Biomedical subjects
Keyanoosh Hosseinzadeh
Publications and source records attributed to Keyanoosh Hosseinzadeh.
Optimization of acquisition time for MRI of fetal head: the eyes have it.
OBJECTIVE: This article describes a technique to minimize MRI time and obtain true orthogonal T2-weighted projections of the fetal head. The technique takes advantage of the symmetry of fetal orbits to establish a line of reference through the orbits to obtain true sagittal, coronal, and axial projections of the intracranial anatomy. CONCLUSION: This technique results in a 50% reduction in imaging time and thus decreases fetal exposure to the electromagnetic field.
Endorectal diffusion-weighted imaging in prostate cancer to differentiate malignant and benign peripheral zone tissue.
PURPOSE: To determine if the apparent diffusion coefficient (ADC) can discriminate benign from malignant peripheral zone (PZ) tissue in patients with biopsy-proven prostate cancer that have undergone endorectal diffusion-weighted imaging (DWI) of the prostate. MATERIALS AND METHODS: Ten patients with prostate cancer underwent endorectal magnetic resonance imaging (MRI) in addition to DWI. A two-dimensional grid was placed over the axial images, and each voxel was graded by a 4-point rating scale to discriminate nonmalignant from malignant PZ tissue based on MR images alone. ADC was then determined for each voxel and plotted for nonmalignant and malignant voxels for the entire patient set. Second, with the radiologist aware of biopsy locations, any previously assigned voxel grade that was inconsistent with biopsy data was regrouped and ADCs were replotted. RESULTS: For the entire patient set, without and with knowledge of the biopsy data, the mean ADCs for nonmalignant and malignant tissue were 1.61 +/- 0.27 and 1.34 +/- 0.38 x 10(-3) mm2/second (P = 0.002) and 1.61 +/- 0.26 and 1.27 +/- 0.37 x 10(-3) mm2/second (P = 0.0005), respectively. CONCLUSION: DWI of the prostate is possible with an endorectal coil. The mean ADC for malignant PZ tissue is less than nonmalignant tissue, although there is overlap in individual values.
From the archives of the AFIP: radiologic staging of ovarian carcinoma with pathologic correlation.
Ovarian cancer is the deadliest gynecologic malignancy, with approximately 70% of patients having peritoneal involvement at the time of diagnosis. It spreads predominantly by direct invasion and intraperitoneal dissemination. The staging system is surgically based, with stage I disease being limited to one or both ovaries. In stage II disease, there is extraovarian spread of tumor, but it does not extend beyond the pelvis. Stages III and IV disease are considered advanced, with stage III ovarian cancer including diffuse peritoneal disease involving the upper abdomen and stage IV disease having distant metastases including hepatic lesions. Common sites of intraperitoneal seeding include the omentum, paracolic gutters, liver capsule, and diaphragm. Thickening, nodularity, and enhancement are all signs of peritoneal involvement. Although computed tomography is the most common imaging modality used to stage ovarian cancer, magnetic resonance imaging has been shown to be equally accurate. Currently, however, no imaging modality allows microscopic spread of disease to be ruled out, and a full staging laparotomy is always required. Early ovarian cancer is treated with comprehensive staging laparotomy, whereas advanced but operable disease is treated with primary cytoreductive surgery (debulking) followed by adjuvant chemotherapy. Patients with unresectable disease may benefit from neoadjuvant (preoperative) chemotherapy before debulking.