseous infusion has become a key tool in the resuscitation of critically ill or injured patients, both in pre-hospital settings and in emergency departments. Intraosseous access is obtained through the percutaneous placement of a needle into the medullary space of a bone, thereby allowing access into the systemic venous circulation via the medullary space, which is essential to treat patients in shock, cardiac arrest, airway compromise, or major trauma. This becomes critically important when obtaining conventional intravenous access is difficult or impossible. Few cases of iatrogenic fracture have been reported for intraosseous access in the tibia and no case to-date has been reported of iatrogenic fracture secondary to humeral access. We report a case of a 55-year-old patient being resuscitated emergently with proximal humeral intraosseous infusion for cardiac and respiratory arrest secondary to status epilepticus. After successful resuscitation and removal of the intraosseous cannula, the patient noted new-onset shoulder pain. The patient was ultimately diagnosed with an iatrogenic fracture of the anatomic neck of the humerus through the intraosseous needle tract when the appropriate history was obtained in conjunction with cross-sectional imaging. As the use of intraosseous access expands, such fractures may well be seen more frequently. Intraosseous access is limited to the period of resuscitation and the cannula is often not present at the time of imaging. It is important for radiologists to recognize the findings related to intraosseous access as well as this complication with its characteristic locations and morphology.

A Newly Described, Highly Prevalent Arterial Pedicle Perfuses Both Gracilis and Profunda Artery Perforator Flap Tissues: An Angiographic Study of the Medial Thigh.

BACKGROUND: Novel secondary flap options are paramount for patients who are not candidates for common reconstructive methods. The purpose of this study is to identify the prevalence of single arterial pedicle supplying both the gracilis muscle and medial thigh tissue carried in a profunda artery perforator (PAP) flap. Such a pedicle could allow the creation of a chimeric gracilis and PAP flap with a single-arterial anastomosis. METHODS: We conducted a retrospective review of 157 lower extremity computed tomography (CT) angiograms to assess the vasculature of the thigh soft tissues. Imaging evaluation was supervised by a board-certified musculoskeletal radiologist. RESULTS: Prevalence of a single-arterial pedicle to a gracilis and PAP flap in each patient was 59% (31% within the right leg and 28% in the left leg). Furthermore, 16% of patients had a common arterial pedicle in both lower extremities. CONCLUSION: Existence of a single-arterial pedicle to both the gracilis muscle and PAP flap tissues is frequently present in most patients in at least one lower extremity. This chimeric flap configuration could serve as a reconstructive avenue for patients, particularly those who have exhausted other more common flap options. Screening angiography is warranted in patients looking for this anatomic variation to establish its presence.

Never Events in Radiology and Strategies to Reduce Preventable Serious Adverse Events.

The term never event in medicine was originally coined by Kenneth W. Kizer, MD, MPH, former chief executive officer of the National Quality Forum, to describe particularly shocking medical errors that should never occur, such as wrong-site surgery or death associated with introduction of a metallic object into the MRI area. With time, the National Quality Forum's list of never events, or "serious reportable events," has been expanded to include adverse events that are unambiguous, serious, and usually preventable. In this article, the never event framework has been used to describe (a) the errors that may occur in an imaging department that are serious and usually preventable with a review of the causative factors and (b) strategies to eliminate and reduce the adverse effects of these avoidable errors. These errors are often rooted in communication breakdowns and can only be eliminated with a true shift to a culture of open reporting and patient safety. ©RSNA, 2018.

Post-operative extra-spinal etiologies of sciatic nerve impingement.

Sciatica is a highly prevalent cause of morbidity, commonly resulting from intra-spinal pathological processes. Many cases can have extra-spinal etiologies and can be clinically challenging. Certain scenarios should suggest an extra-spinal etiology, particularly total and revision hip arthroplasty, surgical hip dislocation, hip arthroscopy, and surgery in the lithotomy position. We review the post-operative clinical scenarios where sciatic neuropathy may occur, along with the pertinent imaging findings.

The Roles of Organized Radiology in Career Development for Trainees and Junior Attending Radiologists: A Road Map.

OBJECTIVE: The full spectrum of organized radiology consists of numerous organizations with varied missions targeting their respective members. CONCLUSION: This article highlights many of these organizations, discusses the benefits they can provide to radiology trainees and junior faculty, and provides a road map for progressive participation among trainees to junior faculty as they advance through training.

Postoperative Imaging in the Setting of Hip Preservation Surgery.

Osteoarthritis of the hip remains a prevalent disease condition that influences ever-changing treatment options. Procedures performed to correct anatomic variations, and, in turn, prevent or slow the progression of osteoarthritis, are aptly referred to as types of hip preservation surgery (HPS). Conditions that predispose individuals to femoroacetabular impingement (FAI), including pincer- and cam-type morphology, and hip dysplasia are specifically targeted in HPS. Common surgical interventions include acetabuloplasty, osteochondroplasty, periacetabular osteotomy (PAO), and derotational femoral osteotomy (DFO). The radiologist's understanding of the surgical approach, pre- and postoperative imaging findings, and common complications of HPS are paramount to providing value to the patient and surgeon. Acetabuloplasty and osteochondroplasty are performed to address pincer- and cam-type morphology in patients with FAI. With both of these HPS techniques, the goal is to restore the normal morphology by resecting excess bone in the acetabulum or femoral head or neck. As a result, a frequently encountered complication is incomplete or excessive resection. Excessive resection can predispose the patient to dislocation in the case of acetabuloplasty and fracture in the case of osteochondroplasty. Iatrogenic injury to adjacent structures such as the ischiofemoral ligament and acetabular cartilage also may occur. Although rare, especially when an arthroscopic approach is used, avascular necrosis remains a risk. Femoral head undercoverage in hip dysplasia is corrected by using PAO, which may be performed as the sole procedure or in conjunction with DFO. Incomplete or excessive rotation during surgery can result in postprocedural complications. As with any orthopedic procedure involving osteotomy, nonhealing is a risk. Iatrogenic injury in the form of fracture or hardware failure also may be seen. ©RSNA, 2016.

RSNA Centennial Article: Gone but Not Completely forgotten­ pictorial review of "antiquated" radiologic procedures [corrected].

The field of diagnostic and therapeutic radiology has always been characterized by constant innovation and creativity to evolve to its current form. There are numerous imaging techniques that were once prevalent but have become outdated and were replaced by the current examinations and modalities, which improve diagnostic accuracy and patient outcomes. Many of these outdated examinations were first described in the journal Radiology during its first 100 years of existence and were subsequently able to be disseminated across its vast readership to become the standard of care across the nation and the world. These earlier techniques, such as pneumoencephalography as it applies to neuroimaging and neurosurgery; kymography, a predecessor of cardiac imaging; contrast agents such as Thorotrast; and miscellaneous cultural tools, such as the shoe-fitting fluoroscope, left lasting impressions on the current practice of radiology and reflect a small subset of the imaging examinations of our predecessors. Knowledge of historic radiologic examinations and procedures is important to understand how we have arrived at the current practice of radiology we embrace today and how our field can continue to evolve to improve our diagnostic and therapeutic abilities to fit the changing needs of our patients.

Diagnosis of Primary Scrotal Lymphedema Using 99mTc-Sulfur Colloid Lymphoscintigram: Correlation With MR Lymphangiogram.

ABSTRACT: We report a case of a 19-year-old man who presented with severe scrotal swelling. His medical history was notable for severe global edema at birth. Most areas of swelling had resolved by adolescence with exception of the scrotum and the left lower extremity. 99mTc-filtered sulfur colloid lymphoscintigraphy of the lower extremities demonstrated prominent dermal backflow into the superficial scrotum and thighs, which were confirmed on the SPECT/CT images, and correlated with findings on MR lymphangiogram. Lymphoscintigram and MR lymphangiogram may provide complementary information to aid diagnosis and management of primary scrotal lymphedema.

The Magnet Is Sometimes "Off"-Practical Strategies for Optimizing Challenging Musculoskeletal MR Imaging.

To describe practical solutions to the unique technical challenges of musculoskeletal magnetic resonance imaging, including off-isocenter imaging, artifacts from motion and metal prostheses, small field-of-view imaging, and non-conventional scan angles and slice positioning. Unique challenges of musculoskeletal magnetic resonance imaging require a collaborative approach involving radiologists, physicists, and technologists utilizing optimized magnetic resonance protocols, specialized coils, and unique patient positioning, in order to reliably diagnose critical musculoskeletal MR image findings.