-
World Journal of Nephrology Nov 2014Computed tomography (CT) is widely used to examine stones in the urinary system. In addition to the size and location of the stone and the overall health of the kidney,... (Review)
Review
Computed tomography (CT) is widely used to examine stones in the urinary system. In addition to the size and location of the stone and the overall health of the kidney, CT can also assess the density of the stone in Hounsfield units (HU). The HU, or Hounsfield density, measured by CT, is related to the density of the tissue or stone. A number of studies have assessed the use of HU in urology. HUs have been used to predict the type and opacity of stones during diagnosis, and the efficacy has been assessed using methods including extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), ureterorenoscopic ureterolithotripsy (URSL), and medical expulsive treatment (MET). Previous studies have focused on the success rate of HU for predicting the type of stone and of ESWL treatment. Understanding the composition of the stone plays a key role in determining the most appropriate treatment modality. The most recent reports have suggested that the HU value and its variants facilitate prediction of stone composition. However, the inclusion of data regarding urine, such as pH and presence of crystals, increases the predictive accuracy. HUs, which now form part of the clinical guidelines, allow us to predict the success of ESWL; therefore, they should be taken into account when ESWL is considered as a treatment option. However, there are currently insufficient data available regarding the value of HU for assessing the efficacy of PCNL, URSL, and MET. Studies performed to date suggest that these values would make a significant contribution to the diagnosis and treatment of urinary system stones. However, more data are required to assess this further.
PubMed: 25374823
DOI: 10.5527/wjn.v3.i4.282 -
Scientific Reports Nov 2022We aimed to identify the association between Hounsfield Unit(HU)-related variables and percutaneous nephrolithotomy (PCNL) outcomes. We enrolled patients with single...
We aimed to identify the association between Hounsfield Unit(HU)-related variables and percutaneous nephrolithotomy (PCNL) outcomes. We enrolled patients with single renal stones (1-3 cm) who underwent single-tract PCNL between January 2014 and October 2019. Demographics and stone characteristics were retrospectively reviewed. Preoperative computerized tomography (CT) and follow-up CT within at least 3 months after PCNL were included in this analysis. Stone-free status was defined as residual stone measuring ≤ 2 mm within 3 months postoperatively. HU and cross-sectional area (CSA) were measured using the free-draw technique. We analyzed HU-related variables using logistic regression model for outcomes. Altogether, 188 out of 683 patients met the inclusion criteria. The stone-free rate (SFR) was 79.2%. There were no significant differences in age, sex, BMI, ASA class, laterality, pre-op shockwave lithotripsy, stone size, stone burden, skin-to-stone distance, and HU between the stone-free and remnant groups. CSA and HU/CSA in the stone-free and remnant groups were 94.5 ± 46.1 and 128.3 ± 98.5 (p = 0.043) and 10.1 ± 5.6 and 7.3 ± 3.4 (p = 0.001), respectively. Multivariate logistic regression analysis revealed that pelvis, ureteropelvic junction stones, and HU/CSA were independent predictors of SFR. HU did not affect PCNL outcomes. We believe that HU/CSA could be used for determining stone treatment plans and predicting outcomes.
Topics: Humans; Nephrolithotomy, Percutaneous; Retrospective Studies; Lithotripsy; Kidney Calculi; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 36323761
DOI: 10.1038/s41598-022-23383-7 -
Therapeutic Advances in Urology 2019Hounsfield unit (HU) is the measure of stone density, and is utilized in the predetermination of type of stone. The purpose of this study was to identify some factors in...
BACKGROUND
Hounsfield unit (HU) is the measure of stone density, and is utilized in the predetermination of type of stone. The purpose of this study was to identify some factors in noncontrast computed tomography (NCCT) of kidney, ureter, and bladder (KUB) that are easily extractable and can be used to determine the outcome of expectant management.
METHODS
All patients 18-50 years of age who presented with flank pain and diagnosed as having lower ureteric calculi of size 5-10 mm by NCCT KUB were included in the study. HU of stone was calculated from the mean HU at three different regions of interest. We prescribed tamsulosin for 4 weeks as medical expulsive therapy. We divided the patients into two groups: group A included patients with successful expulsion of stone, and group B included patients who failed to pass stone. We compared age, gender, laterality, stone size in axial and coronal section of NCCT, HU of stone, blood urea, creatinine, and renal parenchymal thickness.
RESULTS
A total of 180 patients with lower ureteric calculus were included in the study. The mean age of patients was 34 years, with male:female ratio of 2.3:1. Of these 180 patients, 119 (66%) successfully expelled the stone and were included in group A, with the remaining 61 (34%) forming group B. In univariate analysis, longitudinal diameter of stone ( < 0.001), transverse diameter of stone ( < 0.001) and high HU ( < 0.001) were significantly associated with failure of expulsion. However, in multivariate analysis only longitudinal diameter of stone ( < 0.001) differed significantly among groups. Differences in HU ( = 0.179) and transverse diameter of stone ( = 0.108) did not reach significance level.
CONCLUSIONS
Lower ureteric calculi are definitely amenable to conservative management. Longitudinal diameter of stone can be a useful parameter; however, HU and its derivatives cannot be used as a predictor of outcome.
PubMed: 31832102
DOI: 10.1177/1756287219887661 -
The British Journal of Radiology Dec 2021The purpose of this study was to analyze the intraosseous tissue changes in recent vertebral compression fractures (VCFs) and to differentiate recent from remote VCFs... (Comparative Study)
Comparative Study
OBJECTIVES
The purpose of this study was to analyze the intraosseous tissue changes in recent vertebral compression fractures (VCFs) and to differentiate recent from remote VCFs using CT Hounsfield unit histogram analysis (HUHA).
METHODS
65 patients with T11 to L3 VCFs were included. HUHA of 2 vertebral bodies (VBs)- a fractured VB and the closest lower-level unaffected VB-was done. The mean Hounsfield unit (HU) value and HU proportions of 5 ranges (HU ≤ 0, 0 < HU ≤ 50, 50 < HU ≤ 100, 100 < HU ≤ 150, and HU > 150) were obtained. Then, ΔHU value and ΔHU proportion were calculated by subtracting the values from the two vertebrae. Finally, the obtained values were compared between the recent and remote VCF groups and subjected to ROC curve analysis.
RESULTS
In recent VCF group, the ΔHU proportion (HU ≤ 0) corresponding to normal fatty marrow was lower (-0.17 0.01) and the ΔHU proportion (HU > 150) representing trabecular bone was higher (0.23 0.04) than in remote VCF group ( < 0.001). In the differentiation of recent from remote VCF, the ΔHU value and ΔHU proportion (HU > 150) showed high area under the curve (AUC, 0.939 and 0.912, respectively).
CONCLUSION
CT HUHA demonstrated both trabecular bone and bone marrow changes in recent VCFs, and showed high diagnostic performance in differentiating between recent and remote VCFs.
ADVANCES IN KNOWLEDGE
With its vendor neutral applicability, CT HUHA can be used for the differentiation of recent and remote VCFs.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Delayed Diagnosis; Diagnosis, Differential; Female; Fractures, Compression; Humans; Male; Middle Aged; Retrospective Studies; Spinal Fractures; Tomography, X-Ray Computed; Young Adult
PubMed: 34538076
DOI: 10.1259/bjr.20210941 -
Frontiers in Endocrinology 2022Retrospective radiological analysis.
STUDY DESIGN
Retrospective radiological analysis.
OBJECTIVE
To assess bone mineral mass distribution within cervical vertebrae based on Hounsfield unit (HU) measurement, and explore its correlation with intervertebral disc degeneration.
METHOD
Three hundred and twenty-four patients with degenerative cervical spine disease were retrospectively reviewed and divided into six groups according to age. HU measurement of the whole vertebrae from C3 through C7 was obtained, then HU measurement within upper and lower part of the vertebrae on sagittal plane were obtained from C3 through C7. Disc degeneration on MRI was graded from I to V using the Pfirrmann classification.
RESULTS
There was a significant difference in the HU value from C3 to C7 among Group II to Group VI, the HU value presented consistently decreasing trend from young patients to old patients. In C6 and C7 vertebrae, there were significant differences in HU values between upper and lower parts of the vertebrae. More importantly. In all groups, HU values were highest in the upper part of the C4 vertebrae and then gradually decreased towards C3 and C7. HU value of both upper and lower vertebrae presented decreasing trend along with the aggravation of the disc degeneration.
CONCLUSION
HU values are not typically consistent throughout all levels of the cervical spine and the distribution within the vertebrae is not homogeneous. Decreased vertebral BMD and vertebral osteoporosis may trigger or exacerbate the adjacent intervertebral disc degeneration.
Topics: Bone Density; Cervical Vertebrae; Humans; Intervertebral Disc Degeneration; Osteoporosis; Retrospective Studies
PubMed: 35872993
DOI: 10.3389/fendo.2022.920167 -
Arab Journal of Urology Sep 2012The goal of percutaneous nephrolithotomy (PCNL) is to ensure complete stone clearance with minimal morbidity. The key to complete clearance is accurate technique,... (Review)
Review
INTRODUCTION
The goal of percutaneous nephrolithotomy (PCNL) is to ensure complete stone clearance with minimal morbidity. The key to complete clearance is accurate technique, expertise and instrumentation.
METHODS
We systematically reviewed available reports that were identified using a PubMed/Medline search. The keywords used were 'PCNL' and 'advances in PCNL'. The findings were reviewed under the topics of newer developments in imaging, techniques and a review of outcomes with an emphasis on stone clearance and complications.
CONCLUSION
The newer developments in imaging methods, such as cone-beam computed tomography and staghorn morphometry, help the surgeon to plan the procedure for a safe and better outcome. The highlight of these newer developments is the miniaturisation of instruments. This has translated into developing newer techniques such as the 'microperc' and 'miniperc'. The data-collection initiative by the Clinical Research Office of the Endourological Society has helped in obtaining a high level of evidence.
PubMed: 26558043
DOI: 10.1016/j.aju.2012.07.005 -
Frontiers in Surgery 2022Low bone mass concomitantly occurs in patients with adolescent idiopathic scoliosis (AIS) and can persist until skeletal maturity. The purpose of this study was to...
BACKGROUND
Low bone mass concomitantly occurs in patients with adolescent idiopathic scoliosis (AIS) and can persist until skeletal maturity. The purpose of this study was to assess the asymmetrical loss of vertebral bone mineral density (vBMD) and its correlation with curve severity in patients with AIS using Hounsfield unit (HU) values measured from computed tomography scans.
METHODS
A total of 93 AIS patients were retrospectively recruited. The HU values of the vertebral body (VB-HU) and pedicle screw trajectory (PST-HU) were measured from four vertebrae above (Apex - 4) to four below (Apex + 4) the apical vertebra (Apex) of the major curve. The VB-HU and PST-HU at the upper end vertebra, Apex, and lower end vertebra within the concave and convex sides of the major and minor curves and stable vertebrae were obtained.
RESULTS
A significant correlation was found between the Cobb angle and VB-HU at the periapical levels of the major curve. VB-HU and PST-HU at periapical levels were significantly greater within the concavity than the convexity of both major and minor curves. The asymmetric ratios of VB-HU and PST-HU were significantly correlated with the major curve Cobb angle, peaked at the apex, and gradually diminished from the apex to the end vertebrae. The asymmetrical loss of vBMD aggravated with the progression of curve severity, presenting as VB-HU, significantly decreased within the convexity and insignificantly decreased within the concavity of the major curve.
CONCLUSION
The asymmetrical loss of vBMD was associated with the progression of curve severity in AIS. For patients with severe AIS, the distraction of the pedicle screws at the concave side should be a priority in correcting the major curve, and supplemental anchors and larger-sized screws should be placed within the convex side around the apex of the major curve to reduce the risk of screw loosening after surgery.
PubMed: 36211282
DOI: 10.3389/fsurg.2022.1000031 -
Quantitative Imaging in Medicine and... Oct 2023Patients with good-grade subarachnoid hemorrhage (SAH) often expect favorable outcomes; however, several patients may experience secondary neurological deterioration....
BACKGROUND
Patients with good-grade subarachnoid hemorrhage (SAH) often expect favorable outcomes; however, several patients may experience secondary neurological deterioration. Hydrocephalus and vasospasm are significant complications affecting SAH prognosis. We aimed to evaluate the relationship between the incidence of symptomatic vasospasm or hydrocephalus and the Hounsfield unit (HU) value of the subarachnoid space on brain computed tomography (CT) in patients with good-grade SAH treated with endovascular coiling.
METHODS
We conducted a retrospective analysis of consecutive initially good-grade pure SAH patients (Hunt-Hess grade I or II, modified Fisher scale I or III) with ruptured anterior circulation aneurysms treated with endovascular coiling in a single tertiary neurosurgical center between January 2010 and December 2019. The HU value within each cisterns of enrolled patients was measured, and after setting an appropriate cutoff value, it was investigated whether it could be a predictor of the occurrence of vasospasm and hydrocephalus.
RESULTS
The study included 108 eligible patients (34 males, mean age 60.88±12.26 years): 26 (24.1%) showed symptomatic vasospasm and 31 (28.7%) developed hydrocephalus. Patients with symptomatic vasospasm had a greater proportion of those with Hunt-Hess grade II (77% 51%, P=0.021) and modified Fisher scale III scores (58% 22%, P=0.001). The hydrocephalus group presented an older mean age (65.90 58.86 years, P=0.006) and a greater proportion of Hunt-Hess grade II (74% 51%, P=0.025) and modified Fisher scale III cases (45% 25%, P=0.037). The mean HU values of the Sylvian cistern (53.23 43.99, P<0.001) and basal cisterns (47.04 40.18, P=0.003) were higher in the vasospasm group. In the hydrocephalus group, only the basal cistern HU value was significantly higher (45.60 40.32, P=0.016). The area under the receiver operating characteristic (ROC) curve to determine the best cut-off HU value for the prediction of patients with symptomatic vasospasm revealed a Sylvian cistern HU value of 50.375 (sensitivity: 0.692, specificity: 0.683) and basal cistern HU value of 44.875 (sensitivity: 0.615, specificity: 0.659). Multivariable logistic analysis showed that age >70 years and Sylvian cistern HU value were independent predictors of any neurological complication at 1 year.
CONCLUSIONS
The HU value of the subarachnoid space on brain CT can predict vasospasm, hydrocephalus, and long-term prognosis in good-grade SAH patients.
PubMed: 37869270
DOI: 10.21037/qims-23-355 -
Arab Journal of Urology Mar 2012To review the current role and outcome of laparoscopic adrenalectomy (LA) in the management of adrenal tumours. (Review)
Review
OBJECTIVE
To review the current role and outcome of laparoscopic adrenalectomy (LA) in the management of adrenal tumours.
METHODS
A Medline search using the keywords (adrenalectomy, laparoscopy, adrenal masses/tumours) was done for reports published between 1990 and 2011. Key articles were used to find more relevant references on the evaluation and laparoscopic management of adrenal masses.
RESULTS
The hormonal evaluation is not standardised, but initial screening tests are recommended and followed with confirmatory ones when positive, equivocal or the clinical presentation suggest adrenal hyperfunction. The imaging studies had, and continued to, advance, especially computed tomography (CT), magnetic resonance imaging and positron-emission tomography/CT. These advances have increased the accuracy of the diagnosis of adrenal masses, with a reported high sensitivity and specificity of 95-100%. The introduction of laparoscopy has resulted in more adrenal lesions being removed, especially incidental lesions smaller than the 5-6 cm that was previously the indication for surgical excision. The technique has developed and larger lesions of >6 cm are now considered for LA in the proper setting. The transperitoneal and retroperitoneal approaches are currently widely practised, with minor differences in the outcome. The reported outcome, although mostly retrospective, is excellent and with fewer complications. The role of LA for adrenal malignancy should be considered cautiously. Preoperative imaging signs of invasion into surrounding structures should be considered a contraindication for LA.
CONCLUSION
LA is the standard procedure for most adrenal lesions of appropriate size and no signs of surrounding tissue invasion, giving an excellent outcome.
PubMed: 26558005
DOI: 10.1016/j.aju.2011.11.003