Investigation of the significance of population-based breast cancer screening among women aged under 40 years.

BACKGROUND: Owing to low incidence rates, population-based breast cancer screening is not recommended by many municipalities in Japan for women aged < 40 years. To evaluate the usefulness of screening in women aged < 40 years, we investigated the results of population-based breast cancer screening among young women performed in the Ibaraki Prefecture. METHODS: Data regarding histological characteristics, recall rates, cancer detection rates, positive predictive values, tumor categories, and status of lymph node metastases were obtained from population-based screening data from Ibaraki Health Service Association Institute. The "number needing to be screened" (NNS) was determined; using Pearson's chi-squared test, these data were compared between women aged < 40 years and > 40 years. RESULTS: The data of 428,560 women were evaluated. Cancer detection rates were significantly lower and the NNS and proportion of women with tumor category T2 or higher was significantly increased in women aged < 40 years than in those aged > 40 years (0.06% vs. 0.21%, 1505 vs. 281-439, and 28.9% vs. 6.3%, respectively; all, p < 0.05). The proportion of early-stage cancers was lower in women aged < 40 years than in those > 40 years, but this was not significant. CONCLUSIONS: These results suggest that population-based breast cancer screening should not be recommended for women aged < 40 years. To reduce the breast cancer-related mortality rate in young women and ensure efficient use of limited medical resources in Japan, a more efficient surveillance system, based on genetic propensity and family history, needs to be established.

Diffusion property differences of the lower leg musculature between athletes and non-athletes using 1.5T MRI.

OBJECT: To compare the differences in diffusion properties--namely fractional anisotropy (FA), three eigenvalues of the diffusion tensor (λ1, λ2, and λ3), and apparent diffusion coefficient (ADC)--between athletically-trained and untrained lower leg musculature. MATERIALS AND METHODS: Twelve athletes (Group A) and 11 non-athletes (Group B) were recruited. All were females in their 20s. We scanned diffusion tensor images of both calves and compared FA, the three eigenvalues, and ADC in the gastrocnemius medialis, gastrocnemius lateralis, soleus (SOL), and anterior tibialis muscles between Groups A and B, and between the right and left sides, using two-factor fractional ANOVA. RESULTS: In all muscles of bilateral calves, all three eigenvalues and ADC were lower in Group A than in Group B, with statistically significant differences in all muscles for λ1, λ2, and λ3 and ADC, with a P value of <0.01. Moreover, statistical differences were also found between right and left for λ1, λ2, and λ3 (P < 0.05), and ADC (P < 0.01) of the SOL muscle. FA showed no statistically significant differences in any muscles. CONCLUSIONS: Our results indicate that training causes a decrease of the three eigenvalues and ADC, which we hypothesize is due to an increase of density of myofilaments in the intracellular space, and deformation of the cell induced by enlargement of extracellular components.

Gender differences in MR muscle tractography.

BACKGROUND: Tractography of skeletal muscle can clearly reveal the 3-dimensional course of muscle fibers, and the procedure has great potential and could open new fields for diagnostic imaging. Studying this technique for clinical application, we noticed differences in the number of visualized tracts among volunteers and among muscles in the same volunteer. To comprehend why the number of visualized tracts varied so that we could acquire consistently high quality tractography of muscle fiber, we started to examine whether differences in individual parameters affected tractography visualization. PURPOSE: To determine whether there are gender- and age-specific differences that differentiate the muscles by gender and age in MR tractography of skeletal muscle fiber. MATERIALS AND METHODS: We divided 33 healthy volunteers by gender and age among 3 groups, A (13 younger men, aged 20 to 36 years), B (11 younger women, 25 to 39 years), and C (9 older men, 50 to 69), and we obtained from each volunteer tractographs of 8 fibers, including the bilateral gastrocnemius medialis (GCM), gastrocnemius lateralis (GCL), soleus (SOL), and anterior tibialis (AT) muscles. We classified the fibers into 5 grades depending on the extent of visualized tracts and used Mann-Whitney U-test to compare scores by gender (Group A versus B) and age (Group A versus C). RESULTS: Muscle tracts were significantly better visualized in women than men (median total visual score, 34 versus 24, P<0.05). In particular, the SOL muscles showed better visualization in the right (4.0 in women, 1.0 in men, P<0.05) and left (3.0 in women, 1.0 in men, P<0.05). Difference by age was not significant. The GCL was the highest scored muscle in all groups. CONCLUSIONS: Our results suggest that group differences, especially by gender, affected visualization of tractography of muscle fiber of the calf.

[Diagnosis of early stage of breast cancer by mammography].

The incidence of small breast carcinoma especially of non-palpable lesion is increasing after introduction of mammography screening. The tumor of which diameter is less than 2 cm, non invasive carcinoma, and Paget's disease are included in early stage of breast cancer. This article introduces the rate of early stage breast cancer in the mammography screening and the feature of these mammographic findings. Furthermore, we are going to reevaluate mammographical findings, occurrence of invasion, and evaluation the size of the lesion by mammography which are thought to be important for the diagnosis of early stage of breast cancer.

High-resolution MR imaging of the elbow using a microscopy surface coil and a clinical 1.5 T MR machine: preliminary results.

OBJECTIVE: To obtain high-resolution MR images of the elbow using a microscopy surface coil with a 1.5 T clinical machine and to evaluate the feasibility of its use for elbow injuries. DESIGN AND PATIENTS: Five asymptomatic normal volunteers and 13 patients with elbow pain were prospectively studied with MR imaging using a microscopy surface coil 47 mm in diameter. High-resolution MR images using a microscopy coil were obtained with fast spin echo (FSE) proton density-weighted sequence, gradient recalled echo (GRE) T2*-weighted sequence, and short tau inversion recovery (STIR) sequence, with a 1-2 mm slice thickness, a 50-70 mm field of view, an imaging matrix of 140-224 x 512 using zero fill interpolation, and 2-6 excitations. RESULTS: High-resolution MR images of normal volunteers using a microscopy coil clearly showed each structure of the medial and lateral collateral ligaments on GRE T2*-weighted images and FSE proton-density weighted images. Partial medial collateral ligament injury, a small avulsion of the medial epicondyle, and osteochondritis dissecans were well demonstrated on high-resolution MR images. CONCLUSION: High-resolution MR imaging of the elbow using a microscopy surface coil with a 1.5 T clinical machine is a promising method for accurately characterizing the normal anatomy of the elbow and depicting its lesions in detail.