CT and MR imaging of the upper extremity vasculature: pearls, pitfalls, and challenges

Upper limb computed tomography (CT) angiography in the emergency department

A range of abnormalities may acutely affect the upper limb (UL) extremity vasculature including trauma, peripheral vascular disease, and inflammatory conditions. Significant technical advances in computed tomography angiography (CTA) have led to the widespread adoption of this noninvasive modality for rapid evaluation of UL arterial abnormalities in the emergency department setting. A key advantage of CTA over traditional digital subtraction angiography (DSA) is the ability to evaluate concurrent osseous and soft tissue injuries. Accurate identification of pathology requires knowledge of normal UL arterial anatomy in addition to a high-quality study, which may be achieved with a robust CTA protocol. We describe the spectrum of imaging findings on upper limb CTA associated with various acute presentations. Traumatic vascular injuries may occur secondary to penetrating and blunt aetiologies appearing on CTA as contrast extravasation, pooling, pseudoaneurysm, occlusion, and arteriovenous fistula. Peripheral vascular disease manifests as atherosclerotic plaques with thready downstream opacification, and these may precipitate acute thromboembolic events. Inflammatory conditions affecting the UL vasculature includes large and small vessel vasculitides characterised by arterial mural thickening. The use of modalities, including ultrasound and magnetic resonance angiography (MRA), should be considered for further characterisation where appropriate.

Temporal Pattern Analysis of Ultrasound Surveillance Data in Vascular Connective Tissue Disorders

BACKGROUND

Ehlers-Danlos syndrome (EDS), Marfan syndrome (MFS), and Loeys-Dietz syndrome (LDS) are connective tissue disorders frequently associated with vascular aneurysm formation, dissections, and subsequent major complications. Regular imaging surveillance is recommended for these conditions. However, no guidelines currently exist regarding imaging modality or surveillance intervals.

METHODS

This retrospective single-center observational study analyzed clinical and imaging data of patients attending an outpatient clinic for vascular connective tissue disorders between August 2008 and January 2024. Imaging (1424 data points in total) and clinical data were extracted from electronic health records. Analysis primarily included a comparison of vessel diameter progression across imaging modalities, with an additional review of the clinical history of vascular events.

RESULTS

In total, 19 patients with vascular connective tissue disorders (vCTDs) underwent consultations at our outpatient clinic. Nine (47.4%) patients experienced vascular events, while two (10.5%) passed away during the study period. Multimodal imaging surveillance revealed a tendency towards arterial diameter increase. Consistent ultrasound monitoring provided more reliable diameter progression data for the same arterial segment than a combination of imaging modalities. Temporal analysis indicated a tendency for the continuous growth of the abdominal aorta, the common and internal carotid artery, and the common femoral and popliteal artery.

CONCLUSION

The study highlights the importance of standardized, modality-specific imaging protocols in monitoring patients with vCTDs. The variability in disease progression among these patients further complicates surveillance strategies, contemplating the need for individualized approaches. Further research and prospective multicenter studies are required to refine and improve monitoring protocols.

ACR Appropriateness Criteria® Soft Tissue Vascular Anomalies: Vascular Malformations and Infantile Vascular Tumors (Non-CNS)-Child

Soft tissue vascular anomalies may be composed of arterial, venous, and/or lymphatic elements, and diagnosed prenatally or later in childhood or adulthood. They are divided into categories of vascular malformations and vascular tumors. Vascular malformations are further divided into low-flow and fast-flow lesions. A low-flow lesion is most common, with a prevalence of 70%. Vascular tumors may behave in a benign, locally aggressive, borderline, or malignant manner. Infantile hemangioma is a vascular tumor that presents in the neonatal period and then regresses. The presence or multiple skin lesions in an infant can signal underlying visceral vascular anomalies, and complex anomalies may be associated with overgrowth syndromes. 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 process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

A rare case of overlapping thoracic outlet syndrome attributed to an anatomical variation in the anterior scalene muscle: Diagnostic challenges and treatment approaches

Mixed thoracic outlet syndrome, which compresses arteries and nerves, is a rare disorder. Mixed thoracic outlet syndrome due to anatomical abnormalities of the anterior scalene muscle is even more sporadic. We report a case of mixed thoracic outlet syndrome in a patient with no history of trauma or vigorous exercise. We reviewed the medical literature, emphasizing the clinical role and the role of diagnostic imaging methods in a sequential approach to this syndrome.

Thoracic outlet syndrome in women

Thoracic outlet syndrome (TOS) is observed more frequently in women, although the exact causes of this sex disparity remain unclear. By investigating the three types of TOS-arterial, neurogenic, and venous-regarding symptoms, diagnosis, and treatment, this article aims to shed light on the current understanding of TOS, focusing on its variations in women.

CT angiography of non-aortic thoracic arterial trauma

While aortic injury is the most commonly cited thoracic arterial injury, non-aortic arterial injuries represent an uncommon but significant source of morbidity and mortality in blunt and penetrating thoracic trauma patients. Knowledge of the spectrum of vascular injury and anatomic considerations that dictate patterns of associated thoracic hemorrhage will assist the radiologist in the accurate and efficient diagnosis of these injuries. This article provides a review of anatomy, pertinent clinical exam and CT angiography findings, as well as therapeutic options for non-aortic thoracic arterial trauma.

Arterial thoracic outlet syndrome by a commonly overlooked anomaly, the cervical rib: A case report

Thoracic outlet syndrome (TOS) is a constellation of symptoms that occur due to the compression of neurovascular structures traversing the thoracic outlet. TOS manifests in 3 distinct forms: neurogenic, venous, and arterial. Among these, arterial TOS is the rarest. A 32-year-old man presenting with severe right arm pain was referred for CT angiography. The imaging revealed bilateral cervical ribs, with the right side showing more pronounced development and fusion with the first thoracic rib. At the fusion site of the right cervical rib and the first thoracic rib, a pseudoaneurysm of the right subclavian artery was detected. Additionally, there was evidence of acute thromboembolism in the right brachial artery at the mid-humerus. Arterial thoracic outlet syndrome is a rare form of TOS that can have detrimental consequences due to associated complications. Cross-sectional imaging, such as CT scans and MRI, is the preferred method for diagnosing TOS and identifying its specific form. Physicians are expected to be familiar with the various forms of TOS, the lesions mimicking TOS, and the imaging tools utilized for diagnosis.

MR Angiography: Contrast-Enhanced Acquisition Techniques

Contrast-enhanced MR angiography (CE-MRA) is a frequently used MR imaging technique for evaluating cardiovascular structures. In many ways, it is similar to contrast-enhanced computed tomography (CT) angiography, except a gadolinium-based contrast agent (instead of iodinated contrast) is injected. Although the physiological principles of contrast injection overlap, the technical factors behind enhancement and image acquisition are different. CE-MRA provides an excellent alternative to CT for vascular evaluation and follow-up without requiring nephrotoxic contrast and ionizing radiation. This review describes the physical principles, limitations, and technical applications of CE-MRA techniques.

MR Angiography for Aortic Diseases

Aortic pathologic conditions represent diverse disorders, including aortic aneurysm, acute aortic syndrome, traumatic aortic injury, and atherosclerosis. Given the nonspecific clinical features, noninvasive imaging is critical in screening, diagnosis, management, and posttherapeutic surveillance. Of the commonly used imaging modalities, including ultrasound, computed tomography, and MR imaging, the final choice often depends on a combination of factors: acuity of clinical presentation, suspected underlying diagnosis, and institutional practice. Further research is needed to identify the potential clinical role and define appropriate use criteria for advanced MR applications such as four-dimenional flow to manage patients with aortic pathologic conditions.

Applications of Vascular Imaging and Interventional Radiology Modalities in the Upper Extremity: A Review

Hand and upper extremity (HUE) vascular disorders are encountered frequently by hand surgeons in clinical practice. A wide array of imaging and vascular interventional radiology modalities exists for the diagnosis and treatment of HUE vascular disorders, some of which may not be familiar to the HUE surgeons. In this review article, we summarize the vascular imaging and vascular interventional radiology modalities and their relative advantages, disadvantages, and indications with respect to HUE pathology. We aim to familiarize HUE surgeons with the available types of diagnostic and therapeutic options for HUE vascular pathologies and aid interdisciplinary communication with vascular interventional radiology specialists during the clinical decision-making process.

Thoracic outlet syndrome: a review for the primary care provider

CONTEXT

Thoracic outlet syndrome (TOS) symptoms are prevalent and often confused with other diagnoses. A PubMed search was undertaken to present a comprehensive article addressing the presentation and treatment for TOS.

OBJECTIVES

This article summarizes what is currently published about TOS, its etiologies, common objective findings, and nonsurgical treatment options.

METHODS

The PubMed database was conducted for the range of May 2020 to September 2021 utilizing TOS-related Medical Subject Headings (MeSH) terms. A Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) systematic literature review was conducted to identify the most common etiologies, the most objective findings, and the most effective nonsurgical treatment options for TOS.

RESULTS

The search identified 1,188 articles. The automated merge feature removed duplicate articles. The remaining 1,078 citations were manually reviewed, with articles published prior to 2010 removed (n=771). Of the remaining 307 articles, duplicate citations not removed by automated means were removed manually (n=3). The other exclusion criteria included: non-English language (n=21); no abstracts available (n=56); and case reports of TOS occurring from complications of fractures, medical or surgical procedures, novel surgical approaches, or abnormal anatomy (n=42). Articles over 5 years old pertaining to therapeutic intervention (mostly surgical) were removed (n=18). Articles pertaining specifically to osteopathic manipulative treatment (OMT) were sparse and all were utilized (n=6). A total of 167 articles remained. The authors added a total of 20 articles that fell outside of the search criteria, as they considered them to be historic in nature with regards to TOS (n=8), were related specifically to OMT (n=4), or were considered sentinel articles relating to specific therapeutic interventions (n=8). A total of 187 articles were utilized in the final preparation of this manuscript. A final search was conducted prior to submission for publication to check for updated articles. Symptoms of hemicranial and/or upper-extremity pain and paresthesias should lead a physician to evaluate for musculoskeletal etiologies that may be contributing to the compression of the brachial plexus. The best initial provocative test to screen for TOS is the upper limb tension test (ULTT) because a negative test suggests against brachial plexus compression. A positive ULTT should be followed up with an elevated arm stress test (EAST) to further support the diagnosis. If TOS is suspected, additional diagnostic testing such as ultrasound, electromyography (EMG), or magnetic resonance imaging/magnetic resonance angiography (MRI/MRA) might be utilized to further distinguish the vascular or neurological etiologies of the symptoms. Initial treatment for neurogenic TOS (nTOS) is often conservative. Data are limited, therefore there is no conclusive evidence that any one treatment method or combination is more effective. Surgery in nTOS is considered for refractory cases only. Anticoagulation and surgical decompression remain the treatment of choice for vascular versions of TOS.

CONCLUSIONS

The most common form of TOS is neurogenic. The most common symptoms are pain and paresthesias of the head, neck, and upper extremities. Diagnosis of nTOS is clinical, and the best screening test is the ULTT. There is no conclusive evidence that any one treatment method is more effective for nTOS, given limitations in the published data. Surgical decompression remains the treatment of choice for vascular forms of TOS.

Low-velocity, civilian firearm extremity injuries-review and update for radiologists

Firearm injuries are a preventable epidemic in the USA. Extremities are commonly affected in gunshot injuries. Such injuries may be complex with concomitant osseous, soft tissue, and neurovascular components. The maximum wounding potential of a projectile is determined by its kinetic energy and the proportion of the kinetic energy that is transmitted to the target. Accurate assessment of ballistic injuries is dependent on utilizing the principles of wound ballistics, accurate bullet count, and ballistic trajectory analysis. The goals of this article are to review wound ballistics and the imaging evaluation of extremity civilian firearm injuries in the adult population, with emphasis on ballistic trajectory analysis, specific ballistic fracture patterns, and diffuse, secondary soft tissue ballistic injuries.

Afterglow Implant for Arterial Embolization and Intraoperative Imaging

Transcatheter arterial embolization (TAE) is wildly used in clinical treatments. However, the online monitoring of the thrombosis formation is limited due to the challenges of the direct visualization of embolic agents and the real-time monitoring of dynamic blood flow. Thus, we developed a photochemical afterglow implant with strong afterglow intensity and a long lifetime for embolization and imaging. The liquid pre-implant injected into the abdominal aorta of mice was rapidly transformed into a hydrogel in situ to embolize the blood vessel. The vascular embolism position can be observed by the enhanced afterglow of the fixed implant, and the long lifetime of afterglow can also be used to monitor the effect of embolization. This provides an excellent candidate in bio-imaging to avoid the autofluorescence interference from continuous light excitation. The study suggests the potential usefulness of the implant as an embolic agent in TAE and artery imaging during a surgical procedure.

Fatal Outcome After Reduction of a Superior Shoulder Dislocation, A Case Report and Literature Review: A Case Report and Literature Review

CASE

An 81-year-old woman presented a superior glenohumeral dislocation after a low-energy fall, with a mechanism of axial load while the shoulder was in adduction and extension. After successful closed reduction, the patient presented sudden symptoms of severe vascular injury with a protruding axillary hematoma and hypovolemic shock.

CONCLUSION

Superior shoulder dislocations and vascular injuries are extremely rare among shoulder dislocations, especially after low-energy trauma. Vascular injuries may result in limb compromise and death. We highlight the importance of high clinical suspicion, particularly in superior dislocations, and the importance of prompt management of vascular complications to avoid catastrophic outcomes.

Extraosseous Ewing's Sarcoma: Pictorial Review of Imaging Findings, Differential Diagnosis, and Pathologic Correlation

Extraosseous Ewing's sarcoma (EES), first described in 1969, is a malignant mesenchymal tumor just like its intraosseous counterpart. Although Ewing's sarcomas are common bone tumors in young children, EESs are rarer and more commonly found in older children/adults, often carrying a poorer prognosis. We discuss the multimodality imaging features of EES and the differential diagnosis of an aggressive appearing mass in proximity to skeletal structures, with pathologic correlates. This review highlights the need to recognize the variability of radiologic findings in EES such as the presence of hemorrhage, rich vascularity, and cystic or necrotic regions and its imaging similarity to other neoplasms that are closely related pathologically.

Surgical treatment of cervical rib-associated arterial thoracic outlet syndrome

The arterial form of thoracic outlet syndrome is rare and is associated with anatomic anomalies, generally a cervical rib. It has a varied range of manifestations. The aim of this article is to describe two cases with different clinical presentations: microembolization and aneurysm. A cervical rib was present in both cases. Diagnosis was made on the basis of history, physical examination, postural maneuvers, and X-rays. Computed tomography angiography provided the anatomic detail necessary to plan surgery. Surgical treatment was performed via supraclavicular access, successfully, in both cases.

High-resolution, non-contrast-enhanced magnetic resonance angiography of the wrist, hand and digital arteries using optimized implementation of Cartesian quiescent interval slice selective (QISS) at 1.5 T

PURPOSE

Non-contrast-enhanced (CE) magnetic resonance angiography (MRA) techniques are of considerable interest for diagnosing vascular diseases in the upper extremities owing to the possibility of repeated examinations, sufficient coverage of the measurement volume, and because possible side effects of administering iodine- or gadolinium-based contrast agents and radiation exposure can be avoided. The aim of this study was to investigate the feasibility of an optimized electrocardiogram (ECG) triggered Cartesian quiescent interval slice selective (QISS) technique for MRA of hand arteries.

MATERIAL AND METHODS

Both hands of 20 healthy volunteers (HVs) were examined using an optimized QISS-MRA pulse sequence at 1.5 Tesla. The wrist and hand arterial trees were divided into 36 segments. Cross-sectional areas (CSA) of all arterial segments were measured. For the technical evaluation of the pulse sequence, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were computed and six imaging artifacts were graded. Two experienced observers used an ordinal scoring system to assess the image quality of each arterial segment. Interobserver agreement was determined.

RESULTS

The median CSA was 7.3 mm2 in the ulnar and radial artery, 3.2 mm2 in the four common digital arteries, and 1.5 mm2 in five proper digital arteries. The median SNR and CNR of the third common proper arteries were 45.9 and 20.3, respectively. None of the arterial segments were contaminated by venous enhancement. The image quality of arterial segments for both hands was considered as diagnostic in 87.2% of all 1440 segments. An interobserver agreement of 0.67 for both hands was determined for image quality of arterial segments using a five-grade scoring system. Optimized QISS-MRA allows as the first MRA technique the classification of superficial palmar arch (SPA) and deep palmar arch (DPA) variants. 5 new SPA and 6 new DPA variants could be classified using QISS-MRA in comparison with previous studies using CE computed tomography angiography and using fixed cadaver hands.

CONCLUSIONS

By using this optimized 2D Cartesian QISS-MRA protocol, contrast agent-free angiography of the wrist and hand arteries provided a high in-plane spatial resolution and an excellent visualization of small digital arteries.

Balloon assisted stent deployment in the cephalic arch (BASCA)

Cephalic arch stenosis causes repeated dysfunction and failure of arteriovenous access. Outcomes following balloon angioplasty alone in this location are unsatisfactory. Stent grafts have very good patency rates in this location. However, stent graft placement is technically challenging in this location due to the adverse angles and vectors of the cephalic arch. Stent graft deployment in this location is associated with a real risk of jailing the axillary vein, thereby precluding the use of that arm for future accesses and/or predisposes to venous edema. We describe a technique that was used to safely and effectively deploy a stent graft in the cephalic arch of a 65-year-old male patient.

The role of ultrasound imaging in vascular compression syndromes

Vascular compression syndromes are rare alterations that have in common the compression of an arterial and/or venous vessel by contiguous structures and can be congenital or acquired. The best known are the Thoracic Outlet Syndrome, Nutcracker Syndrome, May–Thurner Syndrome, and Dunbar Syndrome. The incidence of these pathologies is certainly underestimated due to the non-specific clinical signs and their frequent asymptomaticity. Being a first-level method, Ultrasound plays a very important role in identifying these alterations, almost always allowing a complete diagnostic classification. If in expert hands, this method can significantly contribute to the reduction of false negatives, especially in the asymptomatic population, where the finding of the aforementioned pathologies often happens randomly following routine checks. In this review, we briefly discuss the best known vascular changes, the corresponding ultrasound anatomy, and typical ultrasound patterns.

Contemporary Management of Arterial Thoracic Outlet Syndrome

BACKGROUND

Arterial thoracic outlet syndrome (aTOS) is characterized by compression of the subclavian artery as it exits the thoracic girdle. Chronic and repetitive compression leads to several degrees of arterial wall damage. The treatment is varied and depends on the presentation severity. This study aimed to describe the contemporary experience in managing arterial thoracic outlet syndrome at a large tertiary hospital.

METHODS

We conducted a single-institution retrospective review of aTOS cases from January 2009 to January 2020. Demographic data, clinical presentation, medical images, operative notes, and outcomes were assessed.

RESULTS

Thirteen aTOS cases were identified. The mean age was 43 ± 10 years, and 11 (85%) were women. Both sides were equally affected: right (7 cases, 54%) and left (6 cases, 46%). The most common clinical presentation was arm claudication (7 cases, 54%). Other presentations were: acute arm ischemia, pulsatile neck mass and distal embolization. Cervical ribs were identified by plain X-rays in most cases. All patients were submitted to surgical decompression through the supraclavicular approach. Patients with early disease stages were not submitted to arterial reconstruction and were followed with duplex scan. Arterial reconstruction was done in advanced disease stages (5 cases, 38%): end-to-end anastomosis, interposition graft, and bypass graft. The mean follow-up duration was 32,6 ± 25 months. In all patients, the subclavian artery/graft was patent, and the vascular symptoms were entirely resolved. There were no deaths or amputations.

CONCLUSIONS

Arterial thoracic outlet syndrome has a varied clinical presentation. Cervical ribs are the most common anatomic abnormalities. The diagnosis was based on history, physical examination, and imaging exams. Surgery consisted of supraclavicular decompression, arterial resection, and vascular reconstruction, according to the disease stage. The outcomes were excellent.

Automatic segmentation, feature extraction and comparison of healthy and stroke cerebral vasculature

Accurate segmentation of cerebral vasculature and a quantitative assessment of its morphology is critical to various diagnostic and therapeutic purposes and is pertinent to studying brain health and disease. However, this is still a challenging task due to the complexity of the vascular imaging data. We propose an automated method for cerebral vascular segmentation without the need of any manual intervention as well as a method to skeletonize the binary segmented map to extract vascular geometric features and characterize vessel structure. We combine a Hessian-based probabilistic vessel-enhancing filtering with an active-contour-based technique to segment magnetic resonance and computed tomography angiograms (MRA and CTA) and subsequently extract the vessel centerlines and diameters to calculate the geometrical properties of the vasculature. Our method was validated using a 3D phantom of the Circle-of-Willis region, demonstrating 84% mean Dice similarity coefficient (DSC) and 85% mean Pearson's correlation coefficient (PCC) with minimal modified Hausdorff distance (MHD) error (3 surface pixels at most), and showed superior performance compared to existing segmentation algorithms upon quantitative comparison using DSC, PCC and MHD. We subsequently applied our algorithm to a dataset of 40 subjects, including 1) MRA scans of healthy subjects (n = 10, age = 30 ± 9), 2) MRA scans of stroke patients (n = 10, age = 51 ± 15), 3) CTA scans of healthy subjects (n = 10, age = 62 ± 12), and 4) CTA scans of stroke patients (n = 10, age = 68 ± 11), and obtained a quantitative comparison between the stroke and normal vasculature for both imaging modalities. The vascular network in stroke patients compared to age-adjusted healthy subjects was found to have a significantly (p < 0.05) higher tortuosity (3.24 ± 0.88 rad/cm vs. 7.17 ± 1.61 rad/cm for MRA, and 4.36 ± 1.32 rad/cm vs. 7.80 ± 0.92 rad/cm for CTA), higher fractal dimension (1.36 ± 0.28 vs. 1.71 ± 0.14 for MRA, and 1.56 ± 0.05 vs. 1.69 ± 0.20 for CTA), lower total length (3.46 ± 0.99 m vs. 2.20 ± 0.67 m for CTA), lower total volume (61.80 ± 18.79 ml vs. 34.43 ± 22.9 ml for CTA), lower average diameter (2.4 ± 0.21 mm vs. 2.18 ± 0.07 mm for CTA), and lower average branch length (4.81 ± 1.97 mm vs. 8.68 ± 2.03 mm for MRA), respectively. We additionally studied the change in vascular features with respect to aging and imaging modality. While we observed differences between features as a result of aging, statistical analysis did not show any significant differences, whereas we found that the number of branches were significantly different (p < 0.05) between the two imaging modalities (201 ± 73 for MRA vs. 189 ± 69 for CTA). Our segmentation and feature extraction algorithm can be applied on any imaging modality and can be used in the future to automatically obtain the 3D segmented vasculature for diagnosis and treatment planning as well as to study morphological changes due to stroke and other cerebrovascular diseases (CVD) in the clinic.

Surgical treatment of cervical rib-associated arterial thoracic outlet syndrome

Resumo A forma arterial da síndrome do desfiladeiro torácico é rara e está associada a uma anomalia anatômica, geralmente uma costela cervical. Suas manifestações são muito variadas. Este artigo tem como proposta relatar dois casos de apresentações clínicas distintas: microembolização e aneurisma. Em ambos, uma costela cervical estava presente. O diagnóstico foi realizado através da história, do exame físico, das manobras posturais e das radiografias. A angiotomografia computadorizada proporcionou o detalhe anatômico necessário para o planejamento operatório. O tratamento cirúrgico foi realizado pela abordagem supraclavicular, com sucesso em ambos casos.

Factors Affecting Radiation Dose in Computed Tomography Angiograms for Pulmonary Embolism: A Retrospective Cohort Study

Objectives

Computed tomography pulmonary angiogram (CTPA) is one of the most commonly ordered and frequently overused tests. The purpose of this study was to evaluate the mean radiation dose to patients getting CTPA and to identify factors that are associated with higher dose.

Material and Methods

This institutionally approved retrospective study included all patients who had a CTPA to rule out acute pulmonary embolism between 2016 and 2018 in a tertiary care center. Patient data (age, sex, body mass index [BMI], and patient location), CT scanner type, image reconstruction methodology, and radiation dose parameters (dose-length product [DLP]) were recorded. Effective dose estimates were obtained by multiplying DLP by conversion coefficient (0.014 mSv•mGy^-1•cm^-1). Multivariate logistic regression analysis was performed to determine the factors affecting the radiation dose.

Results

There were 2342 patients (1099 men and 1243 women) with a mean age of 58.1 years (range 0.2-104.4 years) and BMI of 31.3 kg/m² (range 12-91.5 kg/m²). The mean effective radiation dose was 5.512 mSv (median - 4.27 mSv; range 0.1-43.0 mSv). Patient factors, including BMI >25 kg/m², male sex, age >18 years, and intensive care unit (ICU) location, were associated with significantly higher dose (P < 0.05). CT scanning using third generation dual-source scanner with model-based iterative reconstruction (IR) had significantly lower dose (mean: 4.90 mSv) versus single-source (64-slice) scanner with filtered back projection (mean: 9.29 mSv, P < 0.001).

Conclusion

Patients with high BMI and ICU referrals are associated with high CT radiation dose. They are most likely to benefit by scanning on newer generation scanner using advance model-based IR techniques.

Risk Factors for Major Hemorrhage Following Percutaneous Image-Guided Renal Biopsy: What is the "core" of the Problem? A Retrospective Case-control Study

Objectives:

Percutaneous renal biopsy (PRB) plays a critical role in the work-up of renal parenchymal disease. Although it is considered a low-risk procedure, additional interventions may be required in about 7% of the cases following biopsy. The purpose of this study was to identify risk factors for major hemorrhage by microscopic analysis of the cores obtained following PRB, with an intent to enhance the sensitivity and specificity of the risk stratification process, especially in patients undergoing this procedure in an outpatient setting.

Material and Methods:

A retrospective review identified 17 of 179 patients (9.50%) with major hemorrhage following PRB between July 2014 and June 2019. Using propensity score matching, 26 controls (without major hemorrhage) were matched to 17 cases (with major hemorrhage). The biopsy cores obtained from the cases and controls were analyzed by a single pathologist for medullary, cortical, total (medullary + cortical) lengths, and the number of arcuate arteries (AAs). Medullary:cortical (M:C), cortical:total (C:T), and medullary:total (M:T) length ratios were then calculated.

Results:

A stratified version of logistic regression was used to test for an association between each of the variables identified on the cores and the probability of a major hemorrhage. The analysis revealed that there was a statistically significant association between the number of AAs per specimen with the risk of major hemorrhage (P = 0.0006). When 0, 1, or >2 AAs were identified, the frequency of major hemorrhage was 13.04%, 66.67%, and 75.00%, respectively. The odds of major hemorrhage were 6 times higher with one AA and (95% CI, 1.28–32.30) and 15 times higher with >2 AAs (95% CI, 1.41–169.57). No significant association was found between medullary length (P = 0.228), medulla:cortex (M:C) (P = 0.089), medulla:total (M:T) (P = 0.108), or cortex:total (C:T) (P = 0.112) length ratios and major hemorrhage.

Conclusion:

There was a strong and incremental correlation between major renal hemorrhage following PRB and the number of AAs per core specimen. Identification of AAs by the pathologist, while assessing for sample adequacy, in the US suite can help predict major hemorrhage in patients undergoing PRBs.

Spotlight on the pediatric eye: a pictorial review of orbital anatomy and congenital orbital pathologies

Orbital lesions in the pediatric population vary from adults in terms of their presentation, unique pathology, and imaging characteristics. The prompt and accurate diagnosis of these lesions is imperative to prevent serious consequences in terms of visual impairment and disfigurement. Along with dedicated ophthalmologic examination, imaging is instrumental in characterizing these lesions, both for accurate diagnosis and subsequent management. In our pictorial essay, we provide a basic review of orbital embryology, anatomy, and congenital orbital pathologies, with emphasis on radiological findings.

Imaging primer for CT angiography in peripheral vascular trauma

The use of computed tomography angiography (CTA) for the evaluation of peripheral vascular trauma has become increasingly prevalent in the past decade with the development of multidetector CT (MDCT) and multiple studies subsequently demonstrating high sensitivity, specificity, and diagnostic accuracy when compared with conventional angiography. Additional benefits of MDCT include the ability to rapidly acquire the images, perform multiplanar and 3D reconstructions, and assess the adjacent soft tissues and bones. Rapid intravenous injection of iodinated contrast material is required for optimal arterial enhancement. CTA manifestations of an arterial injury may be direct, and include active contrast extravasation, pseudoaneurysm, arteriovenous fistula (AVF), intimal injury, dissection, or occlusion. There are also indirect signs which have a high association with vascular injury, and should raise suspicion, when present. Pitfalls related to image acquisition or patient factors can be mitigated with appropriate planning and post-processing techniques.

Chemorefractory liver metastasis from cervical cancer successfully treated with a combination of yttrium-90 and immunotherapy

Liver metastases in cervical cancer is rare and can be difficult-to-treat. The current guidelines established by the Gynecologic Oncology Group recommend platinum-based systemic chemotherapy in combination with an anti-angiogenic agent such as bevacizumab, however, overall survival remains poor following diagnosis and options for patients who fail chemotherapy are limited. Yttrium-90 (Y90) radioembolization (RE) has shown great promise in the treatment of chemo-refractory colorectal liver metastases. We describe a 30-year-old female with a history of stage IB endocervical adenocarcinoma who later developed metastases to the liver, that were unresponsive to multiple chemotherapeutics and chemoembolization, and was successfully treated with Y90 RE with concurrent systemic Pembrolizumab. The Y90 RE treatment resulted in positive clinical and imaging responses with improvement in her quality of life, all of which continue to persist at the time of writing this manuscript about 8-months into her RE treatment.

Appendiceal diverticulosis in a patient with family history of Birt-Hogg-Dubé syndrome--a case report

Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant disorder that predisposes patients to cutaneous tumors, pulmonary cysts with recurrent spontaneous pneumothoraces, and a variety of renal neoplasms including hybrid oncocytic and chromophobe renal cell carcinomas. There has been much debate regarding the genetic link with the occurrence of colorectal cancer and other colonic anomalies. Associations between BHD and intestinal adenomatous polyposis and sigmoid diverticulosis have been described in the literature, but there have been no prior reports of appendiceal diverticulosis in patients with BHD. Here, we present a 40-year-old female patient with a known family history of BHD, who was found to have diverticulosis of the appendix and pulmonary blebs on computed tomography upon routine screening for renal and pulmonary abnormalities, suggesting additional focus be given to the gastrointestinal tract (including the appendix) at the time of CT assessment.

Metastatic retro-crural lymph nodes from transitional cell carcinoma of bladder successfully treated with single session cryoablation

Bladder cancer (BC) is a relatively common tumor, with a male preponderance. High-grade muscle invasive bladder cancer (MIBC) has a very high incidence of pelvic lymph node metastasis at presentation. Involvement of the retro-crural lymph nodes, although has been described in other pelvic tumors, is very uncommon for BC. Cryoablation in the retro-crural region is extremely challenging due to the proximity to the critical structures like inferior venacava and aorta and has not been extensively reported. We describe a 56-year old male patient with MIBC who underwent extensive treatments including radical cystoprostatectomy, chemoradiation and immunotherapy, ultimately with localized disease in the retro-crural region. Single session cryoablation of these lymph nodes was performed with a curative intent yielding a positive response that has persisted for more than 2 years.

Role of Computed Tomography-guided Biopsies in the Era of Electromagnetic Navigational Bronchoscopy: A Retrospective Study of Factors Predicting Diagnostic Yield in Electromagnetic Navigational Bronchoscopy and Computed Tomography Biopsies

Objectives:

Over 25% of the high-risk population screened for lung cancer have an abnormal computed tomography (CT) scan. Conventionally, these lesions have been biopsied with CT guidance with a high diagnostic yield. Electromagnetic navigational bronchoscopy (ENB) with transbronchial biopsy has emerged as a technology that improves the diagnostic sensitivity of conventional bronchoscopic biopsy. It has been used to biopsy lung lesions, due to the low risk of pneumothorax. It is, however, a new technology that is expensive and its role in the diagnosis of the solitary pulmonary nodule (SPN) is yet to be determined. The purpose of this study was to evaluate the diagnostic yield of CT-guided biopsy (CTB) following non-diagnostic ENB biopsy and identify characteristics of the lesion that predicts a low diagnostic yield with ENB, to ensure appropriate use of ENB in the evaluation of SPN.

Materials and Methods:

One hundred and thirty-five lung lesions were biopsied with ENB from January 2017 to August 2019. Biopsies were considered diagnostic if pathology confirmed malignancy or inflammation in the appropriate clinical and imaging setting. We evaluated lesions for several characteristics including size, lobe, and central/peripheral distribution. The diagnostic yield of CTB in patients who failed ENB biopsies was also evaluated. Logistic regression was used to identify factors likely to predict a non-diagnostic ENB biopsy.

Result:

Overall, ENB biopsies were performed in 135 patients with solitary lung lesions. ENB biopsies were diagnostic in 52% (70/135) of the patients. In 23 patients with solitary lung lesions, CTBs were performed following a non-diagnostic ENB biopsy. The CTBs were diagnostic in 87% of the patients (20/23). ENB biopsies of lesions <21.5 mm were non-diagnostic in 71% of cases (42/59); 14 of these patients with non-diagnostic ENB biopsies had CTBs, and 86% of them were diagnostic (12/14). ENB biopsies of lesions in the lower lobes were non- diagnostic in 59% of cases (35/59); 12 of these patients with non-diagnostic ENB biopsies had CTBs, and 83% were diagnostic (10/12). ENB biopsies of lesions in the outer 2/3 were non-diagnostic in 57% of cases (50/87); 21 of these patients with non-diagnostic ENB biopsies had CTBs, and 86% were diagnostic (18/21).

Conclusion:

CTBs have a high diagnostic yield even following non-diagnostic ENB biopsies. Lesions <21.5 mm, in the outer 2/3 of the lung, and in the lower lung have the lowest likelihood of a diagnostic yield with ENB biopsies. Although CTBs have a slightly higher pneumothorax rate, these lesions would be more successfully diagnosed with CTB as opposed to ENB biopsy, in the process expediting the diagnosis and saving valuable medical resources.

Metalophagia: Splenic artery pseudoaneurysm after foreign body ingestion and retrieval

Persistent eating of non-nutritive, nonfood substances (Pica) is seen in children and adult patients with psychiatric problems. Ingestion of multiple metallic FBs with resultant bezoar formation is rare. While many FBs are passed without complication, mucosal injury, bleeding, obstruction or perforation can occur in some cases. Endoscopic FB removal is performed in 20% of patients following FB ingestion. Generally, these are safe procedures, and very effective in extracting ingested FBs. We report, a 25-year-old male patient with a metal ingestion predominant Pica, requiring multiple prior extraction procedures (including open gastrostomy). He developed a splenic artery pseudoaneurysm following his latest endoscopic FB removal, that was successfully treated with transarterial coil embolization. The unique circumstances leading to this rare complication and its successful endovascular management make this case worthy of report.

Spontaneous hemorrhage of an adrenal myelolipoma treated with transarterial embolization: A case report

Adrenal myelolipoma is a benign tumor of the adrenal cortex composed predominantly of fat and hematopoietic tissue. These lesions are usually asymptomatic, and most often incidentally detected on imaging. Uncommonly, they present with retroperitoneal hemorrhage, and these have been traditionally treated with emergent surgery. Although, transarterial embolization has been effectively and safely used in patients presenting with active hemorrhage from acute traumatic and nontraumatic causes, literature specifically pertaining to adrenal artery embolization is scant, perhaps due to smaller size and variability of adrenal arteries. With recent advances in endovascular techniques and imaging, there are emerging case reports and series of adrenal artery embolization in acute and nonacute settings. We report a case of spontaneous hemorrhage within an adrenal myelolipoma in a 43-year-old male patient, successfully treated with transarterial embolization, thereby avoiding major surgery. Our report adds to the growing body of literature pertaining to adrenal artery embolization.

Imaging of the aortic root on high-pitch non-gated and ECG-gated CT: awareness is the key!

The aortic pathologies are well recognized on imaging. However, conventionally cardiac and proximal aortic abnormalities were only seen on dedicated cardiac or aortic studies due to need for ECG gating. Advances in CT technology have allowed motionless imaging of the chest and abdomen, leading to an increased visualization of cardiac and aortic root diseases on non-ECG-gated imaging. The advances are mostly driven by high pitch due to faster gantry rotation and table speed. The high-pitch scans are being increasingly used for variety of clinical indications because the images are free of motion artifact (both breathing and pulsation) as well as decreased radiation dose. Recognition of aortic root pathologies may be challenging due to lack of familiarity of radiologists with disease spectrum and their imaging appearance. It is important to recognize some of these conditions as early diagnosis and intervention is key to improving prognosis. We present a comprehensive review of proximal aortic anatomy, pathologies commonly seen at the aortic root, and their imaging appearances to familiarize radiologists with the diseases of this location.

A Novel Approach for Imaging of Thoracic Outlet Syndrome Using Contrast-Enhanced Magnetic Resonance Angiography (CE-MRA), Short Inversion Time Inversion Recovery Sampling Perfection with Application-Optimized Contrasts Using Different Flip Angle Evolutions (T2-STIR-SPACE), and Volumetric Interpolated Breath-Hold Examination (VIBE)

Background

The aim of this study was to introduce a novel method combining contrast-enhanced magnetic resonance angiography (CE-MRA), short inversion time inversion recovery sampling perfection with application-optimized contrasts using different flip angle evolutions (T2-STIR-SPACE) and volumetric interpolated breath-hold examination (VIBE) sequences in the assessment of thoracic outlet syndrome (TOS).

Material/Methods

CE-MRA, T2-STIR-SPACE, and VIBE techniques were employed to evaluate neurovascular bundles in 27 patients clinically suspected of TOS. Images were evaluated to determine the cause of neurovascular bundle compression. Surgical exploration was performed in patients with abnormal magnetic resonance imaging (MRI) results.

Results

Twenty patients were found to be abnormal: 6 cases showed only neurogenic TOS and the correlates included infraclavicular hemangiomas (n=1) and transverse cervical artery (n=5). Arterial-neurogenic TOS was found in 4 cases, including subclavian lymph node metastasis from breast cancer (n=3) and schwannoma (n=1). Arterial-venous-neurogenic TOS was found in 1 subject, and the correlates included a fibrous band from the cervical rib and elongated C7 transverse process. In this case, the subclavian artery/vein was compressed dynamically. Venous–neurogenic TOS was noted in one subject. Nine patients were considered as post-traumatic TOS, including brachial plexus edema (n=3), the brachial plexus rupture (n=2), peri-brachial plexus effusion (n=3), and stenosis of the SCA (n=1). In the remaining 7 patients, MRI did not detect abnormalities.

Conclusions

TOS can be evaluated by CE-MRA, T2-STIR-SPACE, and VIBE during a single examination, with a reduced contrast material dose. This imaging modality performs well in showing the anatomical structure of the neurovascular bundle and the cause of the compression.