Characteristics of culture-negative subclinical pulmonary tuberculosis: a single-center observation

BACKGROUND

Little is known about culture-negative subclinical pulmonary tuberculosis (TB), and its diagnosis remains challenging. Therefore, this study aimed to identify the characteristics and the extent of disease associated with culture-negative subclinical pulmonary TB.

METHODS

This retrospective cohort study was conducted on immunocompetent individuals with subclinical pulmonary TB at a university hospital in Thailand from January 2014 to December 2019. Subclinical pulmonary TB was diagnosed based on the presence of radiographic abnormalities consistent with TB in the absence of TB symptoms. All subjects demonstrated significant improvement or resolution of radiographic abnormalities following the completion of treatment. At least two negative sputum cultures were needed to fulfill the definition of culture-negative pulmonary TB. Data were analyzed using univariate and multiple logistic regression analyses to determine the characteristics of those with culture-negative subclinical pulmonary TB compared to culture-positive ones.

RESULTS

Out of the 106 individuals identified with subclinical pulmonary TB, 84 met the criteria for inclusion in the analysis. The study found lower radiographic extent and increasing age were key attributes of culture-negative subclinical pulmonary TB. The odds ratios (95% confidence interval) were 7.18 (1.76 to 29.35) and 1.07 (1.01 to 1.13), respectively. They tend to have lower rates of bilateral involvement in both chest x-ray (8.5% vs. 32.0%, p=0.006) and computed tomography (15.4% vs. 42.9%, p=0.035). However, no other specific radiographic findings were identified.

CONCLUSIONS

People with culture-negative subclinical pulmonary TB were likely to have less radiographic -severity, reflecting early disease. Nevertheless, no radiographic patterns, except for unilaterality, were related to culture-negative subclinical pulmonary TB.

Comparing performance measures and clinical outcomes between mobile stroke units and usual care in underserved areas

BACKGROUND

The efficacy of mobile stroke units (MSUs) in improving acute ischemic stroke (AIS) care in developing countries is unknown. We compared performance measures and stroke outcomes in AIS patients between MSU and usual care: emergency medical services (EMS) and walk-in.

METHODS

We enrolled patients > 18 years of age with an AIS within 4.5 h after onset. Demographic data, types, and time of reperfusion therapies and clinical outcomes were recorded. A favorable outcome was defined as a modified Rankin Scale (mRS) 0-2 at 3 months.

RESULTS

A total of 978 AIS patients (MSU = 243, EMS = 214, walk-in = 521) were enrolled between June 1, 2018, and April 30, 2021. The mean age (± SD) was 66 (± 14) years, and 510 (52.1%) were male. AIS time metrics were the shortest in the MSU with a mean (± SD) door to needle (DN) time of 20 (± 7), 29 (± 13), and 35 (± 16) min (p < 0.001) and door to puncture (DP) time of 73 ± 19, 86 ± 33, and 101 ± 42 min (p < 0.001) in MSU, EMS, and walk-in, respectively. Participants in the MSU (56.8%) received higher rate of reperfusion therapie(s) when compared to the EMS (51.4%) and walk-in (31.5%) (p < 0.001). After adjustment for any potential confounders and using the EMS as a reference, the MSU has the highest likelihood of achieving a favorable outcome (adjusted OR 2.15; 95% CI 1.39-3.32).

CONCLUSIONS

In underserved populations, MSUs significantly reduced DN time, increased the likelihood of receiving reperfusion treatment, and achieved independency at 3 months when compared to usual care.

Biliary complications and efficacy after ablation of peribiliary tumors using irreversible electroporation (IRE) or radiofrequency ablation (RFA)

OBJECTIVE

To evaluate the biliary complication rates and efficacy of peribiliary tumor ablation using irreversible electroporation (IRE) or radiofrequency ablation (RFA).

MATERIAL AND METHODS

This is a retrospective study of 42 consecutive patients with 44 peribiliary tumors (≤5 mm distance between the tumor margin and the primary or secondary bile duct). Data were collected between January 2014 and September 2020 from patients who underwent percutaneous liver ablation using IRE (n = 13) or RFA (n = 31).

RESULTS

The median length of follow-up was 23.1 months. The mean tumor size was 17.2 ± 5.2 mm in IRE vs. 18.4 ± 7.0 mm in RFA (p= .56). Complete tumor ablation was achieved in 100% with a significantly larger ablation zone in the IRE group (3.8 ± 0.3 cm vs. 2.6 ± 0.6 cm, p<.001). Significant biliary complications occurred in one patient (7.7%) of the IRE group and in five patients (16.1%) of the RFA group. Significant risk factors for biliary complications included the RFA procedure (HR 9.71, p=.032) and proximity of the tumor to the bile duct (HR 0.63, p=.048). The local tumor progression (LTP) rates were 7.7% (IRE) vs. 21.5% (RFA) at 1 year, 23.1% (IRE) vs. 32.7% (RFA) at 2 years and 23.1% (IRE) vs. 44% (RFA) at 3 years, respectively (p=.289).

CONCLUSIONS

The IRE and RFA procedures are safe and effective to treat peribiliary liver tumors. However, the RFA may have a higher risk of significant bile duct injury than IRE. The shorter distance between the bile duct and the tumor is a strong risk factor for biliary complications.

A clinical evaluation study of cardiothoracic ratio measurement using artificial intelligence

Background

Artificial intelligence, particularly the deep learning (DL) model, can provide reliable results for automated cardiothoracic ratio (CTR) measurement on chest X-ray (CXR) images. In everyday clinical use, however, this technology is usually implemented in a non-automated (AI-assisted) capacity because it still requires approval from radiologists. We investigated the performance and efficiency of our recently proposed models for the AI-assisted method intended for clinical practice.

Methods

We validated four proposed DL models (AlbuNet, SegNet, VGG-11, and VGG-16) to find the best model for clinical implementation using a dataset of 7517 CXR images from manual operations. These models were investigated in single-model and combined-model modes to find the model with the highest percentage of results where the user could accept the results without further interaction (excellent grade), and with measurement variation within ± 1.8% of the human-operating range. The best model from the validation study was then tested on an evaluation dataset of 9386 CXR images using the AI-assisted method with two radiologists to measure the yield of excellent grade results, observer variation, and operating time. A Bland–Altman plot with coefficient of variation (CV) was employed to evaluate agreement between measurements.

Results

The VGG-16 gave the highest excellent grade result (68.9%) of any single-model mode with a CV comparable to manual operation (2.12% vs 2.13%). No DL model produced a failure-grade result. The combined-model mode of AlbuNet + VGG-11 model yielded excellent grades in 82.7% of images and a CV of 1.36%. Using the evaluation dataset, the AlbuNet + VGG-11 model produced excellent grade results in 77.8% of images, a CV of 1.55%, and reduced CTR measurement time by almost ten-fold (1.07 ± 2.62 s vs 10.6 ± 1.5 s) compared with manual operation.

Conclusion

Due to its excellent accuracy and speed, the AlbuNet + VGG-11 model could be clinically implemented to assist radiologists with CTR measurement.

Percutaneous Radiofrequency Ablation Treatment of Hepatocellular Carcinoma in Caudate Lobe Using Expandable Electrodes

Objective: To evaluate the outcome of radiofrequency (RF) ablation using expandable electrodes in the treatment of hepatocellular carcinoma (HCC) located in the caudate lobe. Materials and Methods: Between January 2011 and April 2017, 29 consecutive patients with HCC at the caudate lobe were treated with RF ablation using expandable electrodes. The electrodes were placed on the targeted tumor under combined ultrasound and computed tomography (CT) guidance for each tumor in all the patients. Out of the 29 cases, 19 (65.5%) were accessed via the left hepatic lobe. The technical success, primary efficacy, local tumor progression, secondary efficacy, overall survival, and complications were evaluated. Univariate analysis was performed of the various prognostic factors for technical success, primary efficacy, and local tumor progression. Results: The technical success rate was 86.2%, primary efficacy was 89.7%, and secondary efficacy was 82.8%. The local tumor progression (LTP) rate was 12.3% at one year and 31.5% at two years. The median time of LTP was 6.9 months. The overall survival rate was 85.8% at one year and 57.1% at two years. Ten patients died during the follow-up period (mean 22.5 months; with a range of 3.6–53.2 months). A minor complication of asymptomatic biloma was found in one patient (3.5%). Small-sized tumors (≤2 cm) and Spiegel’s lobe location had significantly better treatment outcomes (p = 0.007 and 0.045, respectively). Conclusion: Radiofrequency ablation using expandable electrodes is feasible and safe in treating HCCs located in the caudate lobe, especially for small-sized tumors (≤2 cm).

Cardiothoracic ratio measurement using artificial intelligence: observer and method validation studies

Background

Artificial Intelligence (AI) is a promising tool for cardiothoracic ratio (CTR) measurement that has been technically validated but not clinically evaluated on a large dataset. We observed and validated AI and manual methods for CTR measurement using a large dataset and investigated the clinical utility of the AI method.

Methods

Five thousand normal chest x-rays and 2,517 images with cardiomegaly and CTR values, were analyzed using manual, AI-assisted, and AI-only methods. AI-only methods obtained CTR values from a VGG-16 U-Net model. An in-house software was used to aid the manual and AI-assisted measurements and to record operating time. Intra and inter-observer experiments were performed on manual and AI-assisted methods and the averages were used in a method variation study. AI outcomes were graded in the AI-assisted method as excellent (accepted by both users independently), good (required adjustment), and poor (failed outcome). Bland–Altman plot with coefficient of variation (CV), and coefficient of determination (R-squared) were used to evaluate agreement and correlation between measurements. Finally, the performance of a cardiomegaly classification test was evaluated using a CTR cutoff at the standard (0.5), optimum, and maximum sensitivity.

Results

Manual CTR measurements on cardiomegaly data were comparable to previous radiologist reports (CV of 2.13% vs 2.04%). The observer and method variations from the AI-only method were about three times higher than from the manual method (CV of 5.78% vs 2.13%). AI assistance resulted in 40% excellent, 56% good, and 4% poor grading. AI assistance significantly improved agreement on inter-observer measurement compared to manual methods (CV; bias: 1.72%; − 0.61% vs 2.13%; − 1.62%) and was faster to perform (2.2 ± 2.4 secs vs 10.6 ± 1.5 secs). The R-squared and classification-test were not reliable indicators to verify that the AI-only method could replace manual operation.

Conclusions

AI alone is not yet suitable to replace manual operations due to its high variation, but it is useful to assist the radiologist because it can reduce observer variation and operation time. Agreement of measurement should be used to compare AI and manual methods, rather than R-square or classification performance tests.

Spontaneously Ruptured Hepatocellular Carcinoma Treated by Transarterial Embolization Compared with Conservative Treatment: Survival Outcome and Prognostic Factors

Objective: To report the survival outcome and prognostic factors in the patients with spontaneously ruptured hepatocellular carcinoma treated by transarterial embolization compared with conservative treatment.Materials and Methods: A retrospective review of 89 patients who had spontaneous rupture of hepatocellular carcinoma (HCC) at Siriraj Hospital between January 2011 and February 2017 were enrolled. Ruptured HCC patients are diagnosed by clinical presentations of abdominal pain/distension, anemia/shock with dynamic liver computed tomography findings as: hemoperitoneum, focal discontinuity or tumor protrusion of the hepatic surface and/or active contrast material extravasation. We compared the survival outcome and prognostic factors of the ruptured HCC patients who received two treatment methods; conservative treatment and transarterial embolization (TAE). Results: The cumulative median survival time of the ruptured HCC patients was significantly higher in the TAE group (81 days) than in the conservative treatment group (29 days) with p-value = 0.006. There were two significant predictors for post-treatment mortality. First, treatment modality in the TAE group showed a significantly lower mortality rate than in the conservative treatment group with a hazard ratio (HR) 0.454 (p-value = 0.003). Second, a pre-treatment high hematocrit level was a significant predictive factor for lower mortality than a low hematocrit level with a hazard ratio (HR) 0.946 (p-value = 0.016). Conclusion: TAE results in a good clinical outcome and increased survival rate in the patients with ruptured HCC. A pre-treatment high hematocrit level was a good prognostic factor for the survival in ruptured HCC patients.

COVID-19 detection and heatmap generation in chest x-ray images

Purpose: The outbreak of COVID-19 or coronavirus was first reported in 2019. It has widely and rapidly spread around the world. The detection of COVID-19 cases is one of the important factors to stop the epidemic, because the infected individuals must be quarantined. One reliable way to detect COVID-19 cases is using chest x-ray images, where signals of the infection are located in lung areas. We propose a solution to automatically classify COVID-19 cases in chest x-ray images. Approach: The ResNet-101 architecture is adopted as the main network with more than 44 millions parameters. The whole net is trained using the large size of 1500 × 1500 x-ray images. The heatmap under the region of interest of segmented lung is constructed to visualize and emphasize signals of COVID-19 in each input x-ray image. Lungs are segmented using the pretrained U-Net. The confidence score of being COVID-19 is also calculated for each classification result. Results: The proposed solution is evaluated based on COVID-19 and normal cases. It is also tested on unseen classes to validate a regularization of the constructed model. They include other normal cases where chest x-ray images are normal without any disease but with some small remarks, and other abnormal cases where chest x-ray images are abnormal with some other diseases containing remarks similar to COVID-19. The proposed method can achieve the sensitivity, specificity, and accuracy of 97%, 98%, and 98%, respectively. Conclusions: It can be concluded that the proposed solution can detect COVID-19 in a chest x-ray image. The heatmap and confidence score of the detection are also demonstrated, such that users or human experts can use them for a final diagnosis in practical usages.

Retrospective analysis of 113 consecutive cases of placenta accreta spectrum from a single tertiary care center

Objective: Placenta accreta spectrum (PAS) remains a major cause of maternal morbidity. We sought to assess the characteristics and treatment outcomes of PAS managed at a tertiary care center with high volume of PAS.Study design: Electronic medical records of all patients with diagnosis of PAS from June 2010 to October 2016 were reviewed. Details of obstetric backgrounds, predelivery diagnosis, peripartum management, and outcomes were analyzed.Results: One hundred thirteen women with PAS were identified from 50,448 deliveries during the study period. Vaginal delivery, emergency, and elective cesarean section were accomplished in 41.6, 30.1, and 28.3%, respectively. There was no maternal mortality. Approximately 41.6% of women with PAS had peripartum hysterectomy. There was a fair inverse correlation between intraoperative blood loss and gestational weeks at delivery (r = -0.311; p=.001), but not gestational weeks at diagnosis (p = .249). Cases with predelivery diagnosis (n = 29) had higher intraoperative blood loss than those diagnosed postdelivery (n = 84) (p<.001). Anterior PAS (n = 58) is associated with attachment to previous uterine scar, antepartum bleeding, and intraoperative blood loss compared to posterior PAS (n = 44) (p<.05). The PAS patients with previous uterine surgery had the highest chance of peripartum hysterectomy (p<.001).Conclusions: Contradictory to previous reports, our data suggest a more severe spectrum of PAS in those with predelivery detection earlier gestational weeks at delivery. Peripartum hysterectomy was highest in anterior PAS that attached to the previous uterine scar.

A Prospective Randomized Controlled Trial Comparing Posterolateral Lumbar Fusion With and Without Bone Marrow Concentrate Augmentation in Single-Level Lumbar Spondylolisthesis

BACKGROUND

Bone marrow (BM), which is a good source of stem cells and biological factors, has the potential to enhance bone fusion. Simple centrifugation technique is one of the procedures used to concentrate BM aspirate for increasing number of cells. However, there are limited clinical study for using BM concentrate augmentation in spinal fusion.

OBJECTIVE

This study was designed to examine the spinal fusion enhancement effects of bone marrow (BM) concentrate augmentation on poster lateral lumbar fusion (PLF) with autologous local bone graft in terms of both quality and quantity, as compared with a control procedure without BM concentrate augmentation.

MATERIAL AND METHOD

Twelve patients with L4-L5 spondylolisthesis scheduled for PLF after decompressive laminectomy and pedicle screw instrumentation were included in this study. This prospective randomized controlled trial was conducted at Siriraj Hospital during the 2009 to 2012 study period. Patients were randomly assigned to two groups. One group underwent PLF with local bone graft with BM concentrate augmentation (BM group) and the other group underwent PLF with local bone graft only (non-BM group). Clinical outcomes were evaluated by the Oswestry Disability Index (ODI) preoperatively and at 3 and 6 months after PLF. Bone fusion quality was evaluated by bony bridging on 3D-CT imaging. Fusion mass volumes were measured on quantitative 3D-CT scans at 1 week and 6 months, postoperatively.

RESULTS

Clinical outcome scores did not differ between groups. Six-month postoperative 3D-CT imaging showed complete PLF bridging in 58.3% and 100% of patients in the BM and non-BM groups, respectively. PLF mass volumes were decreased at 6 months by 51.1% in the BM group and by 48.5% in the non-BM group. One patient in the BM group had local inflammation at the BM aspiration site.

CONCLUSION

Bone marrow concentrate augmentation in this small randomized controlled trial failed to demonstrate positive effects on autologous local bone graft in posterolateral lumbar fusion relative to both quality and quantity. The high percentage of incomplete bridging should also be noted and further investigated.

The Outcome of Radiofrequency Ablation of Metastatic Liver Tumors

OBJECTIVE

To determine outcome of radiofrequency ablation (RFA) in metastatic liver tumor and to evaluate related factors of residual or local tumor recurrences.

MATERIAL AND METHOD

With Institutional Review Board approval, we retrospectively reviewed RFA procedure between June 2006 and September 2013. Fifty-seven metastatic nodules in 36 patients were treated. The primary tumors were colorectal carcinoma (n = 30), neuroendocrine tumor (n = 2), gallbladder carcinoma (n = 1), adenocarcinoma of head of pancreas (n = 1), and gastrointestinal stromal tumor (n = 2). Tumor characteristics, RFA techniques, success rate, complication, and follow-up imaging were reviewed and recorded Clinical outcome and overall survival were analyzed.

RESULTS

Complete ablation were found in 48/57 nodules (84.2%). The mean follow-up time was 17.9 ± 13.1 months (range, 1 to 47 months). Local tumor recurrence were noted in 12/57 nodules (21.1%), which mean time to recurrence was 8.3 ± 3.8 months (2 to 15 months). Residual tumor was associate with tumor larger than 3 cm (p = 0.009). The 1-, 3-, and 5-year overall survival rates were 93.6%, 56.2%, and 20%, respectively. Median overall survival was 37.8 ± 10.9 months. Major complication rate occurred about 5.3%.

CONCLUSION

Radiofrequency ablation is effective and feasible method to treat small metastatic liver tumor Tumor size larger than 3 cm is significant risk factor of residual tumor. Tumor in high-risk location is not associated either incomplete ablation or local tumor recurrence.

Radiofrequency Ablation of Lung Metastasis Not Suitable for Surgery: Experience in Siriraj Hospital

BACKGROUND

Percutaneous image-guided radiofrequency ablation (RFA) is being promoted as a novel technique with low morbidity rate in treatment of inoperable lung tumor either primary lung tumor or metastatic disease.

OBJECTIVE

To report our experiences of RFA treated for lung metastasis in Siriraj Hospital and to evaluate the efficacy and complication of RFA.

MATERIAL AND METHOD

All patients who underwent RFA for lung metastasis at Siriraj Hospital, between January 2007 and December 2013, were included in the present study. Clinical data, pre-procedure image findings including lesion size, location, post-procedure image findings, complications, and outcome were retrospectively reviewed.

RESULTS

Fourteen patients (10 male, 4 female) with 27 lung metastasis were treated with RFA. The ablated lung nodules consist of metastasis from hepatocellular carcinoma (n = 13), colorectal adenocarcinoma (n = 9), insular cell thyroid carcinoma (n = 3), and adenocarcinoma of prostate gland (n = 2). Mean patient age was 50 years (age range 28-67 years). Size of the ablated nodules range from 0.5 to 5.0 cm (median = 1.3 cm). The most common complication was pneumothorax, occurring in 71% (10 of 14 patients). Other complications included surgical site infection, atelectasis, loculated hemothorax, loculated empyema, and bronchopleural fistula, occurred in one patient each. Post-procedure image findings showed complete ablations without local tumor recurrence in 81% (22 of 27 nodules). Local tumor recurrences were seen in 19% (5 of 27 nodules).

CONCLUSION

Radiofrequency ablation for lung metastasis can be considered as a relatively safe, effective alternative treatment for lung metastasis. Risk factors that may associate with local recurrence include large size nodules and subpleural location.

Incidence of complication and tumor recurrence after radiofrequency ablation in high-risk location of hepatocellular carcinoma patients

OBJECTIVE

To evaluate complication, rate of residual, and tumor recurrence in high-risk location compared to non-high-risk location in hepatocellular carcinoma patients.

MATERIAL AND METHOD

Radiofrequency ablation was performed on 409 tumors in Siriraj Hospital between October 2009 and May 2012. Eighty-eight nodules in 78 atients were treated by RF ablation, which divided into high risk and non-high-risk location. Complete ablation rate, residual tumor recurrent tumor, and complication were retrospectively reviewed.

RESULTS

HCC nodules were in non-high-risk location 34 nodules (38.6%) and in high-risk location 54 nodules (61.4%). Complete tumor ablations were done in 34 nodules (100%) of non-high-risk location group and 50 nodules (92.6%) of high-risk location group. All residual tumors were four nodules (7.2%), which located in subcapsular location. Recurrent tumors were found in six nodules (6.8%), and mean time to recurrence were 210.2 days. Early complication was 10.2% and late complication was 4.5%. The recurrent tumor and complication were not significantly different between two groups.

CONCLUSION

Radiofrequency ablation is effective treatment of hepatocellular carcinoma in high-risk location tumor There is no significant difference in complication and tumor recurrent rate between high-risk and non-high-risk group. However incidence of residual tumor is significantly increased in subcapsular location tumor

Evaluation of standard liver volume in adult Thai population using CT volumetric measurement

OBJECTIVE

1) to assess the various existing formulas and the simple, diameter-base equation for calculation of standard liver volume (SLV) in a Thai population, using CT volumetric measurement (CTV) as gold standard. 2) to develop a new formula for calculation of SLV in a Thai population.

MATERIAL AND METHOD

Liver volume of 117 patients who underwent abdominal MDCT for various indications was measured, using CTV. Correlation between CTV and calculated liver volume, acquired from the simple, diameter-base equation and six previously reported formulas, were analyzed. The new formula correlating body weight (BW) or body surface area (BSA) to the measured liver volume from CTV were established using regression analysis.

RESULTS

All existing formulas offer fair to moderate agreement with the measured liver volume from CTV with intra-class correlation (ICC) ranging from 0.280 to 0.576. BW was found to correlate with the measured liver volume from CTV more closely than BSA, then the new formula based on BW was constructed; 21.127 x BW (kg). However our new formula still has only moderate agreement with measured liver volume from CTV (ICC = 0.598). Liver volume calculated from simple, diameter-base equation offer very strong agreement with the measured liver volume from CTV (ICC = 0.829).

CONCLUSION

All formulas based on BW and BSA offer only fair to moderate agreement with measured liver volume CTV, which can lead to high degree error in liver volume estimation. The present study supports that liver volume can be more accurately estimated on CT scan using simple, diameter-based equation. This simple, reproducible method can be used as a good alternative for liver volume calculation. It is particularly useful in case where there is no Digital Imaging and Communications in Medicine (DICOM) data or dedicated 3D software with volumetric measurement application available.

A study of wall thickness of gastric antrum: comparison among normal, benign and malignant gastric conditions on MDCT scan

OBJECTIVE

To evaluate the normal antral wall thickness on MDCT and to determine the optimal cut-off value for differentiating normal and benign from malignant gastric wall thickening.

MATERIAL AND METHOD

MDCT scans of 154 patients, 22 malignancies, 66 benign conditions, and 66 normal findings, whose underwent both gastroscopy and MDCT within 30 days were retrospectively reviewed. The degree of gastric distention, antral wall thickness, pattern of wall thickness, and enhancement, the presence or absence of perigastric fat stranding and perigastric lymphadenopathy were evaluated. ROC curve analysis was used to determine the optimal cut-off value of antral wall thickness to differentiate normal and benign from malignant antral wall thickening.

RESULTS

The antral wall thickness in malignancy, benign and normal groups were 16.64 +/- 7.28 mm, 5.265 +/- 2.21 mm, and 5.68 +/- 2.13 mm, respectively. There was statistically significant difference between the normal and malignant group (p < 0.001) as well as benign and malignant group (p < 0.001). Whereas, there was no significant difference between normal and benign group (p = 0.78). By using a 10 mm-cutoff value, the sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) for prediction of gastric malignancy were 81.8%, 97.7%, 97.0%, 85.7%, and 95.5%, respectively. Most gastric malignancies had diffused irregular gastric antral wall thickening (87.7%), heterogeneous enhancement with obliterated normal gastric wall layering (88.1%), perigastric fat stranding (72.7%), and perigastric lymphadenopathy (72.7%).

CONCLUSION

Normal antral wall thickness ranges from 1 to 16 mm, depends on degree of antral luminal distention. The authors suggest 10 mm antral wall thickness as the optimal cut-off point for differentiating malignancy and non-malignancy conditions. Moreover the diffuse irregular wall thickening, heterogeneous wall enhancement, presence of perigastric fat stranding and perigastric lymphadenopathy often associate with malignancy. These findings are particularly helpful in interpreting MDCT of patients with inadequate antral luminal distention.

Distinguishing small primary lung cancer from pulmonary tuberculoma using 64-slices multidetector CT

OBJECTIVE

To evaluate which CT findings help in distinguishing small primary lung cancer from tuberculoma.

MATERIAL AND METHOD

Forty-two chest CT studies with pathological diagnosis of primary lung cancer (n = 27) and tuberculoma (n = 15) were retrospectively reviewed by two radiologists who were blind to the pathological results. The CT findings of number; size, shape, border and location of the nodules, the presence or absence of satellite nodule, contrast enhancement, internal air bronchogram, internal calcification, internal cavitation, bronchovascular invasion, and bony destruction were evaluated.

RESULTS

About 96% of primary lung cancer had a solitary lesion compared to only 60% among tuberculoma (p < 0.05). The nodule size > 2-3 cm is more likely to be primary lung cancer compared with tuberculoma (p = 0.058). Both primary lung cancer and tuberculoma can occur in all lobes of both lungs but more frequently in the upper lobe, which has no statistically significant difference between these two groups. Tuberculoma seems to be round or polygonal shape and primary lung cancer is more likely to be lobulated shape. The smooth border nodule is found only in tuberculoma (27%) whereas 93% of primary lung cancer had spiculated border compared to 73% among tuberculoma (p < 0.05). Tuberculoma seems to have more satellite nodule than primary lung cancer (47% vs. 22%, p = 0.163). The enhancement of nodule and air bronchogram are significantly found in primary lung cancer compared with tuberculoma (p < 0.05). Tuberculoma seems to have dense central calcification and primary lung cancer seems to have punctate calcification (p < 0.05). Most of the primary lung cancer and tuberculoma do not have internal cavity. The presence of bronchovascular invasion was significantly found in primary lung cancer compared with tuberculoma (p < 0.05). No evidence of bony destruction was observed in both pulmonary tuberculoma and primary lung cancer groups.

CONCLUSION

The solitary lesion size < 3 cm in diameter with spiculated border contrast enhancement, presence of air bronchogram, punctate calcification and bronchovascular invasion are useful CT findings for diagnosis of primary lung cancer However, the lesions with inconclusive findings, tissue diagnosis may be necessary.

Radiofrequency ablation alone versus radiofrequency ablation combined with chemoembolization in unresectable hepatocellular carcinoma

OBJECTIVE

To determine the effectiveness of the treatment in unresectable hepatocellular carcinoma between radiofrequency ablation (RFA) alone and combination of RFA and transcatheter arterial chemoembolization (TACE).

MATERIAL AND METHOD

Forty-six patients with 57 hepatic nodules smaller than 5 cm in maximum diameter were treated with RFA alone in 37 nodules and combined RFA with TACE in 20 nodules. RFA electrode size was varying from 2 to 5 cm diameter. The chemotherapeutic drugs in TACE were mixture of flurouracil with lipiodol and mitomycin-C with lipiodol. The residual tumor local recurrent, and tumor progression was evaluated by dynamic enhanced CT or MRI study of the liver after treatment.

RESULTS

Local response in RFA alone and combined treatment were 97.3% and 70%, respectively. Recurrence rate in RFA alone and combined treatment were 6.9% and 20%, respectively. The average ablative margin visualized on post RFA images were 0.7 cm and 0.4 cm in RFA alone and combined treatment, respectively. Complication rate was 0.07% and all of complications were minor complication.

CONCLUSION

For small unrespectable HCC nodules, RFA ablation alone is the effective treatment. Additional TACE may not be necessary if RFA is performed completely under controlling the important factors, especially ablated margin.

64-slice MDCT angiography of upper extremity in assessment of native hemodialysis access

OBJECTIVE

To compare multidetector row computed tomographic (MDCT) angiography with conventional digital subtraction angiography (DSA) in the evaluation of vascular access stenoses in hemodialysis patients.

MATERIALS AND METHODS

Twenty-one consecutive patients were imaged with MDCT angiography and subsequent DSA. The superficial vein of leg was used as the route for intravenous administration. The vascular stenosis was assessed in not significant (<50% stenosis), moderate stenosis (50%-74% stenosis), severe stenosis (75%-99%), and total occlusion (100%). The accuracy, sensitivity, specificity, positive, and negative predictive values were calculated for significant vascular stenosis using DSA as the standard reference.

RESULTS

The sensitivity and specificity of MDCT angiography for the detection of significant hemodialysis vascular access were 100% (95% CI, 89.3%-100%) and 94.8% (95% CI, 89.1%-97.6%), respectively. The positive and negative predictive values were 84.2% (95% CI, 68.1%-93.4%) and 100% (95% CI, 95.8%-100%), respectively. The accuracy of MDCT angiography for detection of significant stenoses was 95.9% (95% CI, 91.4%-97.0%).

CONCLUSIONS

MDCT angiography provides excellent correlation in vascular stenosis as compared with DSA in hemodialysis access. Complete assessment of entire vascular segments could be performing with MDCT angiography in planning before endovascular intervention or surgical correction.

Accuracy of multidetector computed tomography cholangiography in evaluation of cause of biliary tract obstruction

OBJECTIVE

To evaluate accuracy of multidetector computed tomography (MDCT) cholangiography in evaluation of cause of biliary tract obstruction.

MATERIAL AND METHOD

MDCT cholangiographs of 50 patients with clinically suspected biliary tract obstruction were retrospectively reconstructed and reviewed. The causes of obstruction identified by MDCT were divided into three groups including calculus, benign stricture, and malignancy. Final diagnosis was based on pathological diagnosis or endoscopic retrograde cholangiopancreatography or follow-up. The MDCT diagnosis and final diagnosis were compared

RESULTS

The sensitivity, specificity, positive predictive value, and negative redictive value of MDCT cholangiography for detection of calculus, benign stricture, and malignancy were 91.7-100%, except for sensitivity and positive predictive value for detection of benign stricture, which were 66.7% and 66.7% respectively.

CONCLUSION

MDCT cholangiography is a fast, noninvasive technique that offers high diagnostic accuracy in evaluation of cause of biliary tract obstruction.

Non-Hodgkin lymphoma with adrenal insufficiency: a case report and literature review

A 62-year-old Thai man was admitted because of nausea and vomiting with incidentally detected bilateral adrenal enlargement. The basal cortisol was low and ACTH level was elevated CT guided percutaneous needle biopsy of adrenal gland showed a diffuse infiltration of medium to large atypical lymphoid cells of B-cell immunophenotype, which are diagnostic for a diffuse large B-cell lymphoma. Involvement by large B-cell lymphoma was documented in bone marrow biopsy as well. The findings confirmed the diagnosis of primary adrenal insufficiency caused by large B-cell lymphoma involving both adrenal glands.

The new effective tool for data migration from old PACS (Rogan) to new PACS (Fuji Synapse) with integrated Thai patient names

OBJECTIVE

To investigate consuming time and amount of data transfer for PACS data migration from the existing system to a new one by using new developed software tools.

MATERIAL AND METHOD

The authors have developed a migration tool for PACS data migration and integrated Thai names into a new PACS by the following steps. First, look up the existing database table for hospital number (HN) and image names for each series number. Second, directly retrieve image from storage. Third, get the Thai name by searching HN from the hospital information system (HIS). Then, send the new study to the new PACS via hospital level 7 (HL7) message. Finally, send images to the new PACS.

RESULTS

The data were migrated from the existing PACS, integrated Thai name and sent them to the new PACS. The total migrated images of CR, CT and MR were 296,269, 692,860 and 42,941 images respectively. The average migrated images per series for CR, CT and MR were about 1.01, 89.84 and 15.53 images in successive order. The consuming time for data migration of CR, CT and MR were 685.8, 283.4 and 34.8 hours, respectively.

CONCLUSION

The authors successfully developed new application tool for PACS migration that used to migrate data from the existing PACS to the new one, which are powerful and highly flexibility tools, and including patient Thai name in patient information during data migration.

Morphology of the radial head: A reverse engineering based evaluation using three-dimensional anatomical data of radial bone

The proximal part of the radius has a complex shape and dimension that cannot be precisely determined by standard roentgenogram for real three-dimensional anatomical shape which is important for prosthesis design. This study presents a method by which computer tomography (CT) images are combined with the reverse engineering technique to obtain and analyse the three-dimensional inner and outer geometry of the proximal radius. The three-dimensional models were reconstructed from CT images obtained from 40 radial bones and approximated with two- and three-dimensional fitting algorithms based on reverse engineering methods. The mean total length of the radius was 240.0mm [standard deviation (SD) = 17.3]. The radial head in this study is more likely to be circular with an average diameter of 20.5 mm (SD = 1.9). The outer diameter of the radial neck averages 14.7 mm (SD = 1.0). The thickness of the radial head averages 12.9 mm (SD = 1.4). The intramedullary canal diameter of the radial neck averages 7.4 mm (SD = 1.4). The depth of the fossa at the articular surface averages 1.5 mm (SD = 0.4).

Volumetric measurement of synthetic lung nodules with multi-detector row CT: effect of various image reconstruction parameters and segmentation thresholds on measurement accuracy

PURPOSE

To evaluate the effect of various multi-detector row computed tomographic (CT) reconstruction parameters and nodule segmentation thresholds on the accuracy of volumetric measurement of synthetic lung nodules.

MATERIALS AND METHODS

Synthetic lung nodules of four different diameters (3.2, 4.8, 6.4, and 12.7 mm) were scanned with multi-detector row CT. Images were reconstructed at various section thicknesses (0.75, 1.0, 2.0, 3.0, and 5.0 mm), fields of view (30, 20, and 10 cm), and reconstruction intervals (0.5, 1.0, and 2.0 mm). The nodules were segmented from the simulated background lung region by using four segmentation thresholds (-300, -400, -500, and -600 HU), and their volumes were estimated and compared with a reference standard (measurements according to fluid displacement) by computing the absolute percentage error (APE). APE was regressed against nodule size, and multivariate analysis of variance (MANOVA) was performed with APE as the dependent variable and with four within-subject factors (field of view, reconstruction interval, threshold, and section thickness).

RESULTS

The MANOVA demonstrated statistically significant effects for threshold (P = .02), section thickness (P < .01), and interaction of threshold and section thickness (P = .04). The regression of mean APE values on nodule size indicates that APE progressively increases with decreasing synthetic nodule size (R2 = 0.99, P < .01).

CONCLUSION

For accurate measurement of lung nodule volume, it is critical to select a section thickness and/or segmentation threshold appropriate for the size of a nodule.

The cost-effectiveness of chest radiography as a screening test for chronic obstructive pulmonary disease among the Bangkok elderly

Regular screening with chest radiography (CXR) in an annual physical check up of the elderly is most frequently practiced. This study aimed to identify the CXR indices and the cost-effectiveness of CXR as a screening test for Chronic Obstructive Pulmonary Disease (COPD) among the elderly in 124 urban communities of Bangkok around Siriraj Hospital. The gold standard for diagnosing COPD followed the guidelines of the Thoracic Society of Thailand. There were 3,094 subjects who participated, completed spirometry and a CXR. The selected nine indices from PA and lateral CXR for diagnosing COPD were based on the presence of hyperinflation. The positive criteria of each index were reported. The cut-off point of best average accuracy ie, Z score of the CXR was 0.07 with a sensitivity of 75.9 per cent (95% CI 70.2-81.6%), specificity of 72.4 per cent (95% CI 70.8-74.0%) and the best average accuracy of 74.1 per cent (95% CI 72.5-75.7%) whereas the cost-effective cut-off point of a Z score of CXR as a screening test for COPD was 0.04 at the lowest grand total cost. The cost to detect one case of COPD was 2,008 baht and needed to screen 17 elderly. It is suggested that CXR is probably not a suitable screening test for COPD in the elderly due to the complicated derivation of the CXR indices. However, its efficacy may be of some value in in-office diagnosis of COPD.

Morphological study of the proximal femur: a new method of geometrical assessment using 3-dimensional reverse engineering

This study presents a new method of using computerized tomography images combined with the reverse engineering technique to obtain and analyse the three-dimensional inner and outer geometry of the proximal cadaveric femur. Three-dimensional models were reconstructed from the computerized tomography images and approximated with 2D and 3D fitting algorithms based on reverse engineering methods. The following parameters were calculated for each femur: femoral head diameter, femoral neck axis, femoral shaft axis, anteversion angle and neck-shaft angle. These data represent the geometry of the studied proximal femur, and can be used for the design of proper size and shape of femoral prostheses and trochanteric nail systems.