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JHEP Reports : Innovation in Hepatology Jun 2020The goal of assessing tumour response on imaging is to identify patients who are likely to benefit - or not - from anticancer treatment, especially in relation to... (Review)
Review
The goal of assessing tumour response on imaging is to identify patients who are likely to benefit - or not - from anticancer treatment, especially in relation to survival. The World Health Organization was the first to develop assessment criteria. This early score, which assessed tumour burden by standardising lesion size measurements, laid the groundwork for many of the criteria that followed. This was then improved by the Response Evaluation Criteria in Solid Tumours (RECIST) which was quickly adopted by the oncology community. At the same time, many interventional oncology treatments were developed to target specific features of liver tumours that result in significant changes in tumours but have little effect on tumour size. New criteria focusing on the viable part of tumours were therefore designed to provide more appropriate feedback to guide patient management. Targeted therapy has resulted in a breakthrough that challenges conventional response criteria due to the non-linear relationship between response and tumour size, requiring the development of methods that emphasize the appearance of tumours. More recently, research into functional and quantitative imaging has created new opportunities in liver imaging. These results have suggested that certain parameters could serve as early predictors of response or could predict later tumour response at baseline. These approaches have now been extended by machine learning and deep learning. This clinical review focuses on the progress made in the evaluation of liver tumours on imaging, discussing the rationale for this approach, addressing challenges and controversies in the field, and suggesting possible future developments.
PubMed: 32514496
DOI: 10.1016/j.jhepr.2020.100100 -
Tomography (Ann Arbor, Mich.) Oct 2021Hounsfield units (HU) are a measure of radiodensity, related to the density of a tissue and the composition of kidney stones. Hounsfield density is what is related to...
Hounsfield units (HU) are a measure of radiodensity, related to the density of a tissue and the composition of kidney stones. Hounsfield density is what is related to the composition of kidney stones. In the standard acquisition method, these measures are arbitrary and dependent on the operator. This study describes the implementation of a technique based on the HU and Hounsfield density to predict the stone compositions of patients with nephrolithiasis. By conventional percutaneous nephrolithotomy, thirty kidney stone samples corresponding to the cortex, middle, and nucleus were obtained. The HU were obtained by CT scanning with a systematic grid. Hounsfield density was calculated as the HU value divided by the stone's greatest diameter (HU/mm). With that method and after analyzing the samples by IR-spectroscopy, anhydrous uric acid and ammonium magnesium phosphate were identified as the compounds of kidney stones. Additionally, anhydrous uric acid, magnesium ammonium phosphate, and calcium oxalate monohydrate were identified via Hounsfield density calculation. The study identified HU ranges for stone compounds using a systematic technique that avoids bias in its analysis. In addition, this work could contribute to the timely diagnosis and development of personalized therapies for patients with this pathology.
Topics: Calcium Oxalate; Humans; Kidney Calculi; Nephrolithotomy, Percutaneous; Retrospective Studies; Struvite
PubMed: 34698253
DOI: 10.3390/tomography7040051 -
Cureus Nov 2020Objectives To evaluate the efficacy of the non-contrast-enhanced computed tomography (NCECT) renal pelvis Hounsfield unit (HU) values in differentiating between the...
Objectives To evaluate the efficacy of the non-contrast-enhanced computed tomography (NCECT) renal pelvis Hounsfield unit (HU) values in differentiating between the hydronephrosis and pyonephrosis in dilated urinary systems. Materials and methods Patients who underwent percutaneous nephrostomy (PN) due to urinary system obstruction in the last three years were retrospectively evaluated. Pyonephrosis and hydronephrosis groups were differentiated according to the clarity of percutaneous needle aspiration. The patients' renal pelvic anteroposterior (AP) diameter, renal pelvic area, and mean HU values were measured on NCECT and compared between two groups. Results PN was performed on a total of 523 patients. The study included 159 patients and 214 renal units. Hydronephrosis was detected in 176 renal units and pyonephrosis in 38 renal units. No statistically significant difference was observed between the measured AP diameter and renal pelvic area in the two groups (28.45 ± 10.1 mm vs. 31.13 ± 14.4 mm, p = 0.36 and 658.51 ± 433.1 mm vs. 755.14 ± 470.6 mm, p = 0.22, respectively). The mean HU value of the pyonephrosis group was significantly higher (2.30 ± 5.02 vs. 10.97 ± 6.68, p < 0.001). At the cut-off value of 8.46, HU had a sensitivity of 68.4% and specificity of 92.6% in the diagnosis of pyonephrosis. Conclusions It is possible to determine differential diagnosis between pyonephrosis and hydronephrosis easily and without additional cost by performing dilated renal pelvis HU measurements on NCECT.
PubMed: 33391912
DOI: 10.7759/cureus.11675 -
Radiological Physics and Technology Jun 2024The purpose of the study is to investigate the variation in Hounsfield unit (HU) values calculated using dual-energy computed tomography (DECT) scanners. A tissue... (Comparative Study)
Comparative Study
The purpose of the study is to investigate the variation in Hounsfield unit (HU) values calculated using dual-energy computed tomography (DECT) scanners. A tissue characterization phantom inserting 16 reference materials were scanned three times using DECT scanners [dual-layer CT (DLCT), dual-source CT (DSCT), and fast kilovoltage switching CT (FKSCT)] changing scanning conditions. The single-energy CT images (120 or 140 kVp), and virtual monochromatic images at 70 keV (VMI) and 140 keV (VMI) were reconstructed, and the HU values of each reference material were measured. The difference in HU values was larger when the phantom was scanned using the half dose with wrapping with rubber (strong beam-hardening effect) compared with the full dose without the rubber (reference condition), and the difference was larger as the electron density increased. For SECT, the difference in HU values against the reference condition measured by the DSCT (3.2 ± 5.0 HU) was significantly smaller (p < 0.05) than that using DLCT with 120 kVp (22.4 ± 23.8 HU), DLCT with 140 kVp (11.4 ± 12.8 HU), and FKSCT (13.4 ± 14.3 HU). The respective difference in HU values in the VMI and VMI measured using the DSCT (10.8 ± 17.1 and 3.5 ± 4.1 HU) and FKSCT (11.5 ± 21.8 and 5.5 ± 10.4 HU) were significantly smaller than those measured using the DLCT (23.1 ± 27.5 and 12.4 ± 9.4 HU) and DLCT (22.3 ± 28.6 and 13.1 ± 11.4 HU). The HU values and the susceptibility to beam-hardening effects varied widely depending on the DECT scanners.
Topics: Phantoms, Imaging; Tomography, X-Ray Computed; Image Processing, Computer-Assisted; Radiation Dosage
PubMed: 38700638
DOI: 10.1007/s12194-024-00802-0 -
International Archives of... Jul 2022High-resolution computed tomography (HRCT) scans of the temporal bone are used to assess the bony erosion of the middle-ear structures whenever cholesteatoma is...
High-resolution computed tomography (HRCT) scans of the temporal bone are used to assess the bony erosion of the middle-ear structures whenever cholesteatoma is suspected. To study the differences in HRCT Hounsfield unit (HU) index measurements of middle-ear bony structures between an ears with and without cholesteatoma. A retrospective study of 59 patients who underwent surgery due to unilateral cholesteatoma. The HRCT HU index of the scutum, of three middle-ear ossicles, of the lateral semicircular canal (LSCC), and of the fallopian canal was measured in both ears. A comparison was made between the cholesteatoma and the non-cholesteatomatous ear (control). All measurements were conducted by an otolaryngologist. To assess the interobserver bias, 10% of the samples were randomly and independently assessed by another otolaryngologist and a neuroradiologist who were blinded. The average HU index was lower in the ear with cholesteatoma when compared with the non-cholesteatomatous ear. While the differences were statistically significant regarding the measurements of the scutum (516.02 ± 311.693 versus 855.64 ± 389.999; = 0.001), the malleus (1049.44 ± 481.765 versus 1413.47 ± 313.376; = 0.01), and the incus (498.03 ± 264.184 versus 714.25 ± 405.631; = 0.001), the differences in the measurements of the LSCC (1042.34 ± 301.066 versus 1154.53 ± 359.609; = 0.69) and of the fallopian canal (467.19 ± 221.556 versus 543.51 ± 263.573; = 0.108) were not significantly different between both groups. The stapes was immeasurable in both groups due to its small size. Hounsfield unit index measurements are a useful tool that may aid in the diagnosis of early-stage cholesteatoma.
PubMed: 35846805
DOI: 10.1055/s-0041-1736580 -
Clinical Neurology and Neurosurgery Jan 2022Neuroinflammatory response is deemed the primary pathogenesis of delayed cerebral ischemia (DCI) caused by aneurysmal subarachnoid hemorrhage (aSAH). Both white blood... (Observational Study)
Observational Study
OBJECTIVE
Neuroinflammatory response is deemed the primary pathogenesis of delayed cerebral ischemia (DCI) caused by aneurysmal subarachnoid hemorrhage (aSAH). Both white blood cell (WBC) count and Hounsfield Unit (HU) are gradually considered can reflect inflammation in DCI. This study aims to identify the relationship between WBC count and HU value and investigate the effects of both indicators in predicting DCI after aSAH.
METHODS
We enrolled 109 patients with aSAH admitted within 24 h of onset in our study. A multivariate logistic regression analysis was used to evaluate the admission WBC count, HU value, and combined WBC-HU associated with DCI. The receiver operating characteristic curve and area under the curve (AUC) were used to determine thresholds and detect the predictive ability of these predictors. These indicators were also compared with the established inflammation markers.
RESULTS
Thirty-six (33%) patients developed DCI. Both WBC count and HU value were strongly associated with the admission glucose level (ρ = .303, p = .001; ρ = .273, p = .004), World Federation of Neurosurgical Societies grade (ρ = .452, p < .001; ρ = .578; p < .001), Hunt-Hess grade (ρ = .450, p < .001; ρ = .510, p < .001), and modified Fisher scale score (ρ = .357, p < .001; ρ = .330, p < .001). After controlling these public variables, WBC count (ρ = .300, p = .002) positively correlated with HU value. An early elevated WBC (odds ratio [OR] 1.449, 95% confidence interval [CI]: 1.183-1.774, p < .001) count and HU value (OR 1.304, 95%CI: 1.149-1.479, p < .001) could independently predict the occurrence of DCI. However, only these patients with both WBC count and HU value exceeding the cut-off points (OR 36.89, 95%CI: 5.606-242.78, p < .001) were strongly correlated with DCI. Compared with a single WBC count (AUC 0.811, 95%CI: 0.729-0.892, p < .001) or HU value (AUC 0.869, 95%CI: 0.803-0.936, p < .001), the combined WBC-HU (AUC 0.898, 95%CI: 0.839-0.957, p < .001) demonstrated a better ability to predict the occurrence of DCI. Inspiringly, the prediction performance of these indicators outperformed the established inflammatory markers.
CONCLUSION
An early elevated WBC count and HU value could independently predict DCI occurrence between 4 and 30 days after aSAH. Furthermore, WBC count was positively correlated with HU value, and the combined WBC-HU demonstrated a superior prediction ability for DCI development compared with the individual indicator.
Topics: Brain Ischemia; Female; Humans; Leukocyte Count; Male; Middle Aged; Neuroinflammatory Diseases; Patient Admission; Prognosis; Retrospective Studies; Subarachnoid Hemorrhage; Tomography, X-Ray Computed
PubMed: 34929583
DOI: 10.1016/j.clineuro.2021.107087 -
PloS One 2021Retrograde intrarenal surgery is a common procedure that carries a risk of radiation exposure for urologists. This study aimed to measure the amount of radiation that...
Retrograde intrarenal surgery is a common procedure that carries a risk of radiation exposure for urologists. This study aimed to measure the amount of radiation that urologists are exposed to during surgery, and to estimate how many procedures can be safely performed by one urologist per year. Variables that affect radiation exposure were also identified. Radiation exposure doses were measured for the eye, neck, chest, arms, and hands of a urologist who performed 226 retrograde intrarenal surgeries. To determine how many procedures could be safely performed per year, the Annual Permissible Occupational Exposure Radiation Dose Guidelines of the National Council on Radiation Protection and Measurements were consulted. Correlations between radiation exposure dose and the patient's age, sex, body mass index, stone number/burden/laterality/location/Hounsfield unit, and their renal calculi were calculated. The mean surgery and fluoroscopy durations were 83.2 and 5.13 min; the mean tube voltage and current were 68.88 kV and 2.48 mA, respectively. Cumulative radiation doses for the eye, neck, chest, right upper arm, left hand, and right hand were 65.53, 69.95, 131.79, 124.43, 165.66, and 126.64 mSv, respectively. Radiation reduction rates for lead collars and aprons were 97% and 98%, respectively. If the urologists wear only radiation shields and lead apron but do not wear safety glasses during RIRS, the recommended by the ICRP publication 103 is taken into consideration, our results showed that 517 RIRS can be performed per year safely. However, if no protective measures are taken, this number decreases to only 85 RIRS per year. At all measurement sites, significant correlations were observed between the radiation exposure dose and stone numbers and Hounsfield unit values. In conclusion, it is imperative that urologists wear protective gear. Greater effort should be made to reduce radiation exposure when renal calculi have a large number of stones or large Hounsfield unit values.
Topics: Adult; Aged; Female; Fluoroscopy; Humans; Male; Middle Aged; Nephrolithotomy, Percutaneous; Occupational Exposure; Radiation Dosage; Radiation Exposure; Urologists
PubMed: 33720938
DOI: 10.1371/journal.pone.0247833 -
Journal of Cachexia, Sarcopenia and... Jun 2023The prognostic role of increased visceral fat attenuation (VFA) remains underexplored. We investigated the long-term prognostic implications of computed tomography...
BACKGROUND
The prognostic role of increased visceral fat attenuation (VFA) remains underexplored. We investigated the long-term prognostic implications of computed tomography (CT)-derived VFA in a health check-up population.
METHODS
This study included consecutive individuals who had positron-emission tomography/CT scans for health check-ups between January 2004 and December 2010. The primary outcome was overall survival (OS), and the secondary outcomes were cancer-specific survival (CSS) and non-cancer-specific survival (NCS). Commercially available body composition analysis software was used to obtain abdominal waist VFA, visceral fat volume index (VFI) and skeletal muscle index (SMI) at the L3 level. Sarcopenia was determined using sex-specific SMI references. VFA and VFI were dichotomized using the thresholds for the highest quartiles. The relationship between CT-derived body composition parameters and body mass index (BMI) was evaluated with Pearson correlation coefficients. The prognostic implications of VFA and sarcopenic obesity (SO) defined by VFA were assessed by multivariable Cox regression analysis and Kaplan-Meier plots with log-rank tests.
RESULTS
A total of 2720 individuals (1530 men [56.3%] and 1190 women [43.7%]; median age: 53 years, inter-quartile range: 47-60 years) were included. During the median follow-up of 138 months, 128 individuals (5%) died (cancer mortality: 2%; non-cancer mortality: 3%), with 0.2% (5 of 2720) and 1.1% (30 of 2720) of 1- and 5-year mortality rates. VFA was negatively correlated with BMI (r = -0.62; P < 0.001) and VFI (r = -0.69; P < 0.001). After adjusting for clinical variables, sarcopenia and VFI, high VFA was a negative prognostic factor for OS (hazard ratio [HR]: 1.05 per Hounsfield unit; 95% confidence interval [CI]: 1.02, 1.08; P = 0.001), CSS (HR: 1.07 per Hounsfield unit; 95% CI: 1.02, 1.12; P = 0.006) and NCS (HR: 1.03 per Hounsfield unit; 95% CI: 1.01, 1.06; P = 0.009). Individuals with high VFA had higher high-sensitivity C-reactive protein levels than those with low VFA (0.11 vs. 0.03 mg/dL; P < 0.001). Individuals with SO defined by VFA had worse OS (9% vs. 4%; P < 0.001), CSS (3% vs. 2%; P = 0.02) and NCS (6% vs. 3%; P < 0.001) than those without SO, even in the same BMI (underweight-to-normal BMI, OS: 8% vs. 4%; overweight-to-obese BMI, OS: 38% vs. 4%; P < 0.001 in both) or VFI category (high VFI, OS: 43% vs. 6%; low VFI, OS: 8% vs. 3%; P < 0.001 in both).
CONCLUSIONS
High VFA was associated with long-term mortality and low-grade inflammation. VFA can further stratify the current SO by BMI or VFI, and SO defined by VFA can identify individuals who are most vulnerable to long-term mortality.
Topics: Male; Humans; Female; Middle Aged; Sarcopenia; Intra-Abdominal Fat; Prognosis; Muscle, Skeletal; Obesity
PubMed: 37016984
DOI: 10.1002/jcsm.13226 -
BMC Musculoskeletal Disorders Mar 2022The fixation strength of bone screws depends on bone mineral density (BMD), so it is important to evaluate bone strength at fracture sites. Few studies have investigated...
Distribution of hounsfield unit values in the pelvic bones: a comparison between young men and women with traumatic fractures and older men and women with fragility fractures: a retrospective cohort study.
BACKGROUND
The fixation strength of bone screws depends on bone mineral density (BMD), so it is important to evaluate bone strength at fracture sites. Few studies have investigated BMD in the pelvis. The aims of this study were to measure the regional Hounsfield unit (HU) values in the cancellous bone of the acetabulum and pelvic ring and to compare these values between young and older patients.
METHODS
This study enrolled young patients with high-energy trauma (aged 20-44 years; young group) and older patients with low-energy trauma (aged 65-89 years; older group). Patients without pelvic computed tomography (CT) scans, those with pelvic bone implants, and those who died were excluded. The HU values on the contralateral (non-fractured) side of the pelvis were measured on CT scans. The CT data were divided into 7 areas: the pubic bone, the anterior and posterior walls and roof of the acetabulum, the ischial tuberosity, the body of the ilium, and the third lumbar vertebra. The HU values in each area were compared between the young and older groups.
RESULTS
Sixty-one young patients and 154 older patients were included in the study. The highest HU value was in the roof of the acetabulum regardless of age and sex. HU values were significantly higher in the ischial tuberosity and body of the ilium and lower in the pubic bone and anterior wall. The HU values in all pelvic areas were significantly lower in the older group than in the young group, especially in the anterior area.
CONCLUSIONS
HU values in the 6 pelvic areas were not uniform and were strongly related to load distribution. The HU distribution and age-related differences could explain the characteristic causes and patterns of acetabular fractures in the older and may help in surgical treatment.
Topics: Adult; Aged; Aged, 80 and over; Bone Density; Female; Fractures, Bone; Humans; Ischium; Male; Retrospective Studies; Spinal Fractures; Young Adult
PubMed: 35351073
DOI: 10.1186/s12891-022-05263-3 -
Arab Journal of Urology Dec 2011Lipomatous tumours of the adrenals are almost always benign. The importance of recognising their characteristic radiological features, leading to their correct... (Review)
Review
BACKGROUND
Lipomatous tumours of the adrenals are almost always benign. The importance of recognising their characteristic radiological features, leading to their correct treatment, is fundamental, as there has been an increase in the identification of these lesions. Our goal was to review all lipomatous tumours of the adrenal glands, particularly myelolipomas, their imaging methods and surgical management, updated in 2011.
METHODS
This was a retrospective review of articles published in the USA and Europe, from 1979 to date. The sites from which information was retrieved covered PubMed, Medscape, Clinical Imaging, Histopathology, Urologia Internationalis, Archives of Surgery, JACS, the American Urological Association, BMJ, Medline, and Springer Link. We report areas of controversies in addition to well established guidelines.
RESULTS
We reviewed 45 articles, that confirmed, with a high level of evidence-based medicine, that the diagnosis of a lipomatous adrenal tumour is made by various imaging procedures, particularly computed tomography (CT). We emphasise the importance to their management of the initial size of the adrenal mass, its increase in size over time, in addition to the presence of symptoms.
CONCLUSION
Lipomatous tumours of the adrenals are most frequently benign. The diagnosis is usually made by various techniques, in particular CT. The fundamental characteristics indicating the necessity of surgical intervention are the symptoms presented, volume of the tumoral mass (>5 cm), and the increase in size of the tumour as shown in two consecutive imaging studies.
PubMed: 26579309
DOI: 10.1016/j.aju.2011.10.003