Did Jesus Die by Suffocation?: An Appraisal of the Evidence.

A majority of medical and lay articles regarding crucifixion, and specifically the crucifixion of Jesus Christ, now state that suffocation was the primary cause of death from crucifixion. An in-depth analysis reveals that this theory is based on a form of torture unrelated to crucifixion and that no evidence directly linking suffocation to crucifixion has been published. Indeed, a thorough review of available ancient evidence from literature, artwork, graffiti, and modern archeology and re-enactment studies reveals no evidence in favor of suffocation and much evidence against suffocation as the cause of death in typically-portrayed crucifixions, and particularly for the crucifixion of Jesus Christ. Researchers are encouraged to look elsewhere for the most likely cause or causes of death from crucifixion. It may be time to abandon the idea that suffocation was the primary cause of death in crucifixion.

Degenerative tears of the posterior horn of the medial meniscus: correlation between MRI findings and outcome following intra-articular steroid/bupivacaine injection of the knee.

AIM: To evaluate the response of symptomatic degenerative tears of the posterior horn of the medial meniscus to guided intra-articular knee steroid/bupivacaine injection and to correlate clinical outcomes with preprocedural findings at magnetic resonance imaging (MRI). MATERIALS AND METHODS: Sixty patients who had clinical and MRI evidence of a symptomatic degenerative tear of the posterior horn of the medial meniscus, isolated or accompanied by additional features of degenerative arthritis, who had failed conservative approaches (physiotherapy, non-steroidal anti-inflammatories, and 3 months rest/knee bracing) were included in the study. Patients underwent intra-articular knee steroid/bupivacaine injection and were followed clinically for a minimum of 6 months. Preprocedural MRI findings were correlated with duration of symptoms, clinical response to injection (recorded as complete, partial or no response) and duration of response to injection. RESULTS: Forty-nine of 60 patients (82%) reported an improvement in symptoms following guided intra-articular knee steroid/bupivacaine injection (complete: 25 patients (42%), partial: 24 (40%) patients). Improvement was sustained in 32 of 60 patients (53%) at follow-up. Thirteen of 18 patients (72%) who had an isolated degenerative tear of the posterior horn of the medial meniscus recorded a complete resolution of symptoms. This was sustained at follow-up in 10 patients (56%). CONCLUSION: Intra-articular steroid/bupivacaine knee joint injection reduced pain symptoms in the majority of patients (81.7%) with degenerative tears of the posterior horn of the medial meniscus, usually with a sustained response. Preprocedural MRI appearances correlate with response to injection. Patients with isolated tears are more likely to have a favourable outcome.

Use of Lean Six Sigma methodology shows reduction of inpatient waiting time for peripherally inserted central catheter placement.

AIM: The aim of this study was to assess the use of Lean Six Sigma methodology to improve the turnaround time (TAT) for inpatient peripherally inserted central catheter (PICC) placement. MATERIALS AND METHODS: Value stream mapping was used to analyse the workflow process for inpatient PICC placement and to divide it into its component parts. Unnecessary steps were eliminated and variation minimised in the remaining processes. The TAT for PICC line placement was recorded for the 6 months prior to implementation of changes, and subsequently, at the 6-month and 2-year follow-up points. RESULTS: Prior to implementing the changes, the mean TAT for PICC line placement was 3.74±3.28 days (95% confidence interval [CI]=3.3-4.17). Six months after implementation, the mean TAT was 1.89±1.82 days (95% CI=1.72-2.06, p<0.0001). The reduction was sustained such that at 2 years post-implementation the mean TAT was 1.88±1.87 days (95% CI=1.78-1.99, p<0.0001). This was achieved despite a 13.8% increase in overall interventional radiological activity. CONCLUSION: By applying Lean Six Sigma methodology to the complex multifactorial processes involved from ordering a PICC to its final insertion, it was possible to identify areas for improvement and to introduce simple, effective measures that resulted in a significant sustained decrease in the TAT without additional resources.

Differing MRI appearances of symptomatic proximal hamstring tendinopathy with ageing: a comparison of appearances in patients below and above 45 years.

AIM: To compare magnetic resonance imaging (MRI) appearances of symptomatic proximal hamstring tendinopathy (PHT) in younger (<45 years) and older (>45 years) patients. MATERIALS AND METHODS: MRI of patients with symptomatic PHT were reviewed and compared to asymptomatic age- and sex-matched controls. Appearances recorded were as: type 0, normal tendon; type I, intra-substance signal abnormality; type II, ischial bone and soft-tissue oedema with/without type I findings; type III, curvilinear fluid signal tearing with/without type II findings; type IV, bony avulsion. Disease pattern was compared between age groups using Fisher's exact test. RESULTS: Thirty-one symptomatic patients (18 male, 13 female; mean age 42 years) were identified. Imaging findings of 16 patients >45 years, 15 patients <45 were as follows: type 0 n=8, type I n=7, type II n=6, type III n=10, type IV n=0. Those >45 years tended to have type III tendinopathy, no examples of type III disease were found in patients <45 years (p<0.001). No significant difference in disease pattern was seen between males and females (p=0.39). Seven of 31 controls >45 years had type III findings and four controls <45 years had type I findings. CONCLUSION: MRI appearances of symptomatic PHT differ with age. Differences may reflect mechanism, whereby overuse-related micro-tearing of healthy tendons occurs in young patients versus degenerative tendinopathy in older patients. Abnormal tendon appearances in patients >45 years may or may not be symptomatic. In contrast, abnormalities identified in younger patients are generally symptomatic. These described differences are important in the primary diagnosis and may impact upon patient response to therapy.

Ozone-augmented percutaneous discectomy: a novel treatment option for refractory discogenic sciatica.

AIM: To assess the short and medium-term efficacy and safety of a novel, minimally invasive therapeutic option combining automated percutaneous lumbar discectomy, intradiscal ozone injection, and caudal epidural: ozone-augmented percutaneous discectomy (OPLD). MATERIALS AND METHODS: One hundred and forty-seven patients with a clinical and radiological diagnosis of discogenic sciatica who were refractory to initial therapy were included. Fifty patients underwent OPLD whilst 97 underwent a further caudal epidural. Outcomes were evaluated using McNab's score, improvement in visual analogue score (VAS) pain score, and requirement for further intervention. Follow-up occurred at 1 and 6 months, and comparison was made between groups. RESULTS: OPLD achieved successful outcomes in almost three-quarters of patients in the short and medium term. OPLD achieved superior outcomes at 1 and 6 months compared to caudal epidural. There was a reduced requirement for further intervention in the OPLD group. No significant complications occurred in either group. DISCUSSION: OPLD is a safe and effective treatment for patients with refractory discogenic sciatica in the short and medium term. OPLD has the potential to offer an alternative second-line minimally invasive treatment option that could reduce the requirement for surgery in this patient cohort.

Medial joint line bone bruising at MRI complicating acute ankle inversion injury: what is its clinical significance?

AIM: To assess the incidence and clinical significance of medial joint line bone bruising following acute ankle inversion injury. MATERIALS AND METHODS: Forty-five patients who underwent ankle magnetic resonance imaging (MRI) within 2 weeks of acute ankle inversion injury were included in this prospective study. Integrity of the lateral collateral ligament complex, presence of medial joint line bone bruising, tibio-talar joint effusion, and soft-tissue swelling were documented. Clinical follow-up at 6 months was carried out to determine the impact of injury on length of time out of work, delay in return to normal walking, delay in return to sports activity, and persistence of medial joint line pain. RESULTS: Thirty-seven patients had tears of the anterior talofibular ligament (ATFL). Twenty-six patients had medial joint line bone bruising with altered marrow signal at the medial aspect of the talus and congruent surface of the medial malleolus. A complete ATFL tear was seen in 92% of the patients with medial joint line bone bruising (p = 0.05). Patients with an ATFL tear and medial joint line bone bruising had a longer delay in return to normal walking (p = 0.0002), longer delay in return to sports activity (p = 0.0001), and persistent medial joint line pain (p = 0.0003). There was no statistically significant difference in outcome for the eight patients without ATFL tears. CONCLUSION: Medial joint line bone bruising following an acute ankle inversion injury was significantly associated with a complete ATFL tear, longer delay in the return to normal walking and sports activity, as well as persistent medial joint line pain. Its presence should prompt detailed assessment of the lateral collateral ligament complex, particularly the ATFL.

Prevalence and clinical significance of chondromalacia isolated to the anterior margin of the lateral femoral condyle as a component of patellofemoral disease: observations at MR imaging.

OBJECTIVE: To determine the prevalence of chondromalacia isolated to the anterior margin of the lateral femoral condyle as a component of patellofemoral disease in patients with anterior knee pain and to correlate it with patient demographics, patellar shape, and patellofemoral alignment. MATERIALS AND METHODS: Retrospective study over a 1-year period reviewing the MR knee examinations of all patients who were referred for assessment of anterior knee pain. Only patients with isolated lateral patellofemoral disease were included. Age, gender, distribution of lateral patellofemoral chondromalacia, and grade of cartilaginous defects were documented for each patient. Correlation between the distribution of lateral patellofemoral chondromalacia and patient demographics, patellar shape, and indices of patellar alignment (femoral sulcus angle and modified Q angle) was then ascertained. RESULTS: There were 50 patients (22 males, 28 females) with anterior knee pain and isolated patellofemoral disease. The majority of the patients (78 %) had co-existent disease with grade 1 chondromalacia. No significant correlation was found between patients with chondromalacia isolated to the anterior margin of the lateral femoral condyle and age, gender, patellar shape, or modified Q angle (p > 0.05). However, patients with chondromalacia isolated to the anterior margin of the lateral femoral condyle had a shallower femoral sulcus angle (mean 141.8°) compared to the patients with lateral patellar facet disease (mean 133.8°) (p = 0.002). CONCLUSIONS: A small percentage of patients with anterior knee pain have chondromalacia isolated to the anterior margin of the lateral femoral condyle. This was associated with a shallower femoral sulcus angle.

Co-existent medial collateral ligament injury seen following transient patellar dislocation: observations at magnetic resonance imaging.

This study reports on a series of patients who were diagnosed as having had a transient lateral patellar dislocation by magnetic resonance imaging (MRI). The images were reviewed with specific reference to the medial collateral ligament (MCL), a heretofore undescribed concomitant injury. Eighty patients were diagnosed on MRI as having had transient lateral patellar dislocation. Their mean age was 23.9 years (SD 7.5). Forty patients (50.0%) had co-existent MCL injuries. These injuries were classified as grade 1 (n = 20), grade 2 (n = 17) and grade 3 (n = 3). These results suggest that MCL injury commonly accompanies transient lateral patella dislocation, most likely due to a shared valgus injury. It appears to occur more commonly in male patients and if unidentified may explain both delayed recovery and persistent morbidity in more severe cases. In this setting, without specifically excluding co-existent MCL injury, the current vogue for early rehabilitation should be adopted with caution.

Does biventricular pacing improve hemodynamics in children undergoing routine congenital heart surgery?

Biventricular (BiV) pacing or cardiac resynchronization therapy (CRT) is an established therapy for heart failure in adults. In children, cardiac dyssynchrony occurs most commonly following repair of congenital heart disease (CHD) where multisite pacing has been shown to improve both hemodynamics and ventricular function. Determining which patient types would specifically benefit has not yet been established. A prospective, repeated measures design was undertaken to evaluate BiV pacing in a cohort of children undergoing biventricular repair for correction of their CHD. Hemodynamics, arterial blood gas, electrocardiographic (ECG), and echocardiographic data were collected. Pacing protocol was undertaken prior to the patient's extubation with 20 min of conventional right ventricular (RV) or BiV pacing, preceded and followed by 10 min of recovery time. Multivariate statistics were used to analyze the data with p values <0.05 considered significant. Twenty-five (14 female) patients underwent surgery at a median (range) age of 5.2 (0.1-37.4) months with no early mortality. The Risk-adjusted classification for Congenital Heart Surgery (RACHS) scores were 2 in 14 patients, 3 in eight patients, and 4 in three patients. None had pre-existing arrhythmias, dyssynchrony, or required pacing pre-operatively. No patient required implantation of a permanent pacemaker post-operatively. The median cardio-pulmonary bypass time was 96 (55-236) min. RV and BiV pacing did not improve cardiac index from baseline (3.23 vs. 3.42 vs. 3.39 L/min/m2; p > 0.05). The QRS duration was not changed with pacing (100 vs. 80 vs. 80 ms; p > 0.05). On echocardiography, the time-to-peak velocity difference between the septal and posterior walls (synchrony) during pacing was similar to baseline and was also not statistically significant. BiV pacing did not improve cardiac output when compared to intrinsic sinus rhythm or RV pacing in this cohort of patients. Our study has shown that BiV pacing is not indicated in children who have undergone routine BiV congenital heart surgery. Further prospective studies are needed to assess the role of multisite pacing in children with ventricular dyssynchrony such as those with single ventricles, those undergoing reoperation or those with high RACHS scores.

Recurrent rectal prolapse following primary surgical treatment.

PURPOSE: The management of recurrent rectal prolapse following initial surgical procedures remains unclear. We present a series of pediatric patients with rectal prolapse and describe their surgical management, and the subsequent care for those children developing recurrence. METHODS: The records of 29 pediatric patients with rectal prolapse refractory to conservative medical management who were managed with primary modified Thiersch procedures over a 14-year period were reviewed. Initial surgical management consisted of a modified version of the Thiersch anal encirclement procedure, which involved a combination of injection sclerotherapy, linear cauterization, and placement of a Thiersch anal encirclement absorbable stitch. Age at initial procedure, predisposing conditions, complications, recurrence, time to recurrence, and subsequent procedures utilized were reviewed. RESULTS: Of 29 patients, 22 (71%) were male with a mean age at time of first Thiersch procedure of 7.1 years (range 3 months to 19 years). Seven patients were lost to follow-up. Nineteen patients (90%) experienced resolution of their prolapse following one or two modified Thiersch procedures; 14 (67%) following an initial Thiersch and 5 (23%) following a subsequent Thiersch. One additional child experienced recurrence after an initial Thiersch procedure, and underwent a perineal resection of redundant rectum (modified Altemeier procedure). Two patients developed a recurrence after their second Thiersch. These cases both required a modified Altemeier procedure. Mean follow-up for all patients was 1.5 years. CONCLUSION: For pediatric rectal prolapse refractory to conservative medical therapy, the modified Thiersch procedure appears reasonable. Initial recurrences are not uncommon, and their incidence increases with the age of the child. Recurrences should be initially managed by a repeat Thiersch procedure. However, subsequent recurrences should be treated with a modified Altemeier.

Alveolar rhabdomyosarcoma originating between the fourth and fifth metatarsal--case report and literature review.

We report a case of alveolar rhabdomyosarcoma arising between the fourth and fifth metatarsal. A 13-year-old boy presented to outpatients with a history of pain and swelling in the lateral aspect of his left forefoot. Plain radiographs and MRI showed a soft tissue mass displacing the fourth metatarsal. Percutaneous biopsy revealed an alveolar rhabdomyosarcoma. Staging scans showed advanced metastatic disease. The patient was treated with chemotherapy. This highly malignant lesion remains challenging to diagnose, and difficult to treat successfully.

Overuse ankle injuries in professional Irish dancers.

BACKGROUND: Overuse ankle injuries have been described in elite athletes and professional ballet dancers however the spectrum of injuries experienced by professional Irish dancers has not been defined. METHODS: A troupe of actively performing dancers from an Irish-dance show were recruited (eight male, ten female; mean age, 26 years). The prevalence of overuse injuries in the right ankle was determined from magnetic resonance imaging. Foot and ankle self-report questionnaires were also completed (AOFAS and FAOS). RESULTS: Only three ankles were considered radiologically normal. Achilles tendinopathy, usually insertional, was the most frequent observation (n=14) followed by plantar fasciitis (n=7), bone oedema (n=2) and calcaneocuboid joint degeneration (n=2). There were limited correlations between MRI patterns and clinical scores indicating that many conditions are sub-clinical. Dancers with ankle pain had poor low (p=0.004) and high (p=0.013) level function. CONCLUSIONS: Overuse ankle injuries are common in Irish dancers. Incorporating eccentric exercises and plantar fascia stretching into a regular training program may benefit this population.

Mineral rich algae with pine bark improved pain, physical function and analgesic use in mild-knee joint osteoarthritis, compared to Glucosamine: A randomized controlled pilot trial.

INTRODUCTION: Osteoarthritis (OA) is characterised by synovial joint pain, functional disability and affects ∼13 % of people worldwide, of which ∼16-27 % report Knee-OA (KOA). Glucosamine (Glu) is the most widely used nutraceutical treatment for OA despite a lack of scientific consensus, therefore alternative nutraceutical treatments are required. The aim of this study was to investigate the effect of Lithothamnion species, seawater-derived magnesium and pine bark (Aq+) on pain, symptoms and improve physical function in symptomatic (sKOA), compared to Glu. METHODS: 358 participants were screened. In a double-blinded crossover pilot-trial, sKOA participant (n = 30) were randomly assigned to either the Glu group (2000 mg day-1) or Aq+ (3056 mg day-1) for 12 weeks (clinicaltrials.gov:NCT03106584). The Knee Injury and Osteoarthritis Outcome Score was used to assess subjective pain and symptoms. Timed-up-and-Go (TuG) and Six minute walking distance were used to assess functional change and analgesic use was recorded. RESULTS: Aq+ improved pain, with a large effect (P < 0.01, d' = 0.73, 95 %CI 0.201-1.265) and no change for Glu (d' = 0.38, P = 0.06). Only Aq+ improved pain (P < 0.05) for males (d' = 0.91, 95 %CI 0.162-1.667) and females (d' = 0.55, 95 %CI 0.210-1.299). In females, Aq+ improved TuG by -7.02 % (d' = 0.92, 95 %CI 1.699-0.141) while Glu worsened performance by 4.18 % (P = 0.04). Aq+ reduced analgesia by 71.6 %, compared to Glu (P = 0.02; d' = 0.82, 95 %CI 1.524-0.123). Aq+ was superior to Glu at improving pain, KOOS subscales, physical function and analgesia use in mild-sKOA. Given these data, Aq+ should be considered as a supplementary treatment for early-stage-KOA and may have the potential to reduce use of pain medication, although larger replication studies are required.

Subtraction of time-resolved magnetic resonance angiography images improves visualization of the pulmonary veins and left atrium in adults with congenital heart disease: a novel post-processing technique.

To describe a novel time-resolved magnetic resonance angiography (TR-MRA) postprocessing technique using the time-resolved angiography with interleaved stochastic trajectories (TWIST) method to evaluate the pulmonary veins and left atrium in adults with congenital heart disease undergoing cardiac MRI. Institutional ethics committee approved the study. 21 consecutive adult patients (14 female, 7 male patients, mean age 28 years) with known congenital heart disease who underwent a cardiac MRI were included. Post-processing of the TR-MRA sequences created novel "subtracted" datasets. Two independent observers reviewed the conventional TWIST and novel subtracted TWIST data sets in source and maximum intensity projection (MIP) coronal reformats to assess visualization of the pulmonary veins and left atrium based on a 5-point scale. Quantitative signal to noise (SNR) comparison was performed. TR-MRA yielded diagnostic image data in 20/21 patients (95.2%). The novel "subtracted" TR-MRA technique improved visualization of the pulmonary veins and left atrium compared to the source TR-MRA sequence in 16/20 patients (mean scores 3.34 ± 0.69 vs. 2.92 ± 0.69, p < 0.008). Further improved visualization of the pulmonary veins and left atrium was observed in the subtracted MIP TWIST sequences compared to the MIP TWIST images (mean scores 4.43 ± 0.80 vs. 3.02 ± 0.87 vs., p < 0.001). No significant SNR difference between the source and novel subtracted group was observed (85.4 vs. 70.4, p = 0.57). Compared to source TR-MRA images, subtraction of TR-MRA images is a novel postprocessing technique that improves visualization of the pulmonary veins and left atrium in a substantial number of patients.

Three Tesla MRI for the diagnosis of meniscal and anterior cruciate ligament pathology: a comparison to arthroscopic findings.

AIM: To assess the accuracy of 3T magnetic resonance imaging (MRI) in the evaluation of meniscal and anterior cruciate ligament (ACL) injury. MATERIALS AND METHODS: Sixty-one consecutive patients were identified who were referred for evaluation of suspected intra-articular pathology with a 3T MRI and who, subsequently, underwent an arthroscopic procedure of the knee were included for the study. Two musculoskeletal radiologists interpreted the images. The sensitivity, specificity, positive predictive value, and negative predictive value were then calculated for the MRI versus the arthroscopic findings as a reference standard. RESULTS: The sensitivity and specificity for the overall detection of meniscal tears in this study was 84 and 93%, respectively. The results for the medial meniscus separately were 91 and 93% and for the lateral 77 and 93%. The evaluation of ACL integrity was 100% sensitive and specific. The meniscal tear type was correctly identified in 75% of cases and its location in 94%. CONCLUSION: This study demonstrates good results of 3T MRI in the evaluation of the injured knee. Caution should still be given to the interpretation on MRI of a lateral meniscus tear, and it is suggested that the standard diagnostic criteria of high signal reaching the articular surface on two consecutive image sections be adhered to even at these higher field strengths.

The posterior cruciate ligament-preserving total knee replacement: do we 'preserve' it? A radiological study.

Our aims were to map the tibial footprint of the posterior cruciate ligament (PCL) using MRI in patients undergoing PCL-preserving total knee replacement, and to document the disruption of this footprint as a result of the tibial cut. In 26 consecutive patients plain radiography and MRI of the knee were performed pre-operatively, and plain radiography post-operatively. The lower margin of the PCL footprint was located a mean of 1 mm (-10 to 8) above the upper aspect of the fibular head. The mean surface area was 83 mm(2) (49 to 142). One-third of patients (8 of 22) had tibial cuts made below the lowest aspect of the PCL footprint (complete removal) and one-third (9 of 22) had cuts extending into the footprint (partial removal). The remaining patients (5 of 22) had footprints unaffected by the cuts, keeping them intact. Our study highlights the wide variation in the location of the tibial PCL footprint when referenced against the fibula. Proximal tibial cuts using conventional jigs resulted in the removal of a significant portion, if not all of the PCL footprint in most of the patients in our study. Our findings suggest that when performing PCL-retaining total knee replacement the tibial attachment of the PCL is often removed.

Whole body MR imaging: applications in oncology.

This article reviews technique and clinical applications of whole body MR imaging as a diagnostic tool in cancer staging. In particular the article reviews its role as an alternative to scintigraphy (bone scan and PET) in staging skeletal spread of disease, its role in assessing total tumour burden, its role in multiple myeloma and finally its evolving non oncologic role predominantly assessing total body composition.

Bertolotti's syndrome. A cause of back pain in young people.

Bertolotti's syndrome is characterised by anomalous enlargement of the transverse process(es) of the most caudal lumbar vertebra which may articulate or fuse with the sacrum or ilium and cause isolated L4/5 disc disease. We analysed the elective MR scans of the lumbosacral spine of 769 consecutive patients with low back pain taken between July 2003 and November 2004. Of these 568 showed disc degeneration. Bertolotti's syndrome was present in 35 patients with a mean age of 32.7 years (15 to 60). This was a younger age than that of patients with multiple disc degeneration, single-level disease and isolated disc degeneration at the L4/5 level (p

Percutaneous vertebroplasty--initial clinical experience in osteoporotic and myelomatous compression fractures.

BACKGROUND: To review the clinical impact of vertebroplasty in osteoporotic and myelomatous compression fractures METHODS: Eleven compression fractures in eight patients were treated by percutaneous cement vertebroplasty over a three-year period, May 2000 to May 2003. RESULTS: Successful percutaneous stabilisation and cement injection was performed in all compression fractures. In five of eight patients (eight of eleven compression fractures) injection of cement yielded dramatic reduction in pain within 24 hours of the procedure. CONCLUSION: Preliminary experience suggests that percutaneous cement vertebroplasty is an effective well tolerated method of stabilisation of spinal wedge compression fractures resulting in dramatic reduction in associated pain in most cases.

A comparison of fast MRI of hips with and without parallel imaging using SENSE.

This study was undertaken to qualitatively and quantitatively compare fast MRI of hips with and without parallel imaging using SENSE (sensitivity encoding). 27 patients underwent MRI of the hips with coronal T1 turbo spin echo (TSE) (repetition time (TR) 500 ms, effective echo time (TEeff) 15 ms, Turbo Factor 4), coronal IR-TSE (TR 2000 ms, TEeff 30 ms, inversion time (TI) 160 ms, Turbo Factor 20) and axial T2 TSE (TR 3000 ms, TEeff 80 ms, Turbo Factor 20) weighted images acquired with and without SENSE with a reduction factor of 2. Conventional imaging was performed in 8 min and 36 s. Images acquired with SENSE were acquired in 5 min and 31 s without a discernible reduction in image quality or a significant quantitative reduction in image signal to noise ratio, contrast to noise ratio or edge enhancement.