scholarly journals Operator’s eye lens dose in computed tomography–guided interventions

2020 ◽  
Author(s):  
Siru Kaartinen ◽  
Minna Husso ◽  
Hanna Matikka
Keyword(s):  
Computed Tomography ◽  
Equivalent Dose ◽  
Eye Lens ◽  
Clinical Settings ◽  
Dose Limit ◽  
Dose Length Product ◽  
Ct Guided ◽  
Eye Lens Dose ◽  
Time Period ◽  
The Mean

Abstract Objectives To survey (1) operator’s eye lens doses in typical computed tomography (CT)-guided interventions, (2) correlation between dose length product (DLP) and the operator’s dose, and (3) different ways for estimating the eye lens dose in clinical settings. Methods Doses of 16 radiologists in 164 CT-guided interventional procedures were prospectively measured during a 6-month time period upon radioprotective garments and descriptive statistical outcomes were calculated. The correlations between DLP and measured doses were surveyed. Results On average, the operator’s dose at the eye level (DEL, Hp(0.07)) was 22 μSv per procedure and the personal equivalent dose Hp(10) at the collar level was 21 μSv per procedure. The mean DLP of a procedure was 320 mGy cm, where 54% resulted from the fluoroscopy, the mean exposure time being 18 s. Based on the results, the operator’s DEL could be estimated from DLP using the equation DEL (μSv) = 0.10 μSv/mGy cm × patient fluoro DLP (mGycm) (p < 0.001), and the dose at the collar level (DCL) using the equation DCL (μSv) = 0.12 μSv/mGy cm × patient fluoro DLP (mGy cm) (p < 0.001). In addition, DEL (μSv) = 0.7 × DCL (μSv). Conclusions The eye lens doses in CT-guided interventions are generally low even without protective equipment, and it is unlikely that the recommended annual equivalent dose limit of 20 mSv for the lens of the eye will be exceeded by conducting CT-guided interventions solely. Eye lens dose can be roughly estimated based on either DLP of the procedure or dose measured at the operator’s collar level. Key Points • Eye lens doses in CT-guided operations are generally low. • It is unlikely that the ICRP recommendation of the yearly equivalent dose limit of 20 mSv will be exceeded by conducting CT-guided interventions solely. • Magnitude of eye lens dose can be estimated based on either DLP of the procedure or dose measured at the operator’s collar level.

Eye Lens Dose in Cranial Computed Tomography with Reference to the Technical Development of CT Scanners

1986 ◽  
Vol 27 (5) ◽  
pp. 599-606 ◽  
Author(s):  
U. Moström ◽  
C. Ytterbergh ◽  
K. Bergström
Keyword(s):  
Computed Tomography ◽  
Spatial Distribution ◽  
Technical Development ◽  
Cranial Computed Tomography ◽  
Eye Lens ◽  
Ct Scanner ◽  
Cranial Ct ◽  
Eye Lens Dose ◽  
Patient Groups ◽  
The Mean

The continuous technical development of cranial CT and the accumulation of clinical experience with this method, have resulted in the use of an increasing number of scan protocols for different clinical situations. An investigation was undertaken to find out how this change has influenced the dose delivered to the patient. The eye lens dose was measured at CT examinations in 245 patients, with appropriate scan protocols, and also at corresponding examinations in an anthropomorphic head phantom. One CT scanner of early (EMI CT 1010) and one of modern design (Siemens Somatom DR2) were investigated. The range of the eye lens dose was wide, namely 4 to 206 mGy for EMI CT 1010 and 6 to 124 mGy for Somatom DR2. In patient groups with comparable scan protocols the mean eye lens dose was higher with the Somatom DR2, mostly on account of a different spatial distribution of the dose in the scan plane. The dose varied less with this scanner, however, mainly because of the possibilities for more accurate positioning.

scholarly journals Safety and reliability of computed tomography-guided lipiodol marking for undetectable pulmonary lesions

2020 ◽  
Vol 30 (4) ◽  
pp. 546-551
Author(s):  
Kazuhiro Ito ◽  
Junichi Shimada ◽  
Masanori Shimomura ◽  
Kunihiko Terauchi ◽  
Motohiro Nishimura ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Lesion Size ◽  
Ct Guided ◽  
Pulmonary Lesions ◽  
Pleural Surface ◽  
Intraoperative Fluoroscopy ◽  
Safety And Reliability ◽  
Preoperative Ct ◽  
The Mean ◽  
Lipiodol Marking

Abstract OBJECTIVES This study aimed to evaluate the safety and reliability of percutaneous computed tomography (CT)-guided lipiodol marking for undetectable pulmonary lesions before video-assisted thoracic surgery (VATS). METHODS We retrospectively analysed the cases of CT-guided lipiodol marking followed by VATS in 9 institutes from May 2006 to March 2018. Lipiodol (0.2–0.5 ml) was percutaneously injected closely adjacent to undetectable pulmonary lesions with computed-tomography guidance. Lipiodol spots were identified using C-arm-shaped fluoroscopy during VATS. We grasped the lipiodol spots, including the target lesions, with ring-shaped forceps and resected them. RESULTS Of 1182 lesions, 1181 (99.9%) were successfully marked. In 1 case, the injected lipiodol diffused, and no spot was created. Of the 1181 lesions, 1179 (99.8%) were successfully resected with intraoperative fluoroscopy. Two lipiodol spots were not detected because of the lipiodol distribution during the division of pleural adhesions. The mean lesion size was 9.1 mm (range 1–48 mm). The mean distance from the pleural surface was 10.2 mm (range 0–43 mm). Lipiodol marking-induced pneumothorax occurred in 495 (57.1%) of 867 cases. Of these, chest drainage was required in 59 patients (6.8%). The other complications were 19 (2.2%) cases of bloody sputum, 3 (0.35%) cases of intravascular air, 1 (0.12%) case of pneumonia and 1 (0.12%) case of cerebral infarction. There were no lipiodol marking-induced deaths or sequelae. CONCLUSIONS Preoperative CT-guided lipiodol marking followed by VATS resection was shown to be a safe and reliable procedure with a high success rate and acceptably low severe complication rate.

scholarly journals Radiation Dose to the Eye Lens Through Radiological Imaging Procedures at the Surgical Workplace During Trauma Surgery

2019 ◽  
Vol 16 (20) ◽  
pp. 3850
Author(s):  
Apelmann ◽  
Kowald ◽  
Weinrich ◽  
Dischinger ◽  
Nienhaus ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Trauma Surgery ◽  
Eye Lens ◽  
Radiological Imaging ◽  
Imaging Procedures ◽  
Drastic Reduction ◽  
Dose Limit ◽  
Eye Lens Dose ◽  
Surgical Assistants ◽  
Trauma Surgeons

Background: Due to the drastic reduction of the eye lens dose limit from 150 mSv per year to 20 mSv per year since 2018, the prospective investigation of the estimated dose of the eye lens by radiological imaging procedures at the surgical site during trauma surgery in the daily work process was carried out. This was also necessary because, as experience shows, with changes in surgical techniques, there are also changes in the use of radiological procedures, and thus an up-to-date inventory can provide valuable information for the assessment of occupationally induced radiation exposure of surgical personnel under the current conditions. Methods: The eye lens radiation exposure was measured over three months for five trauma surgeons, four hand surgeons and four surgical assistants with personalized LPS-TLD-TD 07 partial body dosimeters Hp (0.07). A reference dosimeter was deposited at the surgery changing room. The dosimeters were sent to the LPS (Landesanstalt für Personendosimetrie und Strahlenschutzausbildung) measuring institute (National Institute for Personal Dosimetry and Radiation Protection Training, Berlin) for evaluation after 3 months. The duration of the operation, occupation (assistant, surgeon, etc.), type of surgery (procedure, diagnosis), designation of the X-ray unit, total duration of radiation exposure per operation and dose area product per operation were recorded. Results: Both the evaluation of the dosimeters by the trauma surgeons and the evaluation of the dosimeters by the hand surgeons and the surgical assistants revealed no significant radiation exposure of the eye lens in comparison to the respective measured reference dosimeters. Conclusions: Despite the drastic reduction of the eye lens dose limit from 150 mSv per year to 20 mSv per year, the limit for orthopedic, trauma and hand surgery operations is well below the limit in this setting.

Percutaneous CT-Guided Cryoablation of the Bilateral Pudendal Nerves for Palliation of Intractable Pain Related to Pelvic Neoplasms

2020 ◽  
Vol 37 (8) ◽  
pp. 619-623 ◽  
Author(s):  
John David Prologo ◽  
Sivasai Manyapu ◽  
Zachary L. Bercu ◽  
Ashmit Mittal ◽  
Jason W. Mitchell
Keyword(s):  
Computed Tomography ◽  
Pelvic Pain ◽  
Pudendal Nerve ◽  
Intractable Pain ◽  
Pelvic Neoplasms ◽  
Ct Guided ◽  
Patient Demographics ◽  
Pain Scores ◽  
The Mean ◽  
Mean Time

Objectives: The purpose of this report is to describe the effect of computed tomography–guided bilateral pudendal nerve cryoablations on pain and time to discharge in the setting of acute hospitalizations secondary to refractory pelvic pain from cancer. Methods: Investigators queried the medical record for patients who underwent pudendal nerve cryoablation using the Category III Current Procedural Technology code assignment 0442T or Category I code 64640 for cases prior to 2015. The resulting list was reviewed, and procedures performed on inpatients for intractable pelvic pain related to neoplasm were selected. The final cohort was then analyzed with regard to patient demographics, procedure details, technical success, safety, pain scores, and time to discharge. Results: Ten patients underwent cryoablation by 3 operators for palliation of painful pelvic neoplasms between June 2014 and January 2019. All probes were satisfactorily positioned and freeze cycles undertaken without difficulty. There were no procedure-related complications or adverse events. The mean difference in pre- and posttreatment worst pain scores was significant (n = 5.20, P = .003). The mean time to discharge following the procedure was 2.3 days. Conclusion: Computed tomography–guided percutaneous cryoablation of the bilateral pudendal nerves may represent a viable option in the setting of acute hospitalization secondary to intractable pain in patients with pelvic neoplasms.

scholarly journals The comparison of bolus tracking and test bolus techniques for computed tomography thoracic angiography in healthy beagles

2013 ◽  
Vol 84 (1) ◽  
Author(s):  
Nicolette Cassel ◽  
Ann Carstens ◽  
Pieter Becker
Keyword(s):  
Computed Tomography ◽  
Contrast Agent ◽  
Test Dose ◽  
Dose Length Product ◽  
Bolus Tracking ◽  
Iodinated Contrast ◽  
Iodinated Contrast Agent ◽  
Test Bolus ◽  
The Mean ◽  
Computed Tomography Dose Index

Computed tomography thoracic angiography studies were performed on five adult beagles using the bolus tracking (BT) technique and the test bolus (TB) technique, which were performed at least two weeks apart. For the BT technique, 2 mL/kg of 300 mgI/mL iodinated contrast agent was injected intravenously. Scans were initiated when the contrast in the aorta reached 150 Hounsfield units (HU). For the TB technique, the dogs received a test dose of 15% of 2 mL/kg of 300 mgI/mL iodinated contrast agent, followed by a series of low dose sequential scans. The full dose of the contrast agent was then administered and the scans were conducted at optimal times as identified from time attenuation curves. Mean attenuation in HU was measured in the aorta (Ao) and right caudal pulmonary artery (rCPA). Additional observations included the study duration, milliAmpere (mA), computed tomography dose index volume (CTDI[vol]) and dose length product (DLP). The attenuation in the Ao (BT = 660 52 HU ± 138 49 HU, TB = 469 82 HU ± 199 52 HU, p = 0.13) and in the rCPA (BT = 606 34 HU ± 143 37 HU, TB = 413 72 HU ± 174.99 HU, p = 0.28) did not differ significantly between the two techniques. The BT technique was conducted in a significantly shorter time period than the TB technique (p = 0.03). The mean mA for the BT technique was significantly lower than the TB technique (p = 0.03), as was the mean CTDI(vol) (p = 0.001). The mean DLP did not differ significantly between the two techniques (p = 0.17). No preference was given to either technique when evaluating the Ao or rCPA but the BT technique was shown to be shorter in duration and resulted in less DLP than the TB technique.

scholarly journals The Safety of CT-Guided Epidural Steroid Injections in an Older Patient Cohort

2016 ◽  
Vol 8;19 (8;11) ◽  
pp. E1139-E1146
Author(s):  
Andrew J. Fenster
Keyword(s):  
Back Pain ◽  
Procedure Time ◽  
Older Patient ◽  
Dose Length Product ◽  
Ct Guided ◽  
Steroid Injections ◽  
Epidural Steroid Injections ◽  
The Mean ◽  
Procedure Duration ◽  
Epidural Steroid

Background: Epidural steroid injections (ESIs) are a common method for treating lower back pain, which is one of the most prevalent health-related complaints in the adult U.S. population. Although the safety of CT-guided ESIs has been extensively studied in adults, there is limited data concerning the procedure’s safety profile in an older patient population. Objective: This retrospective study analyzed safety data among a single-center cohort of patients > 65 years-old who received one or more CT-guided interlaminar ESIs from 2012 to 2015. Study Design: An Institutional Review Board (IRB)-approved retrospective chart review. Setting: University hospital center. Methods: A total of 688 CT-guided ESI procedures were evaluated and a linear regression analysis was conducted to examine the relationship between dose length product (DLP), body mass index (BMI), procedure duration, and kVp/mA settings. Further analysis was performed on a sample of long procedure time, average-DLP and high-DLP procedures. Results: Average age was 75.77 years, with 44% having a BMI > 30. The mean DLP was 55.58 mGy x cm and the mean procedure duration was 5.94 minutes. All procedures were technically successful and no complications were observed during or after any of the procedures, including at one-month follow-up office visits. The kVp and mA settings were the strongest predictors of DLP, followed by procedure time. The high-DLP cases had a greater number of needle placement series, more intervertebral disc spaces included in each planning series and higher machine settings (kVp 120; mA 87.5) than the average-DLP cases (kVp 100; mA 49.9). Limitations: This study is limited by its retrospective design. Conclusion: CT-guided interlaminar ESIs can be performed safely, with low procedure times, relatively low DLP’s and without complications in an older patient population. Key words: Epidural steroid injection, interlaminar approach, CT-guidance, older adults, back pain, lumbar spine, thoracic spine, cervical spine, dose length product, radiation exposure

Effectiveness of Ultrasound-Guided Radiofrequency Ablation in the Treatment of 36 Renal Cell Carcinoma Tumours Compared with Published Results of Using Computed Tomography Guidance

2012 ◽  
Vol 63 (3_suppl) ◽  
pp. S23-S32 ◽  
Author(s):  
Kellie Davis ◽  
Ania Kielar ◽  
Katayoun Jafari
Keyword(s):  
Computed Tomography ◽  
Radiofrequency Ablation ◽  
Residual Disease ◽  
Tumour Size ◽  
Complication Rates ◽  
Ct Guided ◽  
Renal Lesions ◽  
Contrast Enhanced Ct ◽  
The Mean

This study aimed to analyse the outcomes of ultrasound (US) guided radiofrequency ablation (RFA) in patients with renal lesions and to compare our outcomes with published results of ablations carried out when using computed tomography (CT) guidance. This retrospective study evaluated RFA of 36 renal tumours in 32 patients (M = 21, F = 11). The mean patient age was 70 years (range, 39–89 years). Ablations were performed by using either multi-tined applicators or cooled and/or cluster applicators under US guidance. Applicator size varied from 2–5 cm, depending on the size of the index tumour. Conscious sedation was administered by an anesthetist. Follow-up imaging by using contrast-enhanced CT was performed 1, 3, 6, and 12 months after RFA, and yearly thereafter. The mean tumour follow-up time was 12 months (range, 1–35 months). The mean tumour size was 2.7 cm (range, 1–5 cm). Primary effectiveness was achieved in 31 cases (86.1%), with patients in 5 cases (11.1%) demonstrating residual disease. Three patients had repeated sessions, which were technically successful. The remaining 2 patients were not re-treated because of patient comorbidities. As a result, secondary effectiveness was achieved in 34 patients (94.4%). In 1 patient, a new lesion developed in the same kidney but remote from the 2 prior areas of treatment. Hydrodissection was performed in 3 patients (8.3%), manipulation or electrode repositioning in 11 patients (30.6%), and ureteric cooling in 1 patient (2.8%). Minor and major complications occurred in 3 (8.3%) and 3 (8.3%) patients, respectively. Correlation coefficients were calculated for distance from skin to tumour and risk of complication as well as compared with primary and secondary effectiveness. This study demonstrates that US-guided RFA is an effective treatment for renal lesions, with rates of effectiveness and complication rates comparable with published CT-guided RFA results.

EYE LENS DOSE OPTIMIZATION THROUGH GANTRY TILTING IN BRAIN CT SCAN: THE POTENTIAL EFFECT OF THE RADIOLOGICAL TECHNOLOGISTS’ TRAINING

2020 ◽  
Vol 189 (4) ◽  
pp. 527-533
Author(s):  
Ali Ebrahiminia ◽  
Mohsen Asadinezhad ◽  
Fereshteh Mohammadi ◽  
Karim Khoshgard
Keyword(s):  
Image Quality ◽  
Signal To Noise Ratio ◽  
Potential Effect ◽  
Quality Parameters ◽  
Eye Lens ◽  
Dose Length Product ◽  
Training Dose ◽  
Eye Lens Dose ◽  
Before And After ◽  
Noise Ratio

Abstract This study was designed to evaluate the effect of the radiological technologists’ training on optimising the eye lens dose in brain computed tomography (CT) examinations. The lens dose of 50 adult patients was measured using thermoluminescent dosimeters before and after technologists’ training. Dose values of lenses, dose length product (DLP), volumetric CT dose index (CTDIvol) as well as image quality in terms of quantitative (contrast to noise ratio and signal to noise ratio) and subjective (artefact) parameters were compared before and after training. Lens dose values were 31.57 ± 9.84 mGy and 5.36 ± 1.53 mGy before and after training, respectively, which was reduced by ~83% (p &lt; 0.05). The values of DLP, CTDIvol and image quality parameters were not significantly different (p &gt; 0.05) and all images were diagnostically acceptable. Excluding the orbits from the scanning range is an efficient approach to optimize the lens dose; the training of the technologists has also a pivotal role in dose reducing.

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