A prospective study of 12-week respiratory outcomes in COVID-19-related hospitalisations.

The long-term respiratory morbidity of COVID-19 remains unclear. We describe the clinical, radiological and pulmonary function abnormalities that persist in previously hospitalised patients assessed 12 weeks after COVID-19 symptom onset, and identify clinical predictors of respiratory outcomes. At least one pulmonary function variable was abnormal in 58% of patients and 88% had abnormal imaging on chest CT. There was strong association between days on oxygen supplementation during the acute phase of COVID-19 and both DLCO-% (diffusion capacity of the lung for carbon monoxide) predicted and total CT score. These findings highlight the need to develop treatment strategies and the importance of long-term respiratory follow-up after hospitalisation for COVID-19.

Pathological Comparisons of Paraseptal and Centrilobular Emphysema in Chronic Obstructive Pulmonary Disease.

Rationale: Although centrilobular emphysema (CLE) and paraseptal emphysema (PSE) are commonly identified on multidetector computed tomography (MDCT), little is known about the pathology associated with PSE compared with that of CLE.Objectives: To assess the pathological differences between PSE and CLE in chronic obstructive pulmonary disease (COPD).Methods: Air-inflated frozen lung specimens (n = 6) obtained from patients with severe COPD treated by lung transplantation were scanned with MDCT. Frozen tissue cores were taken from central (n = 8) and peripheral (n = 8) regions of each lung, scanned with micro-computed tomography (microCT), and processed for histology. The core locations were registered to the MDCT, and a percentage of PSE or CLE was assigned by radiologists to each of the regions. MicroCT scans were used to measure number and structural change of terminal bronchioles. Furthermore, microCT-based volume fractions of CLE and PSE allowed classifying cores into mild emphysema, CLE-dominant, and PSE-dominant.Measurements and Main Results: The percentages of PSE measured on MDCT and microCT were positively associated (P = 0.015). The number of terminal bronchioles per milliliter of lung and cross-sectional lumen area were significantly lower and wall area percentage was significantly higher in CLE-dominant regions compared with mild emphysema and PSE-dominant regions (all P < 0.05), whereas no difference was found between PSE-dominant and mild emphysema samples (all P > 0.5). Immunohistochemistry showed significantly higher infiltration of neutrophils (P = 0.002), but not of macrophages, CD4, CD8, or B cells, in PSE compared with CLE regions.Conclusions: The terminal bronchioles are relatively preserved, whereas neutrophilic inflammation is increased in PSE-dominant regions compared with CLE-dominant regions in patients with COPD.

How to Approach a Hip PARTI With Confidence: Ultrasound-Guided Parallel Transverse in-Plane Technique for Intra-articular Hip Interventions.

The "parallel transverse in-plane" technique for ultrasound-guided intra-articular hip interventions ensures needle visualization for the entire procedure, with the needle clearly shown entering the joint. With the widely described longitudinal in-plane approach, needle visualization can be poor, necessitating reliance on tissue distortion, which can reduce user confidence and safety. The parallel transverse in-plane approach is invaluable in those with anterior thigh skin breakdown and where anterior access is contraindicated. The approach also allows a broad width of the synovium to be traversed and is therefore well suited to synovial biopsy. This short Technical Innovation highlights this alternative approach to hip joint intervention.

Dynamic ultrasound-guided trochanteric bursal injection.

Injection of steroid and anesthetic into the greater trochanteric bursa is commonly performed for trochanteric bursitis, gluteus medius/minimus tendinopathy, or as a part of a barbotage procedure for gluteus medius or minimus calcific tendonosis. Trochanteric bursal injection is widely performed both with and without image guidance, and is typically viewed as low-difficulty; however optimum needle tip position can be challenging. We discuss a simple dynamic technique to aid the practitioner in optimal needle placement.

Impact of sublingual nitroglycerin dosage on FFRCT assessment and coronary luminal volume-to-myocardial mass ratio.

OBJECTIVES: Fractional flow reserve computed tomography (FFRCT) depends upon nitroglycerin (NTG) inducing maximal hyperemia. However, the impact of NTG dosages on FFRCT analysis including coronary volume-to-mass ratio (V/M) is unknown. METHODS: Eighty patients with repeat coronary CT angiograms (CCTAs) with different sublingual spray NTG doses (0.4 mg and 0.8 mg) were retrospectively analyzed with 45 patients excluded. Patient and scan demographics, post-stenosis and nadir FFRCT values, coronary volume, and coronary volume-to-mass ratio (V/M) were compared at initial CCTA (0.4 mg NTG) and follow-up CCTA (0.8 mg NTG). Differences were compared by Wilcoxon signed-rank test. RESULTS: Thirty-five patients were included (time between CCTAs, 3.9 ± 1.6 years). Segment involvement score was 2.4 ± 3.3 and 2.8 ± 3.4 at initial and repeat CCTA (0.4 and 0.8 mg NTG), respectively (p = 0.004). There was similar image quality (4.1 ± 0.7 vs 4.1 ± 0.8; p = 0.51). Nadir FFRCT values did not differ in the left (0.4 mg, 0.80 ± 0.08 vs 0.8 mg, 0.80 ± 0.03; p = 0.66), right (0.4 mg, 0.90 ± 0.04 vs 0.8 mg, 0.90 ± 0.06; p = 0.25), or circumflex coronaries (0.4 mg, 0.87 ± 0.06 vs 0.8 mg, 0.88 ± 0.06; p = 0.34). Post-stenosis FFRCT values did not differ (p = 0.65). Coronary volume increased with 0.8 mg of NTG (2639 ± 753 mm3 vs 2844.8 ± 827 mm3; p = 0.009) but V/M ratio did not (p = 0.20). CONCLUSIONS: Use of 0.8 mg versus 0.4 mg of NTG in routine clinical CCTAs significantly increased coronary volume determined from FFRCT analysis but did not alter FFRCT or V/M. Further evaluation of repeat CCTAs in a more contemporaneous fashion using varied nitrate doses and disease severity is needed. KEY POINTS: • Fractional flow reserve from computed tomography (FFRCT) is a noninvasive method for evaluating the coronary arteries and relies on nitroglycerin (NTG) to induce coronary vasodilation, but the impact of different NTG dosages is unknown. • Retrospective analysis evaluated use of different NTG doses on FFRCT. • Increased NTG dose increased coronary luminal volume on FFRCTanalysis, but did not change FFRCTvalues.

Anatomic Considerations for Injection of the Lateral Atlanto-Axial Joint.

OBJECTIVE: We aimed to define the potential complications of intra-articular steroid injections into the lateral C1-2 articulations and safety margins to the relevant structures. METHODS: A total of 488 contrast-enhanced computed tomography angiogram (CTA) "arch to vertex" studies were retrospectively reviewed for theoretical intersection of the vertebral artery or thecal sac and distance of the named structures from the anticipated/theoretical trajectory of injection into the lateral C1-C2 joint. RESULTS: Patients were 60.4±15.8 years old and 55.5% male. In total, seven vertebral arteries and 11 thecal sac theoretical intersections were found. In cases without a direct intersection, the distance from the trajectory (range) was 0.71±0.18 (0.22-1.44) cm to the vertebral artery and 0.6±0.22 (0.14-1.8) cm to the thecal sac. CONCLUSIONS: Although injection of steroid into the lateral C1-C2 articulation for pain management has historically been reported to carry risk of severe complications due to close proximity and location variability of surrounding structures, our study quantifies the potential risk of such injections. Further, our analysis suggests that preprocedural imaging should be considered.

Radial artery aneurysm secondary to dynamic entrapment by extensor pollicis longus tendon: a case of snapping thumb.

Aneurysms of the distal radial artery at the level of the wrist are rare. Most reported cases are posttraumatic, either from iatrogenic arterial puncture for radial arterial access or from a penetrating injury. Other causes include infection and connective tissue disorders. Early diagnosis is important to avoid the potential complications of thrombus formation, distal digital ischemia, and rupture. Evaluation of the radial artery is typically performed using non-invasive modalities like ultrasonography, computed tomographic angiography (CTA), and magnetic resonance angiography (MRA). Invasive angiography can also be performed, particularly if minimally invasive treatment options are being considered. We report a case of a 35-year-old male mechanic who presented with pain at the base of the left thumb dorsally, with reproducible painful snapping on dynamic exam. Ultrasound demonstrated a fusiform aneurysm of the radial artery. At the level of the aneurysm, there was dynamic entrapment of the artery between the extensor pollicis longus (EPL) tendon and the underlying trapezium. The patient's symptoms improved with conservative management and avoidance of the snapping-producing maneuvers. To our knowledge, this is the first published case of snapping at the base of the thumb resulting in repetitive entrapment of the radial artery by the EPL tendon captured on dynamic ultrasound examination.

MR epidurography: distribution of injectate at caudal epidural injection.

OBJECTIVE: To (a) evaluate the feasibility of MR epidurography (MRE) and (b) assess the distribution of injectate using two different volumes at caudal epidural steroid injection. MATERIALS AND METHODS: Twenty patients who were referred with symptomatic low back pain for caudal epidural steroid injection were assigned to have either 10 ml (9/20) or 20 ml (11/20) of injectate administered. Gadolinium was included in the injection. The patients proceeded to MRI where sagittal and coronal T1-weighted fat-saturated sequences were acquired and reviewed in the mid-sagittal and right and left parasagittal views at the level of the exit foramina. RESULTS: Gadolinium was observed at or above the L3/4 disc level in all 11 patients who received 20 ml (100 %), compared with only five of nine patients who received 10 ml (56 %). Injectate was seen to the L4 nerve root level in all 11 patients who received 20 ml (100 %) but only four out of nine patients who received 10 ml (44 %), not even reaching the L5 nerve root level in four further of these nine patients (44 %). Overall, there was a trend to visualize gadolinium at higher levels of the epidural space with higher volumes injected. CONCLUSIONS: Firstly, MR epidurography is a safe technique that allows excellent visualization of the distribution of gadolinium in the epidural space following injection via the caudal hiatus. Secondly, a volume of 10 ml is unlikely to treat L5/S1 disease in almost half of patients at caudal epidural steroid injection and at least 20 ml of injectate is likely required for any medication to reach the desired level.

Plantar plate tear diagnosis using dual-energy computed tomography collagen material decomposition application.

Computed tomography (CT) scans of the feet are often obtained in the context of trauma or suspected stress fracture mainly for assessment of osseous pathology. However, compared with magnetic resonance imaging (MRI), soft-tissue assessment on CT is typically limited. Plantar plate injury is a common cause of metatarsalgia and, along with other soft-tissue injuries, is typically diagnosed with MRI. We present a case of plantar plate tear detected on dual-energy CT scan using a collagen material decomposition algorithm confirmed on subsequent MRI.

Ultrasound assessment of the posterolateral elbow ulnohumeral gap in normal subjects with and without posterolateral drawer testing.

Background: Posterolateral rotator instability (PLRI) is the most common pattern of recurrent elbow instability, and current imaging to aid PLRI diagnosis is limited. Thus, we sought to define use of ultrasound (US) to determine normal lateral ulnohumeral joint measurements, with and without posterolateral drawer testing to provide an insight into how US may aid diagnosis. Methods: Sixty elbows were evaluated in thirty healthy volunteers. The lateral ulnohumeral gap (LUHG) was measured with US in the resting position while the posterolateral drawer stress test maneuver was applied. Joint laxity was calculated as the difference between maximum stress and average rest measurements. Two independent readers assessed each elbow with comparison performed between stress and rest positions. Results: Differences in the LUHG were evident between stress and rest conditions (reader 1: P < .0001 and reader 2: P = .0002). At rest, median LUHG values were 2.31 mm and 2.05 mm for readers 1 and 2 respectively, while at stress 2.88 mm and 2.9 mm for readers 1 and 2. Median joint laxity was 0.8 mm for reader 1 and 1.1 mm for reader 2. Pearson correlation was r = 0.457 (absolute intraclass correlation coefficient [ICC] = 0.608) while under stress and r = 0.308 (absolute intraclass correlation coefficient [ICC] = 0.417) at rest. Median joint laxity demonstrated a Pearson correlation of r = 0.161 and absolute intraclass correlation coefficient [ICC] = 0.252. Conclusions: This study demonstrates a dynamic US assessment for PLRI, which aimed to assess the usefulness and feasibility of a laxity measurement after the application of a posterolateral drawer stress maneuver in a healthy population. Although establishing concordance between readers in measuring an LUHG under stress, the utility of a laxity measurement alone is not clear as correlation of measurements is not excellent; hence, an upper limit of normal for the ulnohumeral gap under stress may be more useful. Further evaluation of this technique is required in patients with PLRI.

Dual-energy CT: a promising new technique for assessment of the musculoskeletal system.

OBJECTIVE: Dual-energy CT (DECT) characterizes the chemical composition of material according to its differential x-ray attenuation at two different energy levels. Applications of DECT in musculoskeletal imaging include imaging of bone marrow edema, tendons, and ligaments and the use of monoenergetic techniques to minimize metal prosthesis beam-attenuating artifacts. CONCLUSION: The most validated application of DECT is undoubtedly its noninvasive and highly specific ability for confirming the presence of monosodium urate deposits in the assessment of gout.

Postoperative imaging of the elbow, wrist, and hand.

There are many bone and soft tissue injuries to the elbow, wrist, and hand that are treated surgically. The operative techniques can be complicated and their indications may change. This article reviews the common injuries at the elbow, wrist, and hand, the indications for surgical management, the current and previous operative techniques used, the expected postoperative appearance on different imaging modalities, and the important potential complications of each technique.

Changes in pulmonary function and patient-reported outcomes during COVID-19 recovery: a longitudinal, prospective cohort study.

OBJECTIVES: The aim of this study was to compare respiratory and patient-reported outcome measures (PROMs) between 3 and 6 months after symptom onset and to identify features that predict these changes. METHODS: This was a consecutive prospective cohort of 73 patients who were hospitalised with coronavirus disease 2019 (COVID-19). We evaluated the changes in pulmonary function tests and PROMs between 3 and 6 months and then investigated the associations between outcomes (change in diffusing capacity of the lung for carbon monoxide (D LCO), dyspnoea and quality of life (QoL)) and clinical and radiological features. RESULTS: There was improvement in forced vital capacity, total lung capacity and D LCO between 3 and 6 months by 3.25%, 3.82% and 5.69%, respectively; however, there was no difference in PROMs. Reticulation and total computed tomography (CT) scores were associated with lower D LCO % predicted at 6 months (coefficients; -8.7 and -5.3, respectively). The association between radiological scores and D LCO were modified by time, with the degree of association between ground glass and D LCO having decreased markedly over time. There was no association between other predictors and change in dyspnoea or QoL over time. CONCLUSIONS: There is improvement in pulmonary function measurements between 3 and 6 months after COVID-19 symptom onset; however, PROMs did not improve. A higher reticulation and total CT score are negatively associated with D LCO, but this association is attenuated over time. Lastly, there is a considerable proportion of patients with unexplained dyspnoea at 6 months, motivating further research to identify the underlying mechanisms.

Cardiac MRI in arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVE: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a cause of sudden cardiac death in otherwise healthy young adults. This article outlines the spectrum of MRI findings in ARVC using a combination of static and cine images. CONCLUSION: The detection of right ventricular enlargement, fatty infiltration, fibrosis, and wall motion abnormalities at MRI is useful in the diagnosis of ARVC.

Effect of a calcium deblooming algorithm on accuracy of coronary computed tomography angiography.

BACKGROUND: Coronary artery calcification is a significant contributor to reduced accuracy of coronary computed tomographic angiography (CTA) in the assessment of coronary artery disease severity. The aim of the current study is to assess the impact of a prototype calcium deblooming algorithm on the diagnostic accuracy of CTA. METHODS: 40 patients referred for invasive catheter angiography underwent CTA and invasive catheter angiography. The CTA were reconstructed using a standard soft tissue kernel (CTASTAND) and a deblooming algorithm (CTADEBLOOM). CTA studies were read with and without the deblooming algorithm blinded to the invasive coronary angiogram findings. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value for the detection of stenosis ≥50% or ≥70% were evaluated using quantitative coronary angiography as the reference standard. Image quality was assessed using a 5-point scale, and the presence of image artifact recorded. RESULTS: All studies were diagnostic with 548 segments available for evaluation. Image score was 3.64 ±â€¯0.72 with CTADEBLOOM, versus 3.56 ±â€¯0.72 with CTASTAND (p = 0.38). CTADEBLOOM had significantly less calcium blooming artifact than CTASTAND (12.5% vs. 47.5%, p = 0.001). Based on a 50% stenosis threshold for defining significant disease, the Sensitivity/Specificity/PPV/NPV/Accuracy were 65.9/84.9/27.6/96.6/83.4 for CTADEBLOOM and 75.0/81.9/26.6/97.4/81.4 for CTASTAND using a ≥50% threshold. CTADEBLOOM specificity was significantly higher than CTASTAND (84.9% vs. 81.5%, p = 0.03), with no difference between the algorithms in sensitivity (p = 0.22), or accuracy (p = 0.15). These results remained unchanged when a stenosis threshold of ≥70% was used. Interobserver agreement was fair with both techniques (CTADEBLOOM k = 0.38, CTASTAND k = 0.37). CONCLUSION: In this proof of concept study, coronary calcification deblooming using a prototype post-processing algorithm is feasible and reduces calcium blooming with an improvement of the specificity of the CTA exam.

Modified prostate volume algorithm improves transrectal US volume estimation in men presenting for prostate brachytherapy.

PURPOSE: To evaluate the accuracy of the conventional transrectal ultrasonographic (US) prostate volume formula and determine whether a more accurate volume formula, calculated on the basis of prostate shape as observed at planimetry, can be described for the majority of prostate glands. MATERIALS AND METHODS: This retrospective study was institutional review board approved, with waiver of informed consent. A total of 138 consecutive patients who underwent prostate brachytherapy were included for analysis. Prostate volume was estimated by using the conventional prolate ellipsoid formula (length x height x width x [pi/6]). A reference standard for prostate volume was calculated by using planimetry. The mean prostate shape was assessed by using three-dimensional volume-rendering of the planimetric images. The prostate shapes were evaluated to determine the best-fit mathematic formula for accurate volume estimation. Statistical analyses were performed by using Pearson correlation, paired Student t test, Bland-Altman plots, and concordance correlation coefficient. RESULTS: Planimetric data showed the majority of prostate glands to be more bullet-shaped than ellipsoid. Only 13.3% of volumes determined by using the conventional prolate ellipsoid formula were within 10% of the planimetric volume. The prolate ellipsoid formula underestimated volume by 17% on average (95% confidence interval: 14%, 19%). A mathematic formula representing a bullet shape (length x height x width x [pi/4.8]) was determined to best represent the majority of prostate glands presented for brachytherapy; 75% of volumes were within 10% of planimetric volume by using this formula. Concordance correlation coefficient increased from 0.87 to 0.95. Formula accuracy was particularly improved in prostate glands smaller than 55 cm(3) (P = .14). CONCLUSION: A modified prostate volume formula that closely represents the shape of the prostate smaller than 55 cm(3) demonstrated improved volume measurement accuracy compared with the prolate ellipsoid formula used in men presenting for brachytherapy.

Phenotyping and outcomes of hospitalized COPD patients using rapid molecular diagnostics on sputum samples.

BACKGROUND: Etiologies of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are heterogeneous. We phenotyped severe AECOPD based on molecular pathogen detection of sputum samples collected at hospitalization of COPD patients and determined their outcomes. METHODS: We phenotyped 72 sputum samples of COPD patients who were hospitalized with a primary diagnosis of AECOPD using a molecular array that detected common bacterial and viral respiratory pathogens. Based on these results, the patients were classified into positive or negative pathogen groups. The pathogen-positive group was further divided into virus or bacteria subgroups. Admission day 1 blood samples were assayed for N-terminal prohormone brain natriuretic peptide, CRP, and complete blood counts. RESULTS: A total of 52 patients had a positive result on the array, while 20 patients had no pathogens detected. The most common bacterial pathogen detected was Haemophilus influenzae and the most common virus was rhinovirus. The pathogen-negative group had the worse outcomes with longer hospital stays (median 6.5 vs 5 days for bacteria-positive group, P=0.02) and a trend toward increased 1-year mortality (P=0.052). The bacteria-positive group had the best prognosis, whereas the virus-positive group had outcomes somewhere in between the bacteria-positive and pathogen-negative groups. CONCLUSION: Molecular diagnostics on sputum can rapidly phenotype serious AECOPD into bacteria-, virus-, or pathogen-negative groups. The bacteria-positive group appears to have the best prognosis, while pathogen-negative group has the worst. These data suggest that AECOPD is a heterogeneous event and that accurate phenotyping of AECOPD may lead to novel management strategies that are personalized and more precise.

Prognosis of CT-derived Fractional Flow Reserve in the Prediction of Clinical Outcomes.

PURPOSE: To examine the prognostic implication of fractional flow reserve (FFR) derived from coronary CT (FFRCT) in routine clinical practice. MATERIALS AND METHODS: Patients referred for FFRCT analysis at a single center between October 2015 and June 2017 were retrospectively included and followed up for rates of invasive angiography and clinical events. Two hundred seven patients underwent successful FFRCT analysis with seven lost to follow-up, leaving 200 (mean age ± standard deviation, 62.4 years ± 10.0; 49 [24.5%] women) patients for analysis. At coronary CT angiography, patients were categorized as having significant stenosis (SS) in the presence of a diameter stenosis greater than or equal to 50% (hereafter, SS positive) and flow limitation in the presence of a postlesion (that is, FFRCT measured 2 cm to the distal aspect of the lesion) FFRCT less than 0.80 (hereafter, FFRCT positive). Vessel-oriented clinical events (VOCEs) were defined as vessel-related late revascularization (>90 days), myocardial infarction, and cardiac mortality. RESULTS: At CT angiography, 130 (65%) studies were SS positive and 63 (31.5%) were FFRCT positive. At median follow-up of 477 days (range, 252-859 days), there were 26 VOCE end points in 22 patients: 22 revascularizations and four nonfatal myocardial infarctions. VOCE end points occurred in zero of 58 (0%) of SS-negative and FFRCT negative patients, in eight of 79 (10.1%) of SS-positive and FFRCT-negative patients, in zero of 12 (0%) of SS-negative and FFRCT-positive patients, and in 18 of 51 (35.3%) of SS-positive and FFRCT-positive patients (log-rank χ2 = 30.1; P < .001). At multivariable Cox regression, both FFRCT (hazard ratio per 0.1 decrease, 1.54 [95% confidence interval: 1.1, 2.2] P = .013) and stenosis (hazard ratio per unit increase, 2.16 [95% confidence interval: 1.25, 3.72] P = .006) were independently associated with VOCE. CONCLUSION: Stenosis and FFRCT are independent predictors of intermediate-term outcomes. In the absence of a stenosis greater than 50%, a positive FFRCT result is not associated with an increased intermediate risk.© RSNA, 2019Supplemental material is available for this article.See also commentary by Fairbairn and Bull in this issue.