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1.
J Card Surg ; 37(12): 4172-4177, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36198144

ABSTRACT

The evaluation of patients following aortic valve replacement has evolved, with multiple imaging modalities available that complement each other and permit better and prompt delineation of specific structural or functional valve complications. Multidetector computed tomography (MDCT) is one of the diagnostic modalities with significant technologic advancements that have made possible to evaluate high detail of the moving heart. The ability to deliver three-dimensional and multiplanar dynamic imaging with fine detail has demonstrated the technique is well suited to investigate valve complications. In this review article, we focus on some of the most contributing roles of MDCT in the diagnosis of complications associated with valvular pathology.


Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis , Thrombosis , Transcatheter Aortic Valve Replacement , Humans , Multidetector Computed Tomography/adverse effects , Multidetector Computed Tomography/methods , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Heart Valve Prosthesis/adverse effects , Transcatheter Aortic Valve Replacement/methods , Aortic Valve Stenosis/surgery , Thrombosis/diagnostic imaging , Thrombosis/etiology , Thrombosis/surgery
2.
J Vasc Interv Radiol ; 32(3): 439-446, 2021 03.
Article in English | MEDLINE | ID: mdl-33414069

ABSTRACT

PURPOSE: To determine physician radiation exposure when using partial-angle computed tomography (CT) fluoroscopy (PACT) vs conventional full-rotation CT and whether there is an optimal tube/detector position at which physician dose is minimized. MATERIALS AND METHODS: Physician radiation dose (entrance air kerma) was measured for full-rotation CT (360°) and PACT (240°) at all tube/detector positions using a human-mimicking phantom placed in a 64-channel multidetector CT. Parameters included 120 kV, 20- and 40-mm collimation, and 100 mA. The mean, standard deviation, and increase/decrease in physician dose compared with a full-rotation scan were reported. RESULTS: Physician radiation exposure during CT fluoroscopy with PACT was highly dependent on the position of the tube/detector during scanning. The lowest PACT physician dose was when the physician was on the detector side (center view angle 116°; -35% decreased dose vs full-angle CT). The highest PACT physician dose was with the physician on the tube side (center view angle 298°; +34% increased dose vs full-angle CT), all doses P <.05 vs full-rotation CT. CONCLUSIONS: Partial-angle CT has the potential to both significantly increase or decrease physician radiation dose during CT fluoroscopy-guided procedures. The detector/tube position has a profound effect on physician dose. The lowest dose during PACT was achieved when the physician was located on the detector side (ie, distant from the tube). This data could be used to optimize CT fluoroscopy parameters to reduce physician radiation exposure for PACT-capable scanners.


Subject(s)
Multidetector Computed Tomography , Occupational Exposure , Radiation Dosage , Radiation Exposure , Radiography, Interventional , Radiologists , Fluoroscopy , Humans , Multidetector Computed Tomography/adverse effects , Multidetector Computed Tomography/instrumentation , Occupational Exposure/adverse effects , Occupational Exposure/prevention & control , Occupational Health , Phantoms, Imaging , Radiation Exposure/adverse effects , Radiation Exposure/prevention & control , Radiography, Interventional/adverse effects , Radiography, Interventional/instrumentation , Risk Assessment , Risk Factors , Tomography Scanners, X-Ray Computed
3.
Clin Orthop Relat Res ; 479(1): 151-160, 2021 01 01.
Article in English | MEDLINE | ID: mdl-32701771

ABSTRACT

BACKGROUND: Cone beam CT (CBCT) is a widely available technique with possible indications in carpal ligament injuries. The accuracy of CBCT arthrography in diagnosing traumatic tears of the scapholunate ligament has not been reported. QUESTIONS/PURPOSES: (1) What is the diagnostic accuracy of CBCT and how does it relate to the accuracy of multislice CT arthrography and conventional arthrography in diagnosing scapholunate ligament tears? (2) What is the estimated magnitude of skin radiation doses of each method? METHODS: This secondary analysis of a previous prospective study included 71 men and women with suspected scapholunate ligament tears and indications for arthroscopy. Preoperative imaging was conventional arthrography and either MSCT arthrography for the first half of patients to be included (n = 36) or flat-panel CBCT arthrography for the remaining patients (n = 35). Index tests identified therapy-relevant SLL tears with dorsal or complete SLL ruptures, and these tears were compared with relevant SLL tears which were determined through arthroscopy as Geissler Stadium III and IV by probing the instable SL joint with a microhook or arthroscope. These injuries were treated by open ligament repair and Kirschner wire fixation. Accuracy values and 95% confidence intervals were calculated. Additional estimates of the radiation skin doses of each CBCT exam and two MSCT protocols were subsequently calculated using dose area products, dose length products, and CT dose indices. RESULTS: The diagnostic accuracy was high for all imaging methods. 95% CIs were broadly overlapping and therefore did not indicate differences between the diagnostic groups: Sensitivity of CBCT arthrography was 100% (95% CI 77 to 100), specificity was 95% (95% CI 76 to 99.9), positive predictive value was 93% (95% CI 68 to 99.8), and negative predictive value was 100% (95% CI 83 to 100). For MSCT arthrography, the sensitivity was 92% (95% CI 64 to 99.8), specificity was 96% (95% CI 78 to 99.9), positive predictive value was 92% (95% CI 64 to 99.8), and negative predictive value was 96% (95% CI 78 to 99.9). For conventional arthrography, the sensitivity was comparably high: 96% (95% CI 81 to 99.9). Specificity was (81% [95% CI 67 to 92]); the positive predictive value was 77% (95% CI 59 to 89) and negative predictive value was 97% (95% CI 86 to 99.9). Estimated mean (range) radiation skin doses were reported in a descriptive fashion and were 12.9 mSv (4.5 to 24.9) for conventional arthrography, and 3.2 mSv (2.0 to 4.8) for CBCT arthrography. Estimated radiation skin doses were 0.2 mSv and 12 mSv for MSCT arthrography, depending on the protocol. CONCLUSION: Flat-panel CBCT arthrography can be recommended as an accurate technique to diagnose scapholunate ligament injuries after wrist trauma. Estimated skin doses are low for CBCT arthrography and adapted MSCT arthrography protocols. LEVEL OF EVIDENCE: Level III, diagnostic study.


Subject(s)
Arthrography , Cone-Beam Computed Tomography , Ligaments, Articular/diagnostic imaging , Multidetector Computed Tomography , Wrist Injuries/diagnostic imaging , Adult , Arthrography/adverse effects , Arthroscopy , Cone-Beam Computed Tomography/adverse effects , Female , Humans , Ligaments, Articular/injuries , Ligaments, Articular/surgery , Male , Middle Aged , Multidetector Computed Tomography/adverse effects , Predictive Value of Tests , Radiation Dosage , Radiation Exposure/adverse effects , Reproducibility of Results , Skin/radiation effects , Wrist Injuries/surgery
4.
Circ J ; 84(4): 601-608, 2020 03 25.
Article in English | MEDLINE | ID: mdl-32074543

ABSTRACT

BACKGROUND: Although coronary computed tomography angiography (CTA) is frequently used for identifying coronary artery disease, no studies have investigated the radiation dose in detail in Japan. The aim of this study was to estimate the radiation dose of coronary CTA in Japanese clinical practice and to identify the independent predictors associated with radiation dose.Methods and Results:A multicenter, retrospective, observational study (54 institutions) was conducted for estimating the radiation dose of coronary CTA in 2,469 patients between January and December 2013. Independent predictors associated with radiation dose were investigated on linear regression analysis. Median dose-length product (DLP) was 809.0 mGy·cm (IQR, 350.0-1,368.8 mGy·cm), corresponding to an estimated radiation dose of 11 mSv. The DLP per site significantly differed between institutions (median DLP per site, 92-2,131 mGy·cm; P<0.05). Independent predictors associated with radiation dose on multivariable linear regression were body weight, heart rate, non-stable sinus rhythm, scan length, tube voltage setting, electrocardiogram (ECG)-gated scanning protocol, and the image reconstruction technique (P<0.05 each). CONCLUSIONS: The coronary CTA radiation dose was relatively high in 2013, and it varied significantly between institutions. Effective strategies for radiation dose reduction were low tube voltage ≤100 kVp, retrospective ECG-gated scanning with dose modulation technique, prospective ECG-gated scanning, and the iterative reconstruction technique.


Subject(s)
Computed Tomography Angiography , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Multidetector Computed Tomography , Radiation Dosage , Radiation Exposure , Aged , Cardiac-Gated Imaging Techniques , Computed Tomography Angiography/adverse effects , Coronary Angiography/adverse effects , Electrocardiography , Female , Humans , Japan , Male , Middle Aged , Multidetector Computed Tomography/adverse effects , Predictive Value of Tests , Radiation Exposure/adverse effects , Radiation Exposure/prevention & control , Registries , Retrospective Studies
5.
Ann Vasc Surg ; 65: 283.e13-283.e17, 2020 May.
Article in English | MEDLINE | ID: mdl-31705991

ABSTRACT

CT angiography with multislice detector has become the preferred method for assessment of hemodynamically stable patients suspected of great vessel injury from iatrogenic and blunt trauma. The CT images obtained can be transformed into a three-dimensional (3D) model using the software within minutes. This allows the clinician to evaluate the injury and the injury's proximity to other vital structures for operative planning. The 3D modeling provides geometric calibration of the c-arm or image intensifier in regard to optimal cranial/caudal and oblique angles to evaluate and treat the vessel injury. We describe a case of a 28-year-old female undergoing a cesarian section and hysterectomy for placenta percreta, who sustained a right subclavian artery injury (presumed wire injury) from inadvertent right common carotid artery cannulation during placement of a right internal jugular 8 French resuscitative central line. A 3D model was created from the CT angiography to locate the small pseudoaneurysm of the right subclavian artery. The optimal projection was obtained using the 3D reconstructive software to visualize the injury and its relation to the right vertebral artery ostium for endovascular planning. This preoperative maneuver allowed for limited radiation exposure and contrast volume used to treat the injury.


Subject(s)
Blood Vessel Prosthesis Implantation , Computed Tomography Angiography , Contrast Media/administration & dosage , Endovascular Procedures , Iatrogenic Disease , Imaging, Three-Dimensional , Multidetector Computed Tomography , Patient-Specific Modeling , Radiography, Interventional , Subclavian Artery/diagnostic imaging , Subclavian Artery/surgery , Surgery, Computer-Assisted , Vascular System Injuries/diagnostic imaging , Vascular System Injuries/surgery , Adult , Blood Vessel Prosthesis Implantation/adverse effects , Catheterization, Central Venous/adverse effects , Computed Tomography Angiography/adverse effects , Contrast Media/adverse effects , Endovascular Procedures/adverse effects , Female , Fluoroscopy , Humans , Imaging, Three-Dimensional/adverse effects , Multidetector Computed Tomography/adverse effects , Predictive Value of Tests , Pregnancy , Radiation Dosage , Radiation Exposure/adverse effects , Radiation Exposure/prevention & control , Radiography, Interventional/adverse effects , Subclavian Artery/injuries , Subclavian Artery/physiopathology , Surgery, Computer-Assisted/adverse effects , Time Factors , Treatment Outcome , Vascular System Injuries/etiology , Vascular System Injuries/physiopathology
6.
Radiol Med ; 124(8): 753-761, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31011995

ABSTRACT

PURPOSE: To compare radiation exposure associated with daily practice cardiovascular (CV) examinations performed on two different multidetector computed tomography (MDCT) scanners, a conventional 64-MDCT and a third-generation dual-source (DS) MDCT. MATERIALS AND METHODS: In this retrospective study, 1458 patients who underwent CV examinations between January 2017 and August 2018 were enrolled. A single-source 64-MDCT (Lightspeed VCT, GE) scan was performed in 705 patients from January to August 2017 (207 coronary examinations and 498 vascular examinations) and 753 patients underwent third-generation 192 × 2-DSCT (Somatom FORCE, Siemens) scan from January to August 2018 (302 coronary examinations and 451 vascular examinations). Volume CT dose index (CTDIvol), dose length product (DLP), effective dose (ED), tube voltage (TV) and exposure time (ET), pitch factor (PF) were registered for each patient. Student's t test was used to compare mean values between each corresponding group of MDCT and DSCT. RESULTS: In coronary examinations with DSCT, CTDIvol was 24.4% lower (23.1 mGy vs 30.6 mGy, p < 0.0001) and DLP and ED reductions were 35.6% than with MDCT (465.0 mGy * cm vs 732.3 mGy * cm and 6.5 mSv and 10.3 mSv; vs p < 0.0001). Concerning scan parameters, kVp and ET reductions were 12.7% and 69.4%, respectively (p < 0.0001); PF increase was 73.8% (p < 0.0001). In all vascular studies, DSCT, compared with MDCT, permitted to reduce CTDIvol from 43.5 to 70.6%; DLP and ED reductions were from 50.3 to 73.1%; kVp and ET decreases were from 10.7 to 32.5% and from 26.3 to 68.7%. PF increase was from 16.7 to 58.1% (all differences with p < 0.0001). CONCLUSIONS: In daily practice, CV examinations CTDI, DLP, ED, ET and TV were lower and PF was higher with 192 × 2-DSCT compared to 64-MDCT.


Subject(s)
Cardiovascular Diseases/diagnostic imaging , Computed Tomography Angiography/methods , Multidetector Computed Tomography/methods , Radiation Exposure , Radiography, Dual-Energy Scanned Projection/methods , Computed Tomography Angiography/adverse effects , Computed Tomography Angiography/instrumentation , Coronary Angiography/adverse effects , Coronary Angiography/instrumentation , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Equipment Safety , Humans , Multidetector Computed Tomography/adverse effects , Multidetector Computed Tomography/instrumentation , Radiation Dosage , Radiography, Dual-Energy Scanned Projection/adverse effects , Radiography, Dual-Energy Scanned Projection/instrumentation , Retrospective Studies , Time Factors
7.
J Stroke Cerebrovasc Dis ; 28(7): 2031-2037, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31047820

ABSTRACT

BACKGROUND: Multimodal computed tomography imaging is used to identify eligible patients for intra-arterial treatment. A concern with this method is the multiple use of iodinated contrast material which presents a possible risk of renal toxicity. We compared the safety of intra-arterial treatment versus intravenous treatment during acute ischemic stroke treatment with a focus on renal safety. METHODS: Adult acute ischemic stroke patients who underwent a baseline Multimodal computed tomography, then intra-arterial treatment and/or intravenous treatment were identified. Primary outcomes were acute kidney injury and changes in serum creatinine at 24-72 hours (Δ serum creatinine). RESULTS: A total of 184 patients received intra-arterial treatment, while 68 received intravenous treatment. There were no differences in mean serum creatinine in the 24-72-hour time period, 24-hour urine volume, or rates of acute kidney injury, dialysis, or mortality. Univariate regression analysis identified diabetes mellitus, operation duration and times of embolectomy as predictors of creatinine increase while the multiple regression model identified diabetes mellitus as the only significant predictor. CONCLUSIONS: There were no significant differences in renal safety between the intra-arterial treatment and intravenous treatment groups. Diabetes mellitus may be a predictor of acute kidney injury. The use of Multimodal computed tomography imaging in the selection of patients who could benefit from endovascular therapy is safe.


Subject(s)
Acute Kidney Injury/chemically induced , Brain Ischemia/diagnostic imaging , Contrast Media/adverse effects , Endovascular Procedures/methods , Iohexol/adverse effects , Multidetector Computed Tomography/adverse effects , Perfusion Imaging/adverse effects , Stroke/diagnostic imaging , Acute Kidney Injury/blood , Acute Kidney Injury/diagnosis , Aged , Biomarkers/blood , Brain Ischemia/therapy , Clinical Decision-Making , Contrast Media/administration & dosage , Creatinine/blood , Endovascular Procedures/adverse effects , Female , Fibrinolytic Agents/administration & dosage , Humans , Infusions, Intra-Arterial , Infusions, Intravenous , Iohexol/administration & dosage , Male , Middle Aged , Multimodal Imaging/adverse effects , Patient Selection , Predictive Value of Tests , Retrospective Studies , Risk Assessment , Risk Factors , Stroke/therapy , Thrombectomy/methods , Thrombolytic Therapy/methods , Treatment Outcome
8.
Eur Radiol ; 28(10): 4370-4378, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29651767

ABSTRACT

OBJECTIVES: To estimate (a) organ doses and organ-specific radiation-induced cancer risk from a single low-dose CT (LDCT) for lung cancer screening (LCS) and (b) the theoretical cumulative risk of radiation-induced cancer for a typical cohort to be subjected to repeated annual LCS LDCT. METHODS: Sex- and body size-specific organ dose data from scan projection radiography (SPR) and helical CT exposures involved in LCS 256-slice LDCT were determined using Monte Carlo methods. Theoretical life attributable risk (LAR) of radiogenic cancer from a single 256-slice chest LDCT at age 55-80 years and the cumulative LAR of cancer from repeated annual LDCT studies up to age 80 years were estimated and compared to corresponding nominal lifetime intrinsic risks (LIRs) of being diagnosed with cancer. RESULTS: The effective dose from LCS 256-slice LDCT was estimated to be 0.71 mSv. SPR was found to contribute 6-12 % to the total effective dose from chest LDCT. The radiation-cancer LAR from a single LDCT study was found to increase the nominal LIR of cancer in average-size 55-year-old males and females by 0.008 % and 0.018 %, respectively. Cumulative radiogenic risk of cancer from repeated annual scans from the age of 55-80 years was found to increase the nominal LIR of cancer by 0.13 % in males and 0.30 % in females. CONCLUSION: Modern scanners may offer sub-millisievert LCS LDCT. Cumulative radiation risk from repeated annual 256-slice LDCT LCS examinations was found to minimally aggravate the lifetime intrinsic cancer risk of a typical screening population. KEY POINTS: • Effective dose from lung cancer screening low-dose CT may be <1 mSv. • Screening with modern low-dose CT minimally aggravates lifetime cancer induction intrinsic risk. • Dosimetry of lung cancer screening low-dose CT should encounter the radiation burden from the localizing scan projection radiography. • DLP method may underestimate effective dose from low-dose chest CT by 27 %.


Subject(s)
Early Detection of Cancer/adverse effects , Lung Neoplasms/diagnostic imaging , Mass Screening/adverse effects , Multidetector Computed Tomography/adverse effects , Neoplasms, Radiation-Induced/epidemiology , Phantoms, Imaging , Aged , Aged, 80 and over , Cohort Studies , Early Detection of Cancer/methods , Female , Humans , Male , Middle Aged , Monte Carlo Method , Radiometry , Radiotherapy Dosage , Risk Assessment/methods , Risk Factors
9.
Cardiovasc Diabetol ; 15: 92, 2016 Jun 28.
Article in English | MEDLINE | ID: mdl-27352620

ABSTRACT

BACKGROUND: It is not clear how severe metabolic syndrome (MS) affects the development of coronary atherosclerosis. METHODS: This was an observational, retrospective cohort study with Koreans who received health check-ups voluntarily. A total of 2426 subjects had baseline and follow-up coronary artery calcium score (CACS) data. Among them, 1079 had coronary computed tomography angiography (CCTA) data. We compared baseline CACS and any progression in subjects with and without MS. A more detailed analysis was conducted for coronary artery disease (CAD), which was defined by coronary artery stenosis (≥50 %), multivessel involvement, and coronary plaques in those patients with CCTA data. RESULTS: At baseline, subjects with MS (34.0 %, n = 825) had higher CACS and more significant coronary artery stenosis, multivessel involvement, and atheromatous plaques than those without MS (P < 0.05 for all). In the follow-up (median 1197 days), subjects with MS showed significant increases in CACS and progression of CAD compared with counterparts without MS, in parallel with the numbers of MS components. Finally, MS was a significant predictor for the progression of CACS (hazard ratio 1.32; 95 % confidence interval 1.06-1.64) and progression of coronary artery stenosis and/or development of vulnerable plaque (hazard ratio 1.47, 95 % confidence interval 1.01-2.15) after adjusting for other cardiovascular risk factors. CONCLUSIONS: Subjects with MS showed progression of CAD as assessed by CACS and CCTA over ~3 years. Therefore, more vigilant screening for coronary vascular health is needed among those with MS.


Subject(s)
Calcium/metabolism , Coronary Angiography , Coronary Artery Disease/complications , Metabolic Syndrome/complications , Multidetector Computed Tomography , Adult , Aged , Coronary Angiography/adverse effects , Coronary Angiography/methods , Disease Progression , Female , Humans , Male , Metabolic Syndrome/diagnostic imaging , Middle Aged , Multidetector Computed Tomography/adverse effects , Plaque, Atherosclerotic/complications , Retrospective Studies , Risk Factors , Vascular Calcification/complications
10.
J Endovasc Ther ; 23(4): 583-92, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27193306

ABSTRACT

PURPOSE: To compare the radiation exposure associated with intraoperative contrast-enhanced cone-beam computed tomography (ceCBCT) acquisitions to standard 3-phase multidetector computed tomography (MDCT) angiography used for assessing technical success after endovascular aortic repair (EVAR). METHODS: Effective doses (EDs) were calculated for 66 EVAR patients (mean age 71 years; 61 men) with a mean 27.7-kg/m(2) body mass index (range 17-49) who had both intraoperative ceCBCT and postoperative 3-phase MDCT angiography between November 2012 and April 2015. In addition, EDs were directly determined using thermoluminescent dosimeters (TLDs) embedded in anthropomorphic phantoms with body mass indexes of 22 and 30 kg/m(2) Effective doses were calculated by summing doses recorded by all TLDs corresponding to a specific tissue type before applying the International Commission on Radiological Protection (ICRP) 60 and 103 weighting factors. EDs were compared with each other for both imaging modalities as well as to TLD measurements. RESULTS: Average EDs of the patient collective were 4.9±1.1 mSv for ceCBCT, 2.6±1.2 mSv for single-phase MDCT (46% decrease, covering solely the area of the implanted endograft), and 13.6±5.5 mSv for comprehensive 3-phase MDCT examinations (178% increase, anatomical coverage from the aortic arch to femoral artery bifurcation). EDs determined in phantom measurements ranged from 3.1 to 4.5 mSv for ceCBCT, amounting to 2.6 mSv for a single MDCT phase (15% to 40% decrease) using ICRP 60 conversion factors. Applying ICRP 103 factors resulted in higher values for ceCBCT and slightly lower ones for MDCT. CONCLUSION: ceCBCT offers the chance for immediate intraoperative revisions of endograft-related problems. Requiring only a single-phase acquisition, ceCBCT is associated with a considerable reduction in ED (50%-75%) compared to standard 3-phase MDCT angiography after EVAR. On the other hand, MDCT has a larger field of view and is associated with less radiation exposure for a single phase (reduction of 20%-60%) if only the stented region is covered; however, MDCT angiography also uses larger amounts of contrast.


Subject(s)
Aortic Aneurysm, Abdominal/diagnostic imaging , Aortic Aneurysm, Abdominal/surgery , Aortography/methods , Blood Vessel Prosthesis Implantation , Computed Tomography Angiography , Cone-Beam Computed Tomography , Endovascular Procedures , Multidetector Computed Tomography , Radiation Dosage , Radiation Exposure , Aged , Aged, 80 and over , Aortography/adverse effects , Aortography/instrumentation , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/instrumentation , Computed Tomography Angiography/adverse effects , Computed Tomography Angiography/instrumentation , Cone-Beam Computed Tomography/adverse effects , Cone-Beam Computed Tomography/instrumentation , Contrast Media/administration & dosage , Contrast Media/adverse effects , Endovascular Procedures/adverse effects , Endovascular Procedures/instrumentation , Female , Humans , Male , Middle Aged , Multidetector Computed Tomography/adverse effects , Multidetector Computed Tomography/instrumentation , Phantoms, Imaging , Predictive Value of Tests , Radiation Exposure/adverse effects , Stents , Thermoluminescent Dosimetry , Time Factors , Treatment Outcome
11.
Vopr Onkol ; 62(3): 460-4, 2016.
Article in Russian | MEDLINE | ID: mdl-30462911

ABSTRACT

The purpose of this study was a comparison of the X-ray density in certain organs and anatomical structures and the determination of the radiation exposure during venous-arterial MSCT scanning and classical two-phase CT of organs of the abdominal cavity. It has been established that the technique of venous-arterial MSCT scanning provided a significant reduction of radiation dose during CT of organs of the abdominal cavity and could be used as an alternative to two-phase examination in the process of dynamic monitoring of cancer patients.


Subject(s)
Contrast Media/administration & dosage , Multidetector Computed Tomography/adverse effects , Tomography, X-Ray Computed/adverse effects , X-Rays/adverse effects , Adolescent , Adult , Aged , Aged, 80 and over , Aorta/diagnostic imaging , Aorta/radiation effects , Female , Humans , Kidney/diagnostic imaging , Kidney/radiation effects , Liver/diagnostic imaging , Liver/radiation effects , Male , Middle Aged , Multidetector Computed Tomography/methods , Pancreas/diagnostic imaging , Pancreas/radiation effects , Portal Vein/diagnostic imaging , Portal Vein/radiation effects , Radiation Dosage , Spleen/diagnostic imaging , Spleen/radiation effects , Tomography, X-Ray Computed/methods , Young Adult
12.
Catheter Cardiovasc Interv ; 85(1): 139-47, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-24403085

ABSTRACT

OBJECTIVES: Our study was aimed at evaluation of three-dimensional (3D)-CT overlay onto the catheterization laboratory fluoroscopy to guide structural cardiac interventions. BACKGROUND: Current imaging for structural cardiac interventions (fluoroscopy, echocardiography) may not provide adequate guidance. The ability to integrate intracardiac 3D-CT imaging data in the cardiac catheterization laboratory may be beneficial, but has not yet been systematically studied. METHODS: Thirty-two patients undergoing various catheterization laboratory procedures (transcatheter aortic valve replacement, paravalvular leak (PVL) closure, pulmonary vein (PV) stenting, etc.) were prospectively enrolled. The goal was to evaluate the feasibility and benefit of overlaying pre-procedural CT data onto the real-time procedural fluoroscopic image using the Syngo DynaCT Cardiac C-arm CT system (Siemens Healthcare, Forcheim, Germany). RESULTS: The overlay was considered most helpful for patients undergoing PVL closure and PV stenting. The additional radiation exposure of the C-arm CT was a fraction of the total procedural dose (3.5% of total skin dose and 9.1% of total DAP). CONCLUSIONS: Overlay of 3D-CT data onto the real-time procedural fluoroscopy in the cardiac catheterization laboratory is feasible to aide procedural guidance. The overlay was considered most helpful for patients undergoing PVL closure and PV stenting. The additional radiation dose is a small fraction of the total dose. © 2014 Wiley Periodicals, Inc.


Subject(s)
Cardiac Catheterization/methods , Cardiovascular Diseases/therapy , Coronary Angiography/methods , Multidetector Computed Tomography/methods , Radiography, Interventional/methods , Cardiac Catheterization/adverse effects , Cardiovascular Diseases/diagnostic imaging , Coronary Angiography/adverse effects , Feasibility Studies , Fluoroscopy , Humans , Imaging, Three-Dimensional , Multidetector Computed Tomography/adverse effects , Multimodal Imaging , Predictive Value of Tests , Prospective Studies , Radiation Dosage , Radiographic Image Interpretation, Computer-Assisted , Radiography, Interventional/adverse effects , Risk Factors
13.
Eur Radiol ; 25(7): 1883-90, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25638220

ABSTRACT

OBJECTIVE: To estimate thyroid doses and cancer risk for paediatric patients undergoing neck computed tomography (CT). METHODS: We used average CTDI(vol) (mGy) values from 75 paediatric neck CT examinations to estimate thyroid dose in a mathematical anthropomorphic phantom (ImPACT Patient CT Dosimetry Calculator). Patient dose was estimated by modelling the neck as mass equivalent water cylinder. A patient size correction factor was obtained using published relative dose data as a function of water cylinder size. Additional correction factors included scan length and radiation intensity variation secondary to tube-current modulation. RESULTS: The mean water cylinder diameter that modelled the neck was 14 ± 3.5 cm. The mathematical anthropomorphic phantom has a 16.5-cm neck, and for a constant CT exposure, would have thyroid doses that are 13-17% lower than the average paediatric patient. CTDI(vol) was independent of age and sex. The average thyroid doses were 31 ± 18 mGy (males) and 34 ± 15 mGy (females). Thyroid cancer incidence risk was highest for infant females (0.2%), lowest for teenage males (0.01%). CONCLUSIONS: Estimated absorbed thyroid doses in paediatric neck CT did not significantly vary with age and gender. However, the corresponding thyroid cancer risk is determined by gender and age. KEY POINTS: • Thyroid doses can be estimated from the CTDI(vol) in paediatric neck CT . • Scan length, neck size, and radiation intensity variation should be accounted for. • Estimated absorbed thyroid doses did not significantly vary with age and gender. • Thyroid cancer incidence risk is primarily determined by gender and age.


Subject(s)
Multidetector Computed Tomography/adverse effects , Neck/diagnostic imaging , Radiation Dosage , Thyroid Neoplasms/epidemiology , Adolescent , Age Factors , Axis, Cervical Vertebra/diagnostic imaging , Child , Child, Preschool , Female , Humans , Infant , Male , Phantoms, Imaging , Radiometry/methods , Retrospective Studies , Risk , Sex Factors , South Carolina/epidemiology , Thyroid Gland/diagnostic imaging
14.
AJR Am J Roentgenol ; 202(6): 1166-70, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24848812

ABSTRACT

OBJECTIVE: The purpose of this study was to compare the performance of a 20-gauge fenestrated catheter with an 18-gauge nonfenestrated catheter for i.v. contrast infusion during MDCT. SUBJECTS AND METHODS: Two hundred five adult outpatients imaged on a dual-source 128-MDCT scanner with arterial phase body CT (flow rates, 5.0-7.5 mL/s) were randomized to either an 18-gauge nonfenestrated or 20-gauge fenestrated catheter. After randomization, any 18-gauge nonfenestrated subjects whose veins were deemed insufficient for that catheter gauge were assigned to a third cohort for placement of a 20-gauge fenestrated catheter. Catheter placement success, infusion rate, contrast volume, maximum pressure, complications, and aortic enhancement levels were recorded. RESULTS: Catheters were placed on the first attempt in 97% (100/103) for 18-gauge nonfenestrated and 94% (96/102) for 20-gauge fenestrated placements and in two or fewer attempts in 99% of both groups. Mean infusion rates (5.74 mL/s for 18-gauge nonfenestrated and 5.58 mL/s for 20-gauge fenestrated placements) and aortic enhancement levels were not significantly different. Maximum pressure was higher with 20-gauge fenestrated catheters (mean ± SD, 230.5 ± 27.6 pounds per square inch [psi]) than 18-gauge nonfenestrated catheters (mean ± SD 215.6 ± 32.8 psi) (p = 0.002). One subject with an 18-gauge nonfenestrated catheter had a high-pressure alarm. In the third cohort, a 20-gauge fenestrated catheter was successfully placed in two or fewer attempts in 85% (28/33), with one minor extravasation attributed to vein insufficiency. CONCLUSION: A 20-gauge fenestrated catheter performs similarly to an 18-gauge nonfenestrated catheter with respect to i.v. contrast infusion rates and aortic enhancement levels and can be placed in most subjects whose veins are deemed insufficient for an 18-gauge catheter.


Subject(s)
Central Venous Catheters/classification , Contrast Media/administration & dosage , Foreign-Body Migration/prevention & control , Infusions, Intravenous/instrumentation , Multidetector Computed Tomography/methods , Radiography, Interventional/methods , Aortography/adverse effects , Aortography/methods , Contrast Media/adverse effects , Extravasation of Diagnostic and Therapeutic Materials/diagnosis , Extravasation of Diagnostic and Therapeutic Materials/etiology , Extravasation of Diagnostic and Therapeutic Materials/prevention & control , Female , Foreign-Body Migration/diagnosis , Foreign-Body Migration/etiology , Humans , Infusions, Intravenous/adverse effects , Male , Middle Aged , Multidetector Computed Tomography/adverse effects , Reproducibility of Results , Sensitivity and Specificity
15.
Folia Morphol (Warsz) ; 83(1): 176-181, 2024.
Article in English | MEDLINE | ID: mdl-36688405

ABSTRACT

BACKGROUND: Various ligaments present in the skull base are of clinical and surgical importance. One among them, is the petrosphenoid ligament (PSL). PSL may ossify either in a partial or complete form and forms the roof of Dorello's canal underneath which the abducens nerve passes. Studies argued both protective and adverse effects of the ossified PSL. Hence, the incidence of PSL ossification has become a relevant subject in clinical practice to radiologists, neurologists and neurosurgeons for understanding its potential role in abducens nerve compression. MATERIALS AND METHODS: We have undertaken this study to investigate the incidence of PSL ossification from multidetector computed tomography (MDCT) images of the patients who had been referred to the Medical Imaging Department of Mubarak Al-Kabeer Hospital in Kuwait. We retrospectively assessed a total of 200 patients' head CT scans (400 petroclival regions) between January 2021 and June 2022 in which 59% were males (n = 118) and 41% were females (n = 82) aged between 18 and 91 years. RESULTS: A total of 37 patients (26 male, 11 female) aged between 18-84 years were presented with ossification of PSL. Among these 37 patients, 28 patients were presented with unilateral ossified PSL, and 9 patients were presented with bilateral ossified PSL, amounting to the total of 46 ossified PSL from 400 CT images of the petroclival regions (11.5%). The genderwise and sidewise occurrence of the PSL ossification seen in different age groups were not statistically significant (p > 0.05). Among all the ossified cases, there was no patient presented with abducens nerve palsy. CONCLUSIONS: We believe our results provide baseline data in the region for understanding PSL ossification and its impact on the abducens nerve palsy.


Subject(s)
Abducens Nerve Diseases , Osteogenesis , Humans , Male , Female , Adolescent , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over , Retrospective Studies , Abducens Nerve Diseases/etiology , Multidetector Computed Tomography/adverse effects , Ligaments
16.
Folia Morphol (Warsz) ; 83(1): 182-191, 2024.
Article in English | MEDLINE | ID: mdl-36794687

ABSTRACT

BACKGROUND: This study aimed to evaluate the congenital anomalies of ribs in the Turkish population using multi-detector computed tomography (CT) and to reveal the prevalence and distribution of these anomalies according to sexes and body sides. MATERIALS AND METHODS: This study included 1120 individuals (592 male, 528 female) over 18 who presented to our hospital with a suspicion of COVID-19 and who had thoracic CT. Anomalies such as a bifid rib, cervical rib, fused rib, Srb anomaly, foramen rib, hypoplastic rib, absent rib, supernumerary rib, pectus carinatum, and pectus excavatum, which were previously defined in the literature, were examined. Descriptive statistics were performed with the distribution of anomalies. Comparisons were made between the sexes and body sides. RESULTS: A prevalence of 18.57% rib variation was observed. Females had 1.3 times more variation than males. Although there was a significant difference in the distribution of anomalies by sex (p = 0.000), there was no difference in terms of body side of anomaly (p > 0.05). The most common anomaly was the hypoplastic rib, followed by the absence of a rib. While the incidence of the hypoplastic rib was similar in females and males, 79.07% of the absent ribs was seen in females (p < 0.05). The study also includes a rare case of bilateral first rib foramen. At the same time, this study includes a rare case of rib spurs extending from the left 11th rib to the 11th intercostal space. CONCLUSIONS: This study demonstrates detailed information about congenital rib anomalies in the Turkish population, which may vary between people. Knowing these anomalies is essential for anatomy, radiology, anthropology, and forensic sciences.


Subject(s)
Musculoskeletal Abnormalities , Thoracic Wall , Humans , Male , Female , Ribs/diagnostic imaging , Ribs/abnormalities , Musculoskeletal Abnormalities/diagnostic imaging , Multidetector Computed Tomography/adverse effects , Radiography
17.
Acta Cardiol ; 68(3): 291-7, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23882875

ABSTRACT

OBJECTIVE: Both computed tomography (CTA) and conventional angiography (CCA) can provide direct visualization of the coronary arteries. The aim of the present study was to compare the radiation exposure between CTA and CCA and to search whether this amount of radiation causes significant DNA damage. METHOD: Seventy-two patients who underwent CTA or CCA were enrolled prospectively. We recorded the radiation dosage that was used during the procedures and calculated the effective dose (ED). We determined the sister chromatid exchange (SCE) level from the blood samples which were drawn from the patients before and after the procedures. The change in SCE is used as the measure of DNA damage induced by the radiation. RESULTS: The patients in the CTA (n = 36) and CCA groups (n= 36) had similar baseline characteristics. The ED was higher in CTA examinations compared to CCA examinations (14.2 +/- 2.7 vs 6.4 +/- 3.1, P <0.001). The SCE level increased significantly after both angiography methods (P <0.001). When the change in SCE after angiography was compared, we did not find a significant difference among the groups (2.73 +/- 1.6 vs 2.54 +/- 1.22, P= NS). CONCLUSION: Although the patients who underwent CTA were exposed to a greater amount of radiation, the radiation-induced genetic damage was similar with both types of the procedures.


Subject(s)
Angina, Stable/diagnostic imaging , Coronary Angiography/adverse effects , DNA Damage/genetics , DNA/radiation effects , Multidetector Computed Tomography/adverse effects , Radiation Injuries/genetics , Angina, Stable/blood , Coronary Angiography/methods , Dose-Response Relationship, Radiation , Female , Humans , Male , Middle Aged , Prospective Studies , Radiation Injuries/diagnosis , Radiation Injuries/etiology , Sister Chromatid Exchange/genetics , Sister Chromatid Exchange/radiation effects
18.
Iran J Med Sci ; 48(6): 572-581, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38094288

ABSTRACT

Background: Cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) are frequently used in dental and maxillofacial problems. This study aimed to assess the genotoxicity and cytotoxicity effects of CBCT and MDCT radiographies on exfoliated buccal epithelial cells during dental examinations. Methods: This prospective experimental study was conducted at Babol University of Medical Sciences (Babol, Iran) from March 2021 to April 2021. Buccal mucosa smears were collected bilaterally pre-exposure and 12 days after CBCT or MDCT examinations. To compare the frequency of micronuclei and other cytotoxic cellular changes such as pyknosis, karyolysis, and karyorrhexis, the paired sample t test and Wilcoxon test were used. In addition, independent sample t test, Mann-Whitney, and Chi square tests were used to investigate the differences between the imaging methods and between men and women. All statistical analyses were performed using the SPSS software, and P≤0.05 was considered statistically significant. Results: The current study included 60 adult patients (30 patients in each group), ranging in age from 21 to 50 years. The micronuclei and the other cytotoxic cellular changes increased significantly after CBCT and MDCT radiographic examinations on the 12th day compared to the pre-exposure results (P<0.001). MDCT had statistically higher cytotoxic and genotoxic effects than CBCT (9.4%, 23.1%, and 40% higher values in micronucleus frequency, the mean frequency of micronuclei, and other cytotoxic changes, respectively). There were no significant differences between men and women in the two examination methods (P=0.46 and P=0.49, respectively). Conclusion: Dental examinations with CBCT and MDCT can increase cytotoxicity and chromosomal damage in both men and women. Due to its lower radiation toxicities, CBCT can be recommended as an alternative to MDCT for dental examinations.


Subject(s)
Cone-Beam Computed Tomography , Multidetector Computed Tomography , Male , Adult , Humans , Female , Young Adult , Middle Aged , Multidetector Computed Tomography/adverse effects , Prospective Studies , Cone-Beam Computed Tomography/methods , Epithelial Cells , DNA Damage
20.
Tunis Med ; 90(3): 201-4, 2012 Mar.
Article in French | MEDLINE | ID: mdl-22481186

ABSTRACT

BACKGROUND: Due to the recent technological progress, multislice computerized tomography (MSCT) allows visualizing the heart and coronary arteries. Multislice computed tomography is non invasive and provides high quality images.Its main limits are arythmia, tachycardia and coronary calcifications. But the main drawback with MSCT is the radiation dose. AIM: Report of usefuluess and indications of multislice CT scanner. METHODS: Rzview of literature RESULTS: Although the indications of MSCT did not reach a guideleness level yet, some trends can be stated. The advantages and limitations of MSCT in cardiac exploration are summarized in this article. The indications are mainly based on the excellent negative predictive value of MSCT regarding coronary artery disease. Hence, patients at low to moderate risk of coronary artery disease mostly benefit of the technique. MSCT can be an alternate examination in case of non feasible or non contributive ischemic test. MSCT is highly contributive in the ostial analysis, in detecting abnormal congenital coronary anomalies or in analysing bypass grafts. MSCT remains limited in patients with heavily calcified coronary arteries, and in patients with stented distal arteries. CONCLUSION: Multislice CT scanner should not be considered as equivalent to invasive coronary angiography bu it is a additional diagnostic tool.


Subject(s)
Coronary Angiography/methods , Heart/diagnostic imaging , Multidetector Computed Tomography/methods , Coronary Angiography/adverse effects , Coronary Angiography/statistics & numerical data , Coronary Disease/diagnostic imaging , Coronary Vessels/pathology , Humans , Image Processing, Computer-Assisted/methods , Multidetector Computed Tomography/adverse effects , Multidetector Computed Tomography/statistics & numerical data
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