Prediction of Pathologic Findings with MRI-Based Clinical Staging Using the Bayesian Network Modeling in Prostate Cancer: A Radiation Oncologist Perspective / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#This study aimed to develop a model for predicting pathologic extracapsular extension (ECE) and seminal vesicle invasion (SVI) while integrating magnetic resonance imaging-based T-staging (cTMRI, cT1c-cT3b). @*Materials and Methods@#A total of 1,915 who underwent radical prostatectomy between 2006-2016 met the inclusion/exclusion criteria. We performed a multivariate logistic regression analysis as well as Bayesian network (BN) modeling based on possible confounding factors. The BN model was internally validated using 5-fold validation. @*Results@#According to the multivariate logistic regression analysis, initial prostate-specific antigen (iPSA) (β=0.050, p < 0.001), percentage of positive biopsy cores (PPC) (β=0.033, p < 0.001), both lobe involvement on biopsy (β=0.359, p=0.009), Gleason score (β=0.358, p < 0.001), and cTMRI (β=0.259, p < 0.001) were significant factors for ECE. For SVI, iPSA (β=0.037, p < 0.001), PPC (β=0.024, p < 0.001), Gleason score (β=0.753, p < 0.001), and cTMRI (β=0.507, p < 0.001) showed statistical significance. BN models to predict ECE and SVI were also successfully established. The overall area under the receiver operating characteristic curve (AUC)/accuracy of the BN models were 0.76/73.0% and 0.88/89.6% for ECE and SVI, respectively. According to internal comparison between the BN model and Roach formula, BN model had improved AUC values for predicting ECE (0.76 vs. 0.74, p=0.060) and SVI (0.88 vs. 0.84, p < 0.001). @*Conclusion@#Two models to predict pathologic ECE and SVI integrating cTMRI were established and installed on a separate website for public access to guide radiation oncologists.

History of the Asian Society of Abdominal Radiology

Diagnostic Performance of MRI for Assessing Parametrial Invasion in Cervical Cancer: A Head-to-Head Comparison between Oblique and True Axial T2-Weighted Images

OBJECTIVE: To directly compare the diagnostic performance of true and oblique axial T2-weighted imaging (T2WI) for assessing parametrial invasion (PMI) in cervical cancer. MATERIALS AND METHODS: This retrospective study included 71 women with treatment-naive cervical cancer who underwent MRI that included both oblique and true axial T2WI, followed by radical hysterectomy. Two blinded radiologists (Radiologist 1 and Radiologist 2) independently assessed the presence of PMI on both sequences using a 5-point Likert scale. Receiver operating characteristic (ROC) curve analysis was performed, with a subgroup analysis for tumors sized > 2.5 cm and ≤ 2.5 cm in diameter. Inter-reader agreement was assessed with kappa (k) statistics. RESULTS: At hysterectomy, 15 patients (21.1%) had PMI. For Radiologist 1, the area under the ROC curve (AUC) was greater for oblique axial than for true axial T2WI {0.941 (95% confidence interval [CI] = 0.858–0.983) vs. 0.917 (95% CI = 0.827–0.969), p = 0.027}. The difference was not significant for Radiologist 2 (0.879 [95% CI = 0.779–0.944] vs. 0.827 [95% CI = 0.719–0.906], p = 0.153). For tumors > 2.5 cm, AUC was greater with oblique than with true axial T2WI (0.906 vs. 0.860, p = 0.046 for Radiologist 1 and 0.839 vs. 0.765, p = 0.086 for Radiologist 2). Agreement between the radiologists was almost perfect for oblique axial T2WI (k = 0.810) and was substantial for true axial T2WI (k = 0.704). CONCLUSION: Oblique axial T2WI potentially provides greater diagnostic performance than true axial T2WI for determining PMI, particularly for tumors > 2.5 cm. The inter-reader agreement was greater with oblique axial T2WI.

Doppler US and CT Diagnosis of Nutcracker Syndrome

Nutcracker syndrome (NCS) is a syndrome caused by compression of the left renal vein (LRV), between the abdominal aorta and the superior mesenteric artery, resulting in hypertension of the LRV and hematuria. Doppler ultrasonography (US) has been commonly used for the diagnosis of NCS. However, several technical issues, such as Doppler angle and sample volume, need to be considered to obtain satisfactory results. In addition, morphologic changes of the LRV and a jetting phenomenon across the aortomesenteric portion of the LRV on contrast-enhanced computed tomography (CECT) are diagnostic clues of NCS. With proper Doppler US and CECT, NCS can be diagnosed noninvasively.

What MRI features suspect malignant pure mesenchymal uterine tumors rather than uterine leiomyoma with cystic degeneration? / 부인종양

OBJECTIVE: To retrospectively assess conventional magnetic resonance imaging (MRI) features that differentiate malignant pure mesenchymal uterine tumors (MPMUT); endometrial stromal sarcoma (ESS) and leiomyosarcoma (LMS) from uterine leiomyoma with cystic degeneration (ULCD). METHODS: We retrospectively reviewed magnetic resonance (MR) images of 30 patients with ULCD, 18 with ESS, and 15 with LMS, to assess tumor location, margin, T2 signal intensity (SI), speckled appearance, and peripheral band using univariate and multivariate analyses. RESULTS: ULCD more frequently showed subserosal location (53.3%), well-defined margin (96.7%), and speckled appearance (90.0%) compared with ESS (0%, 33.3%, and 33.3%, respectively) or LMS (20.0%, 33.3%, and 60.0%, respectively). In quantitative T2 SI comparisons, the T2 SI ratio of the main solid tumor portion to gluteus maximus muscle differed significantly among the three groups, with ULCD showing a lower SI ratio (0.62) compared with ESS (2.44) and LMS (1.13). On multivariate analysis, an ill-defined margin (odds ratio [OR]=44.885; p=0.003) and high T2 SI (OR=4.396; p=0.046) were the significant MR differentiators. CONCLUSION: An ill-defined tumor margin and high T2 SI ratio of the main solid tumor-to-gluteus maximus muscle were useful MRI features in the differentiation of MPMUT from ULCD.

Use of Iterative Reconstruction and a Small Contrast Volume in Rabbit Kidney CT: Comparison with Conventional Protocol

PURPOSE@#To investigate the quality of rabbit kidney computed tomography (CT) images obtained using a small contrast volume and iterative reconstruction (IR).@*MATERIALS AND METHODS@#Twenty sedated rabbits were used. Four milliliters of contrast material and the IR technique were used for the study group. In the control group, 6 mL of contrast and the filtered back projection (FBP) technique were used. The image quality was evaluated by two radiologists in consensus. For qualitative image assessment, the sharpness, noise, texture, and streak artifacts were rated. For quantitative analysis, the CT attenuation values, image noise, signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR), and figures of merit (FOM) were calculated.@*RESULTS@#Images obtained from the study group were sharper and contained less noise and fewer streak artifacts (all, p < 0.05) compared to those obtained from the control group. However, the texture of images from the study group was worse (p < 0.05). Although the CT attenuation values were comparable between the study and control groups, the image noise was considerably lower for the study group than that for the corresponding control group (all, p < 0.05). Thus, the SNR, CNR, and FOM were higher in the study group (all, p < 0.05) than in the control group.@*CONCLUSION@#The use of the IR technique and a small volume of contrast material yielded CT images with better qualities compared to those obtained using the FBP technique and conventional contrast volume in a rabbit model.

Evaluation of factors influencing arterial Doppler waveforms in an in vitro flow phantom

PURPOSE: The aim of this study was to investigate factors that influence arterial Doppler waveforms in an in vitro phantom to provide a more accurate and comprehensive explanation of the Doppler signal. METHODS: A flow model was created using a pulsatile artificial heart, rubber or polyethylene tubes, a water tank, and a glass tube. Spectral Doppler tracings were obtained in multiple combinations of compliance, resistance, and pulse rate. Peak systolic velocity, minimum diastolic velocity, resistive index (RI), pulsatility index, early systolic acceleration time, and acceleration index were measured. On the basis of these measurements, the influences of the variables on the Doppler waveforms were analyzed. RESULTS: With increasing distal resistance, the RI increased in a relatively linear relationship. With increasing proximal resistance, the RI decreased. The pulsus tardus and parvus phenomenon was observed with a small acceleration index in the model with a higher grade of stenosis. An increase in the distal resistance masked the pulsus tardus and parvus phenomenon by increasing the acceleration index. Although this phenomenon occurred independently of compliance, changes in the compliance of proximal or distal tubes caused significant changes in the Doppler waveform. There was a reverse relationship between the RI and the pulse rate. CONCLUSION: Resistance and compliance can alter the Doppler waveforms independently. The pulse rate is an extrinsic factor that also influences the RI. The compliance and distal resistance, as well as proximal resistance, influence the pulsus tardus and parvus phenomenon.

Value of sagittal color Doppler ultrasonography as a supplementary tool in the differential diagnosis of fetal cleft lip and palate

PURPOSE: The purpose of this study was to evaluate the feasibility and usefulness of sagittal color Doppler ultrasonography (CDUS) for the diagnosis of fetal cleft lip (CL) and cleft palate (CP). METHODS: We performed targeted ultrasonography on 25 fetuses with CL and CP, taking coronal and axial images of the upper lip and maxillary alveolar arch in each case. The existence of defects in and malalignment of the alveolus on the axial image, hard palate defects on the midsagittal image, and flow-through defects on CDUS taken during fetal breathing or swallowing were assessed. We compared the ultrasonography findings with postnatal findings in all fetuses. RESULTS: Alveolar defects were detected in 16 out of 17 cases with CP and four out of eight cases with CL. Alveolar malalignment and hard palate defects were detected in 11 out of 17 cases and 14 out of 17 cases with CP, respectively, but not detected in any cases with CL. Communicating flow through the palate defect was detected in 11 out of 17 cases of CL with CP. The accuracy of detection in axial scans of an alveolar defect and malalignment was 80% and 76%, respectively. Accuracy of detection of in mid-sagittal images of hard palate defect and flow was 80% and 86%, respectively. The overall diagnostic accuracy of combined axial and sagittal images with sagittal CDUS was 92%. CONCLUSION: Sagittal CDUS of the fetal hard palate is a feasible method to directly reveal hard palate bony defects and flow through defects, which may have additional value in the differential diagnosis of fetal CL and CP.

Xp11.2 translocation renal cell carcinoma in the autosomal dominant polycystic kidney disease patient with preserved renal function

No abstract available.

The diagnostic ability of an additional midline peripheral zone biopsy in transrectal ultrasonography-guided 12-core prostate biopsy to detect midline prostate cancer

PURPOSE: The goal of this study was to evaluate the diagnostic effect of adding a midline peripheral zone (PZ) biopsy to the 12-core biopsy protocol used to diagnose prostate cancer (PC), and to assess the clinical and pathologic characteristics of midline-positive PC in order to identify a potential subgroup of patients who would require midline PZ biopsy. METHODS: This study included 741 consecutive patients who underwent a transrectal ultrasonography-guided, 12-core prostate biopsy with an additional midline core biopsy between October 2012 and December 2013. We grouped patients by the presence or absence of PC and subdivided patients with PC based on the involvement of the midline core. The clinical characteristics of these groups were compared, including serum prostate-specific antigen (PSA) concentrations, PSA density, and pathological features in the biopsy specimens. RESULTS: PC was detected in 289 patients (39.0%). Among the PC patients, 66 patients (22.8%) had midline PC. No patients were diagnosed with PC based only on a midline core. The Gleason scores, number of positive cores, tumor core length, serum PSA concentrations, and PSA density were significantly higher in patients with midline-positive PC (P<0.001). Furthermore, significant cancer was more frequent in the midline-positive group (98.5% vs. 78.0%). CONCLUSION: Patients showing a positive result for PC in a midline PZ biopsy were more likely to have multiple tumors or large-volume PC with a high tumor burden. However, our data indicated that an additional midline core biopsy is unlikely to be helpful in detecting occult midline PC.

Factors influencing the renal arterial Doppler waveform: a simulation study using an electrical circuit model (secondary publication)

PURPOSE: The goal of this study was to evaluate the effect of vascular compliance, resistance, and pulse rate on the resistive index (RI) by using an electrical circuit model to simulate renal blood flow. METHODS: In order to analyze the renal arterial Doppler waveform, we modeled the renal blood-flow circuit with an equivalent simple electrical circuit containing resistance, inductance, and capacitance. The relationships among the impedance, resistance, and compliance of the circuit were derived from well-known equations, including Kirchhoff's current law for alternating current circuits. Simulated velocity-time profiles for pulsatile flow were generated using Mathematica (Wolfram Research) and the influence of resistance, compliance, and pulse rate on waveforms and the RI was evaluated. RESULTS: Resistance and compliance were found to alter the waveforms independently. The impedance of the circuit increased with increasing proximal compliance, proximal resistance, and distal resistance. The impedance decreased with increasing distal compliance. The RI of the circuit decreased with increasing proximal compliance and resistance. The RI increased with increasing distal compliance and resistance. No positive correlation between impedance and the RI was found. Pulse rate was found to be an extrinsic factor that also influenced the RI. CONCLUSION: This simulation study using an electrical circuit model led to a better understanding of the renal arterial Doppler waveform and the RI, which may be useful for interpreting Doppler findings in various clinical settings.

Erratum: Shear Wave Elastography for Detection of Prostate Cancer: A Preliminary Study

The publisher and authors would like to draw the reader's attention to an error.

Usefulness of resistive index on spectral Doppler ultrasonography in the detection of renal cell carcinoma in patients with end-stage renal disease

PURPOSE: The aim of this study was to explore the usefulness of the resistive index (RI) on spectral Doppler ultrasonography (US) in the detection of renal cell carcinoma (RCC) in patients with end-stage renal disease (ESRD). METHODS: Seventeen ESRD patients with kidneys in which renal masses were suspected in routine US were subjected. They underwent computed tomography scans and additional Doppler US for the characterization of the detected lesions. All underwent radical nephrectomy with the suspicion of RCC. Fourteen patients finally were included. RI measurements were conducted in the region of the suspected renal mass and the background renal parenchyma. The intraclass correlation coefficient was used to assess the reproducibility of the RI measurement. A paired t-test was used to compare the RI values between the renal mass and the background renal parenchyma (P<0.05). RESULTS: The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma (0.41-0.65 vs. 0.75-0.89; P<0.001). The intrareader reproducibility proved to be excellent and good for the renal masses and the parenchyma, respectively (P<0.001). CONCLUSION: RI on spectral Doppler US is useful in detecting RCC in patients with ESRD. The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma.

Shear Wave Elastography for Detection of Prostate Cancer: A Preliminary Study

OBJECTIVE: To assess the diagnostic value of shear wave elastography (SWE) for prostate cancer detection. MATERIALS AND METHODS: In this retrospective study, 87 patients with the suspicion of prostate cancer (prostate-specific antigen > 4 ng/mL and abnormal digital rectal examination) underwent a protocol-based systematic 12-core biopsy followed by targeted biopsy at hypoechoic areas on grey-scale ultrasound. Prior to biopsy, SWE was performed by placing two circular 5 mm-sized regions of interest (ROIs) along the estimated biopsy tract in each sector and one ROI for hypoechoic lesions. SWE parameters, S (mean stiffness) and R (mean stiffness ratio), were calculated and compared regarding different histopathologic tissues and their accuracy for diagnosing prostate cancer was analyzed. SWE parameters were correlated with Gleason score and were compared between indolent ( or = 8) tissues in prostate cancer patients. RESULTS: Prostate cancer was detected in 7.5% of 1058 cores in 29.9% of 87 patients. Seven (43.8%) of 16 hypoechoic lesions were confirmed as prostate cancer. SWE parameters were significantly different among the histopathologic entities (p 43.9 kPa and 60.8%, 66.4%, and 0.653, respectively, for R > 3. Both, S and R showed a significant correlation with Gleason score (r > or = 0.296, p < or = 0.008) and were significantly different between indolent and aggressive prostate cancer (p < or = 0.006). CONCLUSION: Shear wave elastographic parameters are significantly different between prostate cancer and benign prostate tissue and correlate with Gleason score.

Contrast-Induced Nephropathy in Patients Undergoing Intravenous Contrast-Enhanced Computed Tomography in Korea: A Multi-Institutional Study in 101487 Patients

OBJECTIVE: To evaluate the prevalence of known risk factors for contrast-induced nephropathy (CIN) and their association with the actual occurrence of CIN in patients undergoing intravenous contrast-enhanced computed tomography (CECT) in Korea. MATERIALS AND METHODS: Patients who underwent CECT in 2008 were identified in the electronic medical records of 16 tertiary hospitals of Korea. Data on demographics, comorbidities, prescriptions and laboratory test results of patients were collected following a standard data extraction protocol. The baseline renal function was assessed using the estimated glomerular filtration rate (eGFR). We identified the prevalence of risk factors along the eGFR strata and evaluated their influence on the incidence of CIN, defined as a 0.5 mg/dL or 25% increase in serum creatinine after CECT. RESULTS: Of 432425 CECT examinations in 272136 patients, 140838 examinations in 101487 patients met the eligibility criteria for analysis. The mean age of the participants was 57.9 +/- 15.5 years; 25.1% of the patients were older than 70 years. The prevalence of diabetes mellitus was 11.9%, of hypertension 13.7%, of gout 0.55% and of heart failure was 1.7%. Preventive measures were used in 40238 CECT examinations (28.6%). The prevalence of risk factors and use of preventive measures increased as the renal function became worse. A CIN was occurred after 3103 (2.2%) CECT examinations, revealing a significant association with decreased eGFR, diabetes mellitus, and congestive heart failure after adjustment. CONCLUSION: Risk factors for CIN are prevalent among the patients undergoing CECT. Preventive measures were seemingly underutilized and a system is needed to improve preventive care.

Prognostic Significance of Ki-67 Expression in Patients Undergoing Surgical Resection for Gastrointestinal Stromal Tumor / 대한소화기학회지

BACKGROUND/AIMS: Assessment of malignant potential in gastrointestinal stromal tumor (GIST) is still problematic. The maximum tumor diameter and the mitotic index are generally used as an index of malignancy of GISTs. The Ki-67 labeling index has recently been used as an index of cell growth. The aim of this study was to investigate the prognostic value of Ki-67 in GIST. METHODS: We retrospectively reviewed the medical records of 32 patients with GIST who underwent surgical resection at Inje University Seoul Paik Hospital. We analyzed their Ki-67 expression, histologic finding, and prognosis. RESULTS: According to the tumor size and mitotic count, 4 patients were classified as very low risk, 9 patients as low risk, 14 patients as intermediate risk and 5 patients as high risk. The average Ki-67 index was 5.56+/-4.48%. The median follow-up duration was 35.72+/-29.04 months, and local/distant recurrences were observed in 6 (18.7%) patients. The overall cumulative disease free survival rates in patients with Ki-67 index 5% were at 1 year, 2 years, and 5 years were 82.1%, 70.3%, and 46.9%, respectively. There was significant relationship between elevated Ki-67 and disease free survival rate (p=0.007). CONCLUSIONS: Our study suggests that Ki-67 index >5% confers a higher risk of relapse in patients with GIST. Future work should focus on standardization of Ki-67 assessment and specification of its role in making treatment decisions.

Magnetic Resonance Evaluation of Mullerian Remnants in Mayer-Rokitansky-Kuster-Hauser Syndrome

OBJECTIVE: To analyze magnetic resonance imaging (MRI) findings of Mullerian remnants in young females clinically suspected of Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome in a primary amenorrhea workup. MATERIALS AND METHODS: Fifteen young females underwent multiplanar T2- and transverse T1-weighted MRI at either a 1.5T or 3.0T MR imager. Two gynecologic radiologists reached consensus decisions for the evaluation of Mullerian remnants, vagina, ovaries, and associated findings. RESULTS: All cases had bilateral uterine buds in the pelvic cavity, with unilateral cavitation in two cases. The buds had an average long-axis diameter of 2.64 +/- 0.65 cm. In all cases, bilateral buds were connected with fibrous band-like structures. In 13 cases, the band-like structures converged at the midline or a paramedian triangular soft tissue lying above the bladder dome. The lower one-third of the vagina was identified in 14 cases. Fourteen cases showed bilateral normal ovaries near the uterine buds. One unilateral pelvic kidney, one unilateral renal agenesis, one mild scoliosis, and three lumbar sacralization cases were found as associated findings. CONCLUSION: Typical Mullerian remnants in MRKH syndrome consist of bilateral uterine buds connected by the fibrous band-like structures, which converge at the midline triangular soft tissue lying above the bladder dome.

Role of Ultrasound Volume Measurements of Testes in Evaluation of Infertile Men with Azoospermia

PURPOSE: The purpose of our study was to assess the usefulness of ultrasounddetermined testicular volume in the evaluation of the infertile men with azoospermia. MATERIALS AND METHODS: A computerized search from October 2005 to June 2010 generated a list of 45 infertile men with azoospermia (mean age, 34 years; age range, 26-44 years) who underwent both scrotal ultrasound and testis biopsy. Ultrasounddetermined testicular volumes were compared between infertile men with obstructive azoospermia and those with non-obstructive azoospermia. RESULTS: Testicular volume for obstructive azoospermia ranged from 6.4 ml to 26.9 ml, with a median volume of 14.0 ml. This volume was significantly larger than that of those with non-obstructive azoospermia, which ranged from 1.0 ml to 12.8 ml, with a median volume of 6.1 ml (p < 0.001). The area under the ROC curve for distinguishing non-obstructive azoospermia from obstructive azoospermia using testicular volume was 0.91. A cutoff value of less than or equal to 11.4 ml could distinguish non-obstructive azoospermia from obstructive azoospermia, with a sensitivity of 94.1% (95% CI; 71.3-99.9%) and a specificity of 73.3% (95% CI; 54.1-87.7%). CONCLUSION: Ultrasound-determined testicular volume can be helpful in the differentiation of obstructive azoospermia from non-obstructive azoospermia.

Medially Directed TRUS Biopsy of the Prostate: Clinical Utility and Optimal Protocol

PURPOSE: The objective of this study is to determine whether medially directed transrectal ultrasound (TRUS)-guided biopsy is necessary for detection of prostate cancer and for establishment of an optimal biopsy regimen tha is equivalent to a systematic 12 core biopsy. MATERIALS AND METHODS: A total of 302 patients underwent a TRUS-guided systematic 12 core biopsy consisting of both medial sextant biopsy obtained between the parasagittal line and midline and lateral sextant biopsy obtained between the parasagittal line and lateral border. We obtained cancer detection rates of various biopsy regimens that were produced from a systematic 12 core biopsy. RESULTS: Using a systematic 12 core biopsy, cancer was detected in 116 (38.4%) of 302 patients. No significant difference was observed between cancer detection rates of medial sextant biopsy and lateral sextant biopsy (33.8% versus 31.5%, p >.05). Biopsy regimens that were equivalent to the systematic 12 core regarding cancer detection rate included medially directed cores that were obtained from both medial portions of the apex. CONCLUSION: Both medially directed biopsy and laterally directed biopsy are necessary for detection of prostate cancer and for establishment of an optimal biopsy regimen.

Radiologic Findings of Local Effect of Right Adrenal Pheochromocytoma on the Adjacent Liver: A Case Report

We report the radiological findings of regional enhancement of the liver adjacent to the right adrenal pheochromocytoma. CT and MRI showed focal strong enhancement of adjacent liver tissue in the arterial phase. However during the delayed phase, the lesion showed iso-attenuation with normal hepatic parenchyma and not delineated. The lesion did not show abnormal signal intensity on neither T1 nor T2 weighted images and indistinguishable from normal parenchyma. The enhancing hepatic lesion was spontaneously regressed on postoperative follow up CT which was taken several months after the adrenalectomy.