Comparison of 3T MR arthrography and 3T MRI in intra-articular hip pathology: a cost-analysis

BACKGROUND

MR arthrography (MRA) has previously been the radiological gold standard for investigating labral and chondral lesions of the hip joint. In recent years, 3T MRI has demonstrated comparable accuracy, being adopted as the first-line imaging investigation in many institutions.

AIMS

We compare the associated increased cost and radiation dose of the fluoroscopic component of the MRA compared to MRI.

METHODS

In this retrospective review over 2 years, 120 patients (mean age 27.3 years ± 13.2, range 8-67) underwent 3T MRA or non-contrast 3T MRI. Three musculoskeletal radiologists reported the data independently. Primary objectives included cost-comparison between each and radiation dose of the fluoroscopic component of the MRA. Secondary objectives included comparing detection of pathology involving the acetabular labrum, femoral cartilage, and acetabular cartilage.

RESULTS

Then, 58 (48%) underwent 3T MRA and 62 (52%) patients underwent 3T MRI. The added cost of the fluoroscopic injection prior to MRA was €116.31/patient, equating to €7211.22 savings/year. MRA was associated with a small radiation dose of 0.003 mSv.

CONCLUSIONS

Transitioning from 3T MRA to 3T MRI in the investigation of intra-articular hip pathology increases cost savings and reduces radiation dose.

Are brake response times altered post CT-guided cervical spine nerve root injections?

OBJECTIVES

To assess if brake response times are altered pre and post CT-guided cervical spine nerve root injections.

METHODS

Brake response times were assessed before and after CT-guided cervical spine nerve root injections in a cohort of patients. The average of 3 brake response times was recorded before and 30 min after injection. Statistical analysis was performed using GraphPad. A paired Student t-test was used to compare the times before and after the injections.

RESULTS

Forty patients were included in this study. The mean age was 55 years. There were 17 male and 23 female patients. There was no significant difference in the mean pre and post CT-guided cervical spine nerve root injection brake response times; 0.94 s (range 0.4-1.2 s) and 0.93 s (range 0.5-1.25 s), respectively (P = .77).

CONCLUSIONS

Brake response time did not significantly differ pre and 30 min post CT-guided cervical spine nerve root injections.

ADVANCES IN KNOWLEDGE

To the authors' best knowledge, there are no current studies assessing brake response times post CT-guided cervical spine nerve root injections. While driving safety cannot be proven by a single metric, it is a useful study in demonstrating that this is not inhibited in a cohort of patients.

Chronic exertional compartment syndrome of the quadriceps femoris

Chronic exertional compartment syndrome is well documented in the distal extremities, but is rare in the thighs. We present the case of a 19-year-old male who presented with chronic, recurrent bilateral thigh pain induced by physical activity, which settled with rest but recurred on immediate return to exercise. Postexercise MRI of both thighs demonstrated changes of symmetrical edema in the proximal quadriceps muscles, reflecting exercise-induce compartment syndrome. The patient underwent selective fasciotomies of each anterior thigh with improvement of symptoms. The patient is now doing well, with some residual milder symptoms and appearances on follow-up MR imaging are not as pronounced. This case describes the clinical presentation and imaging appearance of a rare case of chronic compartment syndrome in the quadriceps femoris.

Imaging of acute lower limb muscle injury and potential gender differences

OBJECTIVES

To assess the most common lower limb acute muscle injuries on MRI imaging in a national specialist centre for orthopaedics and sports medicine and to explore potential gender differences.

METHODS

Over a 3-year time period, all MRI lower limb studies with acute muscle injury (AMI) were reviewed. A British Athletics muscle injury classification (BAMIC) was given and a statistical analysis was performed.

RESULTS

A total of 195 AMIs were diagnosed: 177 (91%) male and 18 (9%) female injuries (M to F = 9.8:1). The most common lower limb AMIs were BAMIC grade 1a injuries (n = 48, 25%). The most commonly injured muscle was biceps femoris (n = 87, 45%), specifically grade 1b and grade 2b injuries. There was no significant difference in age between men and women with acute lower limb muscle injuries (p = 0.19). Females were 1.5 times more likely to have a lower grade AMI than males, although this did not reach statistical significance (p = 0.7) owing to a striking lower number of female patients. There was no significant difference between genders in the likelihood of sustaining a hamstring or quadricep AMI (hamstrings OR = 2.47, p = 0.14 and quadriceps OR = 0.926, p 0.99).

CONCLUSIONS

Grade 1a is the most common lower limb AMI grade in our institution, accounting for 25%. Biceps femoris is the most commonly injured muscle (45%) with grade 1b and grade 2b being the most frequently encountered grades of biceps femoris injuries. Lower-grade injuries are more common in females compared to males, although not significantly so. Further studies are required to explore possible reasons for this gender gap.

Radiographic appearances of a continuous glucose monitor in a patient with lipodystrophy

We report the case of a 50-year old woman with a known history of lipodystrophy. A pelvic radiograph was taken for the investigation of right hip pain. The image shown demonstrates an indeterminate artefact projected over the right iliac fossa. A previous CT renal study was reviewed, demonstrating the same device in the subcutaneous tissues of the contralateral left lower quadrant which on close inspection was consistent with a continuous glucose monitoring device. Features of lipodystrophy were also noted on review of the CT imaging. Although many devices such as vagal stimulators and prosthetic valves are easily recognized by radiologists on radiographic images, they may be less familiar with devices such as continuous glucose monitors. The aim of this case report is to familiarize radiologists with the appearances of continuous glucose monitors to allow for effective reporting.

Combined autologous blood patch-immediate patient rollover does not reduce the pneumothorax or chest drain rate following CT-guided lung biopsy compared to immediate patient rollover alone

PUPROSE

The purpose of this study was to evaluate a combined autologous blood-patch (ABP)-immediate patient rollover (IPR) technique compared with the IPR technique alone on the incidence of pneumothorax and chest drainage following CT-guided lung biopsy.

METHODS

In this interventional cohort study of both prospectively and retrospectively acquired data, 652 patients underwent CT-guided lung biopsy. Patient demographics, lesion characteristics and technical biopsy variables including the combined ABP-IPR versus IPR alone were evaluated as predictors of pneumothorax and chest drain rates using regression analysis.

RESULTS

The combined ABP-IPR technique was performed in 259 (39.7 %) patients whilst 393 (60.3 %) underwent IPR alone. There was no significant difference in pneumothorax rate or chest drains required between the combined ABP-IPR vs IPR groups (p =.08, p =.60 respectively). Predictors of pneumothorax adjusted for the combined ABP-IPR and IPR alone groups included age (p =.02), lesion size (p =.01), location (p =.005), patient position (p =.008), emphysema along the needle track (p =.005) and lesion distance from the pleura (p =.02). Adjusted predictors of chest drain insertion included lesion location (p =.09), patient position (p =.002), bullae crossed (p =.02) and lesion distance from the pleura (p =.02).

CONCLUSION

The combined ABP-IPR technique does not reduce the pneumothorax or chest drain rate compared to the IPR technique alone. Utilising IPR without an ABP following CT-guided lung biopsy results in similar pneumothorax and chest drain rates while minimising the potential risk of systemic air embolism.

cytoNet: Spatiotemporal network analysis of cell communities

We introduce cytoNet, a cloud-based tool to characterize cell populations from microscopy images. cytoNet quantifies spatial topology and functional relationships in cell communities using principles of network science. Capturing multicellular dynamics through graph features, cytoNet also evaluates the effect of cell-cell interactions on individual cell phenotypes. We demonstrate cytoNet’s capabilities in four case studies: 1) characterizing the temporal dynamics of neural progenitor cell communities during neural differentiation, 2) identifying communities of pain-sensing neurons in vivo, 3) capturing the effect of cell community on endothelial cell morphology, and 4) investigating the effect of laminin α4 on perivascular niches in adipose tissue. The analytical framework introduced here can be used to study the dynamics of complex cell communities in a quantitative manner, leading to a deeper understanding of environmental effects on cellular behavior. The versatile, cloud-based format of cytoNet makes the image analysis framework accessible to researchers across domains.

Pre-operative radiomics model for prognostication in resectable pancreatic adenocarcinoma with external validation

OBJECTIVES

In resectable pancreatic ductal adenocarcinoma (PDAC), few pre-operative prognostic biomarkers are available. Radiomics has demonstrated potential but lacks external validation. We aimed to develop and externally validate a pre-operative clinical-radiomic prognostic model.

METHODS

Retrospective international, multi-center study in resectable PDAC. The training cohort included 352 patients (pre-operative CTs from five Canadian hospitals). Cox models incorporated (a) pre-operative clinical variables (clinical), (b) clinical plus CT-radiomics, and (c) post-operative TNM model, which served as the reference. Outcomes were overall (OS)/disease-free survival (DFS). Models were assessed in the validation cohort from Ireland (n = 215, CTs from 34 hospitals), using C-statistic, calibration, and decision curve analyses.

RESULTS

The radiomic signature was predictive of OS/DFS in the validation cohort, with adjusted hazard ratios (HR) 2.87 (95% CI: 1.40-5.87, p < 0.001)/5.28 (95% CI 2.35-11.86, p < 0.001), respectively, along with age 1.02 (1.01-1.04, p = 0.01)/1.02 (1.00-1.04, p = 0.03). In the validation cohort, median OS was 22.9/37 months (p = 0.0092) and DFS 14.2/29.8 (p = 0.0023) for high-/low-risk groups and calibration was moderate (mean absolute errors 7%/13% for OS at 3/5 years). The clinical-radiomic model discrimination (C = 0.545, 95%: 0.543-0.546) was higher than the clinical model alone (C = 0.497, 95% CI 0.496-0.499, p < 0.001) or TNM (C = 0.525, 95% CI: 0.524-0.526, p < 0.001). Despite superior net benefit compared to the clinical model, the clinical-radiomic model was not clinically useful for most threshold probabilities.

CONCLUSION

A multi-institutional pre-operative clinical-radiomic model for resectable PDAC prognostication demonstrated superior net benefit compared to a clinical model but limited clinical utility at external validation. This reflects inherent limitations of radiomics for PDAC prognostication, when deployed in real-world settings.

KEY POINTS

• At external validation, a pre-operative clinical-radiomics prognostic model for pancreatic ductal adenocarcinoma (PDAC) outperformed pre-operative clinical variables alone or pathological TNM staging. • Discrimination and clinical utility of the clinical-radiomic model for treatment decisions remained low, likely due to heterogeneity of CT acquisition parameters. • Despite small improvements, prognosis in PDAC using state-of-the-art radiomics methodology remains challenging, mostly owing to its low discriminative ability. Future research should focus on standardization of CT protocols and acquisition parameters.

Ireland's recent contribution to the radiological literature; a bibliometric analysis

The aim of this study was to identify and analyse all articles published by Irish radiology departments in the medical literature since the year 2000. The PubMed database was searched to identify and review all articles published by radiologists based in the Republic of Ireland or Northern Ireland. Citation counts were then obtained and the top ten most cited articles were identified. There were 781 articles published during the study period. Of these, 558 (71%) were published in radiology journals and the remaining 223 (29%) were published in general medical journals. Abdominal radiology was the most represented sub-specialty (33% of all articles). There was a general trend of increased publications per year. Only 75 (9.6%) of articles were collaborative efforts by more than one radiology department. Irish radiology departments have a considerable research output and this has increased since the year 2000. More collaborative research between Irish radiology departments is encouraged.

Evaluation of a computer tracking program for resident-patient encounters

OBJECTIVE

To examine the effectiveness of a formal tracking system for residents' clinical experiences.

DESIGN

We examined three shifts, selected at random, for each resident (without residents' knowledge) during emergency rotations. Information from patient charts was compared with residents' computerized records for rotation (location and preceptor) and patient (age, sex, diagnosis, and procedure) information.

SETTING

The Northeastern Ontario Family Medicine Program, a program designed to provide remote, rural, and northern resident experience.

PARTICIPANTS

First-, second-, and third-year residents on emergency rotations in the academic years 1992 to 1994.

MAIN OUTCOME MEASURES

Compliance, reliability, and validity of tracking records.

RESULTS

Residents recorded patient encounters 88% of the time. Compliance with rotation information was high (100% rotation, 94% preceptor). Agreement on patient age and sex was high. Procedure compliance was somewhat lower (83%). Intrarater reliability (91%) and inter-rater reliability (78%) are acceptably high, as is validity when compared with a gold standard entry (88%).

CONCLUSIONS

Regular entry of reliable and valid data is facilitated by the computerized resident-patient encounter tracking program. This computer tool should prove useful for multilevel program evaluation in the future.

First-year family medicine residents' use of computers: knowledge, skills and attitudes

OBJECTIVE

To identify the computer knowledge, skills and attitudes of first-year family medicine residents.

DESIGN

Cross-sectional survey of family medicine residents during the academic year 1993-94; sampling began in July 1993 and ended in October 1993.

SETTING

Canada.

PARTICIPANTS

All 727 first-year family medicine residents, of whom 433 (60%) responded.

OUTCOME MEASURES

Previous computer experience or training, current use, barriers to use, and comfort with and attitudes regarding computers.

RESULTS

There was no difference in age or sex between the respondents and all first-year family medicine residents in Canada. French-speaking respondents from Quebec were underrepresented (p < 0.001). Only 56 respondents (13%) felt extremely or very comfortable with computer use. The most commonly cited barriers to obtaining computer training were lack of time (243 respondents [56%]) and the high cost of computers (214 [49%]) but not lack of interest (69 [16%]). Most residents wanted more computer training (367 [85%]) and felt that computer training should be a mandatory component of family medicine training programs (308 [71%]).

CONCLUSIONS

Computer knowledge and skills and comfort with computer use appear low among first-year family medicine residents in Canada, and barriers to acquisition of computer knowledge are impressive. Computer training should become an integral part of family medicine training in Canada, and user-friendly applicable computer systems are needed.

Hay supplements to overcome underfeeding of dairy cows. 1. Early lactation

Seventy-seven cows of mixed breeds were allocated a range of pasture only or pasture/hay diets for the first 60 days of lactation. The variation in level of pasture intake was achieved by stripgrazing. The average in vitro dry matter digestibility and nitrogen content of the pasture offered was 72.0 and 3.11 % respectively, while those of the hay were 63.3 and 2.24%. The pasture alone treatments examined the effects of underfeeding on dairy cow productivity and the pasture/hay treatments established the extent to which these effects could be overcome by the use of hay as a supplement to limited pasture. After 60 days, all cows were grazed as one group at a stocking rate of 6.0 cows ha-1. Underfeeding in the first 60 days of lactation resulted in a loss of 68.3 kg milk/cow for each kg reduction in daily pasture intake, together with a decline in liveweight and body condition. When hay was offered as a supplement, it overcame the effects of underfeeding to a large extent although milk production still declined by 31.3 kg/cow for each kg reduction in daily pasture intake. There was a residual loss in milk production of 0.6 times the immediate loss for 60 days of underfeeding. The residual benefit gained from feeding hay at any level of underfeeding averaged 0.5 times the immediate benefit. Hay was unable to counteract completely the effects of underfeeding because its nutritive value for production was only half that of pasture, and the cows could not eat enough of it to overcome this. Some possible variations to these results are considered, taking into account the quality of the pasture and hay used. The economic use of hay as a supplement to limited pasture is discussed. Providing hay is used as a genuine supplement, the use of it will be economic as long as the cost of a kg of hay is less than the price paid for 0.049 kg butterfat. The limitations to this calculation are discussed.