Expandable Metallic Stent for Endobronchial Metastasis from Colorectal Cancer: Reports of 2 Cases.

In recent years, there have been many reports about the efficacy of stenting for central bronchial stenosis. When central bronchial stenosis is due to metastasis of a malignant tumor to the trachea and/or bronchi (endobronchial metastasis: EM), it is classified as "narrow EM" and "broad EM." [1] We managed two patients in whom bilateral stent placement was required for narrow and broad EM arising from colorectal cancer. Case 1: In September 2011, a 66-year-old man underwent low anterior resection for advanced colorectal cancer associated with unresectable liver metastasis. The liver metastasis became resectable after chemotherapy, with two resection procedures and radiofrequency ablation (RFA) being performed. Thereafter, lung metastasis occurred and a tumor in the left lung was resected. In May 2015, he developed respiratory distress. CT identified multiple lesions protruding into the lumen of the trachea and the left and right main bronchi. There was no evidence of mediastinal relapse or local relapse at the resection margin, and tumors were only detected in the tracheobronchial walls. Accordingly, narrow EM was diagnosed. An expandable metallic stent (EMS) was placed on the right side where stenosis was more severe, and radiation therapy was conducted for the non-stented tumors. The patient died 8 months later. Case 2: A 69-year-old woman had undergone laparoscopic right hemicolectomy and adjuvant chemotherapy for Stage lllb cancer of the ascending colon. Due to subsequent elevation of tumor markers, PET-CT was conducted and abnormal uptake was seen in the apex of the right lung and right upper abdomen. Both lesions were resected, and omental and lung metastases were diagnosed. She received treatment with UFT / calcium folinate, but relapse occurred at the resection margin in the right lung. At 7 years and 5 months after initial surgery, she complained of respiratory distress at an outpatient visit. CT demonstrated displacement of the trachea and right main bronchus due to enlargement of upper mediastinal lymph nodes. There was also severe stenosis of the right main bronchus due to tumor infiltration. Because there was both infiltration from local recurrence after resection and upper mediastinal lymph node enlargement, broad EM was diagnosed. An EMS was placed at the site of severe stenosis in the right main bronchus. Similar to Case 1, radiation therapy was also conducted, but respiratory distress occurred after 3 months due to tumor re-growth at the stent margin. Accordingly, stent-in-stent placement was performed and her respiratory symptoms improved. However, superior vena cava syndrome occurred 1 month later and the patient died. We consider that placing an EMS is effective in patients with tracheal stenosis due to EM that is judged to be an oncological emergency.

Pulmonary artery hypoplasia associated with posterior mediastinal hematoma accompanied by a ruptured pseudoaneurysm of the esophageal branch of the left gastric artery.

A 65-year-old woman with no significant medical history visited the emergency department complaining of epigastric discomfort. A computed tomography of the thorax and abdomen showed the attenuation of the pulmonary artery and a posterior mediastinal hematoma. Angiography showed a tortuous esophageal branch of the left gastric artery and a pseudoaneurysm, and during the later phase, the left lower lobe of the lung was enhanced, and finally, the left pulmonary vein was enhanced. We considered that the patient was exhibiting hypoperfusion of the left pulmonary artery arising from left pulmonary artery hypoplasia, since the left lung was supplying the systemic circulation. Transcatheter arterial embolization was performed. The patient has not experienced any recurrence of a ruptured pseudoaneurysm or epigastric discomfort. Here, we report the first documented case of pulmonary artery hypoplasia associated with posterior mediastinal hematoma accompanied by a ruptured aneurysm of the left gastric artery.

Successful Eradication Therapy for Helicobacter pylori-positive Atrophic Gastritis at the Sixth Attempt: A Case Report.

A 74-year-old woman undergoing outpatient follow-up for reflux esophagitis and atrophic gastritis tested positive for Helicobacter pylori and underwent primary eradication therapy with lansoprazole (LPZ) 30 mg, amoxicillin (AMPC) 750 mg, and clarithromycin (CAM) 200 mg twice daily for 1 week in August 2012. A urea breath test (UBT) after this treatment revealed that eradication had failed. Secondary eradication therapy was carried out with esomeprazole (EPZ) 20 mg, AMPC 750 mg, and metronidazole (MNZ) 250 mg twice daily for 1 week, but this also failed. The third attempt at eradication consisted of EPZ 20 mg, AMPC 750 mg, and sitafloxacin (STFX) 100 mg twice daily for 1 week, but this also ended in failure. A fourth attempt using rabeprazole (RPZ) 20 mg (4 times daily) with MNZ 250 mg and STFX 100 mg twice daily for 2 weeks also failed, as did a fifth attempt in April 2015 using vonoprazan (VPZ) 20 mg, AMPC 750 mg, and MNZ 250 mg twice daily for 1 week. Eradication was finally successful after the sixth attempt, in which the patient was treated with vonoprazan 20 mg, MNZ 250 mg, and STFX 100 mg twice daily for 2 weeks.

Balloon-Occluded Retrograde Transvenous Obliteration for the Treatment of Gastric Varices: Polidocanol Foam Versus Liquid Ethanolamine Oleate.

OBJECTIVE: The purpose of this study was to evaluate the clinical results of the management of gastric varices by balloon-occluded retrograde transvenous obliteration with polidocanol foam versus ethanolamine oleate. MATERIALS AND METHODS: Twenty patients treated with ethanolamine oleate and 21 patients treated with polidocanol foam were enrolled in this study. Early therapeutic effects were assessed mainly by dynamic contrast-enhanced CT. Subjective symptoms, objective findings associated with the procedures, and changes in laboratory data during the obliteration process were evaluated. Rebleeding from gastric varices was assessed after the procedures. RESULTS: Complete obliteration was confirmed in all but one case of early recanalization after treatment with polidocanol foam. One patient died of acute respiratory distress syndrome after treatment with ethanolamine oleate. The total sclerosant volume was significantly lower for 3% polidocanol foam (13.5 ± 6.8 mL) than for 5% ethanolamine oleate (30.6 ± 15.6 mL) (p < 0.01). Polidocanol foam caused fewer severe reactions, including pain, during and after injection. High body temperature, hemoglobinuria, and reactive pleural effusion were not observed with polidocanol foam. The variance in laboratory data values associated with hemolysis was significantly greater with ethanolamine oleate. No postprocedural rebleeding from the gastric varices was observed during a median follow-up time of 39.5 months after procedures with ethanolamine oleate and 34 months after procedures with polidocanol foam. CONCLUSION: Polidocanol foam can achieve obliteration of gastric varices comparable to that of ethanolamine oleate but with a significantly lower sclerosant dose and reduced risk of hemolysis-induced complications and harmful reactions, including pain and fever.

Foam sclerotherapy for a symptomatic hepatic cyst: a preliminary report.

PURPOSE: We evaluated our initial experience of performing sclerotherapy for symptomatic hepatic cysts using polidocanol foam instead of a liquid sclerosant. METHODS: Three consecutively registered patients with symptomatic hepatic cysts (one with polycystic liver disease) underwent polidocanol foam sclerotherapy. A pigtail catheter was inserted into the targeted cyst following percutaneous cyst puncture under ultrasound guidance, and the cyst fluid was aspirated. To confirm the absence of communications between the cyst and surrounding hepatic vessels, 3 % polidocanol foam sclerosant was injected at a 1:4 ratio of polidocanol to air following digital subtraction cystography with carbon dioxide. C-arm computed tomography (CT) guidance also was used to monitor foam filling of the targeted cyst. The maximum dose of sclerosant injected per treatment session did not exceed 10 ml. The catheter was kept unclamped overnight for open drainage, and additional sclerotherapy sessions were performed on subsequent days, if needed. RESULTS: Efficient sclerotherapy was achieved with an average of two sessions. The initial mean cyst volume was 1,052 ml, and gradual resolution was observed without recurrence. The mean reduction rate was 97.9 % (97.7-98.3 %), and all cyst-associated symptoms disappeared. The median follow-up period was 17 (range 6-21) months. Although one patient experienced moderate-grade fever and another moderate pain at the puncture site, no major complications were observed. CONCLUSION: Polidocanol foam sclerotherapy is a safe and effective treatment for symptomatic hepatic cysts.

A case of refractory chylous ascites after nephrectomy successfully treated with percutaneous obliteration using adhesive glue.

Here we report a case of uncontrollable chylous ascites that developed after nephrectomy and was successfully treated with percutaneous obliteration of the lymphocele-like extravasation using ethiodized oil during lymphangiography. Under computed tomographic and fluoroscopic guidance, an N-butyl cyanoacrylate-ethiodized oil mixture was used with metallic coils to obliterate the extralymphatic leakage site. The volume of intraperitoneal drainage decreased steadily over the next 5 days, and the tube was removed. Percutaneous obliteration can be characterized as filling of the leakage site from outside the lymph vessel with no flow disruption, which contrasts with the conventional embolization approach via the cisterna chyli.

Partial splenic embolisation using n-butyl cyanoacrylate: intraprocedural evaluation by magnetic resonance imaging.

OBJECTIVES: To evaluate the use of diffusion-weighted imaging (DWI) for estimating infarcted splenic volume during partial splenic embolisation (PSE) using n-butyl cyanoacrylate (NBCA). METHODS: Twenty consecutive patients (57.2 ± 11.7 years) with hypersplenism underwent PSE. Intrasplenic branches were embolised using NBCA via a 2.1-French microcatheter aiming at infarction of 50 to 80 % of total splenic volume. Immediately after PSE, signal intensities (SI) of embolised and non-embolised splenic parenchyma were measured on DWI. Semi-automated volumetry (SAV) on DWI was compared with conventional manual volumetry (MV) on contrast-enhanced CT 1 week after PSE. Platelet counts were recorded before and after PSE. RESULTS: The SI on DWI in the embolised parenchyma decreased significantly (P < 0.01) to 24.7 ± 8.1 % as compared to non-embolised parenchyma. SAV and MV showed a strong correlation (r = 0.913 before PSE, r = 0.935 after PSE, P < 0.01) and significant (P < 0.01) reduction of normal splenic volume was demonstrated on both SAV (71.9 ± 12.4 %) and MV (73.6 ± 9.3 %) after PSE. Based on the initial SAV, three patients (15 %) underwent additional branch embolisation to reach sufficient infarction volume. Platelet counts elevated significantly (522.8 ± 209.1 %, P < 0.01) by 2 weeks after PSE. No serious complication was observed. CONCLUSION: Immediate SI changes on DWI after PSE allowed semi-automated splenic volumetry on site. KEY POINTS: • Partial splenic embolisation (PSE) is an important interventional technique for hypersplenism • Diffusion-weighted MR reveals an immediate decrease in signal in the embolised parenchyma • Such signal reduction permits semi-automated splenic volumetry on site. • This allows precise quantification of the amount of parenchyma infarcted, avoiding additional PSE.

Carbon dioxide (CO2) vs iodinated contrast digital subtraction angiography during balloon-occluded retrograde transvenous obliteration (BRTO) using foam sclerosant for gastric varices.

PURPOSE: To compare the visualization of the target gastric varices (GV) on balloon-occluded retrograde transvenous venography (BRTV) using iodinated contrast material vs carbon dioxide (CO(2)) in preparation for subsequent balloon-occluded retrograde transvenous obliteration (BRTO) using foam sclerotherapy. MATERIALS AND METHODS: In 16 consecutive patients with nonruptured GV, BRTV was performed first using iodinated contrast material and then with CO(2). BRTV was repeated whenever there were changes in the catheter or patient position or when coil embolization of collaterals was needed. Each visualization grade of GV (grade 1 = GV only; grade 2 = GV > collaterals; 3 = GV < collaterals; grades 4-5 = collaterals only) was determined by two observers in consensus. During foam BRTO, the GV visualization grade was recorded again and confirmed by C-arm computed tomography (CT). RESULTS: In 38 pairs of BRTV, GV grades were significantly (P < .0001) lower (ie, favoring BRTO) on CO(2) BRTV (mean ± standard deviation, 1.8 ± 0.8) than on iodine BRTV (3.4 ± 0.8). GV grades on foam BRTO (1.4 ± 0.7) were similar to the grades obtained on the most recent CO(2) BRTV (1.3 ± 0.5) but were significantly smaller (P < .0001) than on iodinated BRTV (3.1 ± 0.9). GV were opacified by foam on initial C-arm CT in 14 patients (87.5%), and complete thrombosis of GV was obtained without any complication in all 16 patients (100%). CO(2) reached the GV even when iodinated contrast material could not (grade 4) in seven of our 16 patients (43.8%), leading to successful BRTO. CONCLUSIONS: CO(2) BRTV visualized GV better than did iodine BRTV and changed the management of more than 40% of patients by enabling successful foam BRTO in patients in which conventional liquid BRTO could not be performed.

Balloon-occluded retrograde transvenous obliteration of gastric varices: use of CT-guided foam sclerotherapy to optimize technique.

OBJECTIVE: Balloon-occluded retrograde transvenous obliteration has been traditionally based on liquid sclerotherapy. However, overdose and systemic spillage of liquid sclerosant can cause severe complications, such as hemolysis, which lead to hemoglobinuria, allergy, acute respiratory distress syndrome, and other disorders. The purpose of this study was to evaluate the performance of foam sclerotherapy with C-arm CT guidance to reduce the amount of sclerosant and to optimize the safety of balloon-occluded retrograde transvenous obliteration while preserving its efficacy. MATERIALS AND METHODS: Twenty consecutively registered patients with gastric varices underwent balloon-occluded retrograde transvenous obliteration with polidocanol foam. C-arm CT guidance was used to confirm gas filling of the target vessels. In this retrospective analysis of a prospectively encoded database, total net doses of polidocanol used for transvenous obliteration and of contrast medium used for venography before transvenous obliteration were compared, and subsequent complications, including hemoglobinuria, were documented. RESULTS: In all patients, foam was observed in the target vessels at C-arm CT. The mean dose of polidocanol used for balloon-occluded retrograde transvenous obliteration (3.9 ± 1.5 mL) was significantly smaller (p < 0.001) than the dose of contrast medium used for venography (16.4 ± 7.9 mL). Hemoglobinuria was found in only one patient. Except in one instance of recanalization, full variceal thrombosis was confirmed at contrast-enhanced CT 1 week after transvenous obliteration (success rate, 95%). In one patient, air migrated into the liver during transvenous obliteration but was spontaneously absorbed. No serious complication occurred. CONCLUSION: Balloon-occluded retrograde transvenous obliteration with polidocanol foam under C-arm CT guidance allowed significant reduction of sclerosant dose and resulted in a low complication rate while a high technical success rate and efficacy were maintained.

Mycotic Celiac Artery Aneurysm Following Infective Endocarditis: Successful Treatment Using N-butyl Cyanoacrylate with Embolization Coils.

Mycotic celiac artery aneurysm following infective endocarditis is extremely rare and, to our knowledge, only four cases have been reported in the literature to date. We describe the case of a 60 year-old man who developed a mycotic aneurysm of the celiac artery, which was detected by computed tomography (CT) following an episode of infective endocarditis. He successfully underwent endovascular isolation and packing of the aneurysm using N-butyl cyanoacrylate (NBCA) with embolization coils.

Three-dimensional quantitation of regional cerebral blood flow in mice using a high-resolution pinhole SPECT system and 123I-iodoamphetamine.

INTRODUCTION: This study is intended to evaluate the feasibility of using a high-resolution pinhole SPECT system and iodine-123-N-isopropyl-4-iodoamphetamine ((123)I-IMP) for three-dimensional (3D) absolute quantitation of regional cerebral blood flow (rCBF) in mice. METHODS: The pinhole SPECT system consists of a rotating stage and a pinhole collimator attached to a clinical gamma camera. The collimator's focal length is 251 mm. Phantom studies were performed to evaluate sensitivity and full-width half-maximum (FWHM) spatial resolution. The aperture-to-object distance was 15 mm. Six mice were studied. Cerebral infarctions were induced by ligating and disconnecting the distal portion of the left middle cerebral artery. Ex vivo SPECT studies were performed using harvested brains and skulls. The CBF volumetric image was computed using the standardized input function. RESULTS: Excellent spatial resolution of 0.9-mm FWHM and uniform sensitivity throughout the 3D volume were demonstrated in the phantom experiments. The CBF images showed a defect in the infarcted areas and a reduction of CBF values in the infarcted region as compared with the control region. CONCLUSIONS: This study demonstrated the feasibility of the 3D quantitation of rCBF in mice using a high-resolution pinhole SPECT system and (123)I-IMP.

Diffusion magnetic resonance imaging with gadofosveset trisodium as a negative contrast agent for lymph node metastases assessment.

PURPOSE: The aim of this study was to assess the feasibility of using intravenously administered gadofosveset trisodium as a negative contrast agent for lymph node (LN) assessment with diffusion-weighted imaging (DWI) using a VX2 tumor model in rabbits. MATERIALS AND METHODS: VX2 cells were injected in the right hind limb of five Japanese white rabbits to induce ipsilateral popliteal LN metastasis. DWI was performed before and every 7.5 min (until 1 h) after intravenous gadofosveset trisodium administration, at 1.5 T. Signal intensities (SIs) of right (metastatic) and left (nonmetastatic) popliteal LNs at each time point were measured and compared to each other using two-sided unpaired t-tests. RESULTS: The SIs of metastatic lymph nodes were significantly higher (P < 0.05) than those of nonmetastatic LNs at each time point after intravenous gadofosveset trisodium administration. Although the SI of metastatic LNs was significantly higher (P = 0.0237) than that of nonmetastatic LNs before contrast injection, this difference became even more significant (P ≤ 0.0105) after gadofosveset trisodium administration. CONCLUSION: The SI of metastatic LNs at DWI is less suppressed than that of nonmetastatic LNs after the intravenous administration of gadofosveset trisodium. Therefore, intravenously administered gadofosveset trisodium shows promise for use as a negative contrast agent for discriminating metastatic from nonmetastatic LNs at DWI.

C-arm CT-guided foam sclerotherapy for the treatment of gastric varices.

The authors describe here the use of foam sclerotherapy under C-arm computed tomography (CT) guidance for the treatment of gastric varices via balloon-occluded retrograde transvenous obliteration in seven patients and percutaneous transhepatic obliteration in one patient. All gastric varices were occluded successfully after replacement of blood by foam, which was trapped in the gastric varices as shown by C-arm CT. It also helped reduce the amount of sclerosant, an issue that is associated with severe complications, such as hemolysis, allergy, acute respiratory distress syndrome, and others. Foam sclerotherapy under C-arm CT guidance is a promising tool in the therapeutic armamentarium against gastric varices.

Granulocyte colony-stimulating factor has a negative effect on stroke outcome in a murine model.

The administration of CD34-positive cells after stroke has been shown to have a beneficial effect on functional recovery by accelerating angiogenesis and neurogenesis in rodent models. Granulocyte colony-stimulating factor (G-CSF) is known to mobilize CD34-positive cells from bone marrow and has displayed neuroprotective properties after transient ischemic stress. This led us to investigate the effects of G-CSF administration after stroke in mouse. We utilized permanent ligation of the M1 distal portion of the left middle cerebral artery to develop a reproducible focal cerebral ischemia model in CB-17 mice. Animals treated with G-CSF displayed cortical atrophy and impaired behavioral function compared with controls. The negative effect of G-CSF on outcome was associated with G-CSF induction of an exaggerated inflammatory response, based on infiltration of the peri-infarction area with CD11b-positive and F4/80-positive cells. Although clinical trials with G-CSF have been started for the treatment of myocardial and limb ischemia, our results indicate that caution should be exercised in applying these results to cerebral ischemia.

Notes on the application of the Matsui-Kitamura stent-graft for endovascular repair of abdominal aortic aneurysm.

Abdominal aortic and left common iliac aneurysms in a 79-year-old man who had undergone Miles' operation for rectal carcinoma were treated with endovascular repair of an abdominal aortic aneurysm (EVAR), taking into consideration the age, surgical history, and wishes of the patient and his family. The Matsui-Kitamura stent-graft (MK-SG) was designed based on preoperative angiographic mapping. At EVAR, the right leg of the MK-SG was caught at the aortic bifurcation because of unexpected contraction of the MK-SG. To resolve the problem, the body of the MK-SG was dilated with a balloon, slightly lifted while being gradually shortened, and eventually successfully connected to the leg of the MK-SG. Made of nitinol mesh, the MK-SG is stable and flexible enough to make it one of the best stent-grafts for EVAR. A serious drawback, however, is the high contraction rate of the MK-SG itself. It is difficult to estimate the appropriate length of the stent-graft owing to unpredictable contraction. It is important to understand its characteristics and to carefully design and acquire sufficient skills in manipulating MK-SG.

Kurozu moromimatsu inhibits tumor growth of Lovo cells in a mouse model in vivo.

OBJECTIVE: In Japan, rice vinegar that has been matured and fermented for years in earthenware jars is considered a health food with anticolon cancer action. It is divided into the liquid component (Kurozu) and the sediment (Kurozu moromimatsu), which contains large amounts of organic materials and minerals. The effect of Kurozu moromimatsu (Kurozu-M) on cancer has not yet been examined. In this study, we examined the activity of Kurozu-M on colon cancer and investigated the mechanisms involved, focusing on active oxygen generation, apoptosis, and metalloproteinases (MMPs). METHODS: We used Lovo cells transplanted into nude mice as an experimental model. We measured the tumor volume and MMP levels and conducted hematoxylin-eosin staining (for polymorphonuclear leukocytes), terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining (for apoptosis), and immunostaining for nitrotyrosine (a marker of active oxygen generation) in control, Kurozu-treated, and Kurozu-M--treated groups. RESULTS: The tumor volume was the same in the control group (231 +/- 36 mm(3)) and Kurozu group (238 +/- 52 mm(3)), but was significantly reduced in the Kurozu-M group (152 +/- 28 mm(3), P < 0.001 versus control). Apoptosis of tumor cells and accumulation of polymorphonuclear leukocytes were not observed. Nitrotyrosine production, total MMP levels, and MMP activation were significantly reduced in the Kurozu-M group. CONCLUSION: The administration of Kurozu-M prolonged the lifespan of cancer cell-transplanted mice, inhibited tumor progression, and reduced nitrotyrosine production and MMP activation, but did not induce apoptosis.

Efficacy of balloon-occluded retrograde transvenous obliteration (B-RTO) performed in a patient with primary biliary cirrhosis with severe recurrent hepatic encephalopathy due to splenorenal shunt.

CASE: A 73 year old female had been diagnosed as primary biliary cirrhosis and Sjögren's syndrome since the age of 50. With persisting hyperammonemia, the patient was admitted on several occasions for the management of hepatic encephalopathy. Computed tomography (CT) scan and magnetic resonance imaging (MRI) of the abdomen showed varices in the splenic hilar region and a splenorenal shunt. A balloon-occluded retrograde transvenous obliteration (B-RTO) using 5% ethanolamine oleate plus iopamidol (EOI) was performed for treatment of recurrent hepatic encephalopathy. Celiac and superior mesenteric angiograms prior to B-RTO demonstrated a hepatofugal portal circulation through the splenic varices, splenorenal shunt, left renal vein and inferior vena cava. Immediately following the B-RTO, the portal circulation became restored to a hepatopetal blood flow and no visualization of the splenic varices and splenorenal shunt was verified. On day 2 post-B-RTO, blood NH3 level was noted to have decreased from 134 to 61 µg/dL, indicating an improvement of hyperammonemia. The liver parenchymal blood flow using the dynamic CT time-concentration curve showed a decrease in hepatic artery blood flow and a marked increase in portal flow following the B-RTO. The patient has since been free from any signs of hepatic encephalopathy due to hyperammonemia for over 5 years following the B-RTO. CONCLUSIONS: B-RTO may be considered useful for the treatment of severe recurrent hepatic encephalopathy due to the collateral shunt in portal hypertension.

Efficient preparation of cationized gelatin for gene transduction.

We previously reported gene therapy using cationized gelatin microspheres of φ20-32 µm, prepared from pig skin, as a transducing agent, but although the gelatin offered various advantages, its yield was extremely low (only 0.1%). In this study, we markedly improved the yield of φ20-32 µm cationized gelatin microspheres and prepared a newly less than φ20 µm cationized gelatin. Conventionally, cationized gelatin is prepared by cationization, particulation by agitation, and cross-linking. The yield is determined by the particulation step, for which we had used a three-necked distillation flask of 500 mL and an agitation speed of 420 rpm. The yield was significantly increased from 0.13 ± 0.02% to 8.80 ± 1.90% by using a smaller flask of 300 mL and an agitation speed of 25000 rpm (p ＜ 0.01). We could also prepare cationized gelatin of less than φ20 µm, which had not been possible previously. We confirmed that efficient gene introduction into peritoneal macrophages could be achieved with the new cationized gelatin.

[Continuous speech recognition system for radiological reporting: comparison with experience of dictation].

PURPOSE: To compare rates of accuracy of recognition between experienced dictators and inexperienced ones in using an enrollment-less continuous speech recognition (CSR) system of radiological reporting, and to evaluate the usefulness of the system. MATERIALS AND METHODS: Twenty board-certified radiologists were classified into 2 groups: a group of 10 members with more than 6 years' experience of conventional dictation by transcriptionist (group A) and a group of 10 members with no experience of dictation (group B). All radiologists created fresh radiological reports on sets of images using free-style dictation in the reports. We counted errors and total words in the reports individually, and compared the rates of accuracy of word recognition in the two groups. We used a CSR system AmiVoice (Advanced Media, Inc., Tokyo, Japan). RESULTS: The average rate of accuracy of word recognition was 96.42 +/- 1.68% in group A and 95.92 +/- 1.15% in group B. There was no significant difference in accuracy rate between the two groups. CONCLUSION: The accuracy of word recognition was independent of the experience of dictation, and the enrollment-less CSR system of radiological reporting was considered convenient and useful.