Percutaneous cryoablation for inoperable malignant lung tumors: midterm results.

OBJECTIVE: To retrospectively analyze the efficacy and short- to mid-term survival rate of cryoablation for malignant lung tumors. METHODS: Percutaneous CT-guided cryoablation for 45 malignant lung tumors in 26 patients during 41 sessions from 2009 to 2013 were performed. Follow up CT-scan were used to determine local tumor progression. Survival rate, local tumor control rate and associated risk factors were analyzed. RESULTS: The immediate during and short-term complications with CTCAE grade 2 or upper include pneumothorax (15%), pleural effusion (20%), pulmonary hemorrhage (24%), pneumonitis (15%), hemothorax (15%), hemoptysis (10%), pain (20%), bronchopleural fistula (n=1), and empyema (n=2). Life-threatening bleeding or hemodynamic instability was not observed. There was no procedural-related mortality. Overall survival rate of 1, 2, 3 years are 96%, 88%, 88%. For curative intent, local tumor control (LTC) rate of 1, 2, 3 years are 75%, 72%, 72%. CONCLUSION: Cryoablation for malignant lung tumors is effective and feasible in local control of tumor growth, with good short- to mid-term survival rate, as an alternative option for inoperable patients.

Impact on outcomes by measuring tortuosity with reporting standards for thoracic endovascular aortic repair.

OBJECTIVE: In this study, we assessed the association between the tortuosity of the thoracic aorta as measured by the reporting standards for thoracic endovascular aortic repair (TEVAR), described by the Society for Vascular Surgery, and midterm outcomes after TEVAR for atherosclerotic aneurysms. METHODS: We analyzed 77 consecutive patients who underwent TEVAR for atherosclerotic aneurysms from November 2006 through May 2013 in a single institution. The preoperative aortic tortuosity index (TI) was calculated by computed tomography aortography, and patients were divided into low-tortuosity (TI ≤ 1.29) and high-tortuosity (TI > 1.29) groups. The relationships between TI and the occurrence of endoleaks, complications, and survival were analyzed. RESULTS: The mean follow-up period was 29 ± 26 months. During this period, endoleaks occurred in 19 patients. Patients in the high-tortuosity group were at greater risk for endoleaks (odds ratio, 9.95; 95% confidence interval, 2.06-48.1; P = .004) and stroke (odds ratio, 13.2; 95% confidence interval, 1.03-169; P = .047) than those in the low-tortuosity group. The overall survival at 1, 3, and 5 years was 73%, 69%, and 63%, respectively, for the high-tortuosity group and 92%, 92%, and 86%, respectively, for the low tortuosity group. CONCLUSIONS: Our findings demonstrated that high tortuosity of the thoracic aorta is associated with higher rates of endoleaks and lower survival in patients undergoing TEVAR for atherosclerotic aneurysms. Patients with aneurysms in a highly tortuous aorta may therefore need greater attention in preoperative planning, perioperative procedures, and follow-up examinations.

Optimal image quality and radiation doses with optimal tube voltages/currents for pediatric anthropomorphic phantom brains.

OBJECTIVE: Using pediatric anthropomorphic phantoms (APs), we aimed to determine the scanning tube voltage/current combinations that could achieve optimal image quality and avoid excessive radiation exposure in pediatric patients. MATERIALS AND METHODS: A 64-slice scanner was used to scan a standard test phantom to determine the volume CT dose indices (CTDIvol), and three pediatric anthropomorphic phantoms (APs) with highly accurate anatomy and tissue-equivalent materials were studied. These specialized APs represented the average 1-year-old, 5-year-old, and 10-year-old children, respectively. The physical phantoms were constructed with brain tissue-equivalent materials having a density of ρ = 1.07 g/cm3, comprising 22 numbered 2.54-cm-thick sections for the 1-year-old, 26 sections for the 5-year-old, and 32 sections for the 10-year-old. They were scanned to acquire brain CT images and determine the standard deviations (SDs), effective doses (EDs), and contrast-to noise ratios (CNRs). The APs were scanned by 21 combinations of tube voltages/currents (80, 100, or 120 kVp/10, 40, 80, 120, 150, 200, or 250 mA) and rotation time/pitch settings of 1 s/0.984:1. RESULTS: The optimal tube voltage/current combinations yielding optimal image quality were 80 kVp/80 mA for the 1-year-old AP; 80 kVp/120 mA for the 5-year-old AP; and 80 kVp/150 mA for the 10-year-old AP. Because these scanning tube voltages/currents yielded SDs, respectively, of 12.81, 13.09, and 12.26 HU, along with small EDs of 0.31, 0.34, and 0.31 mSv, these parameters and the induced values were expediently defined as optimal. CONCLUSIONS: The optimal tube voltages/currents that yielded optimal brain image quality, SDs, CNRs, and EDs herein are novel and essentially important. Clinical translation of these optimal values may allow CT diagnosis with low radiation doses to children's heads.

Variation in tube voltage for pediatric neck 64VCT: Effect on radiation dose and image quality.

Exposure to ionizing radiation can cause cancer, especially in children. In computed tomography (CT), a trade-off exists between the radiation dose and image quality. Few studies have investigated the effect of dose reduction on image quality in pediatric neck CT. We aimed to assess the effect of peak kilovoltage on the radiation dose and image quality in pediatric neck multidetector-row CT. Measurements were made using three phantoms representative of children aged 1, 5, and 10 years, with tube voltages of 80, 100, and 120 kilovoltage peak (kVp); tube current of 10, 40, 80, 120, 150, 200, and 250 mA; and exposure time = 0.5 s (pitch, 0.984:1). Radiation dose estimates were derived from the dose-length product with a 64-multidetector-row CT scanner. Images obtained from the control protocol (120 kVp) were compared with the 80- and 100-kVp protocols. The effective dose (ED) was determined for each protocol and compared with the 120-kVp protocol. Quantitative analysis entailed noise measurements by recording the standard deviation of attenuation for a circular 1-cm2 region of interest placed on homogeneous soft tissue structures in the phantom. The mean noise of the various kVp protocols was compared using the unpaired Student t-test. Reduction of ED was 37.58% and 68.58% for neck CT with 100 kVp and 80 kVp, respectively. The image noise level increased with the decrease in peak kilovoltage. Noise values were higher at 80 kVp at all neck levels, but did not increase at 100 kVp, compared to 120 kVp in the three phantoms. The measured noise difference was the greatest at 80 kVp (absolute increases<2.5 HU). The subjective image quality did not differ among the protocols. Thus, reducing voltage from 120 to 80 kVp for neck CT may achieve ED reduction of 68.58%, without compromising image quality.

DIAGNOSTIC REFERENCE LEVELS OF CARDIAC COMPUTED TOMOGRAPHY ANGIOGRAPHY IN A SINGLE MEDICAL CENTER IN TAIWAN: A 3-Y ANALYSIS.

This study aimed to establish the diagnostic reference levels (DRLs) for coronary computed tomography angiography (CCTA) and coronary arterial calcium score (CACS) owing to a large variability in patient radiation dose and the lack of dose recommendations in Taiwan. Volume computed tomography dose index (CTDIvol) and dose-length product (DLP) were obtained using CCTAs and the CACS of 445 patients over a 3-y period in a single medical center in Taiwan. CCTAs were performed using routine protocols and 256-detector CT scanners. Electrocardiogram gating was retrospective. The obtained data were analyzed using Prism 6 to determine the 25th, 50th (median) and 75th DRL percentiles for CTDIvol and DLP. These DRL results were compared with existing DRLs from seven countries. The DRLs for CCTA determined from this survey were similar to the existing data from other countries. Such DRLs could provide a useful tool for the optimization of radiation dose for CCTA in Taiwan.

The impact of catheter ablation on the dynamic function of the left atrium in patients with atrial fibrillation: insights from four-dimensional computed tomographic images.

INTRODUCTION: Elucidating the functional properties and remodeling process of the entire left atrium (LA) is important not only for offering the mechanistic insight into atrial fibrillation (AF) but also for assessing the effectiveness of catheter ablation. METHODS: We included 65 patients with paroxysmal AF and 29 controls. Baseline multidetector computed tomography (MDCT) was acquired in all subjects and a follow-up MDCT was available in 48 patients after pulmonary vein and LA ablation. The 3-dimensional images at atrial end-diastole (ED) and end-systole (ES) were analyzed. RESULTS: The LA volume (ED: 61.11 +/- 15.94 vs 54.12 +/- 8.94 mL/m(2), P = 0.03; ES: 45.29 +/- 17.64 vs 33.38 +/- 7.78 mL/m(2), P < 0.001) was increased, and ejection fraction (EF) (26.93 +/- 13.40 vs 38.09 +/- 11.62%, P < 0.001) decreased in AF patients as compared to controls. After ablation, the ES LA volume (44.73 +/- 14.93 vs 38.04 +/- 11.51 mL/m(2), P = 0.04) decreased and the LA EF (25.04 +/- 13.13 vs 30.82 +/- 7.85%, P = 0.03) increased in patients without any AF recurrence. The wall motion (WM) analysis of the 18 segments of LA revealed increased motional magnitudes of entire LA except for the anterior roof. In contrast, the volume, EF, and WM of LA remained similar in patients with recurrence. CONCLUSION: Dilated LA with global hypokinesia was noted in AF patients. Improved LA transport function was demonstrated in patients without any recurrence after ablation. However, the anatomic and functional reverse remodeling was not significant in patients with AF recurrence.

Myocardial bridging in Taiwan: depiction by multidetector computed tomography coronary angiography.

BACKGROUND/PURPOSE: Myocardial bridging (MB) is a condition in which a segment of the major epicardial coronary artery is tunneled within and surrounded by the myocardium. This condition has been linked to severe complications. The aim of this study was to evaluate the incidence of MB in Taiwanese subjects examined with electrocardiogram-gated, 16-slice, multidetector computed tomography (MDCT) coronary angiography, as well as to determine the location, depth, and length of the bridged segments and the concomitant atherosclerosis of MB. METHODS: From August 2004 to May 2005, 276 consecutive subjects referred to our department for MDCT coronary angiography were enrolled in the study after written informed consent was obtained from each participant. RESULTS: Twenty-four subjects (8.7%) had at least one coronary segment that was completely surrounded by myocardium. Patients ranged in age from 27 to 76 years, with an average of 54 +/- 12 years. Thirty coronary segments were found to have MB. The most common location of MB was in segment 7, which accounted for 14 coronary segments (46.7%) of the total number of bridged segments; left anterior descending artery (LAD) segments accounted for 23 (76.7%); and right coronary artery and left circumflex artery segments accounted for three (10%) and two (6.7%), respectively. The length of bridged segments ranged from 5.2 to 50.6 mm, with an average length of 24.6 +/- 11.8 mm, and the depth of the bridged segments ranged from 0.5 to 9.1 mm, with an average depth of 3.65 +/- 1.89 mm. Two bridged segments (6.7%) had concomitant atherosclerosis; these were located in segment 7 (24.0 mm long and 6.10 mm deep) and segment 8 (27.1 mm long and 7.0 mm deep). Bridged segments with concomitant atherosclerosis were deeper, but not longer, compared with bridged segments without concomitant atherosclerosis (p < 0.05). CONCLUSION: Electrocardiogram-gated MDCT is an effective noninvasive tool for evaluating MB in a clinical setting. The most common location of MB was in the LAD, especially in segment 7. Bridged segments with concomitant atherosclerosis were deeper, but not longer, compared with bridged segments without concomitant atherosclerosis.

Close relationship between the bronchi and pulmonary veins: implications for the prevention of atriobronchial fistula after atrial fibrillation ablation.

INTRODUCTION: Atrio-bronchial fistula (ABF) can be a rare but potentially lethal complication following the catheter ablation of atrial fibrillation (AF). Understanding the extent of the contact between the bronchial tree and pulmonary veins (PVs) is critical to avoid this complication. We investigated the anatomic relationship between the four PVs and bronchial tree using multi-detector computed tomography (MDCT) images. METHODS AND RESULTS: Seventy patients with drug refractory AF were included. They underwent 16-slice MDCT before the ablation. The spatial relationship between the bronchus and PVs was demonstrated by the multi-planar images. The bronchus was in direct contact with four PVs in the vast majority of patients. The mean distances between the bronchus and the ostia of right superior, left superior, right inferior, and left inferior PV were 7.1 +/- 5.5, 3.5 +/- 4.8, 12.3 +/- 5.6, and 17.9 +/- 6.8 mm, respectively. Patients were categorized into two groups: Group I: proximal contact (<5 mm from the PV ostium) and Group II: distal contact (>5 mm from the PV ostium). For the right superior pulmonary vein (RSPV), the Group I patients were associated with thinner connective tissue between them (P = 0.001), a larger RSPV (17.2 +/- 2.2 vs 15.5 +/- 2.1 mm, P < 0.001), and right inferior pulmonary vein (RIPV) diameter (15.9 +/- 1.9 vs 14.6 +/- 1.6 mm, P < 0.01). For the left superior pulmonary vein (LSPV), the Group I patients were associated with an older age (P = 0.02). CONCLUSION: Isolation of the superior PVs may carry the potential risk of bronchial damage. The clinical or anatomic characteristics associated with the proximal contact between the bronchi and superior PVs can provide useful information to prevent this complication.

Morphological changes of the left atrial appendage after catheter ablation of atrial fibrillation.

INTRODUCTION: The left atrial appendage (LAA) has been proven to be the most important site of thrombus formation in patients with atrial fibrillation (AF). However, the information regarding the morphometric alteration of the LAA related to the outcome of AF ablation is still lacking. Thus, we evaluated the long-term changes of the LAA morphology in patients undergoing catheter ablation of AF using magnetic resonance angiography (MRA). METHODS AND RESULTS: Group 1 included 15 controls without any AF history. Group 2 included 40 patients with drug-refractory paroxysmal AF. They were divided into two subgroups: group 2a included 30 patients without AF recurrence after pulmonary vein (PV) ablation. Group 2b included 10 patients with late recurrence of AF. The LAA morphology before and after (20 +/- 11 months) ablation was evaluated by three-dimensional MRA. The group 2 patients had a larger baseline LAA size (including the LAA orifice, neck, and length) and less eccentric LAA orifice and neck. After the AF ablation, there was a significant reduction in the LAA size in the group 2a patients, and the morphology of the LAA neck became more eccentric during the follow-up period. In group 2b, the LAA size increased and no significant change in the eccentricity of the orifice and neck could be noted. CONCLUSIONS: The morphometric remodeling of the LAA in the AF patients could be reversed after a successful ablation of the AF. Progressive dilation of the LAA was noted in the patients with AF recurrence. These structural changes in the LAA may play a role in reducing the potential risk of cerebrovascular accidents.

Morphologic characteristics of the left atrial appendage, roof, and septum: implications for the ablation of atrial fibrillation.

INTRODUCTION: The left atrium (LA) ablation in different regions, including LA appendage (LAA), LA roof, and LA septum, has recently been proposed to improve the success rate of treating patients with atrial fibrillation (AF). The purpose of this study was to investigate the anatomy of LAA, LA roof, and LA septum, using computed tomography (CT). METHODS AND RESULTS: Multidetector CT scan was used to depict the LA in 47 patients with drug-refractory paroxysmal AF (39 males, age = 50 +/- 12 years) and 49 control subjects (34 males, age = 54 +/- 11 years). The area of LAA orifice, neck, and the length of roof line were greater in AF group than in control subjects. Three types of LAA locations and two types of LAA ridges were observed. Higher incidence of inferior LAA was noted in AF patients. The different morphologies of LA roof were described. Roof pouches were revealed in 15% of AF and 14% of controls. Moreover, we found septal ridge in 32% of AF and 23% of controls. CONCLUSIONS: Considerable variations of LAA and LA roof morphologies were demonstrated. Peculiar structures, including roof pouches and septal ridges, were delineated by CT imaging. These findings were important for determining the strategy of AF ablation and avoiding the procedure-related complications.

Anatomic characteristics of the left atrial isthmus in patients with atrial fibrillation: lessons from computed tomographic images.

INTRODUCTION: Left atrial (LA) isthmus ablation was reported to improve the success rate of catheter ablation of paroxysmal atrial fibrillation (AF). LA isthmus ablation could also cure a subset of LA flutter. Therefore, understanding the anatomy of the LA isthmus is important for performing the ablation effectively. METHODS AND RESULTS: Group I included 45 patients (40 male, mean age = 50 +/- 13 years) with paroxysmal AF who underwent catheter ablation. Group II included 45 patients (37 male, mean age = 54 +/- 10 years) without a history of AF. They underwent a 16-slice multidetector computed tomography (MDCT) scan to delineate the LA structures before the ablation procedure. The average length of the LA isthmus was longer in group I than in group II (lateral isthmus: 3.30 +/- 0.68 vs 2.71 +/- 0.60 cm, P < 0.001; medial isthmus: 5.12 +/- 0.94 vs 4.45 +/- 0.63 cm, P < 0.001), and morphological patterns of lateral and medial isthmus were similar between groups. In addition, the average depth of lateral isthmus was similar between groups (0.62 +/- 0.32 vs 0.55 +/- 0.33 cm, P = 0.41), but the average depth of medial isthmus was larger in group I than in group II (0.60 +/- 0.32 vs 0.44 +/- 0.25 cm, P = 0.01). The medial isthmus had more ridges, as compared to the lateral isthmus (13% vs 0%, P = 0.026). Furthermore, the distances between esophagus and lateral isthmus were longer in group I than in group II (at the middle of isthmus and mitral annulus level: 21.0 +/- 4.8 vs 18.4 +/- 6.0 mm, P < 0.001; and 37.1 +/- 5.7 vs 29.6 +/- 8.1 mm, P < 0.001, respectively). CONCLUSION: The LA isthmus was longer in the AF patients. The morphology of the isthmus was variable. Compared with the lateral isthmus, the medial isthmus was longer and had more ridges. A peculiar configuration of the isthmus provided by CT images could influence the ablation strategy.

Electron beam computed tomography evidence of aortic calcification as an independent determinant of coronary artery calcification.

BACKGROUND: Imaging of the aorta has received less attention than imaging of the coronary beds, despite the possible link between aortic and coronary artery disease (CAD). Electron beam computed tomography (EBCT) with 100 ms scanning speed can eliminate pulsation-related motion artifacts. The goals of this study were to evaluate EBCT-detected subclinical atherosclerosis over the whole aorta as in routine abdominal and thoracic CT scans and analyze whether or not the measurements of aortic calcification (AC) can independently predict the presence of coronary artery calcification (CAC), which is a surrogate marker of CAD. METHODS: A consecutive series of 196 adults (male:female, 127:69; mean age, 65.9 +/- 10.5 years) were enrolled for EBCT examinations of the coronary arteries and whole aorta. CAC and AC were calculated by the Agatston method. Major cardiovascular risk factors were also recorded. RESULTS: The greatest amount of AC was seen at the abdominal aorta, followed by the descending aortic arch, thoracic aorta, and ascending aorta. Total AC was significantly correlated with CAC (r = 0.51, p < 0.001). After adjustment for major cardiovascular risk factors of age, gender, diabetes, hypertension, hypercholesterolemia, and family history, the three independent significant determinants of CAC were abdominal AC, thoracic descending AC, and male gender (model r2 = 0.495, p < 0.001). For receiver operating characteristic analysis in predicting the presence of CAC, the threshold of descending AC was 11, with 68.3% sensitivity and 75.0% specificity. The optimal threshold of abdominal AC was 123, with 74.1% sensitivity and 67.9% specificity. CONCLUSION: AC values in different portions of the aorta are independent predictors for the presence of CAC.

Knowledge-based iterative model reconstruction technique in computed tomography of lumbar spine lowers radiation dose and improves tissue differentiation for patients with lower back pain.

PURPOSE: To evaluate the image quality and diagnostic confidence of reduced-dose computed tomography (CT) of the lumbar spine (L-spine) reconstructed with knowledge-based iterative model reconstruction (IMR). MATERIALS AND METHODS: Prospectively, group A consisted of 55 patients imaged with standard acquisition reconstructed with filtered back-projection. Group B consisted of 58 patients imaged with half tube current, reconstructed with hybrid iterative reconstruction (iDose(4)) in Group B1 and knowledge-based IMR in Group B2. Signal-to-noise ratio (SNR) of different regions, the contrast-to-noise ratio between the intervetebral disc (IVD) and dural sac (D-D CNR), and subjective image quality of different regions were compared. Higher strength IMR was also compared in spinal stenosis cases. RESULTS: The SNR of the psoas muscle and D-D CNR were significantly higher in the IMR group. Except for the facet joint, subjective image quality of other regions including IVD, intervertebral foramen (IVF), dural sac, peridural fat, ligmentum flavum, and overall diagnostic acceptability were best for the IMR group. Diagnostic confidence of narrowing IVF and IVD was good (kappa=0.58-0.85). Higher strength IMR delineated IVD better in spinal stenosis cases. CONCLUSION: Lower dose CT of L-spine reconstructed with IMR demonstrates better tissue differentiation than iDose(4) and standard dose CT with FBP.

Demonstration of large bladder diverticulum on bone scan.

A 74-year-old man underwent low anterior resection for rectal cancer. Technetium-99m methylene diphosphonate (MDP) bone scanning was performed as part of the patient's postoperative follow-up study. Scans revealed an area of increased tracer uptake in the left hemipelvis. Coronal single-photon emission computed tomography and caudal images clearly separated the lesion from the skeletal structures. Transverse magnetic resonance images showed a large diverticulum originating from the left lateral wall of the bladder. The pelvic findings on the bone scan were the result of tracer retained within this diverticulum.

Bicycle-handlebar hernia: a rare traumatic abdominal wall hernia.

Handlebar hernia is a rare, traumatic, abdominal wall hernia caused by high-velocity direct trauma. It involves disruption of the abdominal wall muscles, with bowel loop herniated through the defect in the abdominal wall, and may have major or even lethal complications. We report a case of bicycle-handlebar hernia in a 9-year-old boy who had all layers of his abdominal wall disrupted by a fall when bicycling; however, his skin and intra-abdominal organs were completely intact. Computed tomography demonstrated subcutaneous intestinal loops protruding through the rent. Primary repair was performed, and his postoperative course was uneventful.

Bowel preparation of outpatients for intravenous urography: efficacy of castor oil versus bisacodyl.

The purpose of this study was to compare the efficacy of two laxatives, castor oil and bisacodyl, in the routine bowel preparation of outpatients for intravenous urography (IVU). We used castor oil in patients undergoing IVU for 1 month, and then used bisacodyl in patients undergoing IVU for another month. Two uroradiologists, unaware of the method of bowel preparation, reviewed the standard radiographs and graded the residue in the large bowel and the clearness of the opacified urinary collecting system. In total, 71 consecutive outpatients received castor oil, and 84 received bisacodyl. For the castor oil group, grades from the two uroradiologists did not differ in terms of fecal residue on plain abdominal images (p = 0.54), and visualization of the urinary system on the left (p = 0.36) and right sides (p = 0.63). Findings were similar for bisacodyl recipients (p = 0.11, 0.59, and 0.32, respectively). When the laxative effect of the two agents was compared, we found no difference in the grading of fecal residue on plain abdominal images (p = 0.14), or in visualization of the urinary system on the left (p = 0.31) and right sides (p = 0.98). In conclusion, we observed no difference in laxative efficacy between castor oil and bisacodyl; thus, bisacodyl may be a useful alternative for bowel preparation before IVU.

Outcome comparison between thoracic endovascular and open repair for type B aortic dissection: A population-based longitudinal study.

BACKGROUND: Management of diseases of the descending thoracic aorta is trending from open surgery toward thoracic endovascular aortic repair (TEVAR), because TEVAR is reportedly associated with less perioperative mortality. However, comparisons between TEVAR and open surgery, adjusting for patient comorbidities, have not been well studied. In this nationwide population-based study, we compared the outcomes between TEVAR and open surgery in type B aortic dissection. METHODS: From 2003 to 2009, data on patients with type B aortic dissection who underwent either open surgery or TEVAR were obtained from the National Health Insurance Research Database. Survival, length of stay, and complications were compared between TEVAR and open repair. To minimize possible bias, we performed an additional analysis after matching patients by age, sex, and propensity score. RESULTS: A total of 1661 patients were identified, of whom 1542 underwent open repair and 119 TEVAR. Patients in the TEVAR group were older (63.0 ± 15.4 years vs. 58.1 ± 13.1 years; p = 0.001), included more males, and had more preoperative comorbidities. Thirty-day mortality in the TEVAR group was significantly lower than that in the open repair group (4.2% vs. 17.8%; p < 0.001). The midterm survival rates in the unmatched cohort between the open surgery and TEVAR groups at 1 year, 2 years, 3 years, and 4 years were 76%, 73%, 71%, and 68% vs. 92%, 86%, 82%, and 79%, respectively. The length of stay in the TEVAR group was shorter than that in the open repair group (p = 0.001). The TEVAR group had less respiratory failure (p = 0.022) and fewer wound complications than the open repair group (p = 0.008). The matched cohort showed similar results. CONCLUSION: TEVAR for type B aortic dissection repair has less perioperative mortality, a shorter length of hospitalization, a higher midterm survival rate, less postoperative respiratory failure, and fewer wound complications than open surgery.

Initial experience using magnetic resonance imaging in prenatal diagnosis of osteogenesis imperfecta type II: a case report.

We report a fetus with osteogenesis imperfecta (OI) first diagnosed by ultrasound in routine prenatal examination and further evaluated by magnetic resonance imaging (MRI). Fetal MRI was undertaken with a 1.5-T magnet using a body-phased array coil and an ultrafast imaging technique, half-Fourier single-shot turbo spin-echo (HASTE). Radiological examination shortly after birth and postmortem examination confirmed the prenatal diagnosis. In this case, fetal MRI provided excellent spatial and tissue resolution with multiplanar display. It revealed additional diagnostic information and improved imaging conspicuity. MRI complemented sonography for further differentiating clinical and sonographic findings.

Urolithiasis in pregnancy.

BACKGROUND: The aim of this study was to review our experience in the diagnosis and management of urolithiasis in pregnant women, and to discuss safety, appropriate diagnostic tools and treatment modalities with review of literatures. METHODS: Nine women with pregnancy proved to have urolithiasis were included in this study. The diagnosis was made according to their symptoms and signs, and ultrasonographic findings. Conservative treatment with hydration, analgesics and antibiotics was applied initially, followed by some minimally invasive procedures, including percutaneous nephrostomy (PCN), double J (DBJ) stenting and ureterorenoscopy (URS), if initial treatment failed. RESULTS: All patients received conservative treatment at first, and 4 patients got well till delivery, another 5 patients needed further minimally invasive procedures; 1 of them received DBJ stenting, another 1 received PCN first and changed to DBJ stenting. The remaining 3 patients were treated by ureterorenoscopy with stone manipulation. All these 5 patiens had full-term delivery without obstetric sequela, except 1 patient who received left salpingoophrectomy due to left ovarian abscess. CONCLUSIONS: During pregnancy, urolithiasis is a diagnostic and therapeutic challenge. Clinical symptoms and signs are most important in establishing diagnosis, and ultrasound examination adds accuracy. Minimally invasive procedures (such as PCN, DBJ stenting, URS) can facilitate the successful management of patients requiring further intervention due to failure of conservative treatment.

Imaging quality and diagnostic reliability of low-dose computed tomography lumbar spine for evaluating patients with spinal disorders.

BACKGROUND CONTEXT: Computed tomography (CT) scans of the lumbar spine (CTLS) have demonstrated a higher level of accuracy than plain films and have been used to assess patients with spinal disorder when magnetic resonance imaging is not available. Nevertheless, radiation exposure remains a serious safety concern. Iterative reconstruction (IR) decreases the CT radiation dose for diagnostic imaging. However, the feasibility of using IR in CTLS is unclear. PURPOSE: To evaluate the imaging quality and diagnostic reliability of CTLS with IR. STUDY DESIGN: A prospective study. PATIENT SAMPLE: All patients from outpatient departments who suffered from spinal disorders and were referred for CTLS. OUTCOME MEASURES: In acquired CT images, the signal-to-noise ratio (SNR) of the dural sac (DS), intervertebral disc (IVD), psoas muscle (PM), and L5 vertebral body, the contrast-to-noise ratio between the DS and IVD (D-D CNR), and the subjective imaging qualities were compared across groups. Interobserver agreement was evaluated with kappa values. METHODS: Patients receiving low radiation CTLS were divided into three groups. A 150 mAs tube current with 120 kVp tube voltage was used with Group A and a 230 mAs tube current with 100 kVp tube voltage with Group B. Intended end radiation exposure was 50% less than that of the control group. Tube modulation was active for all groups. The images of the two low-radiation groups were reconstructed by IR; those of the control group by filtered back-projection (FBP). RESULTS: The SNRs of the DS, IVD, PM, BM, and D-D CNR of Group A were not inferior to those of the control group. All SNRs and D-D CNRs for Group B were inferior to those of the control group. Except for that of the facet joint, all subjective imaging ratings for anatomic regions were equivalent between Groups A and B. Interobserver agreement was highest for the control group (0.72-0.88), followed by Group A (0.69-0.83) and B (0.55-0.83). CONCLUSIONS: Fifty percent tube current reduction combined with IR provides equivalent diagnostic accuracy and improved patient safety when compared with conventional CTLS. Our results support its use as a screening tool. With the tube modulation technique, further adjustments in weighting IR and FBP algorithms based on body mass index become unnecessary.