Menisci are small fibrocartilaginous structures that are essential for the knee stability and preservation of articular cartilage. This article discusses the anatomy and function, variations, appearance and consequence of tears, and postoperative evaluation. We also address pitfalls and signs which can help improve diagnostic accuracy.

Objectives: The effect of platelet-rich plasma (PRP) treatment on recovery in acute hamstring injuries is controversial. Previous study results are inconsistent, and a standardized therapeutic approach has not been established yet. The objective of the study was to assess the treatment effect using a combination of hematoma aspiration and muscle strain PRP injection in partial hamstring muscle tears (grade 2 strains) in athletes. Methods: MRIs of athletes with grade 2 hamstring strains were reviewed from 2013 to 2018. From 2013 to 2015 athletes were treated conservatively and from 2016 to 2018 with a combination of ultrasound-guided hematoma aspiration and PRP muscle strain injection. The outcome, including return-to-play (in days) and recurrence rate, was compared retrospectively between both groups (conservative vs. aspiration/PRP) using ANOVA and Fisher’s Exact test. There was no significant difference in age, type of sport, and muscle involvement (including injury grade/location, hamstring muscle type, and length/cross-sectional area of the strain). Results: Fifty-five athletes (28 treated conservatively, 27 with hematoma aspiration/PRP injection) were included. Average return-to-play time (mean) was 32.4 days in the conservative group and 23.5 days in the aspiration/PRP group (p<0.001). Recurrence rate of the hamstring strain was 28.6% (8/28) in the conservative treatment group and less than 4% (1/27) in the aspiration/PRP group (p=0.025). Conclusions: Athletes with grade 2 hamstring strains treated with a combination of hematoma aspiration and PRP injection had a significantly shorter return-to-play and a lower recurrence rate compared to athletes receiving conservative treatment. Axial T2-weighted fat saturated image in a 24-year-old athlete shows a grade 2 strain of the biceps femoris muscle with hemorrhage/hematoma (dashed arrow) surrounding the sciatic nerve (solid arrow). Corona STIR image of the thighs in a 27-year-old athlete with a grade 2 strain of the right biceps femoris muscle shows muscle edema and fluid (solid arrow). A feathery pattern of edema is also present (dashed arrow). Axial/cross-sectional ultrasound image of the right hamstring muscle in a 25-year-old athlete shows a grade 2 strain of the semitendinosus muscle (dashed arrow) and the adjacent normal portion of the muscle (solid arrow). Long axis ultrasound image in the same patient shows hemorrhage/hematoma (solid arrow) surrounding the sciatic nerve (asterisk).

•fMRI utilization for Medicare population tremendously increased from 2007 to 2018 after the introduction of CPT codes.•fMRI is becoming standard of care for the presurgical assessment of brain tumors.•Radiologists contribute most to the fMRI services.

Objectives: The effect of platelet-rich plasma (PRP) treatment on recovery in acute hamstring injuries is controversial. Previous study results are inconsistent, and a standardized therapeutic approach has not been established yet. The objective of the study was to assess the treatment effect using a combination of hematoma aspiration and muscle strain PRP injection in partial hamstring muscle tears (grade 2 strains) in athletes. Methods: MRIs of athletes with grade 2 hamstring strains were reviewed from 2013 to 2018. From 2013 to 2015 athletes were treated conservatively and from 2016 to 2018 with a combination of ultrasound-guided hematoma aspiration and PRP muscle strain injection. The outcome, including return-to-play (in days) and recurrence rate, was compared retrospectively between both groups (conservative vs. aspiration/PRP) using ANOVA and Fisher’s Exact test. There was no significant difference in age, type of sport, and muscle involvement (including injury grade/location, hamstring muscle type, and length/cross-sectional area of the strain). Results: Fifty-five athletes (28 treated conservatively, 27 with hematoma aspiration/PRP injection) were included. Average return-to-play time (mean) was 32.4 days in the conservative group and 23.5 days in the aspiration/PRP group (p<0.001). Recurrence rate of the hamstring strain was 28.6% (8/28) in the conservative treatment group and less than 4% (1/27) in the aspiration/PRP group (p=0.025). Conclusions: Athletes with grade 2 hamstring strains treated with a combination of hematoma aspiration and PRP injection had a significantly shorter return-to-play and a lower recurrence rate compared to athletes receiving conservative treatment. Axial T2-weighted fat saturated image in a 24-year-old athlete shows a grade 2 strain of the biceps femoris muscle with hemorrhage/hematoma (dashed arrow) surrounding the sciatic nerve (solid arrow). Corona STIR image of the thighs in a 27-year-old athlete with a grade 2 strain of the right biceps femoris muscle shows muscle edema and fluid (solid arrow). A feathery pattern of edema is also present (dashed arrow). Axial/cross-sectional ultrasound image of the right hamstring muscle in a 25-year-old athlete shows a grade 2 strain of the semitendinosus muscle (dashed arrow) and the adjacent normal portion of the muscle (solid arrow). Long axis ultrasound image in the same patient shows hemorrhage/hematoma (solid arrow) surrounding the sciatic nerve (asterisk).

BACKGROUND AND PURPOSE: Prior research has shown substantial shifts in procedure shares between specialty groups providing lumbar punctures. Our aim was to analyze national trends in lumbar punctures among the Medicare population from 2010 to 2018. MATERIALS AND METHODS: Medicare Part B Physician/Supplier Procedure Summary Master Files from 2010 to 2018 were analyzed for all Current Procedural Terminology, Version 4 codes related to lumbar punctures (62270 and 62272). Lumbar puncture procedure volume and utilization rates were assessed and stratified by place of service and specialty background of the providers. RESULTS: From 2010 to 2018, the overall number of lumbar puncture procedures essentially has not changed (92,579 versus 92,533). Radiologists hold the largest and an increasing procedure share of diagnostic and overall lumbar punctures (overall share, 45.7% in 2010 [n = 42,296] versus 52.3% in 2018 [n = 48,414]). Advanced practice providers have increased their procedure share (3.7% in 2010 [n = 3388] versus 8.4% in 2018 [n = 7785], + 129.8% procedure volume). Emergency medicine physicians and neurologists have a decreasing procedure share (21.8% versus 15.3% and 12.5% versus 8.8%, respectively). The inpatient hospital setting remains the largest place of service for lumbar punctures, recording a 5.3% increase in procedure share. The emergency department lumbar puncture volume has declined, with a 7.4% decrease in the overall procedure share. Similarly, the hospital outpatient department procedure volume has increased (+4%), while the private office volume has decreased (-1.7%). CONCLUSIONS: During the past decade, lumbar puncture procedures among the Medicare population have remained stable, with a shift in procedure volume from the emergency department and private offices to the hospital setting, which has mainly affected radiologists and advanced practice providers.

Evaluation for intracranial hemorrhage is a common indication when performing imaging of the head in the emergency setting. We present a rare case of active, spontaneous extravasation of blood into the brain parenchyma, which evolved during a magnetic resonance imaging examination. A 70-year-old woman who had no previous history of hypertension or trauma underwent magnetic resonance imaging of the brain for confusion and dysarthria. Initial imaging sequences did not demonstrate an acute cerebral hemorrhage; however, subsequent fluid-attenuated inversion recovery, T2- and T1-weighted sequences demonstrated a progressively enlarging signal abnormality. Extravasation of contrast was noted after the administration of gadolinium-based contrast, indicating active intraparenchymal hemorrhage. A computed tomography scan was performed after magnetic resonance imaging to confirm the findings.

The novel coronavirus disease-2019 (COVID-19) illness and deaths, caused by the severe acute respiratory syndrome coronavirus-2, continue to increase. Multiple reports highlight the thromboembolic complications, such as pulmonary embolism (PE), in COVID-19. Imaging plays an essential role in the diagnosis and management of COVID-19 patients with PE. There continues to be a rapid evolution of knowledge related to COVID-19 associated PE. This review summarises the current understanding of prevalence, pathophysiology, role of diagnostic imaging modalities, and management, including catheter-directed therapy for COVID-19 associated PE. It also describes infection control considerations for the radiology department while providing care for patients with COVID-19 associated PE.

Doppler ultrasound (US) is a well-established and useful technique for evaluating the renovascular system and associated pathologic conditions. As with other US examinations, advantages include its noninvasive nature, relatively low-costs, and generally well-tolerated. However, the technique is highly operator-dependent and can be time-consuming. Furthermore, the interpretation of renal Doppler US examinations might be challenging for those with limited experience or those unfamiliar with fundamental concepts and nomenclature.Nevertheless, due to its benefits, the American College of Radiology (ACR) Appropriateness Criteria guidelines rate renal Doppler US as appropriate or even first-line imaging technique in various clinical scenarios, especially in patients with decreased renal function or renal transplants when contrast administration for computed tomography or magnetic resonance imaging examinations might be problematic. In this article, we review the vascular anatomy, imaging indications, and technique, along with a short discussion about clinical significance and common pathologies.

To assess the effect of gadobenate dimeglumine on magnetic resonance cholangiopancreatography (MRCP) and determine an appropriate time frame for performing MRCP sequences. 2D MRCP sequences obtained after intravenous administration of gadobenate dimeglumine or gadobutrol over 14 months were reviewed retrospectively in randomized order by five abdominal radiologists, using a 3-point scale to rate biliary and pancreatic duct clarity (1 = no-, 2 = limited-, 3 = good visualization). Intraclass correlation coefficients were computed and mean scores were compared for both agents. For gadobenate dimeglumine exams, time delays between arterial phase and MRCP acquisition times were analyzed concerning duct clarity. For gadobutrol, only exams with delays ≥ 15 min were included. 134 exams (107 gadobenate dimeglumine, 27 gadobutrol) were included. Moderate reliability for pancreatic duct visualization and excellent reliability for visualization of intrahepatic bile ducts and upper and lower extrahepatic bile ducts were noted. No difference in mean scores was noted for pancreatic duct visualization (p = 0.66). Bile duct segment scores were lower with gadobenate dimeglumine (mean: 2.1–2.6) compared with gadobutrol (mean: 2.8–2.9) (p ≤ 0.006). For gadobenate dimeglumine, visualization scores varied depending on the delay between the arterial phase and MRCP acquisition (p ≤ 0.047). Good visualization for all bile duct segments was noted with delays of 7.2–9.4 min (95% confidence interval; mean 8.3 min). Bile duct clarity degraded on MRCP images with an increasing delay following gadobenate dimeglumine injection. 2D MRCP, thus, should be performed within 7.2 min after obtaining the arterial phase sequence to ensure good visualization of the entire biliary system.

Osteoblastomas infrequently occur in the calvarium, displaying a preference for temporal and frontal bones when it does. We present an unusual case of a large, expansile osteoblastoma in the occipital bone of a 23-year-old man who presented with a nontender lump at the back of his head. Initial computed tomography scan showed a large occipital bone mass, and after additional imaging, a gross total resection was performed. Histopathological examination revealed an osteoblastoma. Although these tumors are benign, overlapping imaging characteristics of lesions affecting the calvarium often present a diagnostic dilemma. This case emphasizes the importance of imaging in the management and work-up of these patients to decrease the risk of complications and assists surgeons in their preoperative planning.

RATIONALE AND OBJECTIVES:To investigate differences in radiation dose and image quality for single-plane flat-panel-detector based interventional fluoroscopy systems from two vendors using phantom study and clinical procedures.MATERIALS AND METHODS:AlluraClarityIQ (Philips) and Artis Q (Siemens-Healthineers) interventional fluoroscopy systems were evaluated. Phantom study included comparison of system-reported air-kerma rates (AKR) for clinical protocols with simulated patient thicknesses (20-40 cm). Differences in system-reported radiation dose estimates, cumulative-air-kerma (CAK) and kerma-area-product (KAP), for different clinical procedures were investigated. Subset analysis investigated differences in CAK, KAP and other factors affecting radiation dose when the same patients underwent repeat embolization procedures performed by the same physician on the two different fluoroscopy systems. Two blinded interventional radiologists reviewed image-quality for these procedures using a five-point scale (1-5; 5-best) for five parameters.RESULTS:Phantom study revealed that air-kerma rates was significantly higher for Artis Q system for 30-40cm of simulated patient thicknesses (p < 0.05). Overall data analysis from 4381 clinical cases revealed significant differences in CAK and KAP for certain procedures (p < 0.05); with significantly lower values for AlluraClarityIQ systems (median CAK lower by: 29%-58%). Subset analysis with 40 patients undergoing repeat embolization procedures on both systems revealed that median CAK and KAP were significantly lower for AlluraClarityIQ systems (p < 0.02) by 45% and 31%, respectively. Image quality scores for AlluraClarityIQ systems were significantly greater (mean difference range for five parameters: 1.3-1.6; p < 0.005).CONCLUSION:Radiation dose and image quality differences were observed between AlluraClarityIQ and Artis Q systems. AlluraClarityIQ systems showed lower radiation utilization and an increase in subjective perception of image quality.

The purpose of this study was to compare radiation dose estimates between state-of-the-art interventional fluoroscopy systems in vitro and in clinical cases. In vitro analysis included verifying system-reported air kerma rates (AKR; with a Radcal detector) and comparing AKR for simulated patient thicknesses (20-40cm) for different dose modes and clinical protocols on Philips 'AlluraClarity' (different generations) and Siemens 'Artis Q' systems (n=4). After IRB approval, system-reported radiation dose estimates i.e., cumulative air kerma (CAK) at the interventional reference point and kerma-area product (KAP), were extracted for interventional cases performed over a 16-month period from GE Centricity RIS and compared split by procedure type. Next, CAK and KAP for patients with metastatic uveal melanoma undergoing repeat chemo/immuno-embolization (potentially high radiation dose procedure) of the same liver lobe by the same physician on AlluraClarity and Artis Q were compared, accounting for differences in patient positioning, reference locations and digital acquisitions obtained from structured dose reports using DoseMetrix (Primordial) and CareAnalytics (Siemens). IBM's SPSS Statistics was used for parametric and non-parametric tests (with Bonferroni corrections for multiple comparisons). In vitro analysis showed significant differences (p < 0.05) in verified AKR (25-45 mGy/min lower with AlluraClarity for thicknesses of 30-40 cm). Clinical data analysis comprised of 5113 cases; significant differences for CAK and KAP were seen for certain procedure (p < 0.05), with significantly lower values for AlluraClarity systems (differences in median: 34-61%). Subset analysis included 61 patients treated on both systems at different time points; accounting for differences in other parameters, CAK and KAP were significantly lower for AlluraClarity systems (p < 0.02; median for CAK lower by 44% and for KAP by 27%). Radiation dose differences observed in vitro between the AlluraClarity and Artis Q systems were reflected in clinical cases (even for same patients undergoing the same procedure). When the differences were significant, AlluraClarity systems showed relatively lower radiation utilization.

To compare radiation dose estimates and image quality between state-of-the-art interventional fluoroscopy systems in phantom and clinical cases. Phantom study used acrylic sheets simulating different patient sizes to compare air kerma rates (AKRs) for different dose modes on Philips Allura-ClarityIQ and Siemens ArtisQ systems (4 systems). After IRB approval, cumulative air kerma (CAK) at the interventional reference point and kerma-area product (KAP) were extracted for cases performed over a 16-month period and compared by procedure type between the two types of systems. Next, CAK and KAP for patients with metastatic uveal melanoma receiving repeat chemo/immuno-embolization of the same liver lobe by the same physician on both types of systems were compared, accounting for differences in patient positioning, reference locations and digital acquisitions. For these cases, image quality was scored by 2 CAQ certified interventional radiologists using a five-point scale for 5 parameters. Interclass correlation coefficient (ICC) was computed and the scores were compared between the two types of systems. IBM's SPSS Statistics was used for analysis (with Bonferroni corrections for multiple comparisons). Phantom study revealed a significant lower AKR (p<0.05) with Allura-ClarityIQ for acrylic thicknesses of 30-40cm. Clinical data contained 5113 cases; significant differences for CAK and KAP were seen in 9/16 and 3/16 procedure-types (p<0.05), respectively, with lower values for Allura-ClarityIQ systems. Subset analysis of 61 patients receiving identical treatment on both systems showed CAK and KAP were significantly lower for Allura-ClarityIQ systems (p<0.02; median for CAK lower by 44% and for KAP by 27%). Good reliability and absolute agreement was noted between readers for 5 parameters (ICC≥0.75). Image quality review scores were significantly higher for images obtained with Allura-ClarityIQ systems across all parameters (p<0.05; mean difference in scores between systems for each parameter ranging from 1.3 to 1.6). Allura-ClarityIQ systems utilized lower radiation dose and were associated with superior image quality compared with ArtisQ.