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This paper describes the experimental results of the beat-to-beat interval measurement from a quadrature Doppler radar system utilizing arctangent demodulation with DC offset compensation techniques. The comparison in SDNN and in RMSDD of both signals demonstrates the potential of using quadrature Doppler radar for HRV analysis.

The objectives of this study were to determine the usefulness of magnetic resonance (MR) imaging in the differentiation of various lesions causing an abnormality of the endometrial cavity by evaluating the imaging features on dynamic contrast-enhanced study and late contrast-enhanced T1-weighted images (T1WI). Contrast-enhanced MR imaging of 59 pathologically proven lesions that showed an abnormality of the endometrial cavity, including 32 endometrial cancers, five sarcomas, nine hyperplastic polyps, nine submucosal myomas, three hyperplasia, and one adenomyoma, were retrospectively reviewed. The enhancement degree and patterns on dynamic contrast-enhanced study and late contrast-enhanced T1WI were compared among different pathologies. On dynamic contrast-enhanced study, 72% (23/32) of endometrial cancers showed early peak enhancement to be reached within 1 min following intravenous administration of contrast material. On late-contrast-enhanced T1WI, lesions showed weak enhancement with gradual washout. Ninety-five percent (21/22) of benign lesions and 100% (5/5) of sarcomas showed late peak enhancement to be reached in 2-3 min following intravenous administration of contrast material. On late contrast-enhanced T1WI, both of these lesions showed persistent strong enhancement. Different enhancement patterns on dynamic contrast-enhanced MR imaging and late contrast-enhanced T1WI can provide a useful clue in the differentiation of various lesions causing an abnormality of the endometrial cavity.

Objectives: To assess the accuracy of CT for the diagnosis of histologically confirmed adrenal adenoma and nonadenoma using CT numbers., Materials and Methods: Our study included 91 adrenal masses in 83 patients; histopathological diagnoses were 45 adenomas, 31 pheochromocytomas, 6 hyperplasias, 4 metastasis, and 5 miscellaneous lesions. Unenhanced CT in 46 patients and unenhanced and delayed contrast-enhanced (DCE) CT in 37 patients were retrospectively reviewed to examine the correlation between CT findings and those on pathological examination and to obtain diagnostic accuracy., Results: Sensitivity, specificity, and accuracy for adenoma were 40% (18/45), 91% (42/46), and 66% (60/91) with unenhanced CT, and 96% (24/25), 61% (11/18), and 81% (35/43) with DCE CT. Adrenal masses falsely diagnosed as adenoma on unenhanced CT included three hyperplasias and one endothelial cyst, and those falsely diagnosed as adenoma on DCE CT were five pheochromocytomas, one oncocytic cortical tumor, and one primary pigmented nodular adrenocortical dysplasia. Twenty-five lipid-poor adenomas were falsely diagnosed as nonadenomas on unenhanced CT and one degenerated adenoma both on unenhanced CT and on DCE CT., Conclusion: Diagnosing adenoma merely on CT numbers can lead to misdiagnosis. The lower specificity than expected is due to pheochromocytomas presenting as false positives.

Objective: To compare dynamic contrast-enhanced imaging and T2-weighted imaging using a 3T MR unit for the localization of prostate cancer., Methods: Twenty consecutive patients with biopsy-proven prostate cancer underwent both T2-weighted imaging and dynamic contrast-enhanced imaging. At T2-weighted imaging and dynamic contrast-enhanced imaging, the presence or absence of prostate cancer confined within the prostate without extracapsular or adjacent organ invasion was evaluated in the peripheral zones of base, mid-gland, and apex on each side. Final decisions on prostate cancer localization were made by consensus between two radiologists. Degrees of depiction of tumor borders were graded as poor, fair, or excellent., Results: Prostate cancer was pathologically detected in 64 (53%) of 120 peripheral zone areas. The sensitivity, specificity, and accuracy for prostate cancer detection were 55%, 88% and 70% for T2-weighted imaging and 73%, 77%, and 75% for dynamic contrast-enhanced imaging, respectively. Three cancer areas were detected only by T2-weighted imaging, 15 only by dynamic contrast-enhanced imaging, and 34 by both T2-weighted imaging and dynamic contrast-enhanced imaging. A fair or excellent degree at depicting tumor border was achieved in 67% by T2-weighted imaging and in 90% by dynamic contrast-enhanced imaging (P<0.05)., Conclusions: Dynamic contrast-enhanced imaging at 3T MRI is superior to T2-weighted imaging for the detection and depiction of prostate cancer and thus is likely to be more useful for preoperative staging.

Purpose: We sought to evaluate diffractive ultrasound (US) in the characterization of solid breast masses., Materials and Methods: Forty-eight patients with solid breast masses (24 malignant and 24 benign) observed at conventional US underwent targeted diffractive US before needle biopsy or surgery. The process of locating the lesion was performed with knowledge of the mammography and conventional US. On diffractive US, imaging features, including shape, brightness, echotexture, margin, and boundary echo were analyzed and odds ratio (OR) were calculated to show how the risk of malignancy was altered by the presence of a given finding., Results: Of the 48 solid breast masses seen on conventional US, 46 (96%) were seen at diffractive US. Diffractive US features suggestive of malignancy were irregular shape (OR 11.5), sono-opacity (OR 204), spiculated margin (OR 17.0), and absent boundary echo (OR 11.5) or thick rim (OR 5.5), whereas those of benignancy were round shape (OR 0.03), sonotransmission (OR 0.07) or isodensity (OR 0.01), well-defined margin (OR 0.03), and thin capsule (OR 0.03; P < 0.05)., Conclusion: The finding of a sono-opaque mass on diffractive US was highly sensitive for malignancy. Further improvement of diffractive US equipment is needed to increase image quality and to permit inclusion of the axillary tail and deep portions of the breast.

Objective: To characterize the imaging features on gray-scale and contrast-enhanced color Doppler US images which differentiate renal ischemia from renal infarction., Materials and Methods: The segmental renal arteries of eight healthy rabbits were surgically ligated. In four of these rabbits, the ligated renal artery was released 60 minutes after arterial occlusion to cause transient ischemia. In the remaining four rabbits, the arterial ligation was retained to cause a permanent infarction. The gray-scale and contrast-enhanced color Doppler US imaging features of the involved renal parenchyma of both ischemia and infarction groups were compared with respect to the presence or absence of parenchymal swelling, echogenicity changes, tissue loss and perfusion defects., Results: Parenchyma swelling, echogenic changes, tissue loss and perfusion defects were found to be more extensive in the infarction than the ischemia group. The hyperechoic areas reperfused with blood flow recovered normal echogenicity and perfusion, whereas the hyperechoic areas without reperfusion became renal infarcts., Conclusion: Gray-scale and contrast-enhanced color Doppler US showed that the hyperechoic areas with reperfusion may reverse to normal parenchyma and allow the differentiation of renal ischemia from renal infarction.

Objective: We wanted to compare the imaging features of renal cell carcinoma (RCC) and their diagnostic accuracy on agent detection imaging (ADI) and grayscale ultrasonography (US)., Materials and Methods: Thirty non-consecutive patients (age range; 32-80 years, mean age; 53.7 years) with 30 RCCs were examined with gray-scale US and with ADI in conjunction with using SH U 508A. We described the imaging features of the renal tumors obtained from ADI according to their enhancement pattern, the intratumoral anechoic areas and the presence of any pseudocapsule. The imaging features and diagnostic accuracy of ADI and gray-scale US were then compared., Results: On the ADI exam, the RCCs were shown as being heterogeneous in 87% of the cases (26/30), homogeneous in 7% of the cases (2/30), and there was peripheral irregular enhancement in 7% of the cases (2/30). Intratumoral anechoic areas and pseudocapsule were seen in 87% and 77% of the RCCs on the ADI exam, whereas these features were seen in 53% and 17% of the cases on the gray-scale US, respectively. The diagnostic sensitivity, specificity, and accuracy for RCC with ADI were 97%, 93%, and 95%, respectively. However, those for RCC with using gray-scale US were 70%, 86%, and 78%, respectively. There was a significant difference for the diagnostic accuracy of RCC between ADI and gray-scale US (p < 0.05)., Conclusion: Agent detection imaging can help visualize the enhancement pattern of RCC and improve the diagnostic accuracy of this tumor by better displaying the intratumoral anechoic areas and the pseudocapsule than does the grayscale US.

Objective: To determine the accuracy of the preoperative staging of uterine cervical cancer by magnetic resonance (MR) imaging in 115 patients in a prospective study., Methods: A prospective study was performed in 115 patients who underwent MR imaging at 1.5 T before surgery or biopsy. Histopathologic findings were correlated with MR imaging results for all patients., Results: The accuracy of preoperative tumor staging by MR imaging in the 115 patients was 77%. In terms of the evaluation of parametrial status, this study had an accuracy of 94% and a sensitivity of 38%. The accuracy and sensitivity of MR imaging for vaginal invasion were 81% and 87%, respectively. In terms of lymph node metastasis, this study had an accuracy of 97% and a sensitivity of 36%., Conclusion: Magnetic resonance imaging has high accuracy in the preoperative staging of uterine cervical cancer.

Nonvascular intervention of the urinary tract is a well-established uroradiologic subspecialty, which is more important for avoiding invasive open surgery in the age of rising demand about the value of less invasive treatment. Various kinds of nonvascular intervention are recently performed under image-guidance and are as follows: percutaneous nephrostomy, percutaneous nephrostolithotomy, percutaneous dilatation of the urinary tract, sclerotherapy for renal cysts, percutaneous catheter drainage, percutaneous foreign body retrieval and biopsy. Percutaneous nephrostomy is a basic technique to provide a direct access to urinary tract, which makes it possible to perform other interventional procedures. Although nonvascular intervention may produce some complications, it is generally considered to be less invasive than open surgery and has advantages such as short hospital stay, early return to normal life and therefore economic savings. This review is described to help clinicians easily understand the procedures, indications, techniques, and complications with figures of cases the authors experienced.