Biomedical subjects

Michael Hartman

Publications and source records attributed to Michael Hartman.

4 recordsLinked to original sources

PubMed2006

A prospective evaluation of uterine abnormalities by saline infusion sonohysterography in 1,009 women with infertility or abnormal uterine bleeding.

OBJECTIVE: To evaluate the role of saline infusion sonohysterography (SIS) in the investigation of uterine abnormalities and malformations in patients referred for infertility work-up compared with women with abnormal uterine bleeding (AUB). DESIGN: Prospective cohort study. SETTING: Academically oriented private practice. PATIENT(S): One thousand nine consecutive women examined by SIS for infertility work-up (n = 600, infertility group) or AUB investigation (n = 409, AUB group). INTERVENTION(S): SIS. MAIN OUTCOME MEASURE(S): Intracavitary abnormalities and uterine anomalies. RESULT(S): Among the women in the infertility group, 16.2% (n = 97) were found to have intracavitary abnormalities, including polyps (13.0%), submucous fibroids (2.8%), and adhesions (0.3%). Significantly, more patients in the AUB group (39.6%, n = 162) revealed intracavitary abnormalities, including polyps (29.8%), submucous fibroids (9.0%), and adhesions (0.7%). In contrast, significantly more uterine anomalies were found in the infertility group (20%, n = 120) compared with the AUB group (9.5%, n = 39). Arcuate uterus was the most common finding (15% vs. 6.4% of patients, respectively). CONCLUSION(S): An SIS procedure for infertility work-up revealed a substantial percentage of infertile patients with intracavitary abnormalities and uterine anomalies. Because the technique is safe, well tolerated, and feasible in an outpatient setting, SIS should be considered routinely in the early stage of infertility and AUB investigation.

Administration, Intravaginal↗

PubMed2005

Evaluation of a signal intensity mask in the interpretation of functional MR imaging activation maps.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the incidence of susceptibility artifacts on functional MR imaging (fMRI) studies and their effect on fMRI readings. We hypothesized that the availability of the signal intensity maps (SIMs) changes the interpretation of fMRI studies in which susceptibility artifacts affected eloquent brain regions. METHODS: We reviewed 152 consecutive clinical fMRI studies performed with a SIM. The SIM consisted of the initial echo-planar images (EPI) in each section thresholded to eliminate signal intensity from outside the brain and then overlaid on anatomic images. The cause of the artifact was then determined by examining the images. Cases with a susceptibility artifact in eloquent brain were included in a blinded study read by four readers, first without and then with the SIM. For each reader, the number of times the interpretation changed on viewing the SIM was counted. RESULTS: Of 152 patients, 44% had signal intensity loss involving cerebral cortex and 18% involving an eloquent brain region. Causes of the artifacts were: surgical site artifact, blood products, dental devices, calcium, basal ganglia calcifications, ICP monitors, embolization materials, and air. When provided with the SIM, readers changed interpretations in 8-38% of patient cases, depending on reader experience and size and location of susceptibility artifact. CONCLUSION: Patients referred for clinical fMRI have a high incidence of susceptibility artifacts, whose presence and size can be determined by inspection of the SIM but not anatomic images. The availability of the SIM may affect interpretation of the fMRI.

Artifacts↗

PubMed2004

The importance of isometric maximum strength and peak rate-of-force development in sprint cycling.

This study was designed to investigate the relationship of whole-body maximum strength to variables potentially associated with track sprint-cycling success. These variables included body composition, power measures, coach's rank, and sprint-cycling times. The study was carried out in 2 parts. The first part (n = 30) served as a pilot for the second part (n = 20). Subjects for both parts ranged from international-caliber sprint cyclists to local-level cyclists. Maximum strength was measured using an isometric midthigh pull (IPF). Explosive strength was measured as the peak rate-of-force development (IPRFD) from the isometric force-time curve. Peak power was estimated from countermovement (CMJPP) and static vertical jumps (SJPP) and measured by modified Wingate tests. Athletes were ranked by the U.S. national cycling coach (part 1). Sprint times (from a standing start) were measured using timing gates placed at 25, 82.5, 165, 247.5, and 330 m of an outdoor velodrome (part 2). Maximum strength (both absolute and body-mass corrected) and explosive strength were shown to be strongly correlated with jump and Wingate power. Additionally, maximum strength was strongly correlated with both coach's rank (parts 1 and 2) and sprint cycling times (part 2). The results suggest that larger, stronger sprint cyclists have an advantage in producing power and are generally faster sprint cyclists.

Adult↗

PubMed2003

Maximum strength-power-performance relationships in collegiate throwers.

Presently the degree to which peak force influences power production or explosive performance such as strength training movements or throwing (shot-put and weight-throw) is unclear. This study describes the relationships between a measure of maximum strength, isometric peak force (IPF), dynamic peak force (PF), peak power (PP), the 1-repetition movement power snatch (SN), and throwing ability over an 8-week training period. Five male and 6 female (n = 11) well-trained collegiate throwers participated. PF was measured using an AMTI force plate; PP was measured using an infrared-ultrasonic tracking device (V-Scope, Lipman Electronics). Clean pulls from the midthigh position were assessed isometrically and dynamically at a constant load, 30% and 60% of IPF. Specific explosive strength was evaluated using an SN and using the shot-put (SP) and weight-throw (WGT) measured under meet conditions. Variables (PF, PP, SN) were assessed 3 times at 0 weeks, 4 weeks, and 8 weeks. Each measurement period preceded a field meet by 3 days. Peak force, peak rate of force development, and PP increased over the 8 weeks. Correlation coefficients (r) indicate that IPF is strongly related to dynamic PF and PP 30%, 60% of the IPF. Furthermore, strong correlations were found for the SN and the distance for the SP and WGT, and these relationships tended to increase over time. Results suggest that maximum strength (i.e., IPF) is strongly associated with dynamic PF. In addition, maximum strength is strongly associated with PP even at relatively light loads such as those associated with sport-specific dynamic explosiveness (i.e., SN, SP, WGT).

Adolescent↗