Flow-preserved coil embolization using a side-holed indwelling catheter for common hepatic artery pseudoaneurysm: report of three cases.

We report three cases of hepatic artery pseudoaneurysm, which were all treated successfully using a combination of coil embolization and a side-holed 5F indwelling catheter for maintaining minimal hepatic artery blood flow with exclusion of the pseudoaneurysm. The tip of an infusion catheter was placed in the right hepatic artery and a side hole was positioned at the celiac axis. Coil embolization was then performed from the proper to the common hepatic artery using detachable coils. Hemostasis was achieved in all patients, with a final angiogram showing the hepatic arteries through the indwelling catheter. One major hepatic infarction and one focal liver abscess caused by reflux cholangitis manifested on postoperative days (PODs) 11 and 87, respectively. All patients survived and the indwelling catheter was removed on POD 136­382 without complication.

Machine learning-based computer-aided simple triage (CAST) for COVID-19 pneumonia as compared with triage by board-certified chest radiologists.

PURPOSE: Several reporting systems have been proposed for providing standardized language and diagnostic categories aiming for expressing the likelihood that lung abnormalities on CT images represent COVID-19. We developed a machine learning (ML)-based CT texture analysis software for simple triage based on the RSNA Expert Consensus Statement system. The purpose of this study was to conduct a multi-center and multi-reader study to determine the capability of ML-based computer-aided simple triage (CAST) software based on RSNA expert consensus statements for diagnosis of COVID-19 pneumonia. METHODS: For this multi-center study, 174 cases who had undergone CT and polymerase chain reaction (PCR) tests for COVID-19 were retrospectively included. Their CT data were then assessed by CAST and consensus from three board-certified chest radiologists, after which all cases were classified as either positive or negative. Diagnostic performance was then compared by McNemar's test. To determine radiological finding evaluation capability of CAST, three other board-certified chest radiologists assessed CAST results for radiological findings into five criteria. Finally, accuracies of all radiological evaluations were compared by McNemar's test. RESULTS: A comparison of diagnosis for COVID-19 pneumonia based on RT-PCR results for cases with COVID-19 pneumonia findings on CT showed no significant difference of diagnostic performance between ML-based CAST software and consensus evaluation (p > 0.05). Comparison of agreement on accuracy for all radiological finding evaluations showed that emphysema evaluation accuracy for investigator A (AC = 91.7%) was significantly lower than that for investigators B (100%, p = 0.0009) and C (100%, p = 0.0009). CONCLUSION: This multi-center study shows COVID-19 pneumonia triage by CAST can be considered at least as valid as that by chest expert radiologists and may be capable for playing as useful a complementary role for management of suspected COVID-19 pneumonia patients as well as the RT-PCR test in routine clinical practice.

Clinical features of acute fibrinous and organizing pneumonia: An early histologic pattern of various acute inflammatory lung diseases.

BACKGROUND: Acute fibrinous and organizing pneumonia (AFOP) is a rare histologic pattern of acute lung involvement with intra-alveolar fibrin deposition. However, the clinical significance of the pathological findings of AFOP remains unclear. This study aimed to explore the clinical significance of AFOP through a comprehensive clinical examination. METHODS: The medical records of patients with lung diseases accompanied by the pathological finding of intra-alveolar organization between January 2010 and December 2019 were retrospectively reviewed. The clinical and radiological findings were compared between the groups with and without the histologic pattern of AFOP. RESULTS: We identified 34 patients with AFOP (AFOP group) and 143 without AFOP (non-AFOP group). The underlying diseases of the AFOP group were as follows: 19 patients had cryptogenic organizing pneumonia (OP), 5 had connective tissue diseases, 3 had radiation pneumonitis, 3 had chronic eosinophilic pneumonia, 2 had myelodysplastic syndromes, and 2 had drug-induced pneumonia. Fever was more common, the time from symptom onset to biopsy was shorter, and the serum C-reactive protein level was higher in the AFOP group than in the non-AFOP group. On high-resolution computed tomography, 85% of patients had OP pattern, and halo sign was more common in the AFOP group. Corticosteroids were effective in 94% of the patients in the AFOP group; however, recurrences were more frequent, and a higher corticosteroid dose was needed during recurrence. CONCLUSIONS: AFOP might be an early phase of a histologic pattern associated with known etiologies. In addition, it could be a marker indicating intense inflammatory diseases with a tendency of recurrence.

Clinical features of chronic summer-type hypersensitivity pneumonitis and proposition of diagnostic criteria.

BACKGROUND: Trichosporon asahii (T. asahii) causes chronic summer-type hypersensitivity pneumonitis (C-SHP); however, little is known about the clinical features of this condition. We aimed to elucidate the clinical features of C-SHP and propose practical diagnostic criteria for C-SHP based on the presence of serum anti-T. asahii antibody (TaAb). METHODS: Patients diagnosed with C-SHP and idiopathic pulmonary fibrosis (IPF) between January 2010 and May 2017 were reviewed retrospectively. Clinical findings were compared between the two groups. Criteria for C-SHP were proposed on the basis of significant characteristics and applied to the development and validation cohorts. RESULTS: Thirty-one patients with C-SHP and 26 with TaAb-negative IPF were identified. C-SHP patients were more likely to live in wooden houses; their serum Krebs von den Lungen-6 (KL-6) and serum surfactant protein-D (SP-D) levels were higher than those of IPF patients. C-SHP patients were more likely to have subpleural consolidation, micronodules, and extensive ground-glass opacification on high-resolution computed tomography (HRCT). The following 3 items were considered to have diagnostic value: I) TaAb positivity; II) an HRCT pattern consistent with chronic hypersensitivity pneumonitis, including mosaic attenuation or micronodules; and III) elevated serum biomarker levels (KL-6 > 1500 U/mL or SP-D > 250 ng/mL). We defined cases satisfying I) and II) as "probable C-SHP" and those satisfying all 3 criteria as "confident clinical diagnosis of C-SHP". The areas under the receiver-operating curve were 0.965 and 0.993 in the development and validation cohorts, respectively, which suggested that these criteria had good discriminative ability in clinical evaluations. CONCLUSIONS: Clinical features could be useful for distinguishing C-SHP from IPF and other etiologies of ILDs.

Observation of gastro-esophageal reflux by MRI: a feasibility study.

PURPOSE: To evaluate the feasibility of detecting and measuring gastro-esophageal reflux (GER) with esophageal MR fluoroscopy in patients suffering from heartburn. MATERIALS AND METHODS: Twenty patients with heartburn underwent esophageal MR fluoroscopy. The T1-FFE sequence was applied for MR imaging. We examined the frequency and the level of GER on MR images. Based on the MRI observations, patients were classified into four MRI grades (grade 1-4). Endoscopic findings were categorized into five grades (grade 0 to D). The overall MRI grade, Carlsson's questionnaire score, and endoscopic findings were compared. RESULTS: GER was observed with MR fluoroscopy in 19 of 20 patients. GER was observed only several times in three patients, and much more frequently in the remaining 16 patients. Elevated levels of GER reached the lower, middle-to-upper esophagus, and the hypopharynx. The observed MRI grades were grade 1 = 1 patient, grade 2 = 3 patients, grade 3 = 2 patients, and grade 4 = 13 patients. There was no statistical correlation between the questionnaire score and the MRI grade. Also, there was no correlation between the grade of endoscopic findings and MRI grade. Six patients demonstrated continuous reflux on MRI did not show mucosal injury at endoscopy. CONCLUSION: Esophageal MR fluoroscopy may be a useful diagnostic tool for GERD for its ability to show GER, even in patients with no mucosal injury, and for suggesting the cause of the reflux.

Primary pulmonary hypertension: 3D dynamic perfusion MRI for quantitative analysis of regional pulmonary perfusion.

OBJECTIVE: The purpose of this study was to determine whether quantitative pulmonary perfusion parameters obtained from 3D dynamic contrast-enhanced MR perfusion data can be used to assess the severity of primary pulmonary hypertension (PPH) as indicated by pulmonary vascular resistance (PVR) and mean pulmonary artery pressure (MPAP). CONCLUSION: Three-dimensional dynamic contrast-enhanced MRI has potential for assessment of disease severity as indicated by PVR and MPAP in patients with PPH.

Influences of prolonged apnea and oxygen inhalation on pulmonary hemodynamics during breath holding: quantitative assessment by velocity-encoded MR imaging with SENSE technique.

PURPOSE: The purpose of our study was to assess the influence of prolonged apnea and administration of oxygen on pulmonary hemodynamics during breath holding (BH) by using velocity-encoded MR imaging combined with the SENSE technique (velocity MRI). MATERIALS AND METHODS: Ten healthy male volunteers underwent velocity MRI during BH with and without O(2) inhalation. All velocity MRI data sets were obtained continuously with the 2D cine phase-contrast method during a single BH period. The data were then divided into three BH time phases as follows: first, second and third. To evaluate the influence of prolonged apnea on hemodynamics, stroke volume (SV) and maximal change in flow rate during ejection (MCFR) of second and third phases were statistically compared with those of first phase by using the ANOVA followed by Turkey's HSD multiple comparison test. To assess the influence of O(2) on hemodynamics, SV and MCFR with or without O(2) were compared by the paired t-test. To assess the measuring agreement of hemodynamic indices during prolonged breath holding, Bland-Altman's analysis was performed. RESULTS: Prolonged apnea had no significant influence on SV and MCFR regardless of administration of O(2) (p>0.05). Mean MCFR for all phases was significantly lower with administration of O(2) than without (p<0.05). The limits of agreement for MCFR with O(2) were smaller than without. CONCLUSION: O(2) inhalation modulated maximal change in flow rate during ejection, and did not influence stroke volume during breath holding. Influence of O(2) inhalation should be considered for MR measurements of pulmonary hemodynamics during breath holding.

Bilateral popliteal artery entrapment syndrome: reemphasis on reading axial tomograms.

A 33-year-old man with bilateral popliteal artery entrapment syndrome (PAES) presented with right calf claudication. He underwent radiological studies including conventional arteriography, multidetector row CT (MDCT), and magnetic resonance imaging (MRI) of the lower extremities. He had been fine since birth and athletic in his school days. Axial tomographic images by MDCT and MRI at the popliteal fossa bilaterally showed an anomalous medial head of the gastrocnemius muscle between the popliteal artery and vein, resulting in right popliteal artery occlusion and leading to the diagnosis of bilateral PAES type II. MDCT or MR facilitates noninvasive computer-aided arteriography and is often utilized for screening patients with claudication for peripheral arterial diseases. However, axial tomograms are more essential for confirming PAES than arteriography, and radiologists should continue to look for possible abnormalities on popliteal fossa tomograms because early diagnosis of PAES allows better choices and outcomes of treatment.

Thin-section multiplanar reformats from multidetector-row CT data: utility for assessment of regional tumor extent in non-small cell lung cancer.

PURPOSE: To determine the clinical utility of thin-section multiplanar reformats (MPRs) from multidetector-row CT (MDCT) data sets for assessing the extent of regional tumors in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: Sixty consecutive NSCLC patients, who were considered candidates for surgical treatment, underwent contrast-enhanced MDCT examinations, surgical resection and pathological examinations. All MDCT examinations were performed with a 4-detector row computed tomography (CT). From each raw CT data set, 5mm section thickness CT images (routine CT), 1.25 mm section thickness CT images (thin-section CT) and 1.25 mm section thickness sagittal (thin-section sagittal MPR) and coronal images (thin-section coronal MPR) were reconstructed. A 4-point visual score was used to assess mediastinal, interlobar and chest wall invasions on each image set. For assessment of utility in routine clinical practice, mean reading times for each image set were compared by means of Fisher's protected least significant difference (PLSD) test. A receiver operator characteristic (ROC) analysis was performed to determine the diagnostic capability of each of the image data sets. Finally, sensitivity, specificity and accuracy of the reconstructed images were compared by McNemar test. RESULTS: Mean reading times for thin-section sagittal and coronal MPRs were significantly shorter than those for routine CT and thin-section CT (p<0.05). Areas under the curve (Azs) showing interlobar invasion on thin-section sagittal and coronal MPRs were significantly larger than that on routine CT (p=0.03), and the Az on thin-section sagittal MPR was also significantly larger than that on routine CT (p=0.02). Accuracy of chest wall invasion by thin-section sagittal MPR was significantly higher than that by routine CT (p=0.04). CONCLUSION: Thin-section multiplanar reformats from multidetector-row CT data sets are useful for assessing the extent of regional tumors in non-small cell lung cancer patients.

Nontuberculous mycobacterial lung disease accompanied by organizing pneumonia.

We herein report our experience with patients who had nontuberculous mycobacterial lung disease (NTM disease) accompanied by organizing pneumonia (OP). Out of 98 NTM disease patients who had undergone a biopsy or surgical resection, 11 patients had OP that was revealed histologically. After excluding six patients who had OP-related diseases (idiopathic interstitial pneumonia, rheumatoid arthritis, etc.), the remaining five patients were studied. Two of them (a 73-year-old man and a 66-year-old woman) showed common clinical feature: acute-onset symptoms of cough and fever, infiltrating shadows and dramatic improvement following treatment with a corticosteroid and anti-mycobacterial therapy. Our cases demonstrate that NTM disease is sometimes accompanied by OP histologically, and some such cases show common clinical features.

Dynamic MR imaging: value of differentiating subtypes of peripheral small adenocarcinoma of the lung.

PURPOSE: To determine the utility of dynamic magnetic resonance imaging (MRI) in the differential subtyping of small adenocarcinomas of the lung. MATERIALS AND METHODS: Twenty-nine pathologically diagnosed peripheral adenocarcinomas (less than 20 mm in diameter) underwent dynamic contrast-enhanced MRI. Maximum relative enhancement ratio, slope of enhancement, and corrected start time of enhancement were calculated from signal intensity-time curve of pulmonary lesion for each subject, and were statistically compared among bronchioloalveolar carcinoma (BAC) group (7 cases), mixed BAC group (10 cases), and adenocarcinoma group (12 cases). RESULTS: Maximum relative enhancement ratio (P<0.001) and slope of enhancement (P<0.001) of BAC group were significantly higher than those of mixed BAC and adenocarcinoma groups. Start times of BAC group were significantly earlier than those of mixed BAC (P=0.0001) and adenocarcinoma groups (P<0.0001). Adapting the thresholds values of MR indexes from the positive tests, sensitivity, specificity, positive predictive value, negative predictive value and accuracy for differentiating BAC from other subtypes were 85.7, 100.0, 100.0, 95.7, and 96.6%, respectively. CONCLUSIONS: Dynamic MRI is useful for differentiating subtypes of small peripheral adenocarcinoma.

Centrically reordered inversion recovery half-Fourier single-shot turbo spin-echo sequence: improvement of the image quality of oxygen-enhanced MRI.

PURPOSE: The purpose of the study presented here was to determine the improvement in image quality of oxygen-enhanced magnetic resonance (MR) subtraction imaging obtained with a centrically reordered inversion recovery half-Fourier single-shot turbo spin-echo (c-IR-HASTE) sequence compared with that obtained with a conventional sequentially reordered inversion recovery single-shot HASTE (s-IR-HASTE) sequence for pulmonary imaging. MATERIALS AND METHODS: Oxygen-enhanced MR imaging using a 1.5 T whole body scanner was performed on 12 healthy, non-smoking volunteers. Oxygen-enhanced MR images were obtained with the coronal two-dimensional (2D) c-IR-HASTE sequence and 2D s-IR-HASTE sequence combined with respiratory triggering. For a 256x256 matrix, 132 phase-encoding steps were acquired including four steps for phase correction. Inter-echo spacing for each sequence was 4.0 ms. The effective echo time (TE) for c-IR-HASTE was 4.0 ms, and 16 ms for s-IR-HASTE. The inversion time (TI) was 900 ms. To determine the improvement in oxygen-enhanced MR subtraction imaging by c-IR-HASTE, CNRs of subtraction image, overall image quality, and image degradation of the c-IR-HASTE and s-IR-HASTE techniques were statistically compared. RESULTS: CNR, overall image quality, and image degradation of c-IR-HASTE images showed significant improvement compared to those s-IR-HASTE images (P<0.05). CONCLUSION: Centrically reordered inversion recovery half-Fourier single-shot turbo spin-echo (c-IR-HASTE) sequence enhanced the signal from the lung and improved the image quality of oxygen-enhanced MR subtraction imaging.

Familial interstitial pneumonia complicated by lung cancer in 2 sisters.

A 29-year-old woman was referred to our hospital because of progressive dyspnea on exertion, and her 36-year-old sister was also referred for the evaluation of an abnormal chest radiograph. Radiologic and pathologic findings of the 2 sisters resembled each other closely. In both cases, computed tomography revealed diffuse reticulation, micronodules, diffusely distributed interlobular septal thickening, and an ill-defined nodule in the left lower lobe. Radiologic-pathologic correlation revealed that the reticulation and micronodules corresponded to centrilobular and perilobular fibrosis without architectural lung distortion and that the nodules represented pulmonary adenocarcinoma. To our knowledge, this is the first report of familial interstitial pneumonia complicated by lung cancer in 2 family members, suggesting a possible etiologic association between familial interstitial pneumonia and lung cancer.

Consolidation with a twisted appearance along the airways: a report of five cases of interstitial pneumonia.

High-resolution CT showed areas of airspace consolidation with a twisted appearance of the airways, along with areas of peribronchial ground-glass attenuation and traction bronchiectasis, in five patients with interstitial pneumonia. These areas of airspace consolidation were termed "twisted consolidation" (TwC). The five patients included two patients receiving treatment for rheumatoid arthritis (RA), one patient with newly diagnosed RA, and one patient who subsequently showed RA. Three patients showed improvement after steroid administration. An association of TwC with RA is suspected, but further studies are necessary.

Cerebral air embolism as a complication of computed tomography-guided marking of the lung: depiction of air inflow route from a pulmonary vein to the left atrium.

Air embolism in the arterial system is a very rare but potentially fatal complication of percutaneous transthoracic needle biopsy or marking. We report a case of a patient with interstitial pneumonia associated with Sjögren syndrome, who presented with systemic arterial air embolism as a complication of computed tomography-guided marking of the lung. The air inflow route was depicted clearly on computed tomography from the peripheral pulmonary vein that crossed the needle pathway to the left atrium.

Whole-body MR imaging vs. FDG-PET: comparison of accuracy of M-stage diagnosis for lung cancer patients.

PURPOSE: To conduct a prospective comparison of the accuracy of whole-body MR imaging and positron emission tomography (PET) with fluorine-18 deoxyglucose (FDG) (FDG-PET) to assess the M-stage in lung cancer patients. MATERIALS AND METHODS: A total of 90 consecutive lung cancer patients (mean age = 68 years) underwent whole-body MR imaging and FDG-PET as well as other standard radiological imaging procedures before and after treatment. Probabilities of metastases on whole-body MR imaging and FDG-PET were assessed by using 5-point scoring systems on a per-site basis and on a per-patient basis. Receiver operating characteristic (ROC) curve analysis was used to compare diagnostic capabilities. Sensitivity, specificity, and accuracy were also compared by using the McNemar's test on a per-site and per-patient basis. RESULTS: For assessment of head and neck metastases and bone metastases, accuracies of whole-body MR imaging (95.0% and 94.8%, respectively) were significantly higher than those of FDG-PET (89.1% and 88.2%, respectively; P < 0.05). For assessment of the M-stage on a per-patient basis, accuracy of whole-body MR imaging (80.0%) was also significantly higher than that of FDG-PET (73.3%; P < 0.05). CONCLUSION: Whole-body MR imaging is an accurate diagnostic technique and may be considered at least as effective as FDG-PET for assessment of the M-stage of lung cancer patients.

Assessment of bolus injection protocol with appropriate concentration for quantitative assessment of pulmonary perfusion by dynamic contrast-enhanced MR imaging.

PURPOSE: To determine the appropriate concentration for quantitative assessment of dynamic contrast-enhanced pulmonary MR imaging. MATERIALS AND METHODS: A total of 40 consecutive patients with small bronchioalveolar carcinoma underwent perfusion single-photon emission tomography (SPECT) and three-dimensional (3D) dynamic MR imaging with a 3D radiofrequency spoiled gradient-echo sequence. In each patient, 5 mL of contrast media with 0.1, 0.3, and 0.5 mmol/mL were administered at a rate of 5 mL/second. All patients were divided into two groups (<70 kg and > or =70 kg) for assessment of appropriate concentration to quantitatively assess regional perfusion parameter in routine clinical practice. Pulmonary blood flow (PBF) in each protocol was calculated from a signal intensity (SI)-time course curve. Differences and limits of agreement of PBF between dynamic MR imaging (PBF(MR)) using three different concentrations and perfusion SPECT (PBF(SPECT)) were statistically compared in both patient groups. RESULTS: PBF(MR) using 0.3 mmol/mL in the <70-kg group and 0.5 mmol/mL in the > or =70-kg group showed no significant difference compared with PBF(SPECT) (P > 0.05). Limits of agreements in 0.3 mmol/mL in the <70-kg group and 0.5 mmol/mL in the > or =70-kg group were smaller than those of the other concentrations and small enough for clinical purposes. CONCLUSION: Appropriate concentrations provide accurate and reproducible assessments of regional pulmonary perfusion parameters on 3D dynamic MR perfusion imaging. We suggest using 5 mL of contrast media with 0.3 mmol/mL for patients weighing less than 70 kg and 0.5 mmol/mL for patients weighing 70 kg or more.

Prognostic value of dynamic MR imaging for non-small-cell lung cancer patients after chemoradiotherapy.

PURPOSE: To determine the prognostic value of dynamic MRI for non-small-cell lung cancer (NSCLC) patients after chemoradiotherapy. MATERIALS AND METHODS: A total of 114 consecutive patients with NSCLC underwent dynamic MRI after chemoradiotherapy. The patients were divided into two groups (local control (n=22) and local failure (n=92)) according to the presence of local recurrence. From the signal intensity-time course curve in each subject, the maximum relative enhancement ratio and slope of enhancement were calculated, and compared between two groups by Student's t-test. To determine the feasible threshold values of both MR indexes for group differentiation, ROC-based positive tests were performed. Finally, the Kaplan-Meier survival curves of each group divided by the adapted threshold value were compared by log-rank test. RESULTS: The maximum relative enhancement ratio and the slope of enhancement in the local control group were significantly lower than those in the local failure group (P<0.05). Using 0.08/sec as the threshold value of the slope of enhancement, the sensitivity and specificity for differentiation between the two groups were 90.9% and 91.3%, respectively. When the slope of enhancement was adopted for estimation of prognosis after therapy, the mean survival period of the slope of enhancement0.08/sec (P<0.0001). CONCLUSION: Dynamic MRI has potential prognostic value for NSCLC patients after chemoradiotherapy.