Utility of magnetic resonance spectroscopy and diffusion-weighted imaging for detecting changes in the femoral head in divers with hip pain at risk for dysbaric osteonecrosis.

BACKGROUND: Ischemia before the development of dysbaric osteonecrosis (DON) in femoral heads has never been investigated. We assessed whether quantitative magnetic resonance spectroscopy (MRS) and diffusion weighted imaging (DWI) could detect dysbaric changes in divers with hip pain. METHODS: This IRB-approved exploratory study recruited 17 divers [9 with hip pain (Group 1); 8 asymptomatic (Group 2)] with normal findings on radiographs and conventional magnetic resonance imaging scans were age-, gender- and body-mass-index matched to 17 non-divers as controls (Group 1C, 2C). Apparent diffusion coefficients (ADCs) and MRS spectra were obtained from regions/voxels of interest on the femoral heads of all subjects. LCModel was used to determine water content, lipid composition, and the unsaturation index in bone marrow. Mann-Whitney non-parametric test was used to compare results of quantitative MRS and ADCs of ipsilateral femoral heads between divers and controls. RESULTS: MRS of the ipsilateral femoral heads revealed higher water (peak: 4.7 ppm) content, lower total lipid fraction (TLF), and higher unsaturation index (UI) of lipids in Group 1 than in Group 2 (water: P=0.040; UI: P=0.022) and Group 1C (water: P=0.027; TLF: P=0.039; UI: P=0.009). In contrast, femoral head ADCs were comparable between divers and controls. Five out of nine symptomatic divers were contacted for follow-up MRS and DWI studies, and the mean difference in water content in the femoral heads of patients with osteonecrosis was also higher than that in patients with symptom relief (osteonecrosis: 0.077±0.130 vs. symptom relief: 0.003±0.010). CONCLUSIONS: Dysbaric change in the femoral heads of divers with hip pain can be detected using quantitative MRS, which reveals increases in water content and UI of lipids, and a decrease in TLF.

Application of Color Doppler Ultrasound to Evaluate Chemotherapeutic Effect on Primary Thyroid Lymphoma.

Primary thyroid lymphoma (PTL) is a rare disease which responds well to rituximab-based chemotherapy. Here, we describe a case who was diagnosed through core needle biopsy as having diffuse large B-cell lymphoma in the right lobe of thyroid gland. Positron emission tomography computed tomography (PET-CT) revealed no other foci of hot spots, so PTL was considered. She was treated with rituximab plus bendamustine for three cycles, and color Doppler ultrasound revealed significant reduction of blood flow signals in the tumor but no significant decrease of its size (<25% extent). Then, the chemotherapy regimen was adjusted to rituximab, cyclophosphamide, vincristine, prednisone (R-COP), and complete remission was noted on ultrasound and PET-CT after three cycles of R-COP treatment. This case is reported to tell that color Doppler ultrasound, in addition to PET-CT, is useful to evaluate chemotherapeutic effect on PTLs.

Nonbifurcating Carotid Artery: A Case Report with a Review of Embryogenesis.

BACKGROUND Vascular anomalies of the carotid vessels can be attributed to false embryogenesis. A rare variant called a nonbifurcating carotid artery (NBCA) exists, where typical carotid bifurcation is not recognizable with its typical branches of the external carotid artery (ECA) and internal carotid artery (ICA). This paper describes a case of this anomaly and reviews the embryogenesis of the carotid arteries for explanation. CASE REPORT A 66-year-old man received a routine health examination at our hospital. Initial carotid ultrasound indicated an absence of bifurcation in the right cervical carotid artery, and magnetic resonance imaging of the brain indicated an absence of the proximal cervical segment of the right ICA, with a remnant arterial stump at the expected bifurcation level. No evidence of the carotid bulb was identified. The common carotid artery seemed to continue cranially in the trunk of the ECA, where it exhibited extracranial branches. After distributing these branches, the carotid artery coursed medially at the C2 level, where it ascended into the carotid canal to become the petrosal segment of the ICA. This carotid anomaly was labelled an NBCA. No aberrant intracranial arteries were derived from the NBCA in this case. CONCLUSIONS In this case, the arterial stump was considered a remnant from agenesis of the right ICA. We assumed that the NBCA most likely developed because of false regression of the third embryogenic aortic arch with persistence of the second aortic arch.

T1-Weighted Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) to Distinguish Between Concurrent Cholesterol Granuloma and Invasive Ductal Carcinoma of the Breast: A Case Report.

BACKGROUND Cholesterol granuloma is a benign condition that can be misdiagnosed as breast cancer on mammographic and ultrasound imaging. A case of concomitant cholesterol granuloma with invasive ductal carcinoma of the left breast was imaged with ultrasound elastography and magnetic resonance imaging (MRI) methods, including T1-weighted dynamic contrast-enhanced MRI (DCE-MRI), before biopsy and histopathology. CASE REPORT A 52-year-old woman, with a previous history of intraduct papillomas in both breasts, underwent six-monthly follow-up breast imaging. The most recent breast mammogram showed a progressively enlarging oval mass in the upper inner quadrant (UIQ) of the left breast, and an adjacent irregular mass with microcalcifications. Virtual Touch IQ (VTIQ) shear wave elastography was used with ultrasound of the breast lesions. T1-weighted fat saturation (T1WFS) MRI, T2-weighted short-tau inversion recovery (STIR) MRI, and T1-weighted DCE-MRI were used to image the left breast. T1-weighted DCE-MRI showed that the oval lesion had a high T1-weighted signal and mild progressive enhancement, with a Type I (benign) time-signal intensity curve; the second, irregular, mass showed rapid, intense enhancement with a washout pattern or Type III (malignant) time-signal intensity curve. Histopathology confirmed that the oval mass was a cholesterol granuloma, and the irregular mass was an invasive ductal carcinoma. CONCLUSIONS A case of concomitant cholesterol granuloma with invasive ductal carcinoma of the left breast, showed that ultrasound with shear wave elastography and T1-weighted DCE-MRI could distinguish between cholesterol granuloma and invasive ductal carcinoma.