Preoperative predictive factors for positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas: a retrospective study.

BACKGROUND: The clinical importance of positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas remains controversial. We evaluated the prognosis of these patients and the predictive preoperative risk factors for positive peritoneal cytology results. METHODS: We retrospectively reviewed patients who underwent curative-intent surgery at our institution between May 2010 and June 2020. Preoperative risk factors for positive peritoneal cytology results were identified using logistic regression analysis. A scoring model was constructed using the total number of significant independent predictors for positive peritoneal cytology results. RESULTS: Of 233 patients, 18 (7.7%) had positive peritoneal cytology results. The recurrence-free survival and cancer-specific survival were markedly worse in patients with positive peritoneal cytology results than in those with negative peritoneal cytology results (recurrence-free survival: 6.0 months vs. 16.6 months, p = 0.050; cancer-specific survival: 19.4 months vs. 47.5 months, p = 0.034). Tumor location (odds ratio: 3.760, 95% confidence interval: 1.099-11.818, p = 0.023), tumor size > 25 mm (odds ratio: 3.410, 95% confidence interval: 1.031-11.277, p = 0.046), preoperative serosal invasion (odds ratio: 5.193, 95% confidence interval: 1.099-24.531, p = 0.038), and preoperative carcinoembryonic antigen level > 5.6 ng/mL (odds ratio: 3.816, 95% confidence interval: 1.248-10.667, p = 0.019) were identified as significant independent predictive factors. Our predictive model's optimal cutoff and positive predictive values for positive peritoneal cytology results were 3 and 27.9%, respectively. CONCLUSIONS: The indications for curative-intent surgery should be considered carefully in patients with high-risk factors for positive peritoneal cytology results.

Computed Tomography-guided Drainage with Modified Trocar Technique Using a Drainaway Drainage Kit.

Purpose: Image-guided percutaneous drainage for abscesses is known as a safe and effective treatment. The computed tomography-guided percutaneous drainage kit Drainaway (SB Kawasumi Co., Ltd.), developed on the basis of a modified trocar method, has made it possible to complete the procedure only under computed tomography guidance without radiographic fluoroscopy. This study investigated the feasibility and safety of Drainaway for abscess drainage. Material and Methods: In this retrospective observational study, 28 procedures in 27 patients (18 men and 9 women; age 67.0 ± 12.3 years) who underwent computed tomography-guided drainage using Drainaway between March and December 2021 at seven affiliated hospitals were analyzed. Patients with symptomatic, puncturable on computed tomography and refractory abscesses were included. Technical success (successful drainage with computed tomography alone), primary clinical success (successful drainage with Drainaway alone), secondary clinical success (avoidance of surgery), and complications were evaluated. Results: The sites of the abscesses were the intraperitoneal, retroperitoneal, and thoracic cavities in 19, 5, and 2 patients, respectively, and subcutaneous tissue in 1 patient. The mean size of the abscesses was 7.1 ± 3.4 cm. The technical success rate was 96.4%; the ligament of the puncture route could not be penetrated in one case. The primary clinical success rate was 77.8%, whereas the secondary clinical success rate of catheter upsizing or replacement was 96.3%. Complications included one case of biliary pleurisy that required drainage. Conclusions: Drainaway is a useful device that allows abscess drainage using only computed tomography guidance without radiographic fluoroscopy.

Initial experience of coaxial percutaneous liver biopsy with tract embolization using N-Butyl cyanoacrylate.

OBJECTIVE: Bleeding occurs after liver biopsy in up to 10.9% cases, and patients with impaired hemostasis or ascites are considered to have absolute or relative contraindications. N-butyl cyanoacrylate enables immediate hemostasis, even in lethal situations. Therefore, percutaneous liver biopsy combined with tract embolization using N-butyl cyanoacrylate is expected to enable safe biopsy, even in patients for whom conventional biopsy is contraindicated. Here we describe our initial experience with coaxial percutaneous biopsy with tract embolization using N-butyl cyanoacrylate. MATERIALS AND METHODS: Eighty-six patients who underwent tract embolization using N-butyl cyanoacrylate between October 2014 and July 2020, including 21 patients who had absolute or relative contraindications for liver biopsy, were retrospectively analyzed. Tract embolization using N-butyl cyanoacrylate comprised two steps: (1) liver biopsy with a biopsy needle inserted via a coaxial introducer needle and (2) embolization of the puncture route by injecting N-butyl cyanoacrylate via the coaxial needle. RESULTS: No complications occurred in any patient. The mean number of biopsies per patient was 3.30 (range, 1-7). Histologically adequate samples were acquired in all cases, and pathological diagnoses were obtained. The mean time required for tract embolization was 52.8 s (range, 6-132 s). The mean peak skin dose was 9.97 mGy (range, 2-68 mGy), which is far below the 3-Gy threshold dose for temporary erythema. CONCLUSIONS: This proposed technique may be a promising and straightforward alternative to improve the management of patients with severe liver disease by allowing safer biopsy, including patients for whom conventional liver biopsy is contraindicated.

Clinical characteristics and predictive factors of postoperative intra-abdominal abscess after distal pancreatectomy.

PURPOSE: The postoperative mortality rate of distal pancreatectomy is lower than that of pancreaticoduodenectomy, although persistent complications may occur after distal pancreatectomy. Fluid collection (FC) is frequently observed after distal pancreatectomy; however, FC may occasionally progress to postoperative intra-abdominal abscess (PIAA), which requires conservative or progressive interventional treatment. This study aimed to compare the status between patients with or without PIAA, identify predictive factors for PIAA and clinically relevant postoperative pancreatic fistula, and investigate the clinical characteristics of patients with PIAA with interventional drainage. METHODS: We retrospectively reviewed data of patients who underwent distal pancreatectomy between January 2012 and December 2019 at two high-volume centers, where hepatobiliary-pancreatic surgeries were performed by expert specialist surgeons. Logistic regression analysis was performed to determine the predictive factors for PIAA. RESULTS: Overall, 242 patients were analyzed, among whom 49 (20.2%) had PIAA. The median postoperative period of PIAA formation was 9 (range: 3-49) days. Among the 49 patients with PIAA, 25 (51.0%) underwent percutaneous ultrasound, computed tomography, or endoscopic ultrasound-guided interventions for PIAA. In the univariate analysis, preoperative indices representing abdominal fat mass (i.e., body mass index, subcutaneous fat area, and visceral fat area) were identified as predictive factors for PIAA; in the multivariate analysis, C-reactive protein (CRP) level (continuous variable) on postoperative day (POD) 3 (odds ratio: 1.189, 95.0% confidence interval: 1.111 - 1.274; P < 0.001) was the only independent and significant predictive factor for PIAA. CONCLUSIONS: CRP level on POD 3 was an independent and significant predictive factor for PIAA after distal pancreatectomy.

Lower limb lymphedema staging based on magnetic resonance lymphangiography.

OBJECTIVE: Dermal backflow (DBF) and reduced lymphatic visualization are common findings of lymphedema on various imaging modalities. However, there is a lack of knowledge about how these findings vary with the anatomic location and severity of lymphedema, and previous reports using indocyanine green lymphography or lymphoscintigraphy show variable results. Magnetic resonance lymphangiography (MRL) is expected to clarify this clinical question due to its superior ability for lymphatic visualization. This retrospective study aimed to investigate the following: (1) Are there any characteristic patterns for DBF and lymphatics' visualization, depending on the anatomic location within lower limbs and severity of lymphedema? (2) Is it possible to classify the severity of lymphedema based on MRL findings? METHODS: Two radiologists performed consensus readings of MRL of 56 patients (112 limbs) with lower-limb lymphedema. The frequency of visualized DBF and lymphatics was analyzed in six regions in each lower limb. The results were compared with the International Society of Lymphology clinical stages and etiology of lymphedema. Characteristic findings were categorized and compared with the clinical stage and duration of lymphedema. RESULTS: DBF and lymphatics were observed more frequently in the distal regions than the proximal regions of lower limbs. DBF appeared more frequently as the clinical stage increased, reaching statistical significance (P < 10-3) between stages 0 or I and II. DBF above the knee joint was rarely observed (0.48%) in early stages (0 and I) but appeared more frequently (13.5%, P < 10-5) in stage II. Lymphatics appeared less frequently as the stage progressed, with significant differences (P < .05) between stages I and II and between II and III. The frequency of lymphatics above the knee joint decreased significantly (P < .05) between stages I and II and between II and III as the stage progressed, reaching 0% in stage III. An MRL staging was proposed and showed significant positive correlations with the clinical stage (r = 0.79, P < .01) and the duration of lymphedema (r = 0.57, P < .01). CONCLUSIONS: MRL-specific patterns of DBF and lymphatics that depended on the site within the lower limb and clinical stage were shown. The DBF pattern differed from those observed in previous studies with other imaging techniques. The proposed MRL staging based on these characteristic findings allows new stratification of patients with lymphedema. Combined with its excellent ability to visualize lymphatic anatomy, MRL could enable a more detailed understanding of individual patient's pathology, useful for determining the most appropriate treatment.

T1ρ magnetic resonance imaging value as a potential marker to assess the severity of liver fibrosis: A pilot study.

PURPOSE: Assessment of liver fibrosis is essential for the management of liver disease. Although liver biopsy is the gold-standard modality for the diagnosis of liver fibrosis, it has some limitations. Thus, other methods are required to overcome the disadvantages of a liver biopsy. T1ρ magnetic resonance imaging (MRI) values are potential biomarkers for liver cirrhosis. This study aimed to assess the relationship between T1ρ MRI values and liver fibrosis severity by measuring the correlation between T1ρ values and shear wave elastography (SWE) values, which are routinely used for the diagnosis of liver fibrosis. METHODS: T1ρ imaging and SWE values were obtained from four healthy volunteers and 16 patients with chronic liver disease. The regions of interest on MR images were drawn and matched with those of the right liver lobe on SWE images. RESULTS: The mean T1ρ values of the right liver lobe correlated positively with the mean SWE values (Pearson's correlation coefficient: 0.783; p < 0.0001; 95 % confidence interval: 0.623-0.880). CONCLUSION: The mean T1ρ values of the right liver lobe may be correlated with the severity of liver fibrosis.

Analysis of collateral lymphatic circulation in patients with lower limb lymphedema using magnetic resonance lymphangiography.

OBJECTIVE: Although the development of lymphatic collaterals is expected following lymphedema, little is known about the anatomic details of such compensatory pathways or their association with symptoms. Magnetic resonance lymphangiography (MRL) has been shown to be superior to lymphoscintigraphy and indocyanine green lymphography in visualizing lymphatics. This study aimed to analyze MRL images of lower limbs to elucidate the patterns of lymphatic collateral formation and their association with the clinical stages of lymphedema. METHODS: We enrolled 56 consecutive patients (112 lower limbs) with lymphedema who underwent MRL. Two radiologists performed a consensus reading of MRL images for the presence or absence of collateral lymphatic pathways, and the results were compared with the clinical stages. Furthermore, the frequency of abnormal MRL findings in 43 asymptomatic lower limbs of patients with unilateral lymphedema was analyzed and compared with that in the 69 symptomatic lower limbs of the patients. The imaging findings were also compared with the cause of lymphedema. RESULTS: All three collateral pathways (anterolateral, deep, and posteromedial lymphatics) were visualized at a higher (P < .05) frequency in stage II than in stage 0 lower limbs. The frequency of visualization of the three collaterals was significantly higher in symptomatic (stages I-III) lower limbs than in asymptomatic (stage 0) lower limbs. Most (76.8%) of the symptomatic limbs exhibited at least one of these collaterals, and the frequency was significantly higher than in the asymptomatic limbs (P < .001). Most (81.4%) of the asymptomatic (stage 0) lower limbs had at least one abnormal finding in terms of lymphatic circulation, although this proportion was significantly lower compared with the symptomatic limbs (98.6%). The collaterals tended to appear less frequently in primary lymphedema than in secondary lymphedema, reaching statistical significance in the posteromedial lymphatics. CONCLUSIONS: These results suggested that the two superficial lymphatic groups and the deep lymphatic system act as major collaterals of the lower limbs in patients with lymphedema. Furthermore, MRL of most patients with unilateral lymphedema demonstrated abnormal findings, including collateral formation, not only in the affected lower limb but also in the asymptomatic lower limb. In primary lymphedema, the collaterals may appear less frequently than in secondary lymphedema. Collaterals should be taken into consideration in planning the site of lymphaticovenous anastomosis and assessing disease progression. MRL can visualize preclinical alterations in lymphatic flow and compensatory pathways; therefore, we expect that it will be useful for the early diagnosis of lymphedema.

A rare case of isolated splenic sarcoidosis: A case report and literature review.

Sarcoidosis is a multisystemic granulomatous disease. It is rarely isolated in the spleen. The present report describes a case of isolated splenic sarcoidosis that was diagnosed histologically following laparoscopic splenectomy. A 76-year-old woman, who underwent radical nephroureterectomy 7 years earlier for left renal pelvic cancer and mastectomy 6 years earlier for left breast cancer in another facility, was referred to our hospital for assessment of splenic tumors that were identified during a follow-up examination. The computed tomography scans revealed multiple nodules in the spleen, which had increased in size over 2 years. Positron emission tomography revealed accumulation of [18F]-fluorodeoxyglucose in the spleen. Laparoscopic splenectomy was performed and the diagnosis of sarcoidosis was confirmed histologically. A review of previous reports and the present case suggested that diagnosis of splenic sarcoidosis should be considered when the CT scans show multinodular splenic tumors, and sarcoidosis might be associated with malignant tumors.

Balloon-occluded retrograde glue embolization for intractable lymphorrhea from bilateral iliac lymphatics following surgery for rectal cancer.

Lymphorrhea is a rare complication of rectal surgery. Although percutaneous embolization of thoracic or lymphatic ducts is now increasingly being reported for various types of lymphatic leakage, there are only sparse data on lymphatic interventions for lymphorrhea following rectal surgery. A novel balloon-occluded retrograde lymphatic embolization (BRLE) technique can be a simple and effective option for intractable lymphorrhea. We report a case of a man with infected lymphorrhea after rectal resection. Transperineal drainage was performed; however, lymphatic leakage persisted after 1 month of conservative treatment. Lymphangiography revealed multifocal leaks from bilateral iliac lymphatics. The proposed BRLE technique was performed via a balloon catheter inserted through the transperineal drainage. The balloon allowed occlusion of lymphatic outflow and forceful retrograde injection to achieve denser accumulation of n-butyl cyanoacrylate. Tight embolization of bilateral iliac lymphatics and drastic improvement of the leakage was achieved. To the best of our knowledge, this is the first report of percutaneous embolization for lymphorrhea after rectal surgery. This case supports the efficacy of the BRLE as a simple and effective therapeutic option for such persistent multifocal lymphatic leaks.

Magnetic Resonance Imaging Findings of Traumatic Bulbar Urethral Stricture Help Estimate Repair Complexity.

OBJECTIVE: To evaluate the magnetic resonance imaging (MRI) findings of traumatic bulbar stricture and to evaluate their ability to estimate repair complexity. METHODS: Eighty-nine men with traumatic bulbar stricture who underwent urethrography and MRI at least 3 months postinjury and subsequent excision and primary anastomosis were retrospectively analyzed. The associations of MRI findings, including continuity of the tunica albuginea of the corpus spongiosum, periurethral fistula, spongiofibrosis length (SFL), and distal and proximal bulbar urethral length from the stricture, with urethrography and operative parameters were evaluated. RESULTS: Mean SFL was significantly longer than mean stricture length on urethrography (14.9 vs 7.9 mm, P <.0001). Periurethral fistula was found in 18 (20.2%) patients on MRI but not in 10 (55.6%) of them on urethrography. The corpus spongiosum was disrupted in 40 patients (55.1%) on MRI. On multivariate linear regression, SFL (standard coefficient, 0.25; t value, 2.31; P = .02) predicted operation time, while SFL (standard coefficient, 0.22; t value, 2.04; P = .04) and proximal bulbar urethral length (standard coefficient, -0.25; t value, -2.11; P = .04) independently predicted blood loss. Corporal splitting to reduce anastomotic tension and/or increase visualization during repair was needed in 33 patients (37.1%). Stricture length on urethrography (odds ratio [OR], 1.22; 95% confidence interval, 1.04-1.42; P = .006) and corpus spongiosum disruption (odds ratio, 5.51; 95% confidence interval, 1.57-19.34, P = .005) were independent predictors for the need of corporal splitting. CONCLUSION: In contrast to urethrography findings, MRI findings help predict traumatic bulbar stricture repair complexity.

Analysis of Diffusion-weighted MR Images Based on a Gamma Distribution Model to Differentiate Prostate Cancers with Different Gleason Score.

PURPOSE: Prostate cancer management includes identification of clinically significant cancers that may require curative treatment. Statistical models based on gamma distribution can describe diffusion signal decay curves of prostate cancer. The purpose of this study was to evaluate the ability of parameters obtained with the gamma model in differentiating prostate cancers with different Gleason score values. METHODS: This study included 155 patients with prostate cancer who underwent multiparametric magnetic resonance imaging prior to prostate biopsy (127 patients) or radical prostatectomy (28 patients) between January 2015 and June 2017; 159 foci of prostate cancer were included in our study. We compared cases scored as Gleason score (GS) 3 + 3 and GS ≥ 3 + 4, and analyzed cases scored as GS ≤ 3+ 4 and GS ≥ 4 + 3 based on the gamma model (Frac < 1.0, Frac < 0.8, Frac < 0.5, Frac < 0.3, and Frac > 3.0), and apparent diffusion coefficient (ADC). RESULTS: Among 159 cancerous lesions in 155 patients, 13 (8.2%) were GS 3 + 3 prostate cancers, 51 (32.0%) were GS 3 + 4 prostate cancers, 30 (18.2%) were GS 4 + 3 cancers, and 65 (40.9%) were GS ≥ 4 + 4 cancers. Frac < 0.3, Frac < 0.5, Frac < 0.8, and Frac < 1.0 were significantly higher and ADC values were significantly lower in GS ≥ 4 + 3 cancers than in GS ≤ 3 + 4 cancers (P < 0.01, P < 0.01, P < 0.01, P = 0.01, and P < 0.01, respectively). With receiver operating characteristic (ROC) analysis, Frac < 0.3 and Frac < 0.5 had significantly greater area under the ROC curve for discriminating GS ≥ 4 + 3 cancers from GS ≤ 3 + 4 cancers than ADC (P = 0.03, P < 0.01, respectively). CONCLUSION: Frac < 0.3 and Frac < 0.5 showed higher diagnostic performance than ADC for differentiating GS ≥ 4 + 3 from GS ≤ 3 + 4 cancers. The gamma model may add additional value in discrimination of tumor grades.

Mobile Spinal Schwannoma with a Completely Cystic Appearance.

BACKGROUND Spinal schwannomas are benign tumors arising from Schwann cells. Although they have been well described, tumor movement in the spinal canal is an extremely rare finding, and entirely cystic spinal schwannomas have rarely been reported. This is the first report of a spinal schwannoma that simultaneously exhibited both these unusual features. CASE REPORT A 48-year-old female presented with dysuria and right leg pain. Initial magnetic resonance imaging (MRI) revealed a well-delineated intradural cystic lesion at the level of L4-S1 vertebrae that was isointense with cerebrospinal fluid on both T1- and T2-weighted images. A follow-up MRI 6 months later showed that the tumor had moved to the level of L2-L4; it also revealed tortuous configuration of nerve roots of the cauda equina. The tumor was resected, and a diagnosis of schwannoma with extensive cystic degeneration was pathologically confirmed. CONCLUSIONS Various possible mechanisms have been suggested for the mobility of extramedullary tumors. In the present case, MRI findings indicated the cause of the tumor movement might be attributed to the laxity of nerve roots. Besides, it is highly atypical for a schwannoma to present an entirely cystic appearance, and the combination of the 2 extraordinary features made preoperative diagnosis difficult. However, 16 out of 22 (73%) of previously reported mobile spinal tumors were schwannomas, so the differential diagnosis for a mobile spinal tumor should include schwannoma, even when the lesion seems entirely cystic on MRI. To minimize the risk of complications and additional surgical dissection, physicians should acknowledge that spinal tumors can migrate.

The benefits of extrinsic ligament release for potentially hemodynamically unstable pancreaticoduodenal arcade aneurysm with median arcuate ligament syndrome: a case report.

BACKGROUND: A pancreaticoduodenal artery aneurysm (PDAA) occurring in close association with median arcuate ligament syndrome (MALS) is rare. A surgical procedure, such as median arcuate ligament (MAL) release, should be considered in such cases, but the operative criteria remain unknown. In this study, we reported an extremely rare case of PDAA with periarteritis nodosa (PAN) and MALS. CASE PRESENTATION: A 60-year-old man was transferred to our department with sudden onset of abdominal pain. We initially diagnosed his condition as a PDAA rupture with MALS based on enhanced computed tomography (CT). We promptly performed transcatheter arterial embolization (TAE) of PDAA, and the angiogram showed stagnant contrast agent in the celiac trunk, indicating total celiac artery occlusion. Follow-up enhanced CT three weeks after the first TAE clearly demonstrated newly formed, multiple aneurysms in the pancreaticoduodenal arcade and the hepatic artery. These findings indicated a systemic disorder, such as PAN or segmental arterial mediolysis, as the underlying cause. Therefore, we started corticosteroid therapy and performed diagnostic angiography to clarify the celiac artery's patency. Contrary to the initial angiography, the second angiography showed sustained blood flow in the celiac artery. Nevertheless, we performed both extrinsic MAL release and consecutive TAE because of the risk of multiple aneurysms rupturing due to an uncontrolled systemic disorder and consequent hepatic ischemia. The patient had no episode of recurrence until one year of follow-up. CONCLUSIONS: It is important to evaluate risk for hemodynamically unstable events to decide the best treatment strategy for MALS.

Atypical Clinical Presentation of Crohn's Disease with Superior Mesenteric Vein Obstruction and Protein-losing Enteropathy.

We herein report a 44-year-old man suffering from systemic edema due to protein-losing enteropathy (PLE) with superior mesenteric vein (SMV) obstruction and development of collateral veins, which subsequently proved to be a chronic result of thrombosis and a complication of Crohn's disease (CD). PLE was supposedly induced by both intestinal erosion and thrombosis-related lymphangiectasia, which was histologically proven in his surgically-resected ileal stenosis. Elemental diet and anti-TNFα agent improved his hypoalbuminemia after surgery. The rarity of the simultaneous coexistence of SMV obstruction and PLE and the precedence of these complications over typical abdominal symptoms of CD made the clinical course complex.

Pubourethral Stump Angle Measured on Preoperative Magnetic Resonance Imaging Predicts Urethroplasty Type for Pelvic Fracture Urethral Injury Repair.

OBJECTIVE: To examine whether the type of delayed urethroplasty required for pelvic fracture urethral injury, which is not easily predicted from conventional urethrography findings, can be predicted from preoperative magnetic resonance imaging (MRI) results. PATIENTS AND METHODS: Records of 74 male patients with pelvic fracture urethral injury who underwent MRI of the pelvis at least 3 months after injury and, subsequently, delayed anastomotic urethroplasty were retrospectively analyzed. Pubourethral stump length (PUL) was defined as the distance between the distal end of the proximal urethral stump and the lower border of the inferior pubic ramus. Pubourethral stump angle (PUA) was defined as the angle between the long axis of the pubis and the line between the distal end of the proximal urethral stump and the lower border of the inferior pubic ramus. Both PUL and PUA were measured in sagittal T2-weighted MRI. RESULTS: Delayed urethroplasty was performed by a simple perineal approach in the 28 patients requiring only bulbar urethral mobilization with or without corporal splitting and by elaborate approach in the 46 additionally requiring inferior pubectomy or an abdominoperineal approach with urethral rerouting. The overall success rate defined as no recurrent stricture on urethroscopy was 94.6%. Disruption at the prostate apex, greater urethral gap length, longer PUL, and lower PUA were in univariate analysis significantly associated with an elaborate approach. In multivariate analysis, only low PUA was an independent predictor of the need for an elaborate approach. CONCLUSION: PUA measured on MRI is useful for predicting the type of reconstruction needed for urethral repair.

Appropriate imaging utilization in Japan: a survey of accredited radiology training hospitals.

PURPOSE: To survey whether imaging is being performed appropriately in Japan, and to survey whether radiologists intervene to ensure imaging requests are appropriate. METHODS: An online survey was sent to radiologists at accredited radiology training hospitals. The survey included the radiologists' perspectives on whether imaging is performed appropriately at their institutions and whether they intervene if the indication for imaging is inappropriate/ambiguous. RESULTS: The response rate was 87.3% (165/189). We observed marked variability in the frequencies that imaging not recommended by the guidelines was performed among modalities and/or body parts; the responses "very frequently/frequently performed" were more common for breast cancer related imaging examinations and for head CT/MRI. The respondents frequently reported that inappropriate/ambiguous indications included requests to expand the craniocaudal range or to perform whole-body imaging. In 80% of the hospitals (132/165), radiologists contacted the physicians who requested unrecommended examinations; the number of CT and MRI examinations that full-time radiologists need to interpret in a half-day session was significantly smaller at these hospitals (median 18 vs 24, P = 0.032). CONCLUSION: We conducted a survey to investigate appropriate imaging utilization in Japan. At the hospitals with numerous examinations to interpret, full-time radiologists may find it difficult to ensure that examinations are ordered appropriately.

Clinical outcomes of percutaneous radiofrequency ablation for small renal cancer.

Partial nephrectomy is the treatment of choice for small renal cell carcinoma (RCC) from the perspective of cancer management and renal function. However, when patients with RCC are of advanced age, exhibit severe comorbidities, including cardiovascular and pulmonary diseases, or have hereditary RCC, ablative therapies, including radiofrequency ablation (RFA) and cryoablation are useful treatment options. In the present study, the clinical outcomes of percutaneous RFA for treating small RCC were evaluated. Between December 2005 and March 2015, 40 patients (41 renal tumors in total) underwent RFA and a total of 50 sessions of RFA were performed. The average tumor size was 2.5 cm. A total of 18 tumors were exophytic and 23 were parenchymal. Of the 41 tumors, 85.4% were completely ablated by initial RFA and the rate of complete ablation following reablation for residual viable lesions was 95.1%. Local recurrence-free survival following complete ablation was 84.2% at 3 years. A patient with a 4.7 cm RCC tumor rapidly progressed following four RFA treatments until complete ablation was achieved. The metastasis-free survival rate following initial RFA was 95.7% at 3 years. The RCC-specific survival was 100% (mean follow-up, 38 months). Adverse events occurred in five sessions (10%); however, only 1 patient with arteriovenous fistula required intervention (transarterial embolization). The mean hospital stay following RFA was 3.2 days. The mean decrease in estimated glomerular filtration rate following RFA was 2.7%. The results of the present study indicate that percutaneous RFA was an effective treatment for small RCCs with respect to management of cancer, minimal invasiveness and minimal loss of renal function, particularly in patients for whom surgery would be a high risk and those at increased risk of deterioration of renal function.

Anterior Prostate Cancer: Diagnostic Performance of T2-Weighted MRI and an Apparent Diffusion Coefficient Map.

OBJECTIVE: Diagnosis of anterior prostate cancer is challenging. The purpose of this study was to evaluate the diagnostic performance of T2-weighted imaging and an apparent diffusion coefficient (ADC) map in the detection of anterior prostate cancer and to compare that with the diagnostic performance in the detection of posterior prostate cancer. MATERIALS AND METHODS: We retrospectively reviewed the records of 87 patients who underwent 3-T MRI that included T2-weighted imaging and diffusion-weighted imaging before radical prostatectomy. The prostate gland was divided into anterior and posterior segments, and the radiologists interpreted two protocols (T2-weighted imaging alone vs T2-weighted imaging and an ADC map) and sorted the confidence levels for the presence of prostate cancer into five grades. ROC analysis was performed to evaluate the diagnostic performance of each protocol for the detection of anterior and posterior prostate cancers. We also assessed the relative fractions of sensitivity and specificity between anterior and posterior prostate cancers. Additionally, the ADCs of noncancerous anterior fibromuscular stroma were measured and compared with the ADCs of anterior prostate cancers. RESULTS: The AUCs with T2-weighted imaging alone and with T2-weighted imaging and an ADC map were 0.75 and 0.88 for anterior prostate cancer, respectively, and were 0.70 and 0.81 for posterior prostate cancer. The sensitivity for detecting anterior prostate cancer was 90% and was significantly higher than that for detecting posterior prostate cancer in the protocol using T2-weighted imaging and an ADC map (p = 0.003) when scores of 3-5 were considered as positive for prostate cancer. The ADC was significantly lower in anterior prostate cancer (mean, 0.80 × 10(-3) mm(2)/s) than in noncancerous anterior fibromuscular stroma (1.13 × 10(-3) mm(2)/s) (p < 0.001). CONCLUSION: The protocol using T2-weighted imaging and an ADC map showed higher accuracy for the detection of anterior prostate cancer than for the detection of posterior prostate cancer.