A case of chylous ascites caused by reflux from the cisterna chyli to the disrupted common iliac lymphatic vessel: fluoroscopic records during intranodal lymphangiography.

A 40-year-old woman underwent laparoscopic common iliac lymphadenectomy for metastasis from rectal cancer. Two weeks after the surgery, she was found to have massive chylous ascites. After failure of conservative treatment, bilateral inguinal intranodal lymphangiography was performed. No definite extravasation was observed while lipiodol injected through the left inguinal node was ascending. When we punctured the right inguinal lymph nodes and started the injection of lipiodol, extravasation of diluted lipiodol was noted at the level of the first sacrum. Careful observation revealed that the ascending lipiodol became diluted in the cisterna chyli, refluxed through the median paraaortic route, leaked from the excised left common iliac lymph vessel, and flowed into the abdominal cavity. Lipiodol used in lymphangiography did not reduce chylous ascites at all. Twenty-seven days after lymphangiography, laparoscopic lymphatic ligation was performed, and the chylous ascites disappeared completely. CT obtained 40 days after surgical repair revealed disappearance of ascites and enlargement of the thoracic duct, which had not been observed on preoperative lymphangiography. Notably, lymphatic reflux from the cisterna chili can occur without obstruction of the thoracic duct and may result in chylous ascites.

Cancer Detection Rate and Abnormal Interpretation Rate of Prostate MRI Performed for Clinical Suspicion of Prostate Cancer.

PURPOSE: To report cancer detection rate (CDR) and abnormal interpretation rate (AIR) in prostate MRI performed for clinical suspicion of prostate cancer (PCa). MATERIALS AND METHODS: This retrospective single-institution, three-center study included patients who underwent MRI for clinical suspicion of PCa between 2017 and 2021. Patients with known PCa were excluded. Patient-level Prostate Imaging-Reporting and Data System (PI-RADS) score was extracted from the radiology report. AIR was defined as number of abnormal MRI (PI-RADS score 3-5) / total number of MRIs. CDR was defined as number of clinically significant PCa (csPCa: Gleason score ≥7) detected at abnormal MRI / total number of MRI. AIR, CDR, and CDR adjusted for pathology confirmation rate were calculated for each of three centers and pre-MRI biopsy status (biopsy-naive and previous negative biopsy). RESULTS: A total of 9,686 examinations (8,643 unique patients) were included. AIR, CDR, and CDR adjusted for pathology confirmation rate were 45.4%, 23.8%, and 27.6% for center I; 47.2%, 20.0%, and 22.8% for center II; and 42.3%, 27.2%, and 30.1% for center III, respectively. Pathology confirmation rate ranged from 81.6% to 88.0% across three centers. AIR and CDR for biopsy-naive patients were 45.5% to 52.6% and 24.2% to 33.5% across three centers, respectively, and those for previous negative biopsy were 27.2% to 39.8% and 11.7% to 14.2% across three centers, respectively. CONCLUSION: We reported CDR and AIR in prostate MRI for clinical suspicion of PCa. CDR needs to be adjusted for pathology confirmation rate and pre-MRI biopsy status for interfacility comparison.

Cancer Detection Rate and Abnormal Interpretation Rate of Prostate MRI in Patients With Low-Grade Cancer.

PURPOSE: The aim of this study was to evaluate the utility of cancer detection rate (CDR) and abnormal interpretation rate (AIR) in prostate MRI for patients with low-grade prostate cancer (PCa). METHODS: This three-center retrospective study included patients who underwent prostate MRI from 2017 to 2021 with known low-grade PCa (Gleason score 6) without prior treatment. Patient-level highest Prostate Imaging Reporting & Data System (PI-RADS®) score and pathologic diagnosis within 1 year after MRI were used to evaluate the diagnostic performance of prostate MRI in detecting clinically significant PCa (csPCa; Gleason score ≥ 7). The metrics AIR, CDR, and CDR adjusted for pathologic confirmation rate were calculated. Radiologist-level AIR-CDR plots were shown. Simulation AIR-CDR lines were created to assess the effects of different diagnostic performances of prostate MRI and the prevalence of csPCa. RESULTS: A total of 3,207 examinations were interpreted by 33 radiologists. Overall AIR, CDR, and CDR adjusted for pathologic confirmation rate at PI-RADS 3 to 5 (PI-RADS 4 and 5) were 51.7% (36.5%), 22.1% (18.8%), and 30.7% (24.6%), respectively. Radiologist-level AIR and CDR at PI-RADS 3 to 5 (PI-RADS 4 and 5) were in the 36.8% to 75.6% (21.9%-57.5%) range and the 16.3%-28.7% (10.9%-26.5%) range, respectively. In the simulation, changing parameters of diagnostic performance or csPCa prevalence shifted the AIR-CDR line. CONCLUSIONS: The authors propose CDR and AIR as performance metrics in prostate MRI and report reference performance values in patients with known low-grade PCa. There was variability in radiologist-level AIR and CDR. Combined use of AIR and CDR could provide meaningful feedback for radiologists to improve their performance by showing relative performance to other radiologists.

Muscle and fat composition in patients with newly diagnosed multiple myeloma.

Measures of muscle and adipose tissue mass have been associated with outcomes in several malignancies, but studies in multiple myeloma (MM) are inconsistent. The aim of this study was to evaluate the association between muscle and fat areas and radiodensity, and overall survival (OS) in patients with newly diagnosed MM. We included 341 patients diagnosed with MM from 2010-2019 who had an 18F-fluorodeoxyglucose positron emission tomography/computed tomography at diagnosis. A cross-sectional image at the third lumbar vertebrae was segmented into muscle and fat components. Median follow up was 5.7 years. There was no association between sarcopenia and baseline disease characteristics or OS. Low muscle radiodensity was associated with higher disease stage, anemia, and renal failure. OS was 5.6 vs. 9.0 years in patients with muscle radiodensity in the lower vs. middle/upper tertiles, respectively (P = 0.02). High subcutaneous adipose tissue (SAT) radiodensity was associated with higher stage, anemia, thrombocytopenia, hypercalcemia, renal failure, and high LDH. OS was 5.4 years vs. not reached in patients with SAT radiodensity in the upper vs. middle/lower tertiles, respectively (P = 0.001). In conclusion, sarcopenia was not associated with OS in MM patients. High SAT radiodensity and low muscle radiodensity were associated with advanced disease stage and adverse laboratory characteristics.

Long-Term Outcomes and Risk of Pancreatic Cancer in Intraductal Papillary Mucinous Neoplasms.

Importance: Intraductal papillary mucinous neoplasms (IPMNs) are pancreatic cysts that can give rise to pancreatic cancer (PC). Limited population data exist on their prevalence, natural history, or risk of malignant transformation (IPMN-PC). Objective: To fill knowledge gaps in epidemiology of IPMNs and associated PC risk by estimating population prevalence of IPMNs, associated PC risk, and proportion of IPMN-PC. Design, Setting, and Participants: : This retrospective cohort study was conducted in Olmsted County, Minnesota. Using the Rochester Epidemiology Project (REP), patients aged 50 years and older with abdominal computed tomography (CT) scans between 2000 and 2015 were randomly selected (CT cohort). All patients from the REP with PC between 2000 and 2019 were also selected (PC cohort). Data were analyzed from November 2021 through August 2023. Main outcomes and Measures: CIs for PC incidence estimates were calculated using exact methods with the Poisson distribution. Cox models were used to estimate age, sex, and stage-adjusted hazard ratios for time-to-event end points. Results: The CT cohort included 2114 patients (1140 females [53.9%]; mean [SD] age, 68.6 [12.1] years). IPMNs were identified in 231 patients (10.9%; 95% CI, 9.7%-12.3%), most of which were branch duct (210 branch-duct [90.9%], 16 main-duct [6.9%], and 5 mixed [2.2%] IPMNs). There were 5 Fukuoka high-risk (F-HR) IPMNs (2.2%), 39 worrisome (F-W) IPMNs (16.9%), and 187 negative (F-N) IPMNs (81.0%). After a median (IQR) follow-up of 12.0 (8.1-15.3) years, 4 patients developed PC (2 patients in F-HR and 2 patients in F-N groups). The PC incidence rate per 100 person years for F-HR IPMNs was 34.06 incidents (95% CI, 4.12-123.02 incidents) and not significantly different for patients with F-N IPMNs compared with patients without IPMNs (0.16 patients; 95% CI, 0.02-0.57 patients vs 0.11 patients; 95% CI, 0.06-0.17 patients; P = .62). The PC cohort included 320 patients (155 females [48.4%]; mean [SD] age, 72.0 [12.3] years), and 9.8% (95% CI, 7.0%-13.7%) had IPMN-PC. Compared with 284 patients with non-IPMN PC, 31 patients with IPMN-PC were older (mean [SD] age, 76.9 [9.2] vs 71.3 [12.5] years; P = .02) and more likely to undergo surgical resection (14 patients [45.2%] vs 60 patients [21.1%]; P = .003) and more-frequently had nonmetastatic PC at diagnosis (20 patients [64.5%] vs 130 patients [46.8%]; P = .047). Patients with IPMN-PC had better survival (adjusted hazard ratio, 0.62; 95% CI, 0.40-0.94; P = .03) than patients with non-IPMN PC. Conclusions and Relevance: In this study, CTs identified IPMNs in approximately 10% of patients aged 50 years or older. PC risk in patients with F-N IPMNs was low and not different compared with patients without IPMNs; approximately 10% of patients with PC had IPMN-PC, and they had better survival compared with patients with non-IPMN PC.

The hemodynamics of adrenal veins with four-dimensional computed tomography using quantitative time-density curve: a study based on aldosteronism patients.

Present study quantitatively analyzed adrenal venous flow using four-dimensional computed tomography (4D CT). We reviewed 4D CT images of 55 patients [mean age, 52 years ± 11 (standard deviation); 23 females] who underwent adrenal venous sampling between August 2017 and February 2021. Time-density curves were referred for the adrenal venous enhancement. The clinical factors affecting hemodynamics were assessed using uni- and multivariate linear regression analyses. The right and left adrenal veins (RAV and LAV, respectively) were visualized in all cases. Mean peak enhancement values in RAV and LAV were 247 ± 67 and 292 ± 70 Hounsfield units (P < 0.01), and were reached at 44.43 ± 6.86 and 45.39 ± 7.53 s (P < 0.01), respectively. The body mass index (BMI), plasma renin activity and potassium were significant factors influencing the peak enhancement of RAV blood flow [standardized regression coefficients, - 0.327 (P = 0.017), - 0.346 (P = 0.013), 0.426 (P = 0.016), respectively]. A linear relationship between sex and the time-to-peak was observed for RAV [standardized regression coefficient, 0.348 (P = 0.046)]. RAV had a lower contrast effect than LAV and reached its peak faster. BMI, plasma renin activity, and potassium were associated with flow density in RAV. Sex independently influenced the time-to-peak.

Artificial intelligence assisted whole organ pancreatic fat estimation on magnetic resonance imaging and correlation with pancreas attenuation on computed tomography.

BACKGROUND: Fatty pancreas is associated with inflammatory and neoplastic pancreatic diseases. Magnetic resonance imaging (MRI) is the diagnostic modality of choice for measuring pancreatic fat. Measurements typically use regions of interest limited by sampling and variability. We have previously described an artificial intelligence (AI)-aided approach for whole pancreas fat estimation on computed tomography (CT). In this study, we aimed to assess the correlation between whole pancreas MRI proton-density fat fraction (MR-PDFF) and CT attenuation. METHODS: We identified patients without pancreatic disease who underwent both MRI and CT between January 1, 2015 and June 1, 2020. 158 paired MRI and CT scans were available for pancreas segmentation using an iteratively trained convolutional neural network (CNN) with manual correction. Boxplots were generated to visualize slice-by-slice variability in 2D-axial slice MR-PDFF. Correlation between whole pancreas MR-PDFF and age, BMI, hepatic fat and pancreas CT-Hounsfield Unit (CT-HU) was assessed. RESULTS: Mean pancreatic MR-PDFF showed a strong inverse correlation (Spearman -0.755) with mean CT-HU. MR-PDFF was higher in males (25.22 vs 20.87; p = 0.0015) and in subjects with diabetes mellitus (25.95 vs 22.17; p = 0.0324), and was positively correlated with age and BMI. The pancreatic 2D-axial slice-to-slice MR-PDFF variability increased with increasing mean whole pancreas MR-PDFF (Spearman 0.51; p < 0.0001). CONCLUSION: Our study demonstrates a strong inverse correlation between whole pancreas MR-PDFF and CT-HU, indicating that both imaging modalities can be used to assess pancreatic fat. 2D-axial pancreas MR-PDFF is variable across slices, underscoring the need for AI-aided whole-organ measurements for objective and reproducible estimation of pancreatic fat.

Benefits of adrenal venous sampling with preoperative four-dimensional CT imaging.

BACKGROUND: The effects of adrenal venous sampling (AVS) may be limited by the anatomical variants of adrenal veins. PURPOSE: To investigate the benefits of AVS for patients who underwent four-dimensional computed tomography (4D CT) before AVS. MATERIAL AND METHODS: We reviewed the images of contrast-enhanced four phase three-dimensional (3D) and 4D CT in patients who received AVS between February 2010 and February 2021. A total of 112 patients (59 women; mean age = 55.3 ± 11.8 years) were enrolled. Of the entire population, 49.1% (55/112) underwent 4D CT, whereas 50.9% (57/112) underwent 3D CT. The anatomical features of adrenal veins and procedural data were obtained. Simple linear regression analyses were performed to determine the relationship between imaging protocols and AVS. RESULTS: On comparison of the two groups, the 4D cohort had a higher success rate (98.2% vs. 78.9%; P = 0.001), shorter procedure and fluoroscopy time (73.6 ± 37.3 min vs. 110.5 ± 47.9 min; P < 0.001 and 28.7 ± 31.2 min vs. 97.4 ± 251.7 min; P = 0.047, respectively), lower radiation exposure (243.5 ± 315.5 mGycm2 vs. 613.4 ± 674.6 mGycm2; P < 0.001) and less contrast volume (46.2 ± 42.7 ml vs. 68.3 ± 47.4 ml vs; P = 0.014). In simple linear regression analysis, positive and negative identification of right adrenal vein before AVS significantly influenced the success rate (unstandardized coefficients [UC] = 0.304, standardized coefficients [SC] = 0.304; P = 0.001) and operation duration (UC = -46.124, SC = -0.318; P = 0.001). CONCLUSION: Pre-procedural 4D CT may facilitate successful AVS. Compared with four-phase 3D CT, this protocol is better to shorten the operation and fluoroscopy time, and to reduce the radiation dose and contrast consumption.

CT findings of type A acute aortic dissection that did and did not result in prehospital death.

ABSTRACT: The differences between the pathologies of cases of type A acute aortic dissection (AAD) that did and did not result in prehospital death (PHD) have not been fully elucidated.This study aimed to compare the CT findings and clarify the differences between the pathologies of such cases.Ninety four consecutive type A AAD patients between 2010 and 2020 were enrolled in this study. There were 47 males and 47 females (mean age: 69.0 ±â€Š14.4 years). The patients were divided into those that did (n = 25, 27%) and did not (n = 69, 73%) suffer PHD. We retrospectively evaluated the CT or postmortem CT findings of each case and analyzed the relationships between clinical factors (CT findings and clinical characteristics) and PHD using logistic regression analysis.Bloody pericardial effusion (96% vs 35%, P < .0001), bloody pleural effusion (40% vs 1%, P < .0001), and mediastinal hematomas (88% vs 14%, P < .0001) were significantly more common in the PHD group than in the no PHD group.In the multivariate logistic regression analysis, bloody pericardial effusion and lung consolidation were found to be significant risk factors for PHD (odds ratio: 21.29 [95% confidence intervals {CI}: 1.19-248.29] and 13.72 [95% CI: 1.79-105.06], respectively; P = .014 and P  = .012, respectively). AD affecting the abdominal aorta was identified as a significant negative risk factor for PHD (odds ratio: 0.02 [95% CI: 0.01-0.65]; P = .0042).Most PHD due to type A AAD are associated with hemorrhaging. Bleeding into the pericardium and type A AAD confined to the thoracic aorta are significant risk factors for PHD. Secondary respiratory failure might contribute to PHD in such cases.

Endovascular Repair of Diffuse Pulmonary Arteriovenous Malformations with Systemic Arterial Shunts.

Diffuse pulmonary arteriovenous malformations (PAVMs) are defined as arteriovenous malformations (AVMs) involving subsegmental, segmental, or both types of arteries in at least 1 lung lobe and are more extensive than multiple PAVMs. Diffuse PAVMs involving systemic arterial shunts are very rare. We describe a rare case, in which diffuse PAVMs involving systemic arterial shunts were successfully treated with coil embolization.

The Successful Treatment of an Ilio-Iliac Fistula and Aneurysms Affecting the Abdominal Aortic and Iliac Arteries via Endovascular Stent Graft Repair.

Spontaneous ilio-iliac arteriovenous fistula (AVF) associated with aneurysms affecting the abdominal aortic and iliac arteries is a rare condition. The classical clinical symptoms of ilio-iliac AVF include high-output heart failure, abdominal pain, abdominal bruits and thrills, a pulsatile abdominal mass, and venous congestion symptoms (leg edema and hematuria). The prompt repair of AVF is necessary to restore the patient's hemodynamics. We report a case in which a patient with aneurysms affecting the abdominal aortic and iliac arteries and an ilio-iliac AVF presented with high-output heart failure and leg ischemia and was successfully treated via endovascular stent graft repair.

Successful application of the snare technique for the deployment of the proximal portion of a Zenith Alpha Thoracic Endovascular Graft: a case report.

BACKGROUND: Open surgery can be required or even fatal if incomplete deployment of stent graft (SG) occurs. We herein report the first case in which a snare was successfully used to perform endovascular therapeutic troubleshooting on the proximal portion of a Zenith Alpha thoracic endovascular graft proximal component that showed incomplete deployment. CASE PRESENTATION: The patient was an 80-year-old woman. She underwent thoracic endovascular aortic repair (TEVAR) for subacute phase Stanford type B ulcer-like projection aortic dissection. Although the ulcer-like projection disappeared, a follow-up computed tomography angiogram (CTA) obtained approximately 1 year postoperatively showed type Ia and Ib endoleaks. Since there is a high risk of rupture as the aneurysm diameter increases, we determined that an additional SG was indicated. An attempt was made to place the SG in Zone 3, but as the lesser curvature side of the proximal portion stopped in a position that was perpendicular to the vascular wall (downward facing), the SG proximal portion did not completely expand. A guiding sheath was inserted into the aortic arch via the left brachial artery, and, using a snare that we inserted via the femoral artery, we grasped the guiding sheath. A catheter and guidewire (GW) were inserted via the guiding sheath and then rotated under the lesser curvature of the SG proximal portion; the GW was then passed through the loop of the snare. This allowed us to insert the hard loop structure under the SG proximal portion, which in turn allowed successful repair of the incomplete deployment of the SG. Type Ia and Ib endoleaks remained but were less than those before additional TEVAR. One week later, she was discharged. One year later, CT showed no interval change in the size of aortic aneurysm with dissection, and she has been followed on an outpatient basis. CONCLUSIONS: When the endovascular diameter of the proximal aortic arch is large, incomplete deployment of the proximal portion of a Zenith Alpha thoracic endovascular graft can occur, but bailout is possible through the use of the snare technique as endovascular therapy.

Clinical importance of minimal enhancement of type B intramural hematoma of the aorta on computed tomography imaging.

OBJECTIVE: To investigate the instability, morphology, natural course, and prognostic value of enhancement of the thrombosed false lumen on contrast-enhanced computed tomography (CT) scans in patients with type B intramural hematoma of the aorta (IMH). METHODS: A total of 65 patients (42 men; mean age, 75 years) with type B IMH were evaluated retrospectively. On initial CT scans, attenuation of the false lumen (AFL) was determined before enhancement and in the early and delayed phases of contrast enhancement. Then enhancement of the false lumen (EFL) was calculated (AFL in the delayed image - AFL in the precontrast image). The Cox proportional hazards model was employed to estimate the risk of IMH-related events, including death or surgical repair. RESULTS: The mean AFL for precontrast CT, arterial phase enhanced CT, and delayed phase enhanced CT was 56.3 ± 10.5, 59.9 ± 10.8, and 63.7 ± 11.1 Hounsfield units, respectively, whereas the mean EFL was 7.4 ± 9.0 Hounsfield units. EFL was the only independent predictor of IMH-related events (n = 23; hazard ratio, 1.008; 95% confidence interval, 1.03-1.15; P = .0044) and IMH-related death/surgical repair (n = 10; hazard ratio, 1.111; 95% confidence interval, 1.017-1.213; P = .0197). CONCLUSIONS: In patients with IMH, EFL is the most powerful predictor of IMH-related events, as well as IMH-related death or surgical repair.

Imaging-Based Predictors of Persistent Type II Endoleak After Endovascular Abdominal Aortic Aneurysm Repair.

OBJECTIVE: The purpose of this study is to determine the imaging-based parameters associated with the occurrence of persistent type II endoleaks after endovascular abdominal aortic aneurysm repair. MATERIALS AND METHODS: We reviewed the imaging and clinical data for 47 patients with early-onset type II endoleak after endovascular repair. Various predictors of persistent type II endoleaks were analyzed on the basis of preoperative CT findings. In addition, the appearance time of endoleak cavity on the operative angiogram and the relative attenuation of the endoleak cavity in the arterial phase image from the first postoperative CT study were analyzed. RESULTS: The early-onset type II endoleak resolved spontaneously in 22 patients (i.e., the transient group), whereas it was identified on CT studies of the remaining 25 patients 6 months after endovascular repair (i.e., the persistent group). The appearance time of the endoleak cavity on angiographic examination was significantly shorter in the persistent group than in the transient group (mean [± SD] appearance time, 4.7 ± 0.3 s vs 8.8 ± 0.3 s). The relative attenuation of the endoleak cavity on the first postoperative CT scan was also significantly higher in the persistent group than in the transient group (mean, 0.70 ± 0.03 vs 0.30 ± 0.04). For each parameter, ROC analysis revealed the following cutoff points for predicting persistent type II endoleak: 6 seconds for the appearance time of the endoleak cavity (sensitivity, 88%; specificity, 86%), and 0.5 for the relative attenuation of the endoleak cavity (sensitivity, 80%; specificity, 95%). Evaluation of other imaging-based parameters revealed no statistically significant differences between the groups. CONCLUSION: The appearance time of the endoleak cavity on the final operative angiogram and the attenuation of the endoleak cavity on the first postoperative CT scan can be strong imaging-based predictors of persistent type II endoleak.

Carbon dioxide digital subtraction angiography as an option for detection of endoleaks in endovascular abdominal aortic aneurysm repair procedure.

OBJECTIVE: The purpose of this study was to evaluate carbon dioxide digital subtraction angiography (CO2-DSA) as an option for the detection of endoleaks (ELs) in the endovascular abdominal aortic aneurysm repair (EVAR) procedure. METHODS: Forty patients with abdominal aortic aneurysm who were scheduled to undergo EVAR were enrolled in the study. There were 35 men and five women (mean age, 77.9 years). All patients had both iodinated contrast conventional DSA (C-DSA) and CO2-DSA immediately after EVAR. The sensitivity and specificity were calculated for the ability of CO2-DSA to detect ELs. We also correlated with computed tomography findings 6 months after EVAR. RESULTS: C-DSA showed that 27 of the 40 patients (68%) had 28 ELs (type I, four; type II, 20; type III, three; type IV, one). CO2-DSA showed that 16 of the 40 patients (40%) had 17 ELs (type I, four; type II, 10; type III, three; type IV, none). For the prediction of direct ELs (type I and type III) with use of C-DSA as the criterion standard, CO2-DSA has a sensitivity of 1.0 and a specificity of 1.0. For the detection of persistent type II ELs (n = 11) with use of computed tomography findings 6 months from EVAR as the criterion standard, CO2-DSA has a sensitivity of 0.87 and a specificity of 0.97. C-DSA has a sensitivity of 0.82 and a specificity of 0.64. CONCLUSIONS: CO2-DSA is reliable for the detection of direct ELs and persistent type II ELs in EVAR. CO2-DSA can be an option to detect ELs in the EVAR procedure.

Endovascular repair of aortic dissection and intramural hematoma: indications and serial changes.

Thoracic aortic dissection (AD) is one of the most common aortic emergencies. It can be fatal if not promptly diagnosed and treated. Intramural hematoma (IMH) of the aorta is recognized as distinct from classic (double-barreled) AD. IMH also frequently leads to aortic emergency, which can be fatal unless rapidly diagnosed and treated. Recently, thoracic endovascular aortic repair (TEVAR) has been used for the treatment of complications caused by AD. TEVAR is also a viable option for the treatment of complicated IHM. In this article, we review the details of TEVAR as treatment options for AD and IMH, including the indications for TEVAR, imaging, and follow-up.

Quantification of lung perfusion blood volume with dual-energy CT: assessment of the severity of acute pulmonary thromboembolism.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of quantification of lung perfused blood volume (PBV) with dual-energy CT (DECT) for assessment of the severity of acute pulmonary thromboembolism (PTE). MATERIALS AND METHODS: We retrospectively analyzed the records of 72 patients with PTE and 168 without PTE who underwent DECT. The PTE patients were divided into high-, intermediate-, and low-risk groups based on clinical symptoms and right ventricular dysfunction. Correlations between quantification of whole-lung PBV and clinical severity were evaluated. Also evaluated was the relation between quantification of whole-lung PBV and right-to-left ventricular diameter ratio on CT images, which was used as an indicator of right ventricular dysfunction. RESULTS: In the PTE and control groups, the whole-lung PBVs were 27.6 ± 7.9 and 29.9 ± 6.8 HU with a significant difference between them (p < 0.0281). In the high-, intermediate-, and low-risk PTE groups, the whole-lung PBVs were 16.0 ± 2.9, 21.0 ± 4.2, and 31.4 ± 5.8 HU with a significant difference between them (p < 0.05). There was no significant difference in whole-lung PBV between the control group and the low-risk PTE group, but there was a significant difference between the control group and the other two PTE groups. In PTE patients, whole-lung PBV had negative correlation with right-to-left ventricular diameter ratio (R = -0.567, p < 0.001). CONCLUSION: Quantification of lung PBV with DECT is useful for assessment of the clinical severity of PTE and can be used as an indicator of right ventricular dysfunction.