Multidetector CT findings differ between surgical grades of pancreatic fistula after pancreaticoduodenectomy.

OBJECTIVES: To define and correlate multidetector CT (MDCT) findings of pancreatic fistula after pancreaticoduodenectomy with surgical grading based on the 2016 Revised International Study Group of Pancreatic Fistula (ISGPF) classification. METHODS: Between May 2011 and December 2016, 235 patients with periampullary tumor underwent pancreaticoduodenectomy and postoperative MDCT. Patients were classified into three groups (clinically no pancreatic fistula (cNo-PF), grade B, and grade C) according to the ISGPF classification. MDCT images were retrospectively evaluated by two radiologists in consensus for the presence of pancreaticojejunostomy (PJ) dehiscence, PJ dehiscence diameter, PJ defect, acute necrotic collection (ANC), peripancreatic fluid collection, and imaging findings of complications. Categorical MDCT findings were compared among the three groups using Pearson's chi-square test, and PJ dehiscence diameter was compared using the Kruskal-Wallis test. RESULTS: There was no significant difference in patient demographics among the groups (cNo-PF = 133, grade B = 68, and grade C = 34), but the MDCT findings were significantly different regarding the presence of PJ dehiscence (p < 0.001), PJ defect (p < 0.001), ANC (p = 0.002), and imaging findings of total complications (p < 0.001). The diameters of PJ dehiscence were significantly different among the groups (cNo-PF [0.42 ± 1.54 mm], grade B [1.47 ± 2.33 mm], and grade C [5.38 ± 6.45 mm]) (p < 0.001). CONCLUSION: With respect to the presence of PF, postoperative MDCT findings may differ between surgical grading based on the ISGPF classification. KEY POINTS: • Regarding the presence of pancreatic fistula, the postoperative multidetector CT findings correlate well with surgical grading based on the International Study Group of Pancreatic Fistula classification. • Multidetector CT may provide reliable information to suggest pancreatic fistula after pancreaticoduodenectomy.

Conventional Chemoembolization Plus Radiofrequency Ablation versus Surgical Resection for Single, Medium-Sized Hepatocellular Carcinoma: Propensity-Score Matching Analysis.

PURPOSE: To retrospectively compare long-term outcomes of conventional chemoembolization plus radiofrequency (RF) ablation vs those of surgical resection in patients with a single 3-5-cm hepatocellular carcinoma (HCC). MATERIALS AND METHODS: From January 2008 to December 2017, 139 of 623 patients who underwent surgical resection and 60 of 186 patients who underwent chemoembolization/RF ablation in a single center were compared with respect to local tumor progression (LTP), intrahepatic distant recurrence (IDR), disease-free survival (DFS), overall survival (OS), major complications, and hospital stay before and after propensity-score matching. RESULTS: Mean follow-up periods were similar in the chemoembolization/RF ablation and surgical resection groups (41.9 mo vs 48.4 mo). Three (5%) and 17 (28.3%) patients in the chemoembolization/RF ablation group and 12 (8.6%) and 57 (41.0%) patients in the surgical resection group showed LTP and IDR (P = .366 and P =.114, respectively). At 1, 3, and 5 years, respective DFS rates were 88.1%, 65.3%, and 49.0% for chemoembolization/RF ablation and 84.2%, 58.2%, and 46.5% for surgical resection (P = .294). Moreover, respective OS rates were 95.0%, 73.5%, and 54.0% for chemoembolization/RF ablation and 97.1%, 87.4%, and 75.0% for surgical resection (P = .055). After matching (n = 52), therapeutic outcomes remained similar (P = .370, P = .110, P = .230, and P = .760, respectively). Surgical resection was associated with higher complication rates (P = .015) and longer hospital stays (8.4 d ± 3.7 vs 16.9 d ± 7.0; P < .001). CONCLUSIONS: Conventional chemoembolization combined with RF ablation may be feasible for single 3-5-cm HCCs, with comparable therapeutic outcomes vs surgical resection and shorter hospital stays.

Combined Therapy with Transarterial Chemoembolization and Radiofrequency Ablation for Hepatocellular Carcinoma: Does the Degree of Ethiodized Oil Accumulation within the Tumor Affect the Therapeutic Efficacy?

PURPOSE: To evaluate the effects of the degree of ethiodized oil accumulation achieved by transarterial chemoembolization followed by radiofrequency (RF) ablation on the treatment efficacy for a single intermediate-sized hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A total of 153 consecutive patients who underwent chemoembolization and RF ablation for a single intermediate-sized HCC (2-5 cm) were included. On the basis of the degree of ethiodized oil accumulation in HCC on cone-beam CT images, patients who underwent chemoembolization and RF ablation were classified into 2 groups: compact accumulation (≥ 75%) and noncompact accumulation (< 75%). The rates of cumulative local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were compared between groups. RESULTS: Of the 153 patients, 89 were classified into the compact ethiodized oil accumulation group and 64 in the noncompact ethiodized oil accumulation group. There were no significant differences in patient demographic or HCC characteristics between groups except for the incidence of liver cirrhosis (P = .038) and the tumor margin morphology (P = .008). The cumulative LTP rate was significantly lower in the compact accumulation group than in the noncompact accumulation group (P = .013). There were no significant differences in the incidences of complications, DFS rates (P = .055), or OS rates (P = .184). CONCLUSIONS: The degree of ethiodized oil accumulation does not play a role in decreasing the OS or DFS rate after chemoembolization and RF ablation for intermediate-sized HCC; however, it may contribute to reducing the rate of LTP.

Intimal flap detected by three-dimensional curved multiplanar reconstruction image in isolated posterior inferior cerebellar artery dissection: a report of two cases.

BACKGROUND: Spontaneous isolated posterior inferior cerebellar artery (PICA) dissection has been reported more frequently since high-resolution vessel wall magnetic resonance imaging (HR vw-MRI) was introduced to the field. The intimal flap or double lumen, which is commonly reported to be a direct sign of the dissection, is not easily detectable on HR vw-MRI because the size of the PICA is very small and tortuous. CASE PRESENTATION: Two patients with posterior circulation ischemic stroke due to spontaneous isolated PICA dissection underwent HR vw-MRI. The curved multiplanar reconstruction image reconstructed using three-dimensional (3D) HR vw-MRI (3D curved MPR imaging) is helpful to observe tortuous blood vessels such as the PICA because it can visualize the entire vessel course in a single plane. In this report, routine HR vw-MRI revealed only an intramural hematoma in both patients. However, 3D curved MPR imaging discovered the intimal flap which was not observed on the routine HR vw-MRI. Therefore, these two patients were diagnosed with spontaneous isolated PICA dissection due to the intimal flap that was observed on the 3D curved MPR image. CONCLUSION: HR vw-MRI is useful for the early diagnosis of isolated PICA dissection. Furthermore, we believe that 3D curved MPR imaging could improve the possibility of diagnosing the dissection early because it can easily confirm direct signs such as an intimal flap or double lumen.

Electrical conductivity-based contrast imaging for characterizing prostatic tissues: in vivo animal feasibility study.

BACKGROUND: Electrical conductivity-based magnetic resonance (MR) imaging may provide unique information on tissue condition because its contrast originates from the concentration and mobility of ions in the cellular space. We imaged the conductivity of normal canine prostate in vivo and evaluated tissue contrast in terms of both the conductivity distribution and anatomical significance. METHODS: Five healthy laboratory beagles were used. After clipping the pelvis hair, we attached electrodes and placed each dog inside the bore of an MRI scanner. During MR scanning, we injected imaging currents into two mutually orthogonal directions between two pairs of electrodes. A multi spin echo pulse sequence was used to obtain the MR magnitude and magnetic flux density images. The projected current density algorithm was used to reconstruct the conductivity image. RESULTS: Conductivity images showed unique contrast depending on the prostatic tissues. From the conductivity distribution, conductivity was highest in the center area and lower in the order of the middle and outer areas of prostatic tissues. The middle and outer areas were, respectively, 11.2 and 25.5% lower than the center area. Considering anatomical significance, conductivity was highest in the central zone and lower in the order of the transitional and peripheral zones in all prostates. The transitional and peripheral zones were, respectively, 7.5 and 17.8% lower than the central zone. CONCLUSIONS: Current conductivity-based MR imaging can differentiate prostatic tissues without using any contrast media or additional MR scans. The electrical conductivity images with unique contrast to tissue condition can provide a prior information on tissues in situ to be used for human imaging.

Metabolic biomarkers for non-alcoholic fatty liver disease induced by high-fat diet: In vivo magnetic resonance spectroscopy of hyperpolarized [1-13C] pyruvate.

Hyperpolarized 13C magnetic resonance spectroscopy (MRS) to assess hepatic metabolism in non-alcoholic fatty liver disease (NAFLD) has not been reported. This study searched for cellular metabolism-based biomarkers for NAFLD induced by a high-fat diet (HFD) in rats. Also, correlations of the biomarkers with enzyme levels and histopathology were identified during a 6-week follow-up. Six rats were fed a control diet (CD) and seven rats were fed the HFD for 6 weeks. Hyperpolarized 13C dynamic MRS was performed on rat liver following an injection of hyperpolarized [1-13C] pyruvate. Compared with CD-fed rats, HFD-fed rats showed significant increases in the levels of serum alanine aminotransferase and low-density lipoprotein cholesterol at weeks 4 and 6 of follow-up. After the 6-week HFD, the ratios of [1-13C] alanine/pyruvate and [1-13C] lactate/pyruvate were significantly increased, as were the levels of alanine aminotransferase and lactate dehydrogenase, which are potentially associated with hepatosteatosis. The results implicate [1-13C] alanine and [1-13C] lactate as potentially useful noninvasive biomarkers of hepatosteatosis occurring in NAFLD.

Prediction of coronary artery calcium progression by FDG uptake of large arteries in asymptomatic individuals.

PURPOSE: The purpose of this study is to evaluate whether fluorodeoxyglucose (FDG) uptake of the large arteries can predict coronary artery calcium (CAC) progression in asymptomatic individuals. METHODS: Ninety-six asymptomatic individuals who underwent FDG positron emission tomography (PET) and CAC scoring on the same day for health screening and follow-up CAC scoring ≥1 year after baseline studies (mean 4.3 years) were included. Vascular FDG uptake was measured and corrected for blood pool activity to obtain peak and average target-to-blood pool ratios (TBRpeak and TBRavg, respectively) for the carotid arteries, and ascending and abdominal aorta. CAC scores at baseline and follow-up of each individual were measured and absolute CAC change (ΔCAC), annual CAC change (ΔCAC/year), and annual CAC change rate (ΔCAC%/year) were calculated. CAC progression was defined as ΔCAC >0 for individuals with negative baseline CAC; ΔCAC/year ≥10 for those with baseline CAC of 0

Combined Therapy of Transcatheter Arterial Chemoembolization and Radiofrequency Ablation versus Surgical Resection for Single 2-3 cm Hepatocellular Carcinoma: A Propensity-Score Matching Analysis.

PURPOSE: To compare therapeutic outcomes of radiofrequency (RF) ablation combined with transcatheter arterial chemoembolization vs surgical resection (SR) for single 2-3 cm hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Seventy patients underwent combined chemoembolization/RF ablation therapy and 84 underwent SR. Local tumor progression (LTP), intrahepatic distant recurrence (IDR), disease-free survival (DFS), and overall survival (OS) rates, as well as major complications and duration of hospital stay, were compared between groups before and after propensity-score matching. RESULTS: LTP and IDR had developed in 9 (12.9%) and 24 (34.3%) patients in the combined treatment group and in 7 (8.3%) and 24 (28.6%) patients in the SR group (P = .262 and P = .252, respectively). The 1-, 3-, 4-, and 5-year DFS rates were similar between groups (82.6%, 53.2%, 53.2%, and 37.6%, respectively, vs 84.5%, 63.6%, 59.2%, and 52.1%, respectively; P = .278), and 1-, 3-, 4-, and 5-year OS rates were also comparable (94.2%, 81.2%, 74.1%, and 59.4%, respectively, vs 95.2%, 86.3%, 84.0%, and 80.3%, respectively; P = .081). After matching (n = 98), LTP, IDR, DFS, and OS rates were still similar (P = .725, P = .826, P = .484, and P = .578, respectively). Major complication rate was not significantly different (2.9% vs. 6.0%; P = .596); however, after matching, major complication rate was higher in SR group (2.0% vs. 6.1%; P < .001). Hospital stays were significantly longer in the SR group (16.6 ± 6.7 d vs 8.5 ± 4.1 d; P < .001). CONCLUSIONS: Before and after matching, there were no significant differences in long-term therapeutic outcomes between combined chemoembolization/RF ablation and SR groups. Therefore, combined chemoembolization/RF ablation therapy may be an alternative treatment for single 2-3 cm HCCs.

Anatomic mapping and clinicopathologic analysis of benign acral melanocytic neoplasms: A comparison between adults and children.

BACKGROUND: The clinicopathologic features of benign acral melanocytic neoplasms (BAMNs) remain poorly understood. OBJECTIVE: To define the clinicopathologic features of BAMNs. METHODS: We analyzed clinical data and mapped BAMNs anatomically. We also reviewed the histopathologic features of BAMNs and compared these between adults and children. RESULTS: We included 396 cases of BAMN: 335 adults and 61 children (376 acquired and 20 congenital lesions). Anatomic mapping revealed that the nonweight-bearing portion of the foot was the most common site in adults (120/335, 35.8%) and the forefoot the most common site in children (17/61, 27.9%) for BAMNs. The long axes of the BAMNs paralleled the dermatoglyphic lines on the palms and soles, as did most tissue sections. The lesion diameters were <5.7 mm in all acquired lesions. Histopathologically, we diagnosed 69 lentigo simplex, 201 junctional, 114 compound, 8 intradermal, and 4 blue nevi. Corneal pigmentation, nests located between rete ridges, dendrite prominence, and cytologic atypia were all significantly more common in children than adults. LIMITATIONS: The retrospective study design and acquiring patients from a single institution of a single country limited the research results. CONCLUSION: BAMNs develop most commonly on nonweight-bearing regions of the soles in adults and on the forefoot in children. The long axis of the lesion follows the dermatoglyphics, and cytologic atypia is more common in children.

Sonographic Findings of Accessory Breast Tissue in Axilla and Related Diseases.

Accessory breast tissue results from failed regression of primitive mammary tissue and is most often located in the axilla. Accessory breast tissue itself is normal and should not be misdiagnosed as an abnormality. Both benign and malignant diseases that occur in the normal breast can also develop in accessory breast tissue in the axilla. In this pictorial essay, we show sonographic findings of normal accessory breast tissue in the axilla and various lesions that occur in accessory axillary breast tissue, along with other imaging findings and pathologic features.

Other primary systemic cancers in patients with melanoma: Analysis of balanced acral and nonacral melanomas.

BACKGROUND: Although other primary systemic cancers in patients with melanoma have been studied, there have been few focusing on acral melanomas. OBJECTIVES: We assessed other primary systemic cancers in patients with acral and nonacral melanomas. METHODS: We analyzed other primary cancers in 452 patients with melanoma from 1994 to 2013. Metachronous cancers were defined as those given a diagnosis more than 2 months after diagnosis of melanoma. The others were considered prechronous or synchronous cancers. RESULTS: Among 51 cases of other primary cancers, gastrointestinal cancer (35.3%, n = 18/51) was the most common, followed by thyroid (17.6%), lung (11.8%), and breast (5.9%). Those were more prevalent in the acral melanoma group (12.8%, n = 31/243) compared with the nonacral melanoma group (9.6%, n = 20/209). Of 23 cases of metachronous cancer, the risk was the highest in bone marrow, followed by oral cavity, bladder, colon, lung, and thyroid. Among 28 cases of prechronous or synchronous cancers, gastrointestinal tract (35.7%, n = 10/28) was the most common site, followed by thyroid (17.9%), breast (10.7%), and lung (7.1%). LIMITATIONS: The study is limited by a small number of patients. CONCLUSION: Careful follow-up and imaging studies are necessary for early detection of other primary cancers and metastatic lesions in patients with melanoma.

Localization of bleeding sites in patients with hemoptysis based on their chest computed tomography findings: a retrospective cohort study.

BACKGROUND: The aim of this study was to propose a localization strategy for bleeding sites in hemoptysis patients using their chest computed tomography (CT) findings. METHODS: Between January 2005 and July 2009, the chest CT findings of 161 hemoptysis patients were retrospectively reviewed. Following chest CT, the lobe with the most prominent ground glass attenuation (GGA) or specific lesions with the potential to cause pulmonary hemorrhage were analysed to develop a localization strategy for bleeding sites. Fibre optic bronchoscopy (FOB) findings of active bleeding were used as the standard reference for the bleeding sites. RESULTS: The concordance rate between the most prominent GGA and FOB findings was higher than that between specific lesions and FOB findings (Kappa value [k] = 0.751 vs. 0.448, p < 0.001). Among the specific lesions, there were high concordance rates between lung cancer and FOB findings (3/3, 100%) and fungus balls and FOB findings (8/9, 89%). The agreement of localization of the bleeding site between FOB findings and the localization strategy based on chest CT findings including the most prominent GGA, lung cancer and fungus balls, showed almost perfect (k = 0.904). CONCLUSIONS: The localization of bleeding sites in hemoptysis patients could be determined by chest CT findings such as the most prominent GGA, malignancy and fungus ball.

Differential Chest Computed Tomography Findings of Pulmonary Parasite Infestation Between the Paragonimiasis and Nonparagonimiatic Parasite Infestation.

OBJECTIVE: The aims of this study were to evaluate the chest computed tomography findings of parasite infestation regardless of pathogen and to compare the differential findings between paragonimiasis and nonparagonimiatic parasite infestation (NPPI). METHODS: Between January 2008 and November 2011, 75 patients (46 men; 52.9 ± 14.1 years) with serologically proven parasite infestation and available chest computed tomography images were evaluated. Computed tomography images of 40 patients with paragonimiasis and 35 patients with NPPI (13 with sparganosis, 12 with toxocariasis, 8 with cysticercosis, and 2 with clonorchiasis) were assessed for the presence or absence of pleural abnormalities, consolidation, cavitary lesions, aggregated cysts, worm-migration tracts, and pure ground-glass opacity. Findings associated with consolidation were further assessed for characteristics including size, perilesional ground-glass opacity, presence of perilesional centrilobular nodules, and internal low attenuation, and multisegmentality and bilaterality were assessed for all patients. RESULTS: In both groups, the most common pleural abnormality was pleural effusion (42.5% in paragonimiasis vs 22.9% in NPPI, P = 0.09), and the most common pulmonary abnormality was consolidation (82.5% vs 80.0%, P = 1.00). Multisegmentality (35% vs 42.9%, P = 0.64) and bilaterality (55.0% vs 60%, P = 0.82) of pleuropulmonary lesions were often observed in both groups. Internal low attenuation, perilesional centrilobular nodules, cavitary lesions, and worm-migration tracts were more frequently found in the paragonimiasis group (P ≤ 0.05). CONCLUSIONS: The presence of internal low attenuation and perilesional centrilobular nodules associated with pulmonary consolidative lesions, along with cavitary lesions and worm-migration tracts, is more frequent in patients with paragonimiasis than in patients with NPPI.

Percutaneous Retrieval of Embolized Amplatzer Septal Occluder after Treatment of Double Atrial Septal Defect: A Case Report.

Embolization of the occlusion device after percutaneous closure of atrial septal defect (ASD) is a potential disastrous complication. The usual site of embolization is the right side of the heart including pulmonary artery, but the device embolization to the extracardiac aorta is extremely rare. Here, we report a successful percutaneous retrieval case of the embolized Amplatzer Septal Occluder (ASO) to the descending thoracic aorta after the successful deployment of two ASO devices in a patient with double ASD. Competition between the two devices to obtain a stable position may be an explanation for the migration of ASO.

Cardioprotective effects of exenatide in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention: results of exenatide myocardial protection in revascularization study.

OBJECTIVE: Experimental evidence suggests that exenatide, a glucagon-like peptide 1 receptor analogue, has significant cardiovascular protective effects in various conditions. We examined whether routine use of exenatide at the time of primary percutaneous coronary intervention would reduce infarct size in patients with ST-segment-elevation myocardial infarction. APPROACH AND RESULTS: Fifty-eight patients with ST-segment-elevation myocardial infarction and thrombolysis in myocardial infarction flow 0 were enrolled in the study and randomly assigned to receive either exenatide or placebo (saline) subcutaneously. Infarct size was assessed by measuring the release of creatine kinase-MB and troponin I during 72 hours and by performing cardiac magnetic resonance imaging at 1 month after infarction. Routine and speckle tracking echocardiography was performed at initial presentation and at 3 days and 6 months after primary percutaneous coronary intervention. The exenatide and control groups had similar results with respect to ischemia time, demographic characteristics, and ejection fraction before primary percutaneous coronary intervention. The releases of creatine kinase-MB and troponin I were significantly reduced in the exenatide group. In 58 patients evaluated with cardiac magnetic resonance, the absolute mass of delayed hyperenhancement was significantly reduced in the exenatide group as compared with the control group (12.8±11.7 versus 26.4±11.6 g; P<0.01). At 6 months, the exenatide group showed a significantly lower value of E/E' with improved strain parameters. No significant adverse effects of exenatide administration were detected. CONCLUSIONS: In patients with ST-segment-elevation myocardial infarction, adjunctive exenatide therapy with primary percutaneous coronary intervention was associated with reduction of infarct size and improvement of subclinical left ventricular function.

New strategy for detection of subclinical coronary atherosclerosis in asymptomatic patients with type 2 diabetes based on cardiac multi-detector computed tomography and treadmill test.

BACKGROUND: The current screening strategy for subclinical coronary atherosclerosis in asymptomatic diabetic patients is not sufficient in real clinical practice. A new strategy was investigated that uses cardiac multi-detector computed tomography (MDCT) and a treadmill test (TMT). METHODS AND RESULTS: A total of 445 self-referred asymptomatic diabetic patients underwent cardiac MDCT. The treatment plan was determined according to the new strategy that uses MDCT and TMT. All patients underwent clinical follow-up and cardiac events were investigated. The incidence of subclinical atherosclerosis was 49.4%. The group without plaque underwent clinical follow-up without treatment and did not experience any cardiac events in 675.1 person-years of follow-up. Among patients with subclinical atherosclerosis without significant stenosis (n=136) who received medical treatment only, 11 patients experienced cardiac events over 326.4 person-years. The patients with significant stenosis (n=84) underwent TMT. Patients with positive TMT (n=14) underwent coronary angiograms and revascularization therapy was performed in all of them over 39.2 person-years. Patients with negative TMT (n=70) underwent medical treatment, and 27 of them experienced cardiac events. The incidence of cardiac death was 0% during 3 years of follow-up. CONCLUSIONS: The new strategy for detecting subclinical atherosclerosis on MDCT combined with TMT may be a useful method for minimizing the mortality rate from cardiovascular disease in asymptomatic diabetic patients.

Imaging of actinomycosis in various organs: a comprehensive review.

Actinomycosis is a chronic suppurative bacterial infection caused by Actinomyces species. Actinomyces israelii is the organism most commonly found in human disease. Actinomycosis usually manifests with abscess formation, dense fibrosis, and draining sinuses. The disease is further characterized by the tendency to extensively spread beyond normal fascial and connective tissue planes. Actinomycosis occurs most commonly in the cervicofacial region (50%-65%), followed by the thoracic (15%-30%) and abdominopelvic (20%) regions, but rarely involves the central nervous system. Most cases of cervicofacial actinomycosis are odontogenic in origin. In the acute form, cervicofacial disease can manifest with soft-tissue swelling, a painful pyogenic abscess, or a mass lesion. In the subacute to chronic form, a painless indurated mass can spread to the skin, leading to draining sinus tracts. Thoracic manifestations include parenchymal, bronchiectatic, and endobronchial actinomycosis. At computed tomography, pulmonary actinomycosis usually appears as chronic segmental airspace consolidation containing necrotic low-attenuation areas with peripheral enhancement. Abdominopelvic actinomycosis preferentially involves the ileocecal region, ovary, and fallopian tube. The imaging findings favoring abdominopelvic actinomycosis include strong enhancement in the solid portion of the mass after contrast material administration, small rim-enhancing abscesses within the mass, and extensive inflammatory extensions. Actinomycosis in the central nervous system may produce brain abscess, meningitis, subdural empyema, actinomycetoma, and spinal and cranial epidural abscess. In general, actinomycosis responds well to antibiotic therapy, but long-term follow-up after treatment is needed because of frequent relapses.

Precise characterization of a solitary pulmonary nodule using tumor shadow disappearance rate-corrected F-18 FDG PET and enhanced CT.

ABSTRACT: We aimed to characterize solitary pulmonary nodule (SPN) using imaging parameters for F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) or enhanced CT corrected by tumor shadow disappearance rate (TDR) to reflect the tissue density.We enrolled 51 patients with an SPN who underwent PET/CT and chest CT with enhancement. The FDG uptake of SPN was evaluated using maximum standardized uptake value (SUVmax) on PET/CT. The mean Hounsfield unit (HU) for each SPN was evaluated over the region of interest on nonenhanced and enhanced CT images. The change in mean HU (HUpeak-pre) was quantified by subtracting the mean HU of the preenhanced CT from that of the post-enhanced CT. TDR was defined as the ratio of the tumor area, which disappears at a mediastinal window, to the tumor area of the lung window. We investigated which parameters (SUVmax or HUpeak-pre) could contribute to the characterization of SPN classified by TDR value and whether diagnostic performance could be improved using TDR-corrected imaging parameters.For SPN with higher tissue density (TDR <42%, n = 22), high value of SUVmax (≥3.1) was a significant factor to predict malignancy (P = .006). High value of HUpeak-pre (≥38) was a significant factor to characterize SPN (P = .002) with lower tissue density (TDR ≥42%, n = 29). The combined approach using TDR-corrected parameters had better predictive performance to characterize SPN than SUVmax only (P = .031).Applying imaging parameters such as SUVmax or HUpeak-pre in consideration of tissue density calculated with TDR could contribute to accurate characterization of SPN.

Usefulness of computed tomographic pulmonary angiography in the risk stratification of acute pulmonary thromboembolism. Comparison with cardiac biomarkers.

BACKGROUND: To evaluate the usefulness of computed tomographic pulmonary angiographic (CTPA) variables in the risk stratification of acute pulmonary thromboembolism (APE) and compare these variables with cardiac biomarkers. METHODS AND RESULTS: Eighty consecutive patients with APE were divided into patients with right ventricular (RV) dysfunction (n=49, 62.1±15.1 years, 31 females) vs. patients without RV dysfunction (n=31, 67.7±13.7 years, 18 females). CTPA variables were analyzed and compared with cardiac biomarkers. The ratio of right to left ventricular dimension (RVD/LVD), CT index of PA clot load, contrast reflux to the inferior vena cava (IVC), and ventricular septal bowing (VSB) were significantly different CTPA variables between the groups. These variables were also significantly associated with cardiac biomarkers. By receiver operation characteristic curve analysis, the area under the curve to predict RV dysfunction was 0.863 for RVD/LVD, 0.841 for PA clot load, 0.744 for contrast reflux to IVC, and 0.635 for VSB. The optimal cut-off value to predict RV dysfunction was 1.12 for RVD/LVD (sensitivity: 89.8%, specificity: 77.4%) and 19.5 for PA clot load (sensitivity: 81.6%, specificity: 77.4%). CONCLUSIONS: RVD/LVD, PA clot load, contrast reflux to IVC, and VSB on CTPA were significantly associated with RV dysfunction and cardiac biomarkers in APE. The present study demonstrated that CTPA is useful not only in the diagnosis, but also in the risk stratification of APE.