Tomomi Tsujimoto

Duration of Venodilation for Peripheral Intravenous Cannulation, as Induced by a Thermal Stimulus on the Forearm:

Background: Application of a thermal stimulus is a common procedure used to promote venodilation for peripheral intravenous cannulation (PIVC); however, the effects of thermal stimulation on the duration of venodilation and skin temperature of the forearm are unclear. Aim: To investigate the duration of venodilation induced by a thermal stimulus on the forearm. Method: Healthy female adults (N = 40) from Japan participated in this study from November to December 2013. A heat pack was warmed to 40°C ± 2°C and placed over the forearm for 15 min. Vein diameter was measured via ultrasound and skin temperature via temperature sensor at six time points: before application of the thermal stimulus and at 1-min intervals for 5 min upon removal of the thermal stimulus. The main outcomes were vein diameter, proportional change in vein diameter, and skin temperature. We calculated proportional change in vein diameter after application of the thermal stimulus using vein diameter before the thermal stimulus to represent 100%. Results: Compared with vein diameter before thermal stimulus, the diameter at each time point after thermal stimulus was significantly increased (p < .05) as were proportional change in vein diameter (p < .05) and skin temperature. Conclusion: A thermal stimulus of 40°C ± 2°C on the forearm dilated veins significantly for PIVC, and the effect persisted for at least 5 min.

Evaluation of the scatter doses in the direction of the buccal mucosa from dental metals

The presence of dental metals creates radiation dose perturbation due to scattered radiation during radiation therapy for the head and neck region. The purpose of our study was to compare the scatter doses resulting from various dental metals in the direction of the buccal mucosa among a single‐field technique, three‐dimensional conformal radiation therapy (3D CRT), and intensity‐modulated radiation therapy (IMRT) during radiation therapy for the head and neck region. We used nine metal cubes with 10 mm sides, which were placed inside a water phantom. The scatter doses from the cubes in the direction of the buccal mucosa were measured using radiochromic films. The films were placed perpendicularly to the surface of the cubes. The phantom was irradiated with a 4 MV photon energy by a linear accelerator for all techniques. In the single‐field technique, the scatter doses from dental metals showed 3.7%–19.3% dose increases, and gold showed the largest dose increase. In 3D CRT, the scatter doses from dental metals showed 1.4%–6.9% dose increases, which were within the measurement uncertainty (except for gold). In IMRT, the scatter doses from dental metals showed only 1.4%–4.3% dose increases, which were all within the measurement uncertainty. During radiation therapy for the head and neck region, the scatter doses from the tested dental metals in the direction of the buccal mucosa in 3D CRT or IMRT were lower than those using the single‐field technique. However, there were no differences between the scatter doses resulting from particular dental metals in the direction of the buccal mucosa in 3D CRT and those in IMRT, except for gold. PACS number: 87

Tourniquet application after local forearm warming to improve venodilation for peripheral intravenous cannulation in young and middle-aged adults: A single-blind prospective randomized controlled trial

BACKGROUND Local forearm warming before tourniquet application is often used to promote venodilation for peripheral intravenous cannulation; however, few studies have compared the effect of tourniquet application with and without local warming on vein size. OBJECTIVE To evaluate the effectiveness of tourniquet application after local forearm warming with that of tourniquet application alone in young and middle-aged adults. DESIGN A single-blind, prospective, parallel group, randomized controlled trial. SETTING A national university in Japan. PARTICIPANTS Seventy-two volunteers aged 20-64 years. METHODS Participants were randomly allocated to one of two groups: tourniquet application for 30s after forearm application of a heat pack warmed to 40°C±2°C for 15min (active warming group; n=36) or tourniquet application for 30s after applying a non-warmed heat pack for 15min (passive warming group; n=36). The primary outcomes were vein cross-sectional area on the forearm, measured after the intervention by blinded research assistants using ultrasound. Secondary outcomes were shortest diameter, and longest diameter of vein on the forearm, forearm skin temperature, body temperature, pulse, systolic blood pressure, and diastolic blood pressure. All outcomes were assessed at the same site before and immediately after the intervention, once per participant. RESULTS Vein cross-sectional area, shortest vein diameter, and longest vein diameter were significantly increased in the active warming group compared with the passive warming group (p <0.01). Tourniquet application after local warming was superior to tourniquet application alone in increasing vein cross-sectional, shortest diameter, and longest diameter (between-group differences of 2.2mm2, 0.5mm, and 0.5mm, respectively), and in raising skin temperature (between-group difference: 5.2°C). However, there were no significant differences in body temperature, pulse, or systolic or diastolic blood pressure between the groups. There were no adverse events associated with either intervention. CONCLUSION Tourniquet application after local warming was associated with increased forearm vein size when compared with tourniquet application alone, and was demonstrated as being safe. Thus, with demonstrable effects on vein size, we recommend local warming before tourniquet application as a safe and effective technique for improving venodilation.

Comparison of the T2 Relaxation Time of the Temporomandibular Joint Articular Disk between Patients with Temporomandibular Disorders and Asymptomatic Volunteers

BACKGROUND AND PURPOSE: T2 relaxation time is a quantitative MR imaging parameter used to detect degenerated cartilage in the knee and lumbar intervertebral disks. We measured the T2 relaxation time of the articular disk of the temporomandibular joint in patients with temporomandibular disorders and asymptomatic volunteers to demonstrate an association between T2 relaxation time and temporomandibular disorder MR imaging findings. MATERIALS AND METHODS: One hundred forty-four patients with temporomandibular disorders and 17 volunteers were enrolled in this study. An 8-echo spin-echo sequence for measuring the T2 relaxation times was performed in the closed mouth position, and the T2 relaxation time of the entire articular disk was measured. Patients were classified according to the articular disk location and function, articular disk configuration, presence of joint effusion, osteoarthritis, and bone marrow abnormalities. RESULTS: The T2 relaxation time of the entire articular disk was 29.3 ± 3.8 ms in the volunteer group and 30.7 ± 5.1 ms in the patient group (P = .177). When subgroups were analyzed, however, the T2 relaxation times of the entire articular disk in the anterior disk displacement without reduction group, the marked or extensive joint effusion group, the osteoarthritis-positive group, and the bone marrow abnormality–positive group were significantly longer than those in the volunteer group (P < .05). CONCLUSIONS: The T2 relaxation times of the articular disk of the temporomandibular joint in patients with progressive temporomandibular disorders were longer than those of healthy volunteers.

Influence of an object's z-axis location and location on the axial plane on the voxel value representation and uniformity in cone beam computed tomography

OBJECTIVE This study aimed to determine the influence of an objects z-axis location and location on the axial plane on the voxel values in cone beam computed tomography. STUDY DESIGN The CTP401 and CTP486 of the Catphan 500 phantom were scanned with an Alphard-3030 at 6 locations in the z-axis. RESULTS In CTP401, the voxel values of 3 inserts showed the lowest values when the center of the radiation field corresponded to under 2 or 4 cm of the z-axis center of CTP401. In CTP486, the voxel values showed the lowest values when the center of the radiation field corresponded to under 2 or 4 cm of the z-axis center of CTP486. On the same axial plane, the voxel values at the center showed significantly lower values than the off-center locations (P = .002). CONCLUSIONS The voxel values in the Alphard-3030 changed based on the z-axis location of the radiation field and were nonuniform on the same axial plane.

Effectiveness of the periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) technique for reducing motion artifacts caused by mandibular movements on fat-suppressed T2-weighted magnetic resonance (MR) images

PURPOSE To compare a fat-suppressed T2-weighted periodically rotated overlapping parallel lines with enhanced reconstruction (T2W-PROPELLER) sequence with a fat-suppressed T2-weighted fast spin-echo (T2W-FSE) sequence in the oral and maxillofacial regions for the evaluation of the presence of motion artifacts caused by mandibular movements. METHODS Fifty-six healthy adult volunteers were examined in a closed mouth position and then with three different rhythmical mandibular movements throughout MR scanning: open-close movement (movement 1), lateral movement (movement 2) and open-close and lateral movement (movement 3). All subjects were scanned first with fat-suppressed T2W-FSE and then with fat-suppressed T2W-PROPELLER while performing the same movements. Motion artifacts, including ghosting or pulsation artifacts, streak artifacts, susceptibility artifacts and the overall image quality were independently evaluated by two oral and maxillofacial radiologists using a five-point scale. The score graded by the two observers was averaged. RESULTS The inter-observer agreement was almost perfect for all evaluated items (κ ≥ 0.81). The T2W-PROPELLER images showed significantly fewer ghosting artifacts than T2W-FSE images in subjects performing the mandibular movements throughout MR scanning (P < .001). T2W-PROPELLER images also showed significantly fewer pulsation artifacts than T2W-FSE images, regardless of the performance of a movement, throughout MR scanning (P < .001). Finally, the T2W-PROPELLER images showed a significantly better overall image quality than T2W-FSE images in subjects performing movements 2 or 3 throughout MR scanning (P < .001). CONCLUSION The PROPELLER technique was found to be effective in reducing the motion artifacts caused by mandibular movements on fat-suppressed T2W MR images in the oral and maxillofacial regions.

How long should local warming for venodilation be used for peripheral intravenous cannulation? A prospective observational study

BACKGROUND Local warming is one of the most common venodilation techniques for achieving peripheral intravenous cannulation, but the time of application is unclear. OBJECTIVE To compare the effectiveness of local warming applied for 5, 10, and 15min. DESIGN A prospective, observational study. SETTING A university in Japan. PARTICIPANTS In total, 40 healthy female volunteers aged 20-45 years were recruited via e-mail. METHODS Participants received 15min of local warming with a warmed heat pack (40±2°C). The primary outcome was the cross-sectional area of the target vein at 5, 10, and 15min of warming, which was measured after the intervention by blinded review using ultrasound. Secondary outcomes included forearm target site temperature at 5, 10, and 15min of local warming, which was measured with a temperature sensor and handheld thermometer. RESULTS Compared to outcomes before local warming, vein cross-sectional area at 5, 10, and 15min of warming significantly (p <0.001) increased by 2.8, 2.9, and 2.3mm2. The target site temperature increased by 6.9°C, 6.4°C, and 6.0°C, respectively. However, no significant differences were found in cross-sectional area among the time points of 5, 10, and 15min of local warming. The target site temperature at 15min of local warming was significantly (p < 0.001) different than that at 5 and 10min. No adverse events occurred with local warming. CONCLUSION Compared with outcomes before local warming, vein size after warming for 5, 10, and 15min was significantly larger. No significant differences were found in vein size among the time points of 5, 10, and 15min of local warming. Our result demonstrated the effectiveness of shorter-duration (5min) local warming for inducing venodilation for peripheral intravenous cannulation.

Does CBCT alter the diagnostic thinking efficacy, management and prognosis of patients with suspected Stage 0 medication-related osteonecrosis of the jaws?

OBJECTIVES To evaluate the impact of cone beam CT (CBCT) in the diagnostic thinking efficacy, management and prognosis of patients with suspected Stage 0 medication-related osteonecrosis of the jaw (MRONJ). METHODS For 15 patients with suspected Stage 0 MRONJ, clinical photographs, a panoramic radiograph and selected CBCT sections were identified. 13 oral surgeons reviewed the material and answered 10 questions in two different sessions. First session included clinical photographs and panoramic radiographs, while second session also included CBCT images. Questions (Qs) referred to dental disease and bone abnormalities (Qs 1, 2 and 3), differential diagnosis (Qs 4 and 5), patient management (Qs 6 and 7) and prognosis (Qs 8 and 9). Q 10 queried indication (first session) and usefulness (second session) of CBCT images. RESULTS Qs 2, 3, 5, 7 and 9 scores increased between sessions, with statistical differences for Qs 2, 3, 5 and 7 (<0.05). Patients 2, 8 and 11 showed a significant increase in the average score of all Qs between sessions, while scores for patient 10 nearly reached statistical significance (p = 0.055). For Q 10, 57.4% of answers reported that CBCT was needed (first session) and was beneficial (second session). CONCLUSIONS CBCT had a significant impact in differential diagnosis and management of patients with suspected Stage 0 MRONJ.