High resolution magnetic resonance imaging of urethral anatomy in continent nulliparous pregnant women

Introduction

To quantify the distribution of morphologic appearances of urethral anatomy and measure variables of urethral sphincter anatomy in continent, nulliparous, pregnant women by high resolution magnetic resonance imaging (MRI).

Materials and methods

We studied fifteen women during their first pregnancy. We defined and quantified bladder neck and urethral morphology on axial and sagittal MR images from healthy, continent women.

Results

The mean (±standard deviation) total transverse urethral diameter, anterior–posterior diameter, unilateral striated sphincter muscle thickness, and striated sphincter length were 15 ± 2 mm (range: 12–19 mm), 15 ± 2 mm (range: 11–20 mm), 2 ± 1 mm (range: 1–4 mm), and 13 ± 3 mm (range: 9–18 mm) respectively. The mean (±standard deviation) total urethral length on sagittal scans was 22 ± 3 mm (range: 17.6–26.4 mm).

Discussion

Advances in MR technique combined with anatomical and histological findings will provide an insight to understand how changes in urethral anatomy might affect the continence mechanisms in pregnant and non-pregnant, continent or incontinent individuals.     

Quadricep and hamstring activation during drop jumps with changes in drop height

Objective

Compare the muscle activation patterns of the quadricep-hamstring during drop jumps with increasing demands of drop heights.

Design

Observational.

Setting

University biomechanics laboratory.

Participants

Fifteen male and eight female college physical education students.

Main outcome measures

Electromyographic activity of the rectus femoris (RF) and biceps femoris (BF) during the landing and takeoff phase of drop jumps from 20 to 60-cm heights. The ground contact time, vertical ground reaction force (vGRF), knee flexion angle during ground contact, and jump height after takeoff were also analyzed.

Results

The activation of RF was higher in the drop jump from 60-cm than that from 20- and 30-cm (comparing 107.0 ± 45.9 to 82.3 ± 30.8 and 88.9 ± 38.9 %MVIC, P < .05) during the landing phase. Activation of BF remained similar across all drop heights. Drop jump from 60-cm resulted in greater contact time during takeoff phase and peak vGRF, and resulted in greater maximum knee flexion but straighter knee at ground contact than from lower drop heights.

Conclusion

At drop height of 60-cm, the altered knee muscular activation and movement patterns may diminish the effectiveness of plyometric training and increase the potential injury risk of knee.     

Game analysis and energy requirements of paddle tennis competition

Objective

To determine the physiological demands as well as the structural characteristics of the competitive practice of paddle tennis.

Equipment and methods

A total of 12 top level male players (age, mean ± standard deviation: 16.57 ± 1.51 years) participated in the study. Twenty-four hours before paddle tennis competition, subjects performed a graded exercise test on a treadmill to determine maximal oxygen uptake, second ventilatory threshold, and maximal heart rate. Total time of game, in-play-time, and out-of-play-time were registered in 12 simulated paddle tennis matches, recording also the frequency and typology of the strokes performed by the analyzed subjects. In addition, oxygen uptake and heart rate values were continuously obtained during the competitive effort.

Results

Mean oxygen uptake values measured during paddle tennis competition reached values below 50% of maximal oxygen uptake assessed in treadmill test, whereas the mean value for heart rate during the matches represented approximately a 74% maximal heart rate reached in the same laboratory test. On the other hand, in-play-time:out-of-play-time ratio was 1:1 s, being the direct strokes, and especially the volley, those which showed higher frequency scores.     

Radiation Dose from Diagnostic Computed Tomography in Saskatchewan

Objective

To calculate the effective dose from diagnostic computed tomography (CT) scans in Saskatchewan, Canada, and compare with other reported dose levels.

Methods

Data from CT scans were collected from 12 scanners in 7 cities across Saskatchewan. The patient age, scan type, and selected technique parameters including the dose length product and the volume computed tomography dose index were collected for a 2-week period. This information then was used to calculate effective doses patients are exposed to during CT examinations. Data from 2,061 clinically indicated CT examinations were collected, and of them 1,690 were eligible for analysis. Every examination during a 2-week period was recorded without selection.

Results

The average provincial estimated patient dose was as follows: head, 2.7 mSv (638 scans; standard deviation [SD], ±1.6); chest, 11.3 mSv (376 scans; SD, ±8.9); abdomen-pelvis, 15.5 mSv (578 scans; SD, ±10.0); abdomen, 11.7 mSv (80 scans; SD, ±11.48), and pelvis, 8.6 mSv (18 scans; SD, ±6.04). Significant variation in dose between the CT scanners was observed (P = .049 for head, P = .001 for chest, and P = .034 for abdomen-pelvis).

Conclusions

Overall, the estimated dose from diagnostic CT examinations was similar to other previously published Canadian data from British Columbia. This dose varied slightly from some other published standards, including being higher than those found in a review conducted in the United Kingdom in 2003.     

Hydrogen MR spectroscopy of neck masses

Purpose

The purpose of this study is to evaluate the role of MR spectroscopy in differentiation between benign and malignant neck masses.

Materials and methods

Thirty-two patients having neck masses underwent routine MRI of the neck as well as Hydrogen 1 (¹H) MR spectroscopy with echo time of 270 ms at 1.5 T. Peak amplitudes of choline (Cho) & creatine (Cr) for each lesion as well as normal appearing muscle of the neck were obtained. Results were compared by using a nonparametric t test.

Results

Thirty-two lesions were included (14 benign) & (18 malignant). Mean value (±standard deviation) was 4.42 ± 0.83 for malignant tumors and 1.93 ± 0.74 for benign tumors. Also spectra were obtained from normal appearing muscles with average Cho/Cr ratio 1.59 ± 0.49. Differences were significant between benign & malignant tumors as well as between malignant tumors & normal appearing muscles (p value < 0.001). No significant difference could be detected between benign tumors & normal appearing muscles (p value = 0.91).

Conclusion

MR spectroscopy should be used in the future as a complementary method to routine MRI to differentiate between benign and malignant lesions.     

Optimized contrast volume for dynamic CT angiography in renal transplant patients using a multiphase CT protocol

Objectives

To study the feasibility of an optimized multiphase renal-CT-angiography (MP-CTA) protocol in patients with history of renal transplantation compared with Doppler-ultrasound (DUS).

Methods

36 Patients underwent both DUS and time-resolved, MP-CTA (12 phases), with a mean contrast-volume of 34.4 ± 5.1 ml. Quality of MP-CTA was assessed quantitatively (vascular attenuation) and qualitatively (grades 1–4, 1 = best). For the assessment of clinical value of MP-CTA, cases were grouped into normal, macrovascular (arterial/venous) and microvascular complications (parenchymal perfusion defect). DUS served as the standard of reference.

Results

Using the best of 12 phases in each patient, optimal attenuation was 353 ± 111 HU, 337 ± 98 HU and 164 ± 51 HU in the iliac arteries, renal arteries, and renal veins, respectively. Mean image quality was 1.1 ± 0.3 (n = 36) and 2.1 ± 0.6 (n = 30) for the transplant renal arteries and veins, respectively. Six renal veins were non-diagnostic in MP-CTA. In 36 patients, MP-CTA showed 13 vascular complications and 10 parenchymal perfusion defects. DUS was not assessable in eight patients. Overall, MP-CTA showed 15 cases with pathology (42%) not identifiable with DUS. The mean effective radiation dose of the MP-CTA protocol was 13.5 ± 5.2 mSv.

Conclusion

MP-CTA can be sufficiently performed with reduced contrast volume at reasonable radiation dose in renal transplant patients, providing substantially higher diagnostic yield than DUS.     

Paradoxical signal pattern of mediastinal cysts on T2-weighted MR imaging: phantom and clinical study

Purpose

To evaluate the intracystic MRI (magnetic resonance imaging) signal intensity of mediastinal cystic masses on T2-weighted images.

Materials and methods

A phantom study was performed to evaluate the signal intensity of a mediastinal cystic mass phantom (rubber balloon containing water) adjacent to a cardiac phantom pulsing at the rate of 60/min. T2-weighted images (sequence, fast spin echo [FSE] and single shot fast spin echo [SSFSE]) were acquired for the mediastinal cystic mass phantom. Further, a clinical study was performed in 33 patients (16 men, 17 women; age range, 19-85 years; mean, 65years) with thymic cysts or pericardial cysts. In all patients, T2-weighted images (FSE and SSFSE) were acquired. The signal intensity of cystic lesion was evaluated and was compared with that of muscle. A region of interest (ROI) was positioned on the standard MR console, and signal intensity of the cystic mass (cSI), that of the muscle (mSI), and the rate of absolute value of cSI–mSI to standard deviation (SD) of background noise (|cSI–mSI|/SD = CNR [contrast-to-noise ratio]) were measured.

Results

The phantom study demonstrated that the rate phantom-ROI/saline-ROI was higher in SSFSE (0.36) than in FSE (0.19). In clinical cases, the degree of the signal intensity was higher in SSFSE than in FSE. The CNR was significantly higher in SSFSE (mean ± standard deviation, 111.0 ± 47.6) than in FSE (72.8 ± 36.6) (p < 0.001, Wilcoxon signed-rank test).

Conclusions

Anterior mediastinal cysts often show lower signal intensity than the original signal intensity of water on T2-weighted images. SSFSE sequence reduces this paradoxical signal pattern on T2-weighted images, which may otherwise cause misinterpretation when assessing cystic lesions.     

MR pelvimetry measurements, analysis of inter- and intra-observer variation

Objective

To set reference standards and then to evaluate the measurement variation in magnetic resonance (MR) pelvimetry between observations and observers.

Methods

The study was carried out retrospectively using 100 MR pelvimetry examinations performed in North Carelian Central Hospital between September 2006 and January 2008. Pelvimetric parameters of pelvic inlet and outlet were measured four times to determine the standard reference for each measurement and then intra- and inter-observer variations were compared.

Results

The accuracy of MR pelvimetry, defined as a deviation of <5 mm from the reference standard, was better in pelvic inlet measurements than in the corresponding outlet measurements (95-99% vs. 86-89%). Intra-observer variation was acceptable in all of the measurements with intraclass correlation coefficient (ICC) in the range 0.956-0.981 in all parameters. Inter-observer variation was higher than intra-observer variation. The largest variation of measurements was in pelvic outlet parameters between observers with the ICC in the range of 0.710-0.813.

Conclusion

MR pelvimetry measurement should be conducted in a centralized location to decrease observer-related variation. Clinicans should be aware that millimeter differences are not reliable in MR pelvimetry and therefore the use of millimeter accurate limits are not recommended in obstetric decision making.     

Does final component alignment correlate with alignment of the bone resection surfaces in cemented total knee arthroplasty?

Purpose

To examine, with a navigation, whether the final component alignments correlate with alignment of the bone resection surfaces in cemented total knee arthroplasty (TKA), and to evaluate the factors affecting alignment deviation.

Methods

A total of 222 patients (276 knees) who underwent navigation-assisted TKA between September 2012 and January 2014 due to osteoarthritis were retrospectively reviewed. The deviation between the alignment of bone resection surfaces and the final alignment of femoral and tibial components was measured. Factors associated with alignment deviation of greater than 2° (outliers) were evaluated. These included age, sex, body mass index, bone mineral density (T score), preoperative and postoperative mechanical femorotibial angle, preoperative and postoperative flexion contractures, and the difference between medial and lateral gaps in knee extension or flexion.

Results

Outliers consisted of 24 cases (8.6%) on the femoral coronal plane, 4 cases (1.4%) on the tibial coronal plane, and 48 cases (17.4%) on the tibial sagittal plane. In the coronal plane (femur and tibia), the outliers were associated with preoperative [p < 0.001; odds ratio (OR) 0.774; 95% confidence interval (CI) 0.672–0.891] and postoperative (p < 0.001; OR 0.240; 95% CI 0.123–0.468) flexion contractures; a difference of 3 mm or more between the medial and lateral gaps in knee extension (p < 0.041; OR 5.805; 95% CI 1.075–31.343); and a T score of less than ?2.5(p < 0.024; OR 5.899; 95% CI 1.258–27.664). In the sagittal plane of the tibia, the outliers were associated with preoperative (p < 0.001; OR 0.886; 95% CI 0.829–0.946) and postoperative (p < 0.031; OR 0.803; 95% CI 0.659–0.980) flexion contractures.

Conclusion

There was a deviation between the alignments of the bone resection surfaces and the final alignments of components. With larger preoperative and postoperative flexion contractures in the coronal and sagittal planes, there were more outlier risks. The outliers in the coronal plane were associated with a difference of 3 mm or more between the medial and lateral gaps in knee extension and poor bone quality. Awareness of such alignment deviation and related factors can help diminish the outliers after TKA.

Level of evidence

IV.

     

Conventional versus doxorubicin-eluting bead transarterial chemoembolization for hepatocellular carcinoma

Purpose

To compare short- and long-term clinical outcomes after conventional transarterial chemoembolization and drug-eluting bead (DEB) transarterial chemoembolization in hepatocellular carcinoma (HCC).

Materials and Methods

Patients with unresectable HCC unsuitable for ablative therapies were randomly assigned to undergo conventional or DEB chemoembolization. The primary endpoints of the study were safety, toxicity, and tumor response at 1 month. Secondary endpoints were number of repeated chemoembolization cycles, time to recurrence and local recurrence, time to radiologic progression, and survival.

Results

In total, 67 patients (mean age, 70 y ± 7.7) were evaluated. Mean follow-up was 816 days ± 361. Two periprocedural major complications occurred (2.9%) that were treated by medical therapy without the need for other interventions. A significant increase in alanine aminotransferase levels 24 hours after treatment was reported, which was significantly greater after conventional chemoembolization (n = 34) than after DEB chemoembolization (n = 33; preprocedure, 60 IU ± 44 vs 74 IU ± 62, respectively; at 24 h, 216 IU ± 201 vs 101 IU ± 89, respectively; P = 0.007). No other differences were observed in liver toxicity between groups. At 1 month, complete and partial tumor response rates were 70.6% and 29.4%, respectively, in the conventional chemoembolization group and 51.5% and 48.5%, respectively, in the DEB chemoembolization group. No differences were observed between groups in time to recurrence and local recurrence, radiologic progression, and survival.

Conclusions

Conventional chemoembolization and DEB chemoembolization have a limited impact on liver function on short- and long-term follow-up and are associated with favorable clinical outcomes.     

Prevention of intraprocedural puncture site bleeding during arterial port implantation by use of a suture-mediated arterial closure system: a prospective randomized trial

Purpose

To investigate a modified technique for arterial port placement that uses a suture-mediated closure system with the aim to reduce delays caused by intraprocedural oozing around the catheter.

Materials and Methods

Forty consecutive patients (age, 63.9 y ± 11.8) stratified for regional arterial infusion chemotherapy were prospectively randomized to undergo conventional or modified port implantation. Time for device placement, total procedure time, number of catheters, size of largest and final catheters placed, duration of bleeding from puncture site, procedural delays, and time until hemostasis was achieved were recorded.

Results

Time for device placement was 3.7 minutes ± 1.1, with no complications encountered. Total procedure times were 133.0 minutes ± 62.8 for conventional port implantation and 100.0 minutes ± 49.5 for modified implantation (P = .13). No differences were found in the number of catheters or size of largest or final catheter used. Duration of groin bleeding necessitating manual compression was 21.8 minutes ± 24.4 for conventional port implantation, resulting in a mean procedural delay of 6.2 minutes ± 7.0. Hemostasis was achieved after a mean of 17.1 minutes ± 20.9. Groin hematoma was observed in three patients. In contrast, with the modified technique, mean duration of oozing and intraprocedural delays were only 0.2 minutes ± 0.6 and 0.1 minutes ± 0.5, respectively (both P < .0001 vs conventional technique). Hemostasis was achieved within 3.2 minutes ± 4.1 (P < .0001), with no cases of hematoma found.

Conclusions

Use of a suture-mediated closure system facilitated arterial port implantation by effective prevention of groin bleeding while allowing the use of a sheath.     

Técnicas de recanalización vertebrobasilar antes de la introducción de las endoprótesis recuperadoras: la reapertura no es sinónimo de buena evolución

Objectives

To evaluate the recanalization rate and clinical outcome three months after endovascular treatment for vertebrobasilar occlusion before the placement of stentrievers.

Material and methods

We reviewed all cases of basilar thrombosis treated with endovascular techniques at our center. We reviewed the clinical outcomes with the main objective of determining the recanalization rate and the secondary objective of evaluating the outcome using the modified Rankin scale (mRS) three months after treatment. We assessed clinical and angiographic variables and correlated them with outcome and complications.

Results

We reviewed a total of 27 consecutive patients (mean age, 58.1 ± 15.5 y; median National Institutes of Health Stroke Scale (NIHSS), 21, interquartile range, 18-29; median Glasgow coma score (GCS) 7, interquartile range, 4-9.5). The mean time between the onset of symptoms and endovascular treatment was 26.3 ± 41.7 hours. Complete or partial recanalization was achieved in 23 (85.1%) patients. Three months after treatment, 16 (59.2%) had died and 6 (22.2%) had good outcome (mRS ≤ 2).

Conclusion

Endovascular treatment achieved a high rate of recanalization of occlusions of the basilar artery. Nevertheless, a high percentage of the patients did not have a good outcome. New materials might improve the prognosis in these patients.     

The story of 12 Chachapoyan mummies through multidetector computed tomography

Objective

To assess the imaging findings in Chachapoyan mummies of Peru through multidetector computed tomography (MDCT).

Materials and methods

Twelve human mummies and three burial objects from Laguna de los Cóndores, Peru, about 500-1000 years old, were studied, using a MDCT unit. In addition to the standard whole-body acquisitions, high-resolution scans from areas of particular interest were acquired individually (e.g., temporal bone, teeth).

Results

Eight mummies were female, three male, and sex was indeterminable in one mummy; the age of the mummies included newborn, 0.7 years, 2.5 years, 13 years, 13 years, 16 years, and six between 20 and 40 years old. The stature of the mummies was reconstructed (mean ± standard deviation; adults: 145 ± 14 cm, adolescents: 116 ± 17 cm, 2.5 years old child: 72 cm, newborns: 41 ± 3 cm). Dental conditions were compromised in seven and excellent in five mummies. Besides a dislocation of the ossicles, temporal bones and ears were normal in all mummies. An occipital osteoma, a tuberculous spondylodiscitis, and also probable tuberculous erosions at one tarsal joint and one sacral bone, osteoarthritis or tuberculous affection of a sacroiliac joint, as well as five cases of pulmonary tuberculosis were observed. Ten mummies were buried in the fetal position, two were found packaged in bundles; the burial technique was studied in detail. A necklace was found with one mummy. The added burial objects were identified as skeletal parts of two leopardis pardalis and one lagothrix flavicauda.

Conclusions

MDCT non-invasively revealed information about age, sex, stature, diseases, burial practices and other cultural aspects of the Chachapoyas.     

Uterine septum structure and reproductive performance: Role of 3D TVUS and MRI

Objective

To evaluate the role 3D TVUS and MRI in diagnosing the nature of uterine septum according to the reproductive performance with histopathological examination as the reference standard.

Patients and methods

The study included 36 patients in the reproductive age presented with infertility or recurrent pregnancy loss, and diagnosed hysteroscopically with double uterine cavity. All patients were subjected to 3D TVUS. Cases in which the diagnosis of septate uterus was not confirmed by 3DUS were excluded from the study. The remaining 29 patients confirmed to have uterine septum partial or complete were included. 3D TVUS with VOCAL, was applied in order to calculate the volume of the septum, echostructure and its vascularity index (VI). The patients were then referred to MRI examination, patients were referred to operative hysteroscopy for hysteroscopic metroplasty. Sample of septal tissue was obtained and sent for histopathological examination.

Results

The Vascularity index (VI) of the muscular septum (16.63 ± 5.7%) was significantly higher than the fibrous septum (3.6 ± 1.17%). The sensitivity, specificity, PPV, and NPV in diagnosing septate uterus were 100%, 90 %, 95%, and 100% for 3D TVUS, and 95%, 80%, 90%, and 89% for MRI respectively.

Conclusion

3D TVUS is an accurate, less expensive, and a rapid examination than MRI in diagnosing uterine septa structure, it can be considered as the reference standard in diagnosing and characterizing septate uterus.     

T2-weighted hypointense lesions within prostate gland: Differential diagnosis using wash-in rate parameter on the basis of dynamic contrast-enhanced magnetic resonance imaging—Hystopatology correlations

Background and aims

Dynamic contrast enhanced magnetic resonance improves prostate cancer detection. The aims of this paper are to verify whether wash-in-rate parameter (speed of contrast uptake in dynamic contrast enhanced magnetic resonance) can help to differentiate prostate cancer from non-neoplastic T2-weighted hypointense lesions within prostate gland and to assess a cut-off for prostate cancer diagnosis.

Methods

Prospective, monocentric, multi-departmental study. Thirty consecutive patients underwent T2-weighted and dynamic contrast enhanced magnetic resonance, and re-biopsy. T2-weighted hypointense lesions, >5 mm in size, were noted. Lesions were assessed as cancerous (showing mass effect, or no defined margin within transitional zone) and non cancerous (no mass effect) and were compared with histopathology by 2 × 2 tables. Wash-in-rate of each lesion was calculated and was correlated with histopathology. Student's t-test was adopted to assess significant differences. Receiver operating characteristic (ROC) analysis was employed to identify the best cut-off for wash-in-rate in detecting prostate cancer.

Results

At re-biopsy, cancer was proven in 43% of patients. On T2-weighted MRI, 111 hypointense lesions ≥5 mm in size were found. Sensitivity, specificity and accuracy of T2-weighted MRI were 80% (±12.4 CI 95%), 74.6% (±10.1 CI 95%), and 76.5% (±7.9 CI 95%), respectively. Mean WR was 5.8 ± 1.9/s for PCa zones and 2.96 ± 1.44/s for non-PCa zones (p < 0.00000001). At ROC analysis, the best area under curve (AUC) for wash-in-rate parameter was associated to 4.2/s threshold with 82.5% sensitivity (CI ± 7.07), 97.2% specificity (CI ± 4.99) and 91.2% accuracy (CI ± 5.27). Eighteen false positive lesions on T2-weighted MRI showed low wash-in-rate values suggesting non-cancer lesions, while in 5/8 false negative cases high wash-in-rate values correctly suggested prostate cancer. Nine lesions with surgically proven cancer were not included in the saturation biopsy scheme, in 2/9 cases the only site of cancer.

Conclusions

Wash-in-rate parameter allows to differentiate prostate cancer from non-neoplastic lesions, helping cancer detection in areas not included in the biopsy scheme.     

Vertebral split fractures: Technical feasibility of percutaneous vertebroplasty

Objective

The treatment of vertebral split fractures remains controversial, consisting of either corset or internal fixation. The aim of this study was to evaluate the technical feasibility of CT- and fluoroscopy-guided percutaneous vertebroplasty in the treatment of vertebral split fractures.

Materials and methods

Institutional review board approval and informed consent were obtained for this study. Sixty-two consecutive adult patients who had post-traumatic vertebral split fractures (A2 according to the AO classification) without neurological symptoms were prospectively treated by percutaneous vertebroplasty. All these procedures were performed by an interventional radiologist under computed tomography (CT) and fluoroscopy guidance by using only local anaesthesia. Postoperative outcome was assessed using the visual analogue scale (VAS) and Oswestry disability index (ODI) scores.

Results

Vertebroplasty was performed on thoracic and lumbar vertebrae, creating a cement bridge between the displaced fragment and the rest of the vertebral body. Seven discal cement leakages (11%) were observed, without occurrence of adjacent vertebral compression fractures. The mean VAS measurements ± standard deviation (SD) significantly decreased from 7.9 ± 1.5 preoperatively to 3.3 ± 2.1 at 1 day, 2.2 ± 2.0 at 1 month, and 1.8 ± 1.4 at 6 months (P < 0.001). The mean ODI scores ± SD had also a significant improvement: 62.3 ± 17.2 preoperatively and 15.1 ± 6.0 at the 6-month follow-up (P < 0.001).

Conclusion

This study suggests that type A2 vertebral fractures could be successfully treated by CT- and fluoroscopy-guided percutaneous vertebroplasty.     

Non-contrast-enhanced hepatic MR angiography: Do two-dimensional parallel imaging and short tau inversion recovery methods shorten acquisition time without image quality deterioration?

Objective

To study whether shortening the acquisition time for selective hepatic artery visualization is feasible without image quality deterioration by adopting two-dimensional (2D) parallel imaging (PI) and short tau inversion recovery (STIR) methods.

Materials and methods

Twenty-four healthy volunteers were enrolled. 3D true steady-state free-precession imaging with a time spatial labeling inversion pulse was conducted using 1D or 2D-PI and fat suppression by chemical shift selective (CHESS) or STIR methods. Three groups of different scan conditions were assigned and compared: group A (1D-PI factor 2 and CHESS), group B (2D-PI factor 2 × 2 and CHESS), and group C (2D-PI factor 2 × 2 and STIR). The artery-to-liver contrast was quantified, and the quality of artery visualization and overall image quality were scored.

Results

The mean scan time was 9.5 ± 1.0 min (mean ± standard deviation), 5.9 ± 0.8 min, and 5.8 ± 0.5 min in groups A, B, and C, respectively, and was significantly shorter in groups B and C than in group A (P < 0.01). The artery-to-liver contrast was significantly better in group C than in groups A and B (P < 0.01). The scores for artery visualization and overall image quality were worse in group B than in groups A and C. The differences were statistically significant (P < 0.05) regarding the arterial branches of segments 4 and 8. Between group A and group C, which had similar scores, there were no statistically significant differences.

Conclusion

Shortening the acquisition time for selective hepatic artery visualization was feasible without deterioration of the image quality by the combination of 2D-PI and STIR methods. It will facilitate using non-contrast-enhanced MRA in clinical practice.     

MELD Score as a Predictor of Early Death in Patients Undergoing Elective Transjugular Intrahepatic Portosystemic Shunt (TIPS) Procedures

Purpose To Evaluate the MELD score as a predictor of 30-day mortality in patients undergoing elective TIPS procedures.Methods This was a retrospective, IRB-approved study. The medical records of all patients who underwent a TIPS procedure between May 1, 1999 and June 1, 2003 in a single institution were reviewed. Patients who underwent elective TIPS were selected. Elective TIPS was performed in 119 patients with a mean age of 55.1 (± 9.6) years. The MELD and Child-Pugh scores before TIPS, etiology of cirrhosis, portosystemic gradients before and after TIPS, procedure time, and procedural complications were obtained from the medical records. The MELD and Child-Pugh scores before TIPS were compared between the survivor group (SG) and the early death (EDG) group. The early death rate was calculated for MELD score subgroups (1–10, 11–17, 18–24, and >24). Data were analyzed using the Fisher exact test, chi-square test and independent-sample t-test. A p value of less than 0.05 was considered significant.Results Technical success rate was 100%. The early death rate was 10.9% (13/119). The mean MELD scores before TIPS were 19.4 (± 5.9) (EDG) and 14 (± 4.2) (SG) (p=0.025). The early death rate was highest in the pre-TIPS MELD > 24 subgroup. The Child-Pugh scores were 9.0 (± 1.6) (SG) and 9.8±1.06 (EDG) (p=0.08). The mean portosystemic gradients before TIPS were 20.5 (± 7.7) mmHg (EDG) and 22.7 (± 7.3) (SG) (p > 1) and the mean portosystemic gradients after TIPS were 6.5 (± 3.5) (EDG) and 6.9 (± 2.4) (SG) (p > 1). The mean procedural times were 95.6 (± 8.4) min (EDG) and 89.2 (± 7.5) min (SG) (p > 1). No early death was attributed to a fatal complication during TIPS.Conclusion The MELD score is useful in identifying patients at a higher risk of early death after an elective TIPS. On th basis of our results, we do not endorse elective TIPS in patients with MELD scores > 24.     

Development of a nomogram combining clinical staging with <Superscript>18</Superscript>F-FDG PET/CT image features in non-small-cell lung cancer stage I–III

Purpose

Our goal was to develop a nomogram by exploiting intratumour heterogeneity on CT and PET images from routine ¹⁸F-FDG PET/CT acquisitions to identify patients with the poorest prognosis.

Methods

This retrospective study included 116 patients with NSCLC stage I, II or III and with staging ¹⁸F-FDG PET/CT imaging. Primary tumour volumes were delineated using the FLAB algorithm and 3D Slicer? on PET and CT images, respectively. PET and CT heterogeneities were quantified using texture analysis. The reproducibility of the CT features was assessed on a separate test–retest dataset. The stratification power of the PET/CT features was evaluated using the Kaplan-Meier method and the log-rank test. The best standard metric (functional volume) was combined with the least redundant and most prognostic PET/CT heterogeneity features to build the nomogram.

Results

PET entropy and CT zone percentage had the highest complementary values with clinical stage and functional volume. The nomogram improved stratification amongst patients with stage II and III disease, allowing identification of patients with the poorest prognosis (clinical stage III, large tumour volume, high PET heterogeneity and low CT heterogeneity).

Conclusion

Intratumour heterogeneity quantified using textural features on both CT and PET images from routine staging ¹⁸F-FDG PET/CT acquisitions can be used to create a nomogram with higher stratification power than staging alone.

     

Incidence and management of inferior vena cava filter thrombus detected at time of filter retrieval

Purpose

To evaluate inferior vena cava (IVC) venograms (ie, cavograms) before filter retrieval to determine the incidence and volume of filter thrombus relative to filter dwell time and evaluate subsequent changes in thrombus volume with additional anticoagulation.

Materials and Methods

IVC filter retrieval attempts between December 2002 and June 2010 were retrospectively reviewed to determine the incidence of filter thrombus and estimate thrombus volume on a preretrieval cavogram. Correlation between filter dwell times (assessed at 30-d intervals) and incidence and volume of thrombus was assessed. Follow-up images and management of filters with thrombus that were not initially removed were analyzed.

Results

A total of 463 retrieval attempts were performed in 440 patients, with a mean filter dwell time of 95 days ± 145 (SD; range, 0–1,762 d). Thirty (6.5%) had filter thrombus on initial cavograms, with a mean thrombus volume of 2.8 cm³ ± 7.3 (range, 0.04–40.02 cm³). Incidence rate and estimated thrombus volume were highest in the 0–30-day dwell interval (8.0% and 6.3 cm³, respectively) and decreased at subsequent time intervals. On linear regression analysis, incidence of filter thrombus was inversely related to dwell time (P < .05; correlation coefficient, −0.86). Seven patients with thrombus underwent additional anticoagulation for a mean of 48 days ± 25 (range, 14–90 d); thrombus resolved completely in five (71%) and partially in one (14%), and increased in one (14%).

Conclusions

The incidence of filter thrombus at the time of filter retrieval appears to decrease with dwell time. If thrombus is detected, an additional period of anticoagulation is likely to reduce the thrombus burden and facilitate later retrieval.