Biomechanical Assessment of Liver Integrity: Prospective Evaluation of Mechanical Versus Acoustic MR Elastography.

BACKGROUND: Magnetic resonance elastography (MRE) can quantify tissue biomechanics noninvasively, including pathological hepatic states like metabolic dysfunction-associated steatohepatitis. PURPOSE: To compare the performance of 2D/3D-MRE using the gravitational (GT) transducer concept with the current commercial acoustic (AC) solution utilizing a 2D-MRE approach. Additionally, quality index markers (QIs) were proposed to identify image pixels with sufficient quality for reliably estimating tissue biomechanics. STUDY TYPE: Prospective. POPULATION: One hundred seventy participants with suspected or confirmed liver disease (median age, 57 years [interquartile range (IQR), 46-65]; 66 females), and 11 healthy volunteers (median age, 31 years [IQR, 27-34]; 5 females). FIELD STRENGTH/SEQUENCE: Participants were scanned twice at 1.5 T and 60 Hz vibration frequency: first, using AC-MRE (2D-MRE, spin-echo EPI sequence, 11 seconds breath-hold), and second, using GT-MRE (2D- and 3D-MRE, gradient-echo sequence, 14 seconds breath-hold). ASSESSMENT: Image analysis was performed by four independent radiologists and one biomedical engineer. Additionally, superimposed analytic plane shear waves of known wavelength and attenuation at fixed shear modulus were used to propose pertinent QIs. STATISTICAL TESTS: Spearman's correlation coefficient (r) was applied to assess the correlation between modalities. Interreader reproducibility was evaluated using Bland-Altman bias and reproducibility coefficients. P-values <0.05 were considered statistically significant. RESULTS: Liver stiffness quantified via GT-2D/3D correlated well with AC-2D (r ≥ 0.89 [95% CI: 0.85-0.92]) and histopathological grading (r ≥ 0.84 [95% CI: 0.72-0.91]), demonstrating excellent agreement in Bland-Altman plots and between readers (κ ≥ 0.86 [95% CI: 0.81-0.91]). However, GT-2D showed a bias in overestimating stiffness compared to GT-3D. Proposed QIs enabled the identification of pixels deviating beyond 10% from true stiffness based on a combination of total wave amplitude, temporal sinusoidal nonlinearity, and wave signal-to-noise ratio for GT-3D. CONCLUSION: GT-MRE represents an alternative to AC-MRE for noninvasive liver tissue characterization. Both GT-2D and 3D approaches correlated strongly with the established commercial approach, offering advanced capabilities in abdominal imaging compared to AC-MRE. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Functional Articulating Antibiotic Spacers for Chronic Native Septic Knee Arthritis.

Background: Semipermanent functional spacers are now utilized for prosthetic joint infection in an attempt to avoid another surgery with 2-stage treatment. This study evaluates the results of metal-on-polyethylene articulating spacers for the treatment of chronic native septic knee arthritis. Methods: This is a retrospective review of 18 patients treated with metal-on-polyethylene articulating antibiotic spacers constructed with all-polyethylene tibial components or with polyethylene inserts (PIs) with Steinmann pins or screws for chronic native knee infection. Demographic information, spacer construct type, prior knee surgery, complications, infecting organisms, infection eradication, and functional results were analyzed. Results: Of 18, 8 (44%) spacers were all-polyethylene tibial components and 10 (56%) were PI. Of 18 patients, 5 (28%) experienced spacer complications. Of 18 patients, 12 (67%) underwent a second reimplantation surgery (mean 106 days), while 6 (33%) retained their spacer (average duration 425 days). The PI group performed better in Knee Injury and Osteoarthritis Outcome score for Joint Replacement according to minimum clinically important difference and patient acceptable symptom state (PASS) criteria. The overall reimplantation group achieved Knee Injury and Osteoarthritis Outcome score for Joint Replacement PASS criteria and minimum clinically important difference criteria, while the maintained articulating spacer group did not achieve PASS criteria; however, they did reach minimum clinically important difference. Conclusions: Functional articulating spacers are a viable treatment for chronic, native knee septic arthritis. The PI patient group had a greater improvement in Knee Injury and Osteoarthritis Outcome score for Joint Replacement scores and had no significant difference in reimplantation rate as the all-polyethylene tibial components patient group. Both planned 2-stage reimplantation and longer-term spacer retention show promising results for this difficult clinical problem.

Enhancing PSMA PET/CT imaging of prostate cancer: investigating the impact of multiple time point evaluation, diuretic administration, cribriform pattern, and intraductal carcinoma.

OBJECTIVE: Our objective was to correlate staging PSMA PET imaging parameters to final histopathology. Second objective was to assess the performance of standard versus delayed PSMA PET to detect primary prostate tumor. METHODS: Thirty-one patients (mean age, 61.4 ± 8.2) who underwent radical prostatectomy and preoperative staging PSMA PET scans were included in the study. After defining dominant lesion in pathology, correlations with PET images were performed. Additionally, two physicians blind to clinical and pathological information retrospectively reviewed staging Ga-68 PSMA PET scans with standard and delayed imaging. RESULTS: Dominant lesion SUV's increased with time 8.2(± 4.5), 10(± 7.1), and 10.2(± 7.8) at 1, 2, and 3 h (P = .03 T1-T3). WHO Grade group 3 had highest SUV (group 3 11.9 ± 5.6 vs. group 2 7.9 ± 1.5, p = .02). Addition of cribriform pattern on intraductal component was associated with higher SUV's (11 ± 2.9 vs. 6.5 ± 2.1, p = .01) and higher Gleason four ratios (64 ± 9% vs. 37 ± 17%, p = .01). Intraductal carcinoma was associated with larger tumors (6.3 ± 2.3 cm3 vs. 2.6 ± 1.7 cm3, p < .001). Physician sensitivities ranged from 61 to 81%. Excluding Gleason 3 + 3 lesions and small lesions (< 1 cm3), sensitivities increased to 80-100%. Differences of sensitivity between different time points were not significant. Combined evaluation of all time points did not increase sensitivity. CONCLUSIONS: Cribriform pattern correlates with higher Gleason 4 ratios and SUVs in PSMA PET. Intraductal carcinoma is associated with larger tumors but not higher Gleason 4 ratios and SUVs. Multiple late imaging times did not enhance tumor detection and may pose tolerability issues for some patients.

Inconsistency and Ambiguity Within the International Classification of Disease 10 Procedure Coding System for Hip Fractures.

BACKGROUND: The International Statistical Classification of Diseases (ICD), 10th Revision Procedure Coding System (PCS) was created to increase the granularity of procedural coding. These codes are entered by hospital coders from information derived from the medical record. Concern exists that this increase in complexity could lead to inaccurate data. METHODS: Medical records and ICD-10-PCS codes were reviewed for operatively treated geriatric hip fractures from January 2016 through February 2019 at a tertiary referral medical center. Definitions for each of the 7-unit figures from the 2022 American Medical Association's ICD-10-PCS official codebook were compared to the medical, operative, and implant records. RESULTS: There were 56% (135 of 241) of PCS codes that had ambiguous, partially incorrect, or frankly incorrect figures within the code. One or more inaccurate figures were noted in 72% (72 of 100) of fractures treated with arthroplasty compared to 44.7% (63 of 141) treated with fixation (P < .01). There was at least 1 frankly incorrect figure contained in 9.5% (23 of 241) of codes. Approach was coded ambiguously for 24.8% (29 of 117) of pertrochanteric fractures. Device/implant codes were partially incorrect in 34.9% (84 of 241) of all hip fracture PCS codes. Hemi and total hip arthroplasties were partially incorrect in 78.4% (58 of 74) and 30.8% (8/26) of device/implant codes, respectively. Significantly more femoral neck (69.4%, 86 of 124) than pertrochanteric fractures (41.9%, 49 of 117) had 1 or more incorrect or partially correct figures (P < .01). CONCLUSION: Despite the increased granularity of ICD-10-PCS codes, the application of this system is inconsistent and often incorrect when applied to hip fracture treatments. The definitions in the PCS system are difficult to be utilized by coders and do not reflect the operation performed.

Physiological fluorodeoxyglucose uptake of spinal cord in adults.

OBJECTIVE: Physiological fluorodeoxyglucose (FDG) uptake of spinal cord needs to be correctly recognized during evaluation of whole-body PET scans, especially for oncological cases. Our aim was to analyze physiological cord FDG uptake and its relation to gender, age, body weight, environmental temperature and time to imaging. MATERIALS AND METHODS: PET scans of 254 patients in a single year, one patient for every working day were retrospectively selected. Temperature data were obtained from meteorology recordings. Maximum standard uptake value (SUVmax) of spinal cord at cervical and lower thoracic levels were noted. Spinal canal at L5 level, cerebellum and liver were used for normalization. Correlations with age, body weight, time to imaging and environmental temperature were analyzed. RESULTS: Cervical SUV was higher than thoracic SUV (2.5-2.3). Cervical and lower thoracic SUV's were strongly correlated, highest when corrected with L5 level vertebral canal and liver (corr coeff 0.84 and 0.75) and lowest with cerebellum (corr coeff 0.4). Cervical spinal cord FDG uptake was higher for females than males (2.6 to 2.4). Temperature and age did not change spinal cord uptake. There were weak positive correlations with body weight (corr coeff 0.16 and 0.28, cervical and thoracic). There was weak negative correlation of cervical uptake with time to imaging (corr coeff -0.17). CONCLUSION: Spinal cord FDG uptake at cervical and lower thoracic levels are strongly correlated. Females have slightly higher cervical SUV. Age and temperature does not change spinal cord FDG uptake in adults. Cord SUV's slightly increased with body weight.

A comparison of propofol-midazolam and midazolam alone for sedation in endobronchial ultrasound-guided transbronchial needle aspiration: a retrospective cohort study.

OBJECTIVES: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a new, minimally invasive, bronchoscopic technique used in the evaluation of inthrathoracic lymph nodes.Use of sedation drugs before the procedure differs among centres. There is no standardization about sedation before EBUS-TBNA.We used a policy decision to shift from use of propofol with midazolam vs midazolam alone in a large tertiary hospital to evaluate the diagnostic yield and safety of EBUS-TBNA procedure. METHODS: Files of all the patients who were performed EBUS-TBNA between the dates of September 2010 and May 2014 were surveyed. All the EBUS-TBNA cases were performed under sedation of propofol and midazolam with an accompanying anesthesiologist in the beginning, however, sedation is applied with midazolam without an accompanying anesthesiologist after April 2013 due to changes in sedation policy. The diagnostic yield and complication rates were compared by chi-squared analysis between two groups. RESULTS: The files of 340 EBUS-TBNA performed patients were evaluated. Of the patients 274 eligible patients were analysed. 152 patients who fulfilled the inclusion criteria were analysed in propofol-midazolam (P) sedated group and 122 patients were analysed in midazolam (M) group. There is no statistically significant difference between two different sedated groups in terms of age and gender. Diagnostic value was detected as 77.6% in P group and 85.7% in M group and the difference was not statistically significant. No difference between complication rates of both groups was observed. CONCLUSION: Both sedation-types for performing EBUS-TBNA showed similar diagnostic value and complication rates in our study. Propofol with midazolam application requires with an accompanying anaesthesiologist, therefore, it increases cost. EBUS-TBNA procedures had been performed in safe with no decrease in diagnostic yield under moderate sedation.

Evaluating the Role of Routine Prone Acquisition on Visual Evaluation of SPECT Images.

UNLABELLED: Attenuation artifacts reduce our ability to evaluate perfusion of affected myocardial segments. The aim of this study was to evaluate the impact of routine prone-position image evaluation within a stepwise visual interpretation of myocardial perfusion studies. METHODS: We have included 279 consecutive patients who were referred for evaluation of myocardial ischemia. All patients underwent routine electrocardiogram-gated supine SPECT imaging and non-electrocardiogram-gated prone-position SPECT imaging. Three nuclear medicine physicians interpreted the images in the following order: polar maps, supine images, raw images, motion-frozen gated images, and prone images, using a scale of 0-4. Segments with perfusion abnormalities were noted. RESULTS: All physicians reported lower proportions of equivocal evaluations after evaluating prone images (18.3% vs. 4.7%, 19% vs. 11.1%, and 12.2% vs. 6.1%, P < 0.0001, P = 0.0077, and P = 0.0125, respectively). At the prone stage, normalcy rates were 89%, 87%, and 91%. Two physicians had significantly increased normalcy rates at the prone stage (72%-89%, P = 0.039, and 66%-87%, P = 0.006). At the prone stage, a decision reversal to normal or probably normal was observed in 40% (29/72), 33% (17/51), and 43% (21/48). In men, apical, mid, and basal inferior walls and in women apical and mid parts of anterior walls were more likely to be attributed to attenuation. The 2 steps that increased normalcy rates for interpreters were the review of raw images and of prone images. CONCLUSION: Routine prone imaging increases interpretive certainty and interobserver agreement and changes the final evaluation in a substantial number of patients and significantly decreases the number of equivocal evaluations.

Inflammatory myofibroblastic tumor: a rare tumor of the lung.

Inflammatory myofibroblastic tumor (IMT) is a rare lesion, representing 0.04-1.2% of all lung tumors. Brunn first described it in 1939, but its etiology remains uncertain. A 16-year-old patient was admitted to our hospital for further examination following abnormal radiological findings. The physical examination showed no abnormality, and routine hematological and biochemical parameters were within normal range. Chest radiograph revealed homogenous opacity of the right upper lobe with regular margins. Thoracic CT showed a nodular lesion, 30×26 mm in dimensions, with lobular contours in the right hilar. Bronchoscopic examination showed a vascular endobronchial lesion in the anterior right upper lobe, with bleeding when palpated. She underwent right thoracotomy for diagnostic and therapeutic purposes since bronchoscopic biopsy failed because of bleeding. With a pathological diagnosis of IMT, the present report discusses her case accompanied by relevant literature as it is a very rare type of lung tumor. IMT is a rare benign tumor. The diagnosis is difficult to make before surgery since its clinical and radiological features are variable and nonspecific. Although it is a benign lesion, it should be completely resected and patients should be closely monitored following the resection in order to avoid local invasion and recurrence.

Comparison of diagnostic performances of three different software packages in detecting coronary artery disease.

PURPOSE: Quantification of myocardial perfusion scintigraphy is frequently performed to assist physicians in detecting coronary artery disease (CAD). Software packages provide automated quantification of perfusion data. We aimed to compare the three commonly used software packages, Emory Cardiac Toolbox (ECT v2 and ECT v3), 4D-MSPECT (4DM v2 and 4DM v4) and Quantitative Perfusion SPECT (QPS v3 and QPS v4). METHODS: We selected 283 patients who had a myocardial perfusion scintigraphy with (201)Tl followed by coronary angiography within 3 months. Summed stress score (SSS), summed difference score (SDS), total stress defect extent (TDE) and regional stress defect extent values were obtained from programs. A ≥70% stenosis in coronary arteries and their major branches was considered positive for CAD. A subgroup of patients was used to form an institutional normal database for QPS and 4DM. Receiver-operating characteristic (ROC) analysis to detect CAD was performed. RESULTS: Mean SSS ± SD (vendor) for ECT v3, QPS v4 and 4DM v4 were 9.2 ± 7.1, 10.1 ± 6.8 and 5.5 ± 6.1, respectively. Area under the curve (AUC) values of SSS ROC analysis were 0.738 ± 0.031 for QPS v3, 0.755 ± 0.030 for QPS v4, 0.758 ± 0.030 for ECT v2, 0.778 ± 0.029 for ECT v3 and 0.771 ± 0.030 for 4DM v4. The AUC values for TDE were 0.755 ± 0.030 for QPS v4, 0.769 ± 0.030 for ECT v3 and 0.775 ± 0.029 for 4DM v4. The differences were not significant for both SSS and TDE. Differences of AUC between regional stress defect extent values of programs and AUC of SSS between institutional and vendor normal databases were not significant. CONCLUSION: The diagnostic performances of programs to detect CAD are similar. However, there are differences in the magnitudes of the quantitative values produced by the programs.

An open-source framework of neural networks for diagnosis of coronary artery disease from myocardial perfusion SPECT.

BACKGROUND: The purpose of this study is to develop and analyze an open-source artificial intelligence program built on artificial neural networks that can participate in and support the decision making of nuclear medicine physicians in detecting coronary artery disease from myocardial perfusion SPECT (MPS). METHODS AND RESULTS: Two hundred and forty-three patients, who had MPS and coronary angiography within three months, were selected to train neural networks. Six nuclear medicine residents, one experienced nuclear medicine physician, and neural networks evaluated images of 65 patients for presence of coronary artery stenosis. Area under the curve (AUC) of receiver operating characteristics analysis for networks and expert was .74 and .84, respectively. The AUC of the other physicians ranged from .67 to .80. There were no significant differences between expert, neural networks, and standard quantitative values, summed stress score and total stress defect extent. CONCLUSIONS: The open-source neural networks developed in this study may provide a framework for further testing, development, and integration of artificial intelligence into nuclear cardiology environment.

Voltammetric studies on the potent carcinogen, 7,12-dimethylbenz[a]anthracene: Adsorptive stripping voltammetric determination in bulk aqueous forms and human urine samples and detection of DNA interaction on pencil graphite electrode.

7,12-Dimethylbenz[a]anthracene (DMBA), is a widely studied polycyclic aromatic hydrocarbon that has long been recognized as a very potent carcinogen. Initially, the electrochemical oxidation of DMBA at the glassy carbon and pencil graphite electrodes in non-aqueous media (dimethylsulphoxide with lithium perchlorate) was studied by cyclic voltammetry. DMBA was irreversibly oxidized in two steps at high positive potentials, resulting in the ill-resolved formation of a couple with a reduction and re-oxidation wave at much lower potentials. Special attention was given to the use of adsorptive stripping voltammetry together with a medium exchange procedure on disposable pencil graphite electrode in aqueous solutions over the pH range of 3.0-9.0. The response was characterized with respect to pH of the supporting electrolyte, pre-concentration time and accumulation potential. Using square-wave stripping mode, the compound yielded a well-defined voltammetric response in acetate buffer, pH 4.8 at +1.15V (vs. Ag/AgCl) (a pre-concentration step being carried out at a fixed potential of +0.60V for 360s). The process could be used to determine DMBA concentrations in the range 2-10nM, with an extremely low detection limit of 0.194nM (49.7ngL(-1)). The applicability to assay of spiked human urine samples was also illustrated. Finally, the interaction of DMBA with fish sperm double-stranded DNA based on decreasing of the oxidation signal of adenine base was studied electrochemically by using differential pulse voltammetry with a pencil graphite electrode at the surface and also in solution. The favorable signal-to-noise characteristics of biosensor resulted in low detection limit (ca. 46nM) following a 300-s interaction. These results displayed that the electrochemical DNA-based biosensor could be used for the sensitive, rapid, simple and cost effective detection of DMBA-DNA interaction.

Cardiac multidetector computed tomography (MDCT) of spontaneously closed ventricular septal defect.

PURPOSE: The authors present the findings of contrast-enhanced electrocardiogram (ECG)-gated cardiac computed tomography (CT) in 18 patients with probably spontaneous closure of muscular ventricular septal defect (VSD). MATERIALS AND METHODS: The study included 2,725 consecutive patients referred to our hospitals for multidetector computed tomography (MDCT) coronary angiography. The patients were between the ages of 5 and 78 [mean+/-standard deviation (SD) 59+/-13.86] years, and 1,816 (66.6%) were male. Evaluating the images for coronary artery pathologies revealed pouches or sacs in the central muscular location of the septa of some patients. RESULTS: All patient records were retrospectively reviewed, and 18 patients were found to have pouches or sacs in the interventricular septum location likely to be spontaneous closure of muscular VSD (0.66% prevalence). MDCT findings of these 18 patients correlated with their echocardiographic findings. Of the patients with muscular VSD, 13 were male and five were female. These 18 patients were initially referred due to indications such as chest pain (n=11), risk-factor assessment (n=3), coronary artery anomaly (n=1), suspected aberrant right subclavian artery due to dysphagia (n=1) and coronary artery bypass graft (n=2). CONCLUSIONS: Our study shows that the incidence of spontaneous closure of muscular VSD with central septum location is probably higher than expected. Thus, some patients initially diagnosed with ventricular diverticula with an apical and marginal septum location may actually have spontaneously closed muscular VSD. This finding may affect previously reported rates of both ventricular diverticula and spontaneous closure of muscular VSD.

Measurements of the lumbar pedicles in the Eastern Anatolian population.

Pedicle screw fixation of the spine has become one of the most stable and versatile methods of spine fixation, and knowledge of pedicle morphology is crucial for the safe application of these systems. We undertook this study because only a few reports have investigated Eastern populations. Lumbar pedicle anatomy, i.e., pedicle width (PW) and pedicle height (PH), transverse and sagittal pedicle angles (TPA, SPA), and pedicle length (PL), were assessed in the following two groups: (1) computed tomography scans of 29 normal adults, and (2) 16 dried lumbar spines obtained from the Anatomy Department. Interpedicular distance was different in each group. PW ranged from 4 mm to 14 mm. In both groups, the narrowest PH was 8.2 mm, the widest 19.7 mm. TPA ranged from 6(o) to 19(o) and increased from L1 to L5. In the sagittal plane, the pedicles angled caudally at L5. PL was longest at L1 and shortest at L5. In conclusion, pedicle dimensions and angles may show individual and structural differences. Our data were not significantly different from previous reported data. A detailed knowledge of these relationships is important for any surgery involving screw purchase via a pedicle, to prevent screw cutout and failure of fixation or neurological injury. Selection of the proper diameter of screw is an important issue for safe placement. Knowledge of the pedicle axis length is essential in choosing screw lengths but should always be checked intraoperatively with fluoroscopic control during screw insertion.

Nonlinear theory of polarization-mode dispersion for fiber solitons.

We consider the evolution of optical solitons inside a nonlinear dispersive fiber with random birefringence, causing polarization-mode dispersion. We convert the pair of coupled nonlinear Schrödinger equations satisfied by the orthogonally polarized components into a Fokker-Planck equation using the collective-variable approach. We solve this equation and derive expressions for the probability density functions associated with the differential group delay and the pulse width in the limit of large propagation distances.

Sliding hernia simulating esophageal tumor on computed tomography.

Diaphragmatic hernias are the most common abnormalities of gastrointestinal system especially in elderly patients. The radiographic findings of diaphragmatic hernias on esophagram are well known, but when incidentally found in an asymptomatic patient on axial computed tomography (CT) sections, the appearance of diaphragmatic hernia may mimic many other conditions. Our purpose is to present the CT findings of sliding hernia in an incidentally found asymptomatic patient, and to differentiate it from the other abnormalities that can be located in the distal paraesophageal area with the same appearance characteristics.

Effect of trapidil, an antiplatelet and vasodilator agent on gentamicin-induced nephrotoxicity in rats.

This study was carried out to evaluate the effect of trapidil, an antiplatelet and vasodilator drug, on the nephrotoxicity by an aminoglycoside, gentamicin, in rats. Forty female Wistar rats were divided into six different groups. One group served as a control group and the other groups were treated as follows: gentamicin (50 mg kg(-1) twice daily)-treated, gentamicin plus trapidil (4 or 20 mg kg(-1) daily)-treated and only trapidil-treated (4 or 20 mg kg(-1) daily) groups. Serum urea, creatinine and nitrite/nitrate levels were measured. Moreover, histopathological as well as electron microscopic examinations were performed. At a lower dose (4 mg kg(-1)) trapidil did not prevent the development of renal tubular damage by gentamicin. However, a higher dose of trapidil (20 mg kg(-1)) inhibited the ability of gentamicin to increase the levels of creatinine and urea. Furthermore, both light and electron microscopic evaluation confirmed the nephroprotective effect of the higher dose of trapidil. The level of the stable nitric oxide (NO) metabolite, nitrite, was also increased by trapidil. In conclusion, trapidil at a higher dose may protect against gentamicin nephrotoxicity. The mechanism underlying trapidil nephroprotection is not known, but may result from the antagonism of platelet-derived growth factor (PDGF), vasodilatation, inhibition of trombosit aggregation, and/or NO release.