The BUILT study: a single-center 5-year experience of Lung Cancer screening in Taiwan.

Background: There are no uniform guidelines on low-dose computed tomography (LDCT) follow-up in lung cancer screening. Few studies have analyzed the incidental abnormalities and role of tumor markers in lung cancer screening. The purpose of this study was to investigate the diagnostic performance of LDCT, optimal follow-up duration, incidental findings, and role of tumor markers in diagnosing lung cancer. Methods: We retrospectively analyzed subjects who underwent their first LDCT in Taipei Tzu Chi Hospital between September 1, 2015, and August 31, 2016. All chest CT scans until August 31, 2020, were recorded. A non-calcified nodule with a diameter ≥2 mm on LDCT was defined as a positive result. We extracted the data, including possible risk factors of lung cancer and follow-up outcomes. Results: A total of 1502 subjects were recruited. Of the 38 subjects who underwent biopsy, 31 had confirmed lung cancer. Lung cancer in all patients was diagnosed within 4 years. Univariate logistic regression analysis revealed that a family history of lung cancer in first-degree relatives and abnormal serum carcinoembryonic antigen (CEA) levels were the significant risk factors for lung cancer. A cumulative lung cancer incidence of 54.7 patients per 1000 person-years was determined solely via radiological follow-up. In total, 271 (18%) subjects exhibited incidental findings on baseline LDCT. Conclusion: The overall lung cancer detection rate in this study was 2.1% in the 5-year study period. A family history of lung cancer and abnormal serum CEA levels are important risk factors for lung cancer. A minimum of 4-year follow-up is required to track suspicious nodules. A purely radiological follow-up detects a high incidence of lung cancer.

Surgical Treatment of an Invasive Thymoma with Intracaval and Intracardiac Extension.

A 53-year-old male with an invasive thymoma extending to the superior vena and right atrium, presenting as superior vena cava syndrome is herein reported. However invasive thymoma with this growth pattern is extremely rare. In this case, the tumor was successfully resected via median sternotomy with cardiopulmonary bypass. After 17 months of follow-up, the patient was still free from any signs and symptoms indicative of superior vena cava syndrome, but recurrent tumor in the right pleura was observed on the follow-up chest computed tomography.

Serial Neuroimaging of a Patient with Minor Stroke due to Isolated Cortical Vein Thrombosis and Convexal Subarachnoid Hemorrhage.

PURPOSE: Convexal subarachnoid hemorrhage (cSAH) comprises less than 5% of cases of nontraumatic SAH and frequently presents as a focal and transient neurological deficits that mimics transient ischemic attack (TIA). Isolated cortical vein thrombosis (ICVT) is rare and accounts for only 6.3% of cerebral venous thrombosis. We present a case of minor stroke due to cSAH secondary to ICVT, and alos put emphasis on the chronological change of those serial imagings. CASE REPORT: An 87-year-old man presented with episodes of numbness and dropping of his left arm, which had lasted for three days. Brain computed tomography disclosed a cSAH in the right frontoparietal region. Brain magnetic resonance (MR) study showed a cSAH in the right fronto-parietal sulci. Focal swelling of the right frontal cortex with an intraluminal filling defect in the right cortical vein and venous congestion were observed using post-contrast T1-weighted images, suggesting partial thrombosis with recanalization of the cortical vein but a patent superior sagittal sinus. Diffuse linear superficial cortical hemosiderosis (SCH) was detected in the right anterior frontal cortex, right fronto-parietal cortex and left high frontal cortex. He spontaneously recovered from his minor neurological deficits within two weeks. A follow-up MR study three weeks later found a hyperintense cord sign indicating a cSAH in the right high central sulcus on fluid-attenuated inversion recovery and T2-weighted images. A further follow-up MR study two months later showed gradual shrinkage of the cSAH with persistent diffuse SCH. CONCLUSION: This case report clearly showed chronological change of brain MRI and head CT findings. MR studies help in recognizing the occurrence of acute and chronic cSAHs, and ICVT.

Internal Carotid Artery Hypoplasia: Role of Color-Coded Carotid Duplex Sonography.

OBJECTIVES: The purpose of this study was to determine the role of color-coded carotid duplex sonography for diagnosis of internal carotid artery hypoplasia. METHODS: We retrospectively reviewed 25,000 color-coded carotid duplex sonograms in our neurosonographic database to establish more diagnostic criteria for internal carotid artery hypoplasia. RESULTS: A definitive diagnosis of internal carotid artery hypoplasia was made in 9 patients. Diagnostic findings on color-coded carotid duplex imaging include a long segmental small-caliber lumen (52% diameter) with markedly decreased flow (13% flow volume) in the affected internal carotid artery relative to the contralateral side but without intraluminal lesions. Indirect findings included markedly increased total flow volume (an increase of 133%) in both vertebral arteries, antegrade ipsilateral ophthalmic arterial flow, and a reduced vessel diameter with increased flow resistance in the ipsilateral common carotid artery. Ten patients with distal internal carotid artery dissection showed a similar color-coded duplex pattern, but the reductions in the internal and common carotid artery diameters and increase in collateral flow from the vertebral artery were less prominent than those in hypoplasia. The ipsilateral ophthalmic arterial flow was retrograde in 40% of patients with distal internal carotid artery dissection. In addition, thin-section axial and sagittal computed tomograms of the skull base could show the small diameter of the carotid canal in internal carotid artery hypoplasia and help distinguish hypoplasia from distal internal carotid artery dissection. CONCLUSIONS: Color-coded carotid duplex sonography provides important clues for establishing a diagnosis of internal carotid artery hypoplasia. A hypoplastic carotid canal can be shown by thin-section axial and sagittal skull base computed tomography to confirm the final diagnosis.

Surgical Treatment of Castleman Disease Using Cardiopulmonary Bypass.

UNLABELLED: Castleman disease is a rare benign lymphoproliferative disorder of unknown etiology. A 29-year-old woman presented with intermittent chest pain for 2 years. Upon examination, computed tomography showed an intensely enhanced solid mass that encased her right pulmonary artery. The tumor was resected safely and completely via standard thoracotomy with cardiopulmonary bypass. KEY WORDS: Castleman disease; Middle mediastinal tumor; Surgery.

Vascular space occupancy MRI during breathholding at 3 Tesla.

PURPOSE: To evaluate the vasodilatory response of normal human brain and meningiomas under repeated breathholding challenges using vascular space occupancy (VASO) MRI at 3 Tesla (T). MATERIALS AND METHODS: Five normal volunteers and five patients with meningiomas were recruited for this study. For the normal group, VASO MRI during repeated breathholds of different duration (5 to 30 s) was acquired. Patients performed a 15-s breathhold paradigm for VASO MRI. The maximum signal change and full-width at half-maximum (FWHM) were determined by curve fitting. RESULTS: Significant VASO signal decreases in the gray matter could be detected for a breathhold period as short as 5 s. The fractional activation volume vs. breathhold duration reached a plateau around 34.21 ± 3.39% at 15 s. In the patient group, there were significant VASO signal decreases in normal gray matters and also in small areas of three large-sized meningiomas. CONCLUSION: The 3T VASO MRI detected significant signal decreases in the gray matter, but not in the white matter, during short periods of breathholding. The fractional activation volume reached the plateau at 15-s breathhold, which is recommended for clinical application.

Is Weisskoff model valid for the correction of contrast agent extravasation with combined T1 and T2* effects in dynamic susceptibility contrast MRI?

PURPOSE: The Weisskoff model has been widely applied for correcting the T1 effect of the contrast agent leakage in the measured dynamic susceptibility contrast (DSC)-MRI signals. This study aimed to modify the Weisskoff model for the inclusion of both T1 and T2 effects of the contrast agent extravasation. METHODS: A two-compartment model was proposed and implemented into the original Weisskoff model to describe the combined T1 and T2 effects from the contrast agent leakage in the measured DSC-MRI signals. A computer simulation was performed to evaluate the dependence of T, versus T2 dominance on imaging parameter, field strength, baseline T1, and severity of the leakage. The modified Weisskoff model was employed to correct the relative cerebral blood volume (rCBV) maps in three patients with brain tumors to demonstrate its use. RESULTS: The resultant equation had the same mathematical form as the original model, but with a different expression for the fitting constant K2. This new parameter can be of either a positive or a negative value. Results of the computer simulation showed more probable T2 dominance with longer TE, higher field strength, shorter baseline T1, and greater extraction of the contrast agent. Clinical data were well fitted by the model, with a positive K2 indicating T1 dominance and underestimated rCBV and a negative K2 indicating T2 dominance and overestimated rCBV. The K2 values of normal-appearing brain tissues were distributed in a much smaller range than the K2 values of enhancing tumors. The ratios of corrected over uncorrected normalized CBV (nCBV) for gray matter (GM) were in the range between 1.04 and 1.05, meaning that the nCBV remained rather stable before and after correction. The ratios for the tumors were 0.65, 0.42, and 2.81, either much smaller or greater than the ratios for GM. CONCLUSIONS: This study proposed a modified Weisskoff model that was able to explain both T1 and T2 dominant effects of the contrast agent extravasation in DSC-MRI. Further development is needed to make the K2 parameter a quantitative indicator of the vessel permeability.

Expertise modulates the perception of pain in others.

Perceiving the pain of others activates a large part of the pain matrix in the observer [1]. Because this shared neural representation can lead to empathy or personal distress [2, 3], regulatory mechanisms must operate in people who inflict painful procedures in their practice with patient populations in order to prevent their distress from impairing their ability to be of assistance. In this functional magnetic resonance imaging MRI study, physicians who practice acupuncture were compared to naive participants while observing animated visual stimuli depicting needles being inserted into different body parts, including the mouth region, hands, and feet. Results indicate that the anterior insula somatosensory cortex, periaqueducal gray, and anterior cingulate cortex were significantly activated in the control group, but not in the expert group, who instead showed activation of the medial and superior prefrontal cortices and the temporoparietal junction, involved in emotion regulation and theory of mind.

Breathhold-regulated blood oxygenation level-dependent (BOLD) MRI of human brain at 3 tesla.

PURPOSE: To investigate the cerebrovascular response to repeated breathhold challenges using blood oxygenation level-dependent (BOLD) MRI at 3T and compare the results with previous data at 1.5T. MATERIALS AND METHODS: Six normal volunteers and six patients with brain tumors were recruited for this 3T study. For the normal group, BOLD MRI during repeated breathholds of different durations (five to 30 seconds) were acquired. Maximum signal change, full-width at half-maximum (FWHM) and onset time (defined as the time to the first half-maximum) were determined by curve fitting. The fractional activation volume was also calculated. Patients performed a 10- or 15-second breathhold paradigm according to individual capability. RESULTS: Significant BOLD signal increases in the gray matter for a breathhold period as short as 5 seconds at 3T, instead of 10 seconds at 1.5T. The fractional activation volume vs. breathhold duration reached a plateau of 49.54 +/- 7.26% at 15 seconds at 3T, which was higher and shorter than that at 1.5T. The maximum signal changes were significantly larger (a 69% increase) at 3T than at 1.5T. In the patient group, there were BOLD signal increases in gray matter but not in tumor bulk or perifocal edema, which agreed with the results previously found at 1.5T. CONCLUSION: BOLD MRI at 3T is more sensitive for detecting breathhold-regulated signal changes than at 1.5T, which allows a shorter and more feasible breathhold paradigm for clinical applications in patients with brain tumors.

Vessel size imaging using dual contrast agent injections.

PURPOSE: To investigate the feasibility of a vessel size imaging (VSI) technique with separate contrast agent injections for evaluation of the vessel caliber in normal tissues and in brain tumors. MATERIALS AND METHODS: Computer simulation was first performed to assess the potential errors in the estimation of vessel caliber that could result from time shifts between the dual contrast agent injections. Eight patients (four female, four male, 37-77 years old) with brain tumors (three high-grade gliomas, two low-grade gliomas, and three meningiomas) were recruited for clinical study. Dynamic susceptibility contrast magnetic resonance imaging (MRI) using gradient echo (GE) and spin echo (SE) echo-planar imaging sequences were performed separately with a 10-minute interval on a 3.0T scanner. Vessel caliber maps were calculated and analyzed in regions of interest at cortical gray matter (GM), thalamus, white matter (WM), and tumors. RESULTS: From the computer simulation, the error of vessel caliber measurement was less than 8% when the difference between the time-to-peak of the GE and the SE studies was 1.5 seconds, and reduced to within 5% when the difference was 1 second. From the patient datasets of a 64 x 64 matrix, the estimated vessel calibers were 37.4 +/- 12.9 microm for cortical gray matter, 20.7 +/- 8.8 microm for thalamus, and 15.0 +/- 5.1 microm for white matter, comparable to results in the literature. Two patients had a VSI with 128 x 128 matrix and showed similar results in vessel calibers of normal tissues. All the tumors had larger mean vessel diameter than normal-appearing tissues. The difference in vascular size between normal tissue and tumor was demonstrated clearly in both the VSIs of regular and high spatial resolution. CONCLUSION: This study suggests that VSI with a dual injection method is a feasible technique for estimating microvascular calibers of normal tissues and brain tumors in clinical scanners.

A retrospective study of CT findings in cases undergoing appendectomy at a single hospital.

The purpose of this study was to determine which clinical information or computed tomography (CT) features can distinguish perforated from nonperforated appendicitis. We collected data from 102 patients (62 men, 40 women; mean age, 49.6 years; age range, 16-85 years) who presented to the emergency department with acute abdominal pain or suspicion of acute appendicitis and underwent appendectomy. In the clinical information, there was no significant factor to predict appendiceal perforation. As for CT features, significant imaging factors for predicting appendiceal perforation included abscess, phlegmon, and thickening of lateroconal fascia. The treatment strategy of acute appendicitis varies according to the integrity of the appendiceal wall. Besides clinical findings, CT features can distinguish perforated from nonperforated appendicitis, facilitating proper decision making in ER.

Use of a B-type natriuretic peptide in evaluating the treatment response of a relapsed lymphoma with cardiac involvement.

A 50-year-old woman received a diagnosis of diffuse large B-cell non-Hodgkin's lymphoma in 2000 and achieved complete remission. In April 2004, echocardiography and computed tomography examinations identified a tumor attached to the tricuspid valve and protruding within the right atrium. Bone marrow and lymph node biopsies showed a relapse of large cell lymphoma. The patient had a markedly elevated level of B-type natriuretic peptide (BNP) but a normal level of cardiac troponin I. The follow-up evaluation of the BNP level after chemotherapy showed that it had returned to within normal limits, and an echocardiogram showed regression of the tumor. Use of the BNP level as a monitor in the treatment of cardiac lymphoma has never been reported. This article is the first to report the use of BNP monitoring before and after chemotherapy to evaluate a patient with an unusual relapsed lymphoma with cardiac involvement.

Gas exchange detection of right-to-left shunt in dyspneic patients: report of three cases.

We evaluated three patients with undiagnosed complaints of progressive dyspnea. Based on gas-exchange findings as the initial diagnostic tool, the high ventilatory equivalents for CO2, low sustained end-tidal PCO2, hypoxemia, and central cardiovascular dysfunction during cardiopulmonary exercise testing (CPET) suggested that each had significant pulmonary vasculopathy with right-to-left shunting. The diagnoses of Osler-Rendu-Weber syndrome, ventricular septal defect with Eisenmenger's complex, and hepatopulmonary syndrome were later confirmed by pulmonary angiography, cardiac catheterization, and contrast enhanced echocardiography respectively. We suggest that CPET is an appropriate noninvasive tool to begin and guide the evaluation of undiagnosed dyspnea.

Surgical consideration to optic nerve protrusion according to sinus computed tomography.

OBJECTIVES: This study aimed to investigate the prevalence of optic nerve protrusion (ONP) and its clinical indicators by using sinus computed tomography (CT) scan. STUDY DESIGN: Sinus CT scans of 260 consecutive patients with chronic inflammatory sinus disease were reviewed. RESULTS: The prevalence of ONP in our study population was 28%. Nineteen percent of the optic nerves protruded into the sphenoid sinuses including indentation of the sinus wall (12%) and coursing through the sphenoid sinus (8%). In the presence of contralateral ONP and/or ipsilateral anterior clinoid process pneumatization, the chance of ONP occurrence was significantly higher (both P < 0.01). They were reliable indicators of ONP (R(2) = 0.47, P < 0.01). CONCLUSIONS: ONP is a common anatomic variation observed in patients with chronic inflammatory sinus disease. To reduce optic nerve damage in surgeries, the presence of ONP according to sinus CT scans and the intraoperative findings should be carefully evaluated. EBM RATING: C-4.

Unusual cardiac papillary fibroelastoma in the right ventricular outflow tract.

Cardiac papillary fibroelastoma (CPF) is the second most common benign neoplasm of the heart. This study describes the case of an 81-year-old man who was admitted to the hospital for severe vertigo and in whom a tumor at the right ventricular outflow tract (RVOT) was identified incidentally during echocardiography. The CPF was excised smoothly following the confirmation of its position by computed tomography. The comprehensive pathologic findings of CPF were reviewed. Detailed immunohistochemical analyses of CD34 and factor VIII-related antigen were performed on the covering endocardial cells. The unique chondroid metaplasia of fibrous tissue in this CPF has never been reported. This work is the first to present an unusual CPF at the RVOT with reactive process of fibrous connective tissue.

Right ventricular dysfunction secondary to acute massive pulmonary embolism detected by helical computed tomography pulmonary angiography.

OBJECTIVE: Acute massive pulmonary embolism causes abrupt pulmonary arterial hypertension and right ventricular dysfunction (RVD). Patients with RVD have a worse prognosis than those with normal right ventricular function. Consequently, recognizing the RVD at the time of pulmonary embolism is useful for risk stratification and enables more aggressive therapy. The study compared the accuracy of helical computed tomographic (CT) scans with echocardiography in the detecting of RVD in patients with acute massive pulmonary embolism. MATERIALS AND METHODS: Specifically, this work reviewed the CT pulmonary angiograms of 14 patients who were positive for acute massive pulmonary embolism during a 52-month period. CT scans were reviewed for findings indicating RVD. Scans were considered positive for RVD if the right ventricle was dilated or there was leftward shift of the interventricular septum. Echocardiographic reports serving as the reference standard for the diagnosis of RVD were also reviewed. CT study results were then correlated with echocardiography results. RESULTS: Among 14 patients with massive pulmonary embolism, echocardiography identified 12 patients having RVD, whereas the remaining two patients were negative for RVD. Meanwhile, CT correctly identified 11 of 12 patients as having RVD, and was negative for RVD in the remaining 3 patients. Correlated with echocardiography, CT scan for RVD detection had a sensitivity of 91.6% and a specificity of 100%. CONCLUSIONS: CT can accurately detect RVD in patients with acute massive pulmonary embolism. However, this result requires confirmation using a larger prospective cohort study.

Diagnosis of malpositioned chest tubes after emergency tube thoracostomy: is computed tomography more accurate than chest radiograph?

OBJECTIVE: The aim of this study was to compare the accuracy between computed tomography (CT) and frontal chest radiography in the diagnosis of malpositioned chest tubes (MCT). MATERIALS AND METHODS: CT scans positive for MCT between March 2000 and March 2004 were reviewed. Two radiologists assessed for intra- and extrathoracic locations of MCT in CT studies. Two physicians who were blinded to the results of CT scans assessed the frontal chest radiographs for location of chest tubes, within the pleural space or outside pleural space. The results of CT were then compared with the results of frontal chest radiographs. Medical records were also reviewed for function of the chest tubes and any complications induced by MCT. RESULTS: CT revealed 28 MCT among the 76 chest tubes that were placed in 54 patients. Among the 28 MCT detected by CT, 23 tubes were in the intrathoracic location (20 intraparenchymal; 3 intrafissural) and 5 tubes were in the extrathoracic location (4 in mediastinum; 1 in chest wall). Frontal chest radiographs only revealed six MCT. Among 28 MCT, 16 sufficient, 8 insufficient, and 4 indeterminate functions of the chest tubes were noted from medical charts. One patient complicated with lung abscess, four patients had suffered pleural empyema, and one patient suffered active lung parenchymal bleeding, resulting from MCT. CONCLUSIONS: CT is more accurate than chest radiograph for the diagnosis of MCT. For selected patients with inadequacy drainage of the tubes and when chest radiograph is noncontributory, CT scan is recommended to clarify the exact location of chest tubes.

Deep venous thrombosis: comparison of indirect multidetector CT venography and sonography of lower extremities in 26 patients.

OBJECTIVE: To compare the accuracy of indirect mutidetector row computed tomographic (MDCT) venography with lower extremity venous sonography for the diagnosis of femoropopliteal deep venous thrombosis (DVT), and to determine the frequency and location of DVT at MDCT venography. MATERIALS AND METHODS: Twenty-six consecutive patients suspected of having pulmonary embolism (PE) underwent both combined MDCT venography and MDCT pulmonary angiography and lower extremity venous sonography. Indirect MDCT venography was acquired from the upper calves to the mid-abdomen following MDCT pulmonary angiography. The CT venographic findings were compared with those of sonography for the diagnosis of femoropopliteal DVT. All CT scans were also reviewed for the frequency and location of DVT. RESULTS: Indirect MDCT venography disclosed DVT in 19 patients, and 12 of whom also had PE. Seventeen patients with thrombosis in the femoropopliteal veins were identified in both indirect MDCT venography and sonography. The sensitivity and specificity of indirect MDCT venography for femoropopliteal DVT, as compared with sonography, were both 100%. In one patient DVT in the superficial femoral vein was detected using only indirect MDCT venography. MDCT venography also showed superior extension of femoropopliteal DVT to the inferior vena cava and iliac veins in four patients and thrombosis isolated to the inferior vena cava and common iliac vein thrombosis in one patient. CONCLUSIONS: Indirect MDCT venography is as accurate as sonography in the diagnosis of femoropopliteal DVT. MDCT venography can further reveal thrombus in large pelvis veins and the inferior vena cava, an important advantage over sonographic screening for DVT.

Multiple complete ring-shaped enhanced MRI lesions in acute disseminated encephalomyelitis.

Acute disseminated encephalomyelitis (ADEM) lesions may or may not enhance with contrast material on contrast T1-weighted magnetic resonance images (T1WI). Enhancing ADEM lesions may show varying patterns of contrast enhancement, which include nodular, diffuse nodular, amorphous, gyral, spotty and incomplete ring-like. Multiple, complete ring-shaped enhanced lesions on contrast T1WI is a rare finding in ADEM. We report such a magnetic resonance imaging (MRI) finding in a 36-year-old female patient with this disease.