Flexed elbow, abducted shoulder, forearm supinated (FABS) reconstruction from three-dimensional elbow MRI: diagnostic performance assessment in biceps head anatomy and pathology

AIM

To determine inter-reader analysis and diagnostic performance on digitally reconstructed virtual flexed, abducted, supinated (FABS) imaging from three-dimensional (3D) isotropic elbow magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Six musculoskeletal radiologists independently evaluated elbow MRI images with virtual FABS reconstructions, blinded to clinical findings and final diagnoses. Each radiologist recorded a binary result as to whether the tendon was intact and if both heads were visible, along with a categorical value to the type of tear and extent of retraction in centimetres where applicable. Kappa and interclass correlation (ICC) were reported with 95% confidence intervals. Areas under the receiver operating curve (AUC) were reported.

RESULTS

FABS reconstructions were obtained successfully in all 48 cases. With respect to tendon intactness, visibility of both heads, and type of tear, the Kappa values were 0.66 (0.53-0.78), 0.24 (0.12-0.37), and 0.55 (0.43-0.66), respectively. For the extent of retraction, the ICC was 0.85 (0.79-0.91) when including the tendons with and without retraction and 0.78 (0.61-0.91) when only including tendons with retraction. For tear versus no tear, AUC values were 0.82 (0.74-0.89) to 0.96 (0.91-1.01).

CONCLUSION

Digital reconstruction of FABS positioning is feasible and allows good assessment of individual tendon head tears and retraction with high diagnostic performance.

MRI Guided Adaptive Radiotherapy (MRgART) in Primary and Metastatic Liver Lesions

PURPOSE/OBJECTIVE(S)

The role of stereotactic body radiotherapy (SBRT) in the management of primary hepatic and metastatic tumors has increased significantly over the past few years. MR-Linac is rapidly gaining evidence in the delivery of ablative doses using MR guided adaptive radiotherapy (MRgART) with improved accuracy and dose coverage to the lesions. We report local control and toxicity of patients with primary and metastatic liver lesions treated with MR guided adaptive SBRT.

MATERIALS/METHODS

All patients were treated with MRgART on the Unity 1.5T MR Linacs at two institutions and consented to the ADAPT-MRL study (1). A 4DCT and MRI with abdominal compression were obtained at simulation and the primary MRI sequence used for online treatment included a T2 3D navigated scan. A balanced turbo field echo (btFFE) 2D cine motion scan was also acquired at every fraction to determine movement of the tumor to aid in internal target volume margin. All plans were treated with SBRT prescribed to 3-5 alternate daily fractions. Acute toxicity was reported according to Common Terminology Criteria for Adverse Events version 5 (CTCAE) v.5. Patient demographics, prescribed dose fractionation, acute toxicity and clinical response at 6 months were analyzed. Clinical response to treatment was measured according to RECIST criteria 1.1.

RESULTS

Between February 2021 to January 2023 a total of 30 patients were treated with 149 fractions to the liver. Patients were majority male (70%) with a median age of 66 (range 36-83). 16 patients were treated for primary hepatocellular carcinoma (HCC) of the liver and 14 patients for metastatic liver lesions. The median prescribed dose was 48 Gy (range 30-50Gy) in median 5 fractions (range (3-5 fractions). All patients completed treatment with no interruptions. The mean time from 'patient setup' to 'beam-off' was 52.6 minutes (range 37-73 minutes). Data on acute toxicity at 3 month follow up was available for 28 patients. Of these patients 7/28 (25%) had grade 1 or 2 toxicity and no >/ = grade 3 toxicity was reported. Clinical response at 6 months was available for 18 patients and showed complete response in 44% (8/18), partial response in 22% (4/18), stable disease in 22% (4/18) and progressive disease in 11.1% (2/18).

CONCLUSION

Our experience on MRgART to the liver has shown good local control and minimal acute toxicity in the treatment of primary and metastatic liver lesions. We continue to collect data on patient reported outcomes, clinical response and toxicity to determine the feasibility and safety of this system.

Direct capture of neutralized RBD enables rapid point-of-care assessment of SARS-CoV-2 neutralizing antibody titer

Neutralizing antibody (NAb) titer is a key biomarker of protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but point-of-care methods for assessing NAb titer are not widely available. Here, we present a lateral flow assay that captures SARS-CoV-2 receptor-binding domain (RBD) that has been neutralized from binding angiotensin-converting enzyme 2 (ACE2). Quantification of neutralized RBD in this assay correlates with NAb titer from vaccinated and convalescent patients. This methodology demonstrated superior performance in assessing NAb titer compared with either measurement of total anti-spike immunoglobulin G titer or quantification of the absolute reduction in binding between ACE2 and RBD. Our testing platform has the potential for mass deployment to aid in determining at population scale the degree of protective immunity individuals may have following SARS-CoV-2 vaccination or infection and can enable simple at-home assessment of NAb titer.

Controlled Apoptosis of Stromal Cells to Engineer Human Microlivers

Engineered tissue models comprise a variety of multiplexed ensembles in which combinations of epithelial, stromal, and immune cells give rise to physiologic function. Engineering spatiotemporal control of cell-cell and cell-matrix interactions within these 3D multicellular tissues would represent a significant advance for tissue engineering. In this work, a new method, entitled CAMEO (Controlled Apoptosis in Multicellular tissues for Engineered Organogenesis) enables the non-invasive triggering of controlled apoptosis to eliminate genetically-engineered cells from a pre-established culture. Using this approach, the contribution of stromal cells to the phenotypic stability of primary human hepatocytes is examined. 3D hepatic microtissues, in which fibroblasts can enhance phenotypic stability and accelerate aggregation into spheroids, were found to rely only transiently on fibroblast interaction to support multiple axes of liver function, such as protein secretion and drug detoxification. Due to its modularity, CAMEO has the promise to be readily extendable to other applications that are tied to the complexity of 3D tissue biology, from understanding in vitro organoid models to building artificial tissue grafts.

Scheduling nab-paclitaxel combined with gemcitabine as first-line treatment for metastatic pancreatic adenocarcinoma

BACKGROUND

Nab-paclitaxel plus gemcitabine (nabP+gemcitabine) offers modest survival gains for patients with metastatic pancreatic ductal adenocarcinoma (PDAC). Sequential scheduling of nabP+gemcitabine in a PDAC mouse model improved efficacy; this hypothesis was tested in a clinical trial.

METHODS

Patients with previously untreated metastatic PDAC were randomised to receive nabP+gemcitabine administered either concomitantly on the same day, or sequentially, with gemcitabine administered 24 h after nabP. The primary outcome measure was progression-free survival (PFS). Secondary outcome measures were objective response rate (ORR), overall survival (OS), safety, quality of life (QoL) and predictive biomarkers.

RESULTS

In total, 71 patients received sequential (SEQ) and 75 concomitant (CON) treatment. Six-month PFS was 46% with SEQ and 32% with CON scheduling. Median PFS (5.6 versus 4.0 months, hazard ratio [HR] 0.67, 95% confidence interval [95% CI] 0.47-0.95, p = 0.022) and ORR (52% versus 31%, p = 0.023) favoured the SEQ arm; median OS was 10.2 versus 8.2 months (HR 0.93, 95% CI 0.65-1.33, p = 0.70). CTCAE Grade ≥3 neutropaenia incidence doubled with SEQ therapy but was not detrimental to QoL. Strongly positive tumour epithelial cytidine deaminase (CDA) expression favoured benefit from SEQ therapy (PFS HR 0.31, 95% CI 0.13-0.70).

CONCLUSIONS

SEQ delivery of nabP+gemcitabine improved PFS and ORR, with manageable toxicity, but did not significantly improve OS.

CLINICAL TRIAL REGISTRATION

ISRCTN71070888; ClinialTrials.gov (NCT03529175).

Adjuvant bevacizumab for melanoma patients at high risk of recurrence: survival analysis of the AVAST-M trial

Background

Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor shown to improve survival in advanced solid cancers. We evaluated the role of adjuvant bevacizumab in melanoma patients at high risk of recurrence.

Patients and methods

Patients with resected AJCC stage IIB, IIC and III cutaneous melanoma were randomised to receive either adjuvant bevacizumab (7.5 mg/kg i.v. 3 weekly for 1 year) or standard observation. The primary end point was detection of an 8% difference in 5-year overall survival (OS) rate; secondary end points included disease-free interval (DFI) and distant metastasis-free interval (DMFI). Tumour and blood were analysed for prognostic and predictive markers.

Results

Patients (n=1343) recruited between 2007 and 2012 were predominantly stage III (73%), with median age 56 years (range 18–88 years). With 6.4-year median follow-up, 515 (38%) patients had died [254 (38%) bevacizumab; 261 (39%) observation]; 707 (53%) patients had disease recurrence [336 (50%) bevacizumab, 371 (55%) observation]. OS at 5 years was 64% for both groups [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82–1.16, P = 0.78). At 5 years, 51% were disease free on bevacizumab versus 45% on observation (HR 0.85; 95% CI 0.74–0.99, P = 0.03), 58% were distant metastasis free on bevacizumab versus 54% on observation (HR 0.91; 95% CI 0.78–1.07, P = 0.25). Forty four percent of 682 melanomas assessed had a BRAF^V600 mutation. In the observation arm, BRAF mutant patients had a trend towards poorer OS compared with BRAF wild-type patients (P = 0.06). BRAF mutation positivity trended towards better OS with bevacizumab (P = 0.21).

Conclusions

Adjuvant bevacizumab after resection of high-risk melanoma improves DFI, but not OS. BRAF mutation status may predict for poorer OS untreated and potential benefit from bevacizumab.

Clinical Trial Information

ISRCTN 81261306; EudraCT Number: 2006-005505-64

Reduction of unnecessary repeat knee radiographs during osteoarthrosis follow-up visits in a large teaching medical center

BACKGROUND

Professional organizations recommend against repeat radiographs for routine follow-up of osteoarthrosis. However, clinics frequently obtain radiographs during or before the clinical visit. The purpose of our project was to determine the baseline frequency of unnecessary knee radiographs and whether educational interventions can reduce this frequency.

METHODS

This QI project was exempt from IRB review. Radiology reports of knee radiographs were searched in our database filtered by presence of the words "severe", "degenerative", "osteoarthritis", and similar variants. We reviewed 500 consecutive corresponding medical records to confirm the presence of severe osteoarthritis, and presence of a repeat radiograph within 6 months. Indications for repeat radiographs were determined. Repeat radiographs were counted as "non-indicated" when medical records revealed no new symptoms. A focused educational intervention was provided to the orthopedic and family practice departments. An additional 500 radiology reports were evaluated 9 months after intervention in the same manner and the rate of non-indicated radiographs was calculated. Follow-up review of additional 500 radiology reports at 1-year time point was performed.

RESULTS

Our initial search returned 1517 reports. Upon evaluation of 500 studies, there were 112/500 repeat radiographs (22%); 77/500 (15%) of knee radiographs were not indicated. Upon initial follow-up evaluation of 500 studies, there were 52/500 repeat radiographs (10%) and 40/500 (8%) radiographs were not indicated. The reduction of unnecessary repeat knee radiographs rate was sustained at 1 year.

CONCLUSIONS

Focused educational intervention results in a substantial (50%) reduction of the number of unnecessary repeat knee radiographs in patients with known severe OA.

Evaluation of giant cell tumors by diffusion weighted imaging-fractional ADC analysis

BACKGROUND

A single ADC value is used in clinical practice on multi b-value acquisitions. Low b-value acquisitions are affected by intravoxel incoherent motion, which is dependent on perfusion. Giant cell tumors (GCTs) are known to exhibit early arterial enhancement and low ADC values. Mean, minimum and fractional ADC characteristics of osseous and tenosynovial GCTs are systematically evaluated.

METHODS

Tenosynovial and osseous GCTs were included. Each lesion was evaluated on conventional MRI and DWI by two musculoskeletal radiologists. ADC was measured by placing an ROI on the most confluent enhancing portion of the lesion. Fractional and best fit ADC calculations were performed using MATLAB software.

RESULTS

No statistically significant difference was found between tenosynovial and osseous lesions' ADC values. Mean ADC for all lesions was 1.0 × 10^-3 mm²/s (SD = 0.2 × 10^-3 mm²/s) and minimum ADC was 0.5 × 10^-3 mm²/s (SD = 0.3 × 10^-3 mm²/s). Average mean ADC value obtained from B50-B400 slope was 1.1 × 10^-3 mm²/s (SD = 0.2 × 10^-3 mm²/s), and the average mean ADC value obtained from B400-B800 slope was 0.8 × 10^-3 mm²/s (SD = 0.1 × 10^-3 mm²/s) [p-value <0.01].

CONCLUSION

Tenosynovial and osseous GCTs demonstrate similar and low ADC values, which become even lower when using high b-value pairs. Our study also supports the theory of intravoxel incoherent motion that becomes apparent at low b values as related to giant cell tumors, which are known to be hyperperfused.

Initial experience of CT-guided pulsed radiofrequency ablation of the pudendal nerve for chronic recalcitrant pelvic pain

AIM

To evaluate initial experience with computed tomography (CT)-guided pulsed radiofrequency ablation (pRFA) of the pudendal nerve in cases of recalcitrant neuropathic pelvic pain. Endpoints include technical feasibility, safety, and efficacy of therapy.

MATERIALS AND METHODS

Ten patients who underwent pRFA ablation for neuropathic pudendal nerve pain during the trial period were followed for response to treatment for 6 months. Each patient was treated with pRFA under CT-guidance with concurrent perineural injection of anaesthetic and/or corticosteroid. Pain scores were then measured using a numeric rating scale at fixed intervals up to 6 months.

RESULTS

All procedures were considered technically successful with no immediate complications. pRFA demonstrated improved duration of pain improvement compared to the most recent perineural injection (p=0.0195), but not compared to the initial injection (p=0.64). Reported pain scores were lower with pRFA than with both the first and most recent injection but this did not reach statistical significance (p=0.1094 and p=0.7539, respectively).

CONCLUSION

Overall, pRFA of the pudendal nerve using CT-guidance can be a safe and effective therapy. This technique provides direct visualisation of the nerve to maximise safety and efficacy while offering a novel form of therapy for patients with chronic, recalcitrant pelvic pain.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Hallux valgus and metatarsus adductus measurements: inter-reader reliability and correlations on radiographs and MRI

AIM

To assess inter-reader reliability of metatarsus adductus (MA) using the traditional method and Engel's angle (EA) on radiography and magnetic resonance imaging (MRI) and assess correlations with hallux valgus (HV).

METHODS AND MATERIALS

Ninety consecutive patients with radiographs and MRI of the foot were included. Two readers measured HV angle (HVA), traditional metatarsus adductus angle (MAA), and EA on radiographs and HVA and EA on MRI. Three- and two-way mixed model analyses were used for reader agreements. Ninety-five percent bootstrap confidence intervals were calculated. The linear mixed model was used for association between HVA and EA/MAA.

RESULTS

Mean age and male to female ratio was 54.2±15.4 and 0.4:1, respectively. Mean HVA and EA were 20.6±9.4 and 21.2±8, 21.2±8.3 and 22.4±7.5 on radiographs and MRI, respectively. Mean MAA was 18.5±5.7 on radiographs. Inter-reader agreement was good for EA (ICC=0.73, 0.6) and moderate for MAA (ICC=0.41). Positive correlations between HVA, MAA, and EA on radiographs and MRI were found, but none were statistically significant (p=0.44 and 0.87).

CONCLUSION

Engel's angle is more reproducible. Although positive correlations exist between the degrees of HV and MA, they are not statistically significant.

Role of MR Neurography for the Diagnosis of Peripheral Trigeminal Nerve Injuries in Patients with Prior Molar Tooth Extraction

BACKGROUND AND PURPOSE

Clinical neurosensory testing is an imperfect reference standard to evaluate molar tooth extraction related peripheral trigeminal neuropathy. The purpose was to evaluate the diagnostic accuracy of MR neurography in this domain and correlation with neurosensory testing and surgery.

MATERIALS AND METHODS

In this retrospective study, nerve caliber, T2 signal intensity ratio, and contrast-to-noise ratios were recorded by 2 observers using MR neurography for bilateral branches of the peripheral trigeminal nerve, the inferior alveolar and lingual nerves. Patient demographics and correlation of the MR neurography findings with the Sunderland classification of nerve injury and intraoperative findings of surgical patients were obtained.

RESULTS

Among 42 patients, the mean ± SD age for case and control patients were 35.8 ± 10.2 years and 43.2 ± 11.5 years, respectively, with male-to-female ratios of 1:1.4 and 1:5, respectively. Case subjects (peripheral trigeminal neuropathy or injury) had significantly larger differences in nerve thickness, T2 signal intensity ratio, and contrast-to-noise ratios than control patients for the inferior alveolar nerve and lingual nerve (P = .01 and .0001, .012 and .005, and .01 and .01, respectively). Receiver operating characteristic analysis showed a significant association among differences in nerve thickness, T2 signal intensity ratio, and contrast-to-noise ratios and nerve injury (area under the curve, 0.83-0.84 for the inferior alveolar nerve and 0.77-0.78 for the lingual nerve). Interobserver agreement was good for the inferior alveolar nerve (intraclass correlation coefficient, 0.70-0.79) and good to excellent for the lingual nerve (intraclass correlation coefficient, 0.75-0.85). MR neurography correlations with respect to clinical neurosensory testing and surgical classifications were moderate to good. Pearson correlation coefficients of 0.68 and 0.81 and κ of 0.60 and 0.77 were observed for differences in nerve thickness.

CONCLUSIONS

MR neurography can be reliably used for the diagnosis of injuries to the peripheral trigeminal nerve related to molar tooth extractions, with good to excellent correlation of imaging with clinical findings and surgical results.

Case study: failure of superior capsular reconstruction using dermal allograft

Superior capsular reconstruction (SCR) is a novel technique for treating irreparable rotator cuff tears in younger patients in whom a reverse total shoulder arthroplasty is not the optimal treatment choice. This case study describes a middle-aged male with a recurrent, massive, irreparable rotator cuff tear treated with SCR that subsequently failed at the glenoid attachment. The patient underwent successful arthroscopic revision of the SCR. The case illustrates the MRI and arthroscopic correlations of the failed dermal allograft reconstruction, which to our knowledge has not been previously shown in the radiology literature.

MR Neurography of Greater Occipital Nerve Neuropathy: Initial Experience in Patients with Migraine

BACKGROUND AND PURPOSE

MR imaging of peripheral nerves (MR neurography) allows improved assessment of nerve anatomy and pathology. The objective of this study was to evaluate patients with unilateral occipital neuralgia using MR neurography and to assess the differences in greater occipital nerve signal and size between the symptomatic and asymptomatic sides.

MATERIALS AND METHODS

In this case-control evaluation using MR neurography, bilateral greater occipital nerve caliber, signal intensity, signal-to-noise ratios, and contrast-to-noise ratios were determined by 2 observers.

RESULTS

Among 18 subjects with unilateral occipital migraines, the average greater occipital nerve diameter for the symptomatic side was significantly greater at 1.77 ± 0.4 mm than for the asymptomatic side at 1.29 ± 0.25 mm (P = .001). The difference in nerve signal intensity between the symptomatic and asymptomatic sides was statistically significant at 269.06 ± 170.93 and 222.44 ± 170.46, respectively (P = .043). The signal-to-noise ratios on the symptomatic side were higher at 15.79 ± 4.59 compared with the asymptomatic nerve at 14.02 ± 5.23 (P = .009). Contrast-to-noise ratios were significantly higher on the symptomatic side than on the asymptomatic side at 2.57 ± 4.89 and -1.26 ± 5.02, respectively (P = .004). Intraobserver performance was good to excellent (intraclass coefficient correlation, 0.68-0.93), and interobserver performance was fair to excellent (intraclass coefficient correlation, 0.54-0.81).

CONCLUSIONS

MR neurography can be reliably used for the diagnosis of greater occipital nerve neuropathy in patients with unilateral occipital migraines with a good correlation of imaging findings to the clinical presentation.

Impact of MR Neurography in Patients with Chronic Cauda Equina Syndrome Presenting as Chronic Pelvic Pain and Dysfunction

BACKGROUND AND PURPOSE

Chronic cauda equina syndrome, defined as persistent damage of the cauda equina nerve roots within the spinal canal can be a challenging diagnosis with varied presentations. MR neurography imaging is more commonly being used to evaluate the lumbosacral spine of patients suspected of having subacute or chronic cauda equina syndrome. Our aim was to evaluate the impact of lumbosacral plexus MR neurography in the diagnostic thinking and therapeutic management of patients presenting with chronic pelvic pain and dysfunction and suspected chronic cauda equina syndrome.

MATERIALS AND METHODS

Consecutive MR neurography lumbosacral plexus examinations at our institution were reviewed retrospectively. Relevant data collected included the following: patient demographics, clinical history, pertinent physical examination findings, preimaging diagnostic impression, prior MR imaging lumbar spine findings, MR neurography findings, postimaging diagnosis, and postimaging treatment plan. The impact of imaging on the preimaging clinical diagnosis and therapeutic management was evaluated.

RESULTS

Of 185 studies of patients who presented with chronic pelvic pain and/or dysfunction, 23 with clinically suspected chronic cauda equina syndrome and imaging findings were included in the study (2 subjects were lost to follow-up). The mean ages were 53 ± 12 years and 53 ± 16 years for men and women, respectively. The common etiologies included arachnoiditis (n = 8), tethered cord (n = 2), and simple/Tarlov cysts (n = 3). Eighteen of 23 (78%) subjects had a change in diagnosis resulting from MR neurography findings, and 5/23 (22%) had no change. Seventeen of 21 (81%) subjects had a change in management, and 4/21 (19%) had no change.

CONCLUSIONS

MR neurography impacts the diagnosis and therapeutic management of patients with suspected chronic cauda equina syndrome.

Extra-pontine myelinolysis secondary to hypernatremia induced by postpartum water restriction

A young adult female with restricted water intake during the postpartum period presented with history of progressive weakness, dizziness and tendency to fall with generalized slowing of movement. On examination, patient was anaemic, febrile and stuporous. Investigations revealed hypernatremia, delta waves in electroencephalogram (EEG) and features suggestive of extra-pontine myelinolysis on magnetic resonance imaging (MRI) of brain. After correcting hypernatremia and instituting anti-cholinergic therapy, there was a gradual but steady improvement in neurological symptoms of the patient over a period of one week and the patient was discharged in a conscious, oriented and ambulant state. As such, neuroimaging findings can be crucial in diagnosing hypernatremic encephalopathy in the postpartum period.

3D MR Neurography of the Lumbosacral Plexus: Obtaining Optimal Images for Selective Longitudinal Nerve Depiction

BACKGROUND AND PURPOSE

The number of centers currently performing 3D fat-suppressed isotropic imaging is limited. If the angular orientations of the major lumbosacral plexus nerves on 3D isotropic MR neurography could be determined, similar planes could be prescribed during acquisition of 2D or 3D nonisotropic techniques for optimal depiction of various nerves. Our aim was to determine oblique sagittal and coronal angular measurements for longitudinal depiction of lumbosacral plexus nerves. Interobserver and intraobserver performance and mean calibers of sciatic and femoral nerves were also determined.

MATERIALS AND METHODS

A consecutive series of lumbosacral plexus MR neurography examinations with 3D nerve-selective imaging performed during a 10-month period on a 3T scanner were evaluated. Two observers performed reconstructions and angular measurements. Sciatic and femoral nerve diameters were measured. Descriptive statistics and intraclass correlation coefficient correlations were used.

RESULTS

There were 52 subjects, 11 men and 41 women. Mean sagittal thecal sac angles for coronal demonstration of lumbosacral plexus nerve roots from L1 to S1 for 2 independent observers measured 13.58° ± 2.87° and 13.61° ± 2.18°. Mean sagittal femoral nerve angles were 27.78° ± 4.81° and 28.94° ± 4.49°, and mean sagittal sciatic nerve angles were -10.7° ± 3.75° and -11.82° ± 2.87°. Coronal angular measurements of the femoral and sciatic nerves were similar. The intraclass correlation coefficient was moderate (0.582-0.671) for interobserver performance. For intraobserver performance among various angular measurements, the intraclass correlation coefficient was moderate to good (0.586-0.788). Femoral nerve caliber on MR imaging was almost half that of the sciatic nerve. Mean right femoral nerve thickness was 4.52 ± 1.11 mm and 4.85 ± 0.64 mm for the 2 observers, and mean left femoral nerve thickness was 4.48 ± 0.97 mm and 4.94 ± 0.57 mm. Mean right sciatic nerve thickness was 9.71 ± 1.76 mm and 9.94 ± 0.83 mm, and mean left sciatic nerve thickness was 10.03 ± 1.71 mm and 9.98 ± 0.99 mm.

CONCLUSIONS

Angular lumbosacral plexus measurements aid in the prescription of different planes on MR imaging for the optimal longitudinal demonstration of nerves.

Engineering a perfusable 3D human liver platform from iPS cells

In vitro models of human tissue are crucial to our ability to study human disease as well as develop safe and effective drug therapies. Models of single organs in static and microfluidic culture have been established and shown utility for modeling some aspects of health and disease; however, these systems lack multi-organ interactions that are critical to some aspects of drug metabolism and toxicity. Thus, as part of a consortium of researchers, we have developed a liver chip that meets the following criteria: (1) employs human iPS cells from a patient of interest, (2) cultures cells in perfusable 3D organoids, and (3) is robust to variations in perfusion rate so as to be compatible in series with other specialized tissue chips (e.g. heart, lung). In order to achieve this, we describe methods to form hepatocyte aggregates from primary and iPS-derived cells, alone and in co-culture with support cells. This necessitated a novel culture protocol for the interrupted differentiation of iPS cells that permits their removal from a plated surface and aggregation while maintaining phenotypic hepatic functions. In order to incorporate these 3D aggregates in a perfusable platform, we next encapsulated the cells in a PEG hydrogel to prevent aggregation and overgrowth once on chip. We adapted a C-trap chip architecture from the literature that enabled robust loading with encapsulated organoids and culture over a range of flow rates. Finally, we characterize the liver functions of this iHep organoid chip under perfusion and demonstrate a lifetime of at least 28 days. We envision that such this strategy can be generalized to other microfluidic tissue models and provides an opportunity to query patient-specific liver responses in vitro.

Elderly patient's knowledge, attitudes and behaviors regarding care and maintenance of the removable prosthesis: a qualitative study

AIM

Regular care and efficient hygiene procedures play a major role in the maintenance of oral health and long-term success of removable prosthodontic treatment. The aim of this study was to assess the knowledge, attitude and behavior of the elderly patients towards care and maintenance of their removable prosthesis.

METHODS

One-hundred and forty elderly patients, who visited the Department of Prosthodontics and Dental Surgery, VMMC and Safdarjung Hospital, Delhi, India for dental treatment were recruited into this study and completed a single interviewer-administered questionnaire. The questionnaire included information on gender, age, socioeconomic status, medical status, length of use of the prosthesis, cleaning material and technique, etc.

RESULTS

It was revealed that the lack of knowledge and awareness of importance of the denture hygiene; poor socioeconomic and compromised medical status of the patients, created barriers to regular and preventive dental care of denture wearers. The oral hygiene and care practices were found to be disappointing and the knowledge about the denture's duration of use, dietary limitations, maintenance, storage methods and follow-up visits was found to be limited.

CONCLUSION

The results of this study indicate that patients' knowledge, attitudes and behavior about the importance of the dental prosthesis need to be improved. Coordinated efforts by prosthodontists, community dentists and other health professionals are required to impart dental health education about oral prosthesis hygiene, care habits, importance of the regular recalls and to promote preventive dental programmes.

Orofacial manifestations and dental considerations in association with Varadi-Papp syndrome: report of a rare case

Varadi-Papp syndrome or oral-facial-digital syndrome type VI (OFDS VI) is a rare, autosomal recessive disorder characterised by a specific congenital malformation of the cerebellum and a broad spectrum of other phenotypic findings. It is distinguished from other OFDSs by metacarpal abnormalities with central polydactyly and by cerebellar abnormalities. Treatment for such patients is often considered challenging due to the presence of intellectual disability, hypotonia, and abnormal respiratory pattern in these patients. The present article reports the oral and systemic manifestations of a 5-year-old female patient having Varadi-Papp syndrome, considerations taken in her dental treatment and the successful management performed. The patient was followed up every 3 months for 2 years, to evaluate plaque control and to continue with the plaque control regimen. Periodic oral examinations and maintenance of good oral hygiene helped to improve the quality of life of the child. This case illustrates the favourable treatment outcomes in a Varadi-Papp syndrome patient. Furthermore, the need for periodic oral examinations and maintenance of good oral hygiene to prevent any complications in such patients has been highlighted.

Glenoid notch MRI findings do not predict normal variants of the anterior and superior labrum

AIM

To determine (1) the relationship of a glenoid notch to the presence of a normal labral variant in the anterior-superior glenoid labrum; (2) the inter- and intra-observer reliability of recognising a glenoid notch; and (3) whether magnetic resonance arthrography (MRA) is more reliable than non-contrast magnetic resonance imaging (MRI) in visualising a glenoid notch.

MATERIALS AND METHODS

From 1995 through 2010, 104 patients underwent MRI or MRA before diagnostic shoulder arthroscopy by the senior author. Five blinded musculoskeletal radiologists independently read the images twice to evaluate for the presence or absence of a glenoid notch. Fifty-nine (57%) patients had normal anterior-superior labral variants. The authors calculated the relationship of the readings to the arthroscopically determined presence or absence of a normal labral variant and the reading's diagnostic performance and rater reliability.

RESULTS

On average, 38% (range 9-65%) of the glenoid scans were read as notched. The sensitivity, specificity, positive predictive value, and negative predictive value of the notch relative to the presence of a normal variant were 43.1%, 71.2%, 70.2%, and 48% versus 44.3%, 77.5%, 79.4%, and 56.1% for MRI and MRA, respectively. The overall average intra-observer κ-values were 0.438 (range 0.203-0.555) and 0.346 (range -0.102 to 0.570) for MRI and MRA, respectively. The average interobserver intra-class correlation coefficient reliability values were 0.730 (range 0.693-0.760) and 0.614 (range 0.566-0.662) for MRI and MRA, respectively.

CONCLUSIONS

A notched glenoid on MRI lacks sufficient diagnostic performance and rater reliability for the clinical detection and prediction of normal anterior-superior labral variants.

Assessment of image quality in soft tissue and bone visualization tasks for a dedicated extremity cone-beam CT system

OBJECTIVE

To assess visualization tasks using cone-beam CT (CBCT) compared to multi-detector CT (MDCT) for musculoskeletal extremity imaging.

METHODS

Ten cadaveric hands and ten knees were examined using a dedicated CBCT prototype and a clinical multi-detector CT using nominal protocols (80 kVp-108mAs for CBCT; 120 kVp- 300 mAs for MDCT). Soft tissue and bone visualization tasks were assessed by four radiologists using five-point satisfaction (for CBCT and MDCT individually) and five-point preference (side-by-side CBCT versus MDCT image quality comparison) rating tests. Ratings were analyzed using Kruskal-Wallis and Wilcoxon signed-rank tests, and observer agreement was assessed using the Kappa-statistic.

RESULTS

Knee CBCT images were rated "excellent" or "good" (median scores 5 and 4) for "bone" and "soft tissue" visualization tasks. Hand CBCT images were rated "excellent" or "adequate" (median scores 5 and 3) for "bone" and "soft tissue" visualization tasks. Preference tests rated CBCT equivalent or superior to MDCT for bone visualization and favoured the MDCT for soft tissue visualization tasks. Intraobserver agreement for CBCT satisfaction tests was fair to almost perfect (κ ~ 0.26-0.92), and interobserver agreement was fair to moderate (κ ~ 0.27-0.54).

CONCLUSION

CBCT provided excellent image quality for bone visualization and adequate image quality for soft tissue visualization tasks.

KEY POINTS

• CBCT provided adequate image quality for diagnostic tasks in extremity imaging. • CBCT images were "excellent" for "bone" and "good/adequate" for "soft tissue" visualization tasks. • CBCT image quality was equivalent/superior to MDCT for bone visualization tasks.

Endothelial function, arterial wall mechanics and intima media thickness in juvenile idiopathic arthritis

OBJECTIVES

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease of children which might persist into adulthood. Systemic inflammation seen in adult RA patients has been shown to be associated with alteration in endothelial function, arterial wall mechanics and intima media thickness. Our study was planned to assess similar changes in JIA patients.

METHODS

Thirty-one newly diagnosed JIA patients and a similar number of age- and sex-matched controls were enrolled in the study. Endothelial function was assessed by measuring flow mediated dilation and glyceryl trinitrate (GTN)-mediated dilation of the brachial artery. To assess arterial stiffness, various arterial wall mechanic parameters such as cross-sectional compliance, cross-sectional distensibility, shear stress and elastic modulus were derived. Intima media thickness of the common carotid artery was measured as a marker of subclinical atherosclerosis.

RESULTS

The brachial artery diameter at rest was found to be slightly lower in the patients than controls (0.258 ± 0.042 vs. 0.264 ± 0.039; p=0.54). No significant difference was found in flow mediated dilation (17.71 ± 9.26 vs. 16.31 ± 8.23; p=0.53), GTN mediated dilation (25.25 ± 10.02 vs. 23.66 ± 9.79; p=0.53) or FMD: GTN mediated dilation ratio (0.730 ± 0.432 vs. 0.717 ± 0.280; p=0.89) between the cases and controls. There was also no significant difference in carotid artery intima media thickness (0.065 ± 0.0068 vs. 0.068 ± 0.007; p=0.084) between cases and controls. Cases in different subsets of JIA were also analysed separately with regards to FMD, GTN mediated dilation and cIMT but no difference was found between cases in each subset and their controls. Cross-sectional compliance was significantly lower in cases than controls (0.0016 ± 0.0005 vs. 0.002 ± 0.001; p=0.034). Cross-sectional distensibility (0.009 ± 0.003 vs. 0.011 ± 0.006; p=0.14) was also found to be lower whereas diastolic wall shear stress (299.9 ± 47.08 vs. 294.9 ± 59.5; p=0.72) and elastic modulus (1138.5 ± 1085.8 vs. 911 ± 453; p=0.19) were found to be higher in cases as compared to controls. But these differences were not statistically significant. When the subsets were analysed separately for vessel wall indices, cross-sectional compliance was found to be significantly lower in systemic arthritis patients as compared to controls. A high level of intra- and inter-observer agreement was found for all the ultrasonographically evaluated parameters.

CONCLUSIONS

Arterial wall indices were found altered in JIA patients indicating increased arterial stiffness. Larger studies are required to assess endothelial dysfunction, intima media thickness and arterial stiffness in each subset of JIA patients.

Genetic basis of dental agenesis--molecular genetics patterning clinical dentistry

Tooth agenesis is one of the most common congenital malformations in humans. Hypodontia can either occur as an isolated condition (non-syndromic hypodontia) or can be associated with a syndrome (syndromic hypodontia), highlighting the heterogeneity of the condition. Though much progress has been made to identify the developmental basis of tooth formation, knowledge of the etiological basis of inherited tooth loss is still lacking. To date, the mutation spectra of non-syndromic form of familial and sporadic tooth agenesis in humans have revealed defects in various such genes that encode transcription factors, MSX1 and PAX9 or genes that code for a protein involved in canonical Wnt signaling (AXIN2), and a transmembrane receptor of fibroblast growth factors (FGFR1). The aim of this paper is to review the current literature on the molecular mechanisms responsible for selective hypodontia in humans and to present a detailed overview of causative genes and syndromes associated with hypodontia.

Humidity effects on the wetting characteristics of poly(N-isopropylacrylamide) during a lower critical solution transition

Poly(N-isopropylacrylamide) (PNIPAM) is expected to find utility in tissue engineering and drug delivery, among other biomedical applications. These applications capitalize on the intrinsic lower critical solution temperature (LCST) of the polymer: below the LCST, enthalpic gain from intermolecular hydrogen bonding between PNIPAM and water molecules dominates the solvation; above the LCST, entropic effects resulting from the intramolecular hydrogen bonding between the carboxyl and amide groups of PNIPAM lead to water expulsion. The dependence of the LCST upon the molecular weight, solvent, and solution activity (i.e., solute concentration) has been studied extensively. However, what has not been previously explored is the effect of humidity on the characteristic properties of the polymer. Herein, we show that the relative humidity affects the water adsorption dynamics of PNIPAM as well as the magnitude of the transition that occurs at the LCST of the polymer. In short, the magnitude of the LCST transition decreases with an increasing relative humidity, and the time period over which adsorption occurs decreases with the temperature.

Parental knowledge, attitudes and cultural beliefs regarding oral health and dental care of preschool children in an Indian population: a quantitative study

AIM

Preschool children are dependent upon their parents for their dental care. The aim of this study was to assess the knowledge, attitude and beliefs of parents towards oral health and dental care of their children aged 1-4 years in an Indian population.

METHODS

Parents of 620 preschool children, who visited Krishna Dental College and Hospital, Ghaziabad, India for dental treatment were recruited into this study and completed a self administered questionnaire.

RESULTS

It was revealed that the lack of knowledge and awareness of importance of the primary teeth, dental fear of the parents and the myths associated with dental treatment, created barriers to early preventive dental care of preschool children. The oral hygiene and feeding practices were found to be disappointing and the knowledge about the essential role of fluoride and transmission of Streptococcus mutans bacteria was found to be limited. The elders in the family, especially grandparents, highly influenced the decisions of the parents regarding dental treatment of their children.

CONCLUSIONS

Parents' knowledge, attitudes and beliefs about the importance of dental health need to be improved. Coordinated efforts by paediatricians, paediatric dentists and other health professionals are required to impart dental health education about oral hygiene, feeding practices, importance of the primary dentition and to promote preventive dental programmes.

Anatomic MR imaging and functional diffusion tensor imaging of peripheral nerve tumors and tumorlike conditions

BACKGROUND AND PURPOSE

A number of benign and malignant peripheral nerve tumor and tumorlike conditions produce similar imaging features on conventional anatomic MR imaging. Functional MR imaging using DTI can increment the diagnostic performance in differentiation of these lesions. Our aim was to evaluate the role of 3T anatomic MR imaging and DTI in the characterization of peripheral nerve tumor and tumorlike conditions.

MATERIALS AND METHODS

Twenty-nine patients (13 men, 16 women; mean age, 41±18 years; range, 11-83 years) with a nerve tumor or tumorlike condition (25 benign, 5 malignant) underwent 3T MR imaging by using anatomic (n=29), functional diffusion, DWI (n=21), and DTI (n=24) techniques. Images were evaluated for image quality (3-point scale), ADC of the lesion, tractography, and fractional anisotropy of nerves with interobserver reliability in ADC and FA measurements.

RESULTS

No significant differences were observed in age (benign, 40±18 versus malignant, 45±19 years) and sex (benign, male/female=12:12 versus malignant, male/female=3:2) (P>.05). All anatomic (29/29, 100%) MR imaging studies received "good" quality; 20/21 (95%) DWI and 21/24 (79%) DTI studies received "good" quality. ADC of benign lesions (1.848±0.40×10(-3) mm2/s) differed from that of malignant lesions (0.900±0.25×10(-3) mm2/s, P<.001) with excellent interobserver reliability (ICC=0.988 [95% CI, 0.976-0.994]). There were no FA or ADC differences between men and women (P>.05). FA of involved nerves was lower than that in contralateral healthy nerves (P<.001) with excellent interobserver reliability (ICC=0.970 [95% CI, 0.946-0.991]). ADC on DTI and DWI was not statistically different (P>.05), with excellent intermethod reliability (ICC=0.943 [95% CI, 0.836-0.980]). Tractography differences were observed in benign and malignant lesions.

CONCLUSIONS

3T MR imaging and DTI are valuable methods for anatomic and functional evaluation of peripheral nerve lesions with excellent interobserver reliability. While tractography and low FA provide insight into neural integrity, low diffusivity values indicate malignancy in neural masses.

miRNA-transcription factor interactions: a combinatorial regulation of gene expression

Developmental processes require a precise spatio-temporal regulation of gene expression wherein a diverse set of transcription factors control the signalling pathways. MicroRNAs (miRNAs), a class of small non-coding RNA molecules have recently drawn attention for their prominent role in development and disease. These tiny sequences are essential for regulation of processes, including cell signalling, cell development, cell death, cell proliferation, patterning and differentiation. The consequence of gene regulation by miRNAs is similar to that by transcription factors (TFs). A regulatory cascade essential for appropriate execution of several biological events is triggered through a combinatorial action of miRNAs and TFs. These two important regulators share similar regulatory logics and bring about a cooperative action in the gene regulatory network, dependent on the binding sites present on the target gene. The review addresses the biogenesis and nomenclature of miRNAs, outlines the mechanism of action and regulation of their expression, and focuses on the combinatorial action of miRNAs and TFs for the expression of genes in various regulatory cascades.

High-resolution 3T MR neurography of the brachial plexus and its branches, with emphasis on 3D imaging

With advancement in 3D imaging, better fat-suppression techniques, and superior coil designs for MR imaging and the increasing availability and use of 3T magnets, the visualization of the complexity of the brachial plexus has become facile. The relevant imaging findings are described for normal and pathologic conditions of the brachial plexus. These radiologic findings are supported by clinical and/or EMG/surgical data, and corresponding high-resolution MR neurography images are illustrated. Because the brachial plexus can be affected by a plethora of pathologies, resulting in often serious and disabling complications, a better radiologic insight has great potential in aiding physicians in rendering superior services to patients.

Central odontogenic fibroma of the mandible

Central odontogenic fibroma (COF) is an extremely rare benign tumor that accounts for 0.1% of all odontogenic tumors. It appears as an asymptomatic expansion of the cortical plate of the mandible or maxilla. Radiologically it presents as a unilocular or multilocular radiolucency. It responds well to surgical enucleation with no tendency for recurrence. We describe a case of COF in mandibular right posterior region in a 16-year-old female. The lesion was surgically removed and analyzed histopathologically.

Prevalence of dental anxiety and fear among five to ten year old children: a behaviour based cross sectional study

AIM

Dental anxiety and fear pose a considerable challenge for the practice of clinical dentistry as these are problematic entities in the management of child patients and present a potential barrier to the utilization of oral health care services. The aim of this study was to estimate the prevalence of dental anxiety and fear among the 5-10 years aged Indian child population.

METHODS

A total of 523 children aged 5-10 years and their parents, visiting Krishna Dental College, Ghaziabad, India were finally recruited in this study. Dental Fear/anxiety distribution in the children was studied using the Indian parent's version of the Dental Subscale of the Children's Fear Survey Schedule (CFSS-DS). Total fear scores were calculated separately for boys and girls and at different age levels. The collected data was statistically analyzed using a SPSS statistical program.

RESULTS

The estimated prevalence of dental anxiety among 5 to 10 year old children in the study population was 6.3%. The overall median CFSS-DS score was 23 and the overall mean value of CFSS-DS score was 24. The prevalence of dental anxiety in children aged 5 years was 7.9%, 7.1% for 6 years old, 6.6% in 7 years old, 6.5% in 8 years old, 6.3% for 9 year old children and 5.8% in children aged 10 years. No statistically significant gender differences were found in the dental anxiety scores. The most fear provoking situations were the sight of injections, the drilling procedures by the dentist, touch of a stranger and noise of drilling by the dentist.

CONCLUSION

The results of this study indicate the need for preventive health education and intervention programmes in India to prevent and reduce dental anxiety/fear and to promote children's oral health.

Peripheral nerve surgery: the role of high-resolution MR neurography

High-resolution MRN is becoming increasingly available due to recent technical advancements, including higher magnetic field strengths (eg, 3T), 3D image acquisition, evolution of novel fat-suppression methods, and improved coil design. This review describes the MRN techniques for obtaining high-quality images of the peripheral nerves and their small branches and imaging findings in normal as well as injured nerves with relevant intraoperative correlations. Various microsurgical techniques in peripheral nerves, such as neurolysis, nerve repairs by using nerve grafts, and conduits are discussed, and MRN findings of surgically treated nerves are demonstrated.

The role of magnetic resonance imaging in the diagnostic evaluation of malignant peripheral nerve sheath tumors

BACKGROUND AND AIMS

Malignant peripheral nerve sheath tumors (MPNSTs) are the leading cause of mortality in patients with neurofibromatosis type-1 (NF1)); however, they may also arise sporadically. Differences in magnetic resonance imaging (MRI) features between MPNSTs arising in NF1 subjects versus non-NF1 subjects have not been studied before. The accuracy of MRI in distinguishing MPNSTs from benign peripheral nerve sheath tumors (BPNSTs) has also been debated. The objective of this study was to determine the potential differentiating MRI features between (a) NF1-related and non-NF1-related MPNSTs and (b) MPNSTs and BPNSTs.

MATERIALS AND METHODS

We retrospectively evaluated the MRI studies of 21 patients (12 NF1 subjects and nine non-NF1 subjects) with MPNSTs and 35 patients with BPNSTs. In all studies, the lesions were assessed in terms of size, margins, T1 and T2 signal characteristics, internal architecture, pattern of contrast enhancement, invasion of adjacent structures and necrosis/cystic degeneration as well as for the presence of tail-, target- and split-fat signs.

RESULTS

MPNSTs of NF1 subjects occurred at an earlier age and displayed a higher incidence of necrosis/cystic degeneration compared with MPNSTs of non-NF1 subjects. Compared with BPNSTs, MPNSTs were significantly larger at the time of diagnosis and demonstrated a higher incidence of ill-defined margins (specificity 91%, sensitivity 52%) and invasion of adjacent structures (specificity 100%, sensitivity 43%).

CONCLUSIONS

Differences exist between NF1-related and non-NF1-related MPNSTs regarding the age of occurrence and MRI appearance. In the MRI evaluation of peripheral nerve sheath tumors, the presence of ill-defined tumor margins and/or invasion of adjacent structures are highly specific for malignancy.

The controversial issue of centric relation: a historical and current dental perspective?

Human mandible is related to the anatomic skull in several positions among these; centric relation is a significant spatial position. It contributes not only as a reference position to build optimal occlusion in artificial dentition, but is also related to sound periodontal health and stomatognatic function. The purpose of this article is to critically discuss the historical and current definitions of centric relation, the different methods used for recording the same and its clinical implication in the restorative dental practice.