Dynamic susceptibility contrast perfusion MR imaging in distinguishing malignant from benign head and neck tumors: A pilot study

Purpose

To preliminarily investigate the utility of dynamic susceptibility contrast perfusion MR imaging in distinguishing malignant from benign head and neck tumors.

Material and methods

Seventy eight patients with head and neck masses underwent single shot dynamic susceptibility contrast T2*-weighted perfusion weighted MR imaging after bolus infusion of gadolinium-DTPA was administrated. The signal intensity time curve of the lesion was created. Dynamic susceptibility contrast percentage (DSC%) was calculated and correlated with pathological findings.

Results

The mean DSC% of malignant tumor (n = 40) was 39.3 ± 9.6% and of benign lesions (n = 38) was 24.3 ± 10.3%. There was a statistically significant difference of the DSC% between benign and malignant tumors (P = 0.001) and within benign tumors (P = 0.001). When DSC% of 30.7% was used as a threshold for differentiating malignant from benign tumors, the best results were obtained: accuracy of 84.6%, sensitivity of 80% and specificity of 89.2%.

Conclusion

Dynamic susceptibility contrast perfusion weighted MR imaging is a non-invasive imaging technique that can play a role in differentiation between malignant and benign head and neck tumors.     

Abdominal aspergillosis: CT findings

Objective

In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients.

Materials and methods

CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome.

Results

All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum.

Conclusion

Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.     

Impact of image noise levels, scout scan dose and lens shield on image quality and radiation exposure in z-axis dose-modulated neck MSCT on 16- and 64-slice Toshiba Aquilion scanners

Objective

Assessing the impact of image noise (IN) levels, scout scan dose and lens shield use on image quality and radiation exposure in neck multislice CT (MSCT) when using z-axis dose modulation (DM).

Methods

Neck MSCT phantom studies with/without z-axis DM were performed by using different IN levels (S.D. 7.5-30 HU) and scout scan tube currents (7.5-50 mA) on Toshiba Aquilion scanners (16-/64-slice). Image quality indices were evaluated by two radiologists and radiation exposure parameters calculated. Cadaveric phantom measurements elucidated lens shield interactions with DM efficacy. The lowest dose scan protocol with diagnostic image quality was introduced into the clinical imaging routine and retrospectively evaluated in 20 age-matched patients undergoing neck MSCT with/without DM.

Results

The highest image noise level in DM neck studies with comparable image quality to standard neck CT amounted to 20 HU, resulting in a mean tube current of 50 mAs (CTDI_w 6.3 mGy). DM reduced effective dose by 35% and organ dose figures (lens, thyroid) by 33%. Scout scan dose lowering to 20 mA resulted in an effective dose (ED) decrease of 0.06 mSv (5%). Avoiding lens shield placement during scout scan effected an organ dose decrease of 20%. Overall contour sharpness and image contrast did not differ significantly (DM/without DM) whereas image noise was rated higher in DM neck CT studies (p < 0.05).

Conclusions

z-Axis dose modulation, as assessed on 16- and 64-slice Toshiba Aquilion scanners, is effective and mandatory in neck MSCT. DM efficacy can be enhanced by optimising scout scan doses and lens shield use.     

Endovascular treatment of abdominal aortic paraanastomotic pseudoaneurysms after surgical reconstruction

Purpose

To evaluate the efficacy of endovascular treatment of paraaortic postoperative abdominal aortic pseudoaneurysms.

Materials and methods

From April 1996 to November 2007 five men with paraaortic postoperative abdominal aortic pseudoaneurysm underwent endovascular treatment. Average age was 64.2 years (range 54-73). The average time interval between the primary surgery and endovascular treatment was 12.4 years (4 months-23 years). Three patients were treated by aortouniiliacal stentgrafts and two patients by tube stentgrafts.

Results

Technical success rate was 100%. Pseudoaneurysms were primarily excluded from circulation without perioperative complications in all patients. At follow-up (mean 38.5 months) there were no deaths and no endoleaks. In one patient thrombosis of stentgraft was found and it was successfully treated by thrombectomy. All pseudoaneurysms still continued to be excluded from circulation in the last follow-up.

Conclusion

Endovascular treatment is minimally invasive, effective and safe option of surgery for paraaortic postoperative pseudoaneurysms.     

Radiographic bone texture analysis is correlated with 3D microarchitecture in the femoral head,and improves the estimation of the femoral neck fracture risk when combined with bone mineral density

Purpose

Femoral neck fracture is a major public health problem in elderly persons, representing the main source of osteoporosis-related mortality and morbidity. In this study, we aimed at comparing radiographic texture analysis with three-dimensional (3D) microarchitecture in human femurs, and at evaluating whether bone texture analysis improved the assessment of the femoral neck fracture risk other than that obtainable by bone mineral density (BMD).

Materials and methods

Thirteen osteoporotic femoral heads from patients who fractured their femoral neck and twelve non-fractured femoral heads from osteoarthritic patients were studied using respectively (1) a new high-resolution digital X-ray device (BMA™, D3A Medical Systems) allowing for bone texture analysis with fractal parameter Hmean, and (2) a micro-computed tomograph (CT) for 3D microarchitecture. BMD was measured postoperatively by DXA in all patients in the contralateral femur.

Results

In these femoral heads, we found that fractal parameter Hmean was correlated with 3D microarchitecture parameters: bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular separation (Tb.Sp) and fractal dimension (FD) respectively (p < 0.05). Then, fractal parameter Hmean was significantly lower in the femoral heads from the fractured group than from the non-fractured group (p < 0.01). Finally, multiple regression analysis showed that combining bone texture analysis and total hip BMD significantly improved the estimation of the femoral neck fracture risk from adjusted r² = 0.46 to adjusted r² = 0.67 (p < 0.05).

Conclusion

Radiographic bone texture analysis was correlated with 3D microarchitecture parameters in the femoral head, provided accurate discrimination between the femoral heads from the fractured and non-fractured groups, and significantly improved the estimation of the femoral neck fracture risk when combined with BMD.     

Effect of different saline chaser volumes and flow rates on intravascular contrast enhancement in CT using a circulation phantom

Purpose

To evaluate the influence of different saline chaser volumes and different saline chaser flow rates on the intravascular contrast enhancement in MDCT.

Materials and methods

In a physiological flow phantom contrast medium (120 ml, 300 mgI/ml, Ultravist 300) was administered at a flow rate of 6 ml/s followed by different saline chaser volumes (0, 30, 60 and 90 ml) at the same injection rate or followed by a 30-ml saline chaser at different injection rates (2, 4, 6 and 8 ml/s). Serial CT-scans at a level covering the pulmonary artery, the ascending and the descending aorta replica were obtained. Time-enhancement curves were computed and both pulmonary and aortic peak enhancement and peak time were determined.

Results

Compared to contrast medium injection without a saline chaser the pushing with a saline chaser (30, 60, and 90 ml) resulted in a statistically significant increased pulmonary peak enhancement (all p = 0.008) and prolonged peak time (p = 0.032, p = 0.024 and p = 0.008, respectively). Highest aortic peak enhancement values were detected for a saline chaser volume of 30 ml. A saline chaser flow rate of 8 ml/s resulted in the highest pulmonary peak enhancement values compared to flow rates of 2, 4 and 6 ml/s (all p = 0.008). Aortic peak enhancement showed the highest values for a flow rate of 6 ml/s.

Conclusion

A saline chaser volume of 30 ml and an injection rate of 6 ml/s are sufficient to best improve vascular contrast enhancement in the pulmonary artery and the aorta in MDCT.     

Abdominal vascular and visceral parenchymal contrast enhancement in MDCT: Effects of injection duration

Purpose

To evaluate and compare the effect of short and long injection durations on aortic, pancreatic and hepatic enhancement in abdominal MDCT.

Methods and materials

Triphasic contrast-enhanced CT images (16-MDCT, 1.25-mm collimation, 5-mm thickness, 6.1-s acquisition time for each phase) were obtained with 2 mL/kg injection of 300 mgI/mL iodine contrast material in 116 patients. Patients were prospectively randomized into two groups: one receiving contrast medium for 25-s injection duration and the other for 35-s injection duration. In both groups, triphasic scans were initiated 5, 15, and 40 s after the completion of contrast injection for the first, second and third phases, respectively. CT values (HU) in the abdominal aorta, liver, spleen, pancreas, splenic and superior mesenteric arteries, and veins (splenic, superior mesenteric, portal, and hepatic) were measured. Quantitative and qualitative analysis for the degree of contrast enhancement between the two groups in various organs was compared at each scan phase.

Results

The aortic and arterial enhancements in the first-phase scan were higher for the 25-s group than those of the 35-s group (P < .001). Hepatic enhancement was higher for the 35-s group in the first (P < .001) and second (P < .01) phases, but no difference in the third-phase. No difference was found between the groups for the pancreatic enhancement at any phases. Qualitative results were in good agreement with quantitative results.

Conclusion

Contrast administration with shorter injection duration increased peak aortic and arterial enhancement and contributed to improvement in the quality of CT angiograms, but for the solid abdominal organs 35-s protocol is recommended.     

Pushable springcoil embolization of pseudoaneurysms caused by gluteal stab injuries

Purpose

To retrospectively review the outcomes of 21 patients with stab wounds to the gluteal region who underwent embolization for pseudoaneurysms causing active bleeding.

Materials and methods

Between 1997 and 2007, 3 superior gluteal artery, 2 inferior gluteal artery and 16 deep femoral artery muscular branch pseudoaneurysms detected by digital subtraction angiography were selectively catheterized with diagnostic catheters with hydrophilic coating and embolized with pushable springcoils. 17 of the 21 pseudoaneurysms were located in a distal end of an artery where outflow vessels could not be depicted. The other 4 lesions were side wall injuries which required the placement of coils distal and proximal to the injury site.

Results

Embolization was successful in controlling the bleeding in all of the patients. 16 patients required 1 or 2 coils, 4 patients required 3 coils and 1 patient required 5 coils. 2 patients had femoral puncture site hematomas which resolved spontaneously. 2 patients required surgical evacuation of large gluteal hematomas following the embolization because of symptoms second to mass effect. There were no procedure related major complications or mortality.

Conclusions

Our experience demonstrates that pushable coil embolization is a relatively simple, effective and economic method for the embolization of pseudoaneurysms caused by penetrating gluteal injuries. Experimenting with other embolization materials does not seem to be justified.     

Time-of-flight MR angiography at 3T versus digital subtraction angiography in the imaging follow-up of 51 intracranial aneurysms treated with coils

Objective

To compare 3D time-of-flight MR angiography (TOF-MRA) at 3 Tesla (3 T) with digital subtraction angiography (DSA) for the evaluation of intracranial aneurysm occlusion after endovascular coiling.

Methods

In a prospective study, 51 consecutive patients (25 females, 26 males; median age, 51 years) with 51 saccular aneurysms treated with endovascular coiling underwent simultaneous DSA and 3 T TOF-MRA at follow-up. DSA and TOF-MRA images were analyzed independently by two senior neuroradiologists. Findings were assigned to 1 of 3 categories in the Raymond classification: complete obliteration, residual neck or residual aneurysm. Agreement between observers and techniques was evaluated using κ statistics.

Results

DSA images were not interpretable for one patient. Interobserver agreement was determined as excellent for DSA (κ = 0.86) and TOF-MRA (κ = 0.80). After reaching a consensus, DSA follow-up showed 26 (51%) complete obliterations, 20 (39%) residual necks and 4 (8%) residual aneurysms. TOF-MRA showed 23 (45%) complete obliterations, 22 (43%) residual necks and 6 (12%) residual aneurysms. Comparison between TOF-MRA and DSA showed excellent agreement between the techniques (κ = 0.86). In the four cases that were misclassified, TOF-MRA findings were assigned to a higher class than for DSA.

Conclusion

TOF-MRA at 3 T is at least as efficient as DSA for the evaluation of intracranial aneurysm occlusion after endovascular treatment with detachable coils. We suggest that TOF-MRA at 3 T might be used as the primary method for imaging follow-up of coiled intracranial aneurysms.     

Percutaneous treatment of non-contained lumbar disc herniation by injection of oxygen-ozone combined with collagenase

Purpose

To evaluate the therapeutic results of oxygen-ozone combined collagenase injection for the treatment of lumbar disc herniation compared to the surgery. And to explore the role of this minimally invasive treatment as an alternative to disc surgery.

Materials and methods

Two groups of patients (n = 108) were treated with different ways respectively. Minimally invasive group of patients was treated with the injection of oxygen-ozone combined with collagenase into the lumbar disc or the epidural space; the other group was treated with traditional surgery. After the treatment, the patients were followed-up and the therapeutic effect was assessed at 2 weeks, 3 and 12 months by the modified Macnab criteria.

Results

The success rate was 86.11% and 88.89% in minimally invasive group at 3 and 12 months respectively, while 92.59% and 95.37% in surgical group. There was no statistically significant difference between two groups at 3 and 12 months (P = 0.123, P = 0.08). However, the surgical group produced a statistically significant greater improvement for back pain and disability in the first few weeks (P = 0.0001). The success rate was 51.86% and 85.18% at 2 weeks in minimally invasive group and surgical group respectively. No serious complication occurred in this group.

Conclusions

The combination of the oxygen-ozone with collagenase shows significant reductions in pain and improvements in function at 3 and 12 months, it can be considered as an option for the treatment of non-contained lumbar disc herniation instead of surgery.     

New proposal for the staging of nonalcoholic steatohepatitis: Evaluation of liver fibrosis on Gd-EOB-DTPA-enhanced MRI

Purpose

We investigated whether the gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI was useful for nonalcoholic steatohepatitis (NASH) staging based on the severity of liver fibrosis.

Materials and methods

Twenty-one male Sprague-Dawley rats aged 7 weeks, weighing about 150 g in NASH group were fed a choline-deficient diet for 4, 7 or 10 weeks, and seven rats in the control group were fed a standard diet (n = 7). After the feeding period, the rats were subjected to contrast-enhanced MRI (2D-FLASH; TR/TE = 101/2.9 ms, flip angle 90°). Gd-DTPA (0.1 mmol Gd/kg) and Gd-EOB-DTPA (0.025 mmol Gd/kg) were injected at 24-h intervals, and the speed of contrast injection was 1 mL/s. Signal intensities of the liver were measured and the relative enhancement (RE), the time of maximum RE (T_max) and elimination half-life of RE (T_1/2) in the liver were compared. The fibrosis rate (%) was calculated with the following formula: fibrosis/whole area × 100.

Results

The fibrosis rates of each group were as follows: 0.52, 0.79, 2.84, and 0.50% (4, 7, 10 weeks and control groups). The fibrosis rate of the 10 weeks group was significantly higher than the control and 4 or 7 weeks groups. Although there was no difference between the T_max and T_1/2 of each group after Gd-DTPA injection, the T_max and T_1/2 of the 10 weeks group were significantly prolonged in comparison with the control and 4 or 7 weeks groups after Gd-EOB-DTPA injection (p < 0.01). There was a significant correlation between the fibrosis rate and T_max or T_1/2 after Gd-EOB-DTPA injection (r = 0.90 or 0.97).

Conclusion

It was possible to assess the progress of liver fibrosis in NASH by evaluating the signal intensity-time course on Gd-EOB-DTPA-enhanced MRI.     

Percutaneous Ablation of Peripheral Pseudoaneurysms Using Thrombin: A Simple and Effective Solution

Purpose: To assess the effectiveness of tissue adhesive and thrombin solution in the percutaneous ablation of peripheral artery pseudoaneurysms. Methods: Twenty-five pseudoaneurysms were treated over a 33-month period; all had failed ultrasound-guided compression. Tissue adhesive or thrombin solution was injected percutaneously, with needle tip position and changes within the aneurysm confirmed with color Doppler ultrasound. In 19 cases we utilized a protective balloon inflated across the aneurysm neck prior to the injection of tissue adhesive and in six cases used thrombin injection alone. Seven patients were anticoagulated. Patients were followed up after the procedure. Results: All 25 aneurysms were treated successfully; two patients required a return visit and there were no immediate complications or peripheral emboli detected. One patient developed a contralateral pseudoaneurysm. Conclusions: The percutaneous injection of pseudoaneurysms is a safe, atraumatic, and effective treatment for femoral artery pseudoaneurysms in the peripheral circulation. There are significant advantages over ultrasound-guided compression or surgical repair.     

Low-dose multidetector-row CT-angiography of abdominal aortic aneurysm after endovascular repair

Purpose

To investigate the possibility of reducing radiation dose exposure while maintaining image quality using multidetector computed tomography angiography (MDCTA) with high-concentration contrast media in patients undergoing follow-up after endovascular aortic repair (EVAR) to treat abdominal aortic aneurysm.

Materials and methods

In this prospective, single center, intra-individual study, patients underwent two consecutive MDCTA scans 6 months apart, one with a standard acquisition protocol (130 mAs/120 kV) and 120 mL of iomeprol 300, and one using a low dose protocol (100 mAs/80 kV) and 90 mL of iomeprol 400. Images acquired during the arterial phase of contrast enhancement were evaluated both qualitatively and quantitatively for image noise and intraluminal contrast enhancement.

Results

Thirty adult patients were prospectively enrolled. Statistically significantly higher attenuation values were measured in the low-dose acquisition protocol compared to the standard protocol, from the suprarenal abdominal aorta to the common femoral artery (p < 0.0001; all vascular segments). Qualitatively, image quality was judged significantly (p = 0.0002) better with the standard protocol than with the low-dose protocol. However, no significant differences were found between the two protocols in terms of contrast-to-noise ratio (CNR) (13.63 ± 6.97 vs. 11.48 ± 8.13; p = 0.1058). An overall dose reduction of up to 74% was observed for the low-dose protocol compared with the standard protocol.

Conclusion

In repeat follow-up examinations of patients undergoing EVAR for abdominal aortic aneurysm, a low-dose radiation exposure acquisition protocol provides substantially reduced radiation exposure while maintaining a constant CNR and good image quality.     

The thickness of the A1 pulleys reflects the disability of hand mobility in scleroderma. A pilot study using high-frequency ultrasound

Background

Hand involvement in scleroderma is a serious concern. Clinical tests to asses hand dysfunction are based on the experience of the clinician.

Objective

To asses if utrasonographic (US) measurement of A1 pulley thickness may be used as an indicator of hand mobility in scleroderma.

Materials and methods

Institutional review board approval and patient informed consent was obtained. Twenty-eight patients affected suffering from scleroderma and 40 healthy controls were prospectively evaluated by two blinded radiologists with US, with a transducer operating at 17 MHz. A1 pulley thickness was measured and correlated with the Hand Mobility in Scleroderma Test (HAMIS) and disease duration.

Results

The thickness of the A1 pulley was greater in sclerodermic patients than in controls (p < 0.05). Intra and inter-observer agreement were better for ultrasound (0.94;0.88) than for HAMIS tests (0.71;0.70). A good correlation between pulley thickness, hand mobility and disease duration was found (r = 0.78, p < 0.018; r = 0.54, p < 0.05).

Conclusion

A1 pulley thickness measured on ultrasound correlates with hand mobility and disease duration. Ultrasound is an useful tool to evaluate hand disability in scleroderma.     

Jugular versus subclavian totally implantable access ports: Catheter position, complications and intrainterventional pain perception

Purpose

To determine the safest and most tolerable method for totally implantable access ports (TIAPs) particularly in regard to patient's pain perception and catheter-related complications.

Materials and methods

From January 2007 to October 2008 a subcutaneous TIAP (Bardport, Bard Access System, UT, USA) was implanted in 138 oncological patients (60 male, 78 female; 18-85 years old; mean age of 56 ± 6 years) by experienced interventional radiologists. 94 TIAP were implanted through the subclavian vein (subclavian group) and 44 TIAP were implanted through the internal jugular vein (jugular group). Intrainterventional pain perception (visual analogue scale from 1 to 10), postinterventional catheter tip migration and radiation dose were documented for each method and implantation side and differences were compared with Wilcoxon t-test. For ordinal variables, comparison of two groups was performed with the Fisher's exact test.

Results

No severe periinterventional complication occurred. Inadvertent arterial punctures without serious consequences were reported in one case for the jugular group versus four cases in the subclavian group. Significantly (p < 0.05) lower pain perception, radiation dose and tip migration rate were observed in the jugular group. Catheter occlusions occurred in 4% (n = 4) of the subclavian group versus 2% (n = 1) of the jugular group. The corresponding values for vein thrombosis and catheter dislocation were 3% (n = 3) and 1% (n = 1) in the subclavian group, while none of those complications occurred in the jugular group.

Conclusion

Both techniques, the TIAP implantation via fluoroscopy-guided subclavian vein puncture and via ultrasound-guided jugular vein puncture, are feasible and safe. Regarding intrainterventional pain perception, radiation dose, postinterventional catheter tip position and port function the jugular vein puncture under ultrasound guidance seems to be advantageous.     

Value of diffusion-weighted MR imaging in the differentiation between benign and malignant cervical lymph nodes

Purpose

To evaluate echo-planar diffusion-weighted MR imaging (DWI) in the differentiation between benign and malignant cervical lymph nodes.

Materials and methods

35 consecutive patients with 55 enlarged (>10 mm) cervical lymph nodes underwent MR imaging at 1.5-T. DWI was performed using a single-shot echo-planar (SSEPI) MR imaging sequence with b values (b: diffusion factor) of 0, 500 and 1000 s/mm². Apparent diffusion coefficient (ADC) maps were reconstructed for all patients and ADC values were calculated for each lymph node. Imaging results were correlated with histopathologic findings after neck dissection or surgical biopsy, findings in PET/CT or imaging follow-up. Mann-Whitney test was used for statistical analysis and a receiver operating characteristic (ROC) curve analysis was performed.

Results

Cervical lymph node enlargement was secondary to metastases from squamous cell carcinomas [n = 25], non-Hodgkin’s lymphoma [n = 6], reactive lymphadenitis [n = 20], cat scratch lymphadenitis [n = 2] and sarcoidosis [n = 2]. The mean ADC values (×10⁻³ mm²/s) were 0.78 ± 0.09 for metastatic lymph nodes, 0.64 ± 0.09 for lymphomatous nodes and 1.24 ± 0.16 for benign cervical lymph nodes. ADC values of malignant lymph nodes were significantly lower than ADC values of benign lymph nodes. 94.3% of lesions were correctly classified as benign or malignant using a threshold ADC value of 1.02 × 10⁻³ mm²/s.

Conclusion

According to our first experience, DWI using a SSEPI sequence allows reliable differentiation between benign and malignant cervical lymph nodes.     

Secretin-stimulated MR cholangio-pancreatography in the evaluation of asymptomatic patients with non-specific pancreatic hyperenzymemia

Purpose

To assess the diagnostic value of secretin-stimulated MRCP (SS-MRCP) compared with conventional MRCP in asymptomatic patients with mild elevations of pancreatic enzymes.

Materials and methods

Eighty asymptomatic patients with pancreatic hyperenzymemia underwent MR imaging at 1.5 T-device (Signa EXCITE, GE Healthcare). After the acquisition of axial T1w,T2w sequences, and conventional MRCP, SS-MRCP was performed using a single-slice coronal breath-hold, thick-slab, SSFSE T2w sequence, repeated every 30 s up to 15 min following intravenous injection of secretin (Secrelux^®, Sanochemia).

Results

On the basis of the standards of reference, our final diagnoses were: negative findings (n = 23), pancreas divisum (n = 22), mild chronic pancreatitis (n = 14), inflammatory ampullary stenosis (n = 3), juxtapapillary duodenal diverticulum (n = 1), small cystic lesions (<1 cm) (n = 22; 5/22 cases associated with pancreas divisum). The image quality of SS-MRCP was significantly higher than that of conventional MRCP (p < 0.0001). Standards of reference did not differ significantly from of SS-MRCP findings (p = 0.5), while was statistically different from those of conventional MRCP (p < 0.0001). A significant difference was found between conventional MRCP and SS-MRCP findings (p < 0.0001).

Conclusion

In asymptomatic patients with non-specific pancreatic hyperenzymemia SS-MRCP may represent the best non-invasive diagnostic technique, since it gives morphological and functional information.     

Change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy: an early predictor of final treatment response

Background

The purpose of this study was to evaluate the change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy (RT) as an early predictor of final treatment response.

Materials

Fifty patients who underwent local RT for HCCs had both pre-RT and post-RT CT scans including 1-month follow-up CT. We assessed the final treatment response by using the change in maximal tumor size on 6-12-month follow-up CT scan after RT. We also evaluated the change in tumor enhancement between pre-RT and 1-month follow-up CT scans.

Results

A final treatment response was achieved in 27 (54%) of 50 patients, who showed either a complete response (n = 11) or a partial response (n = 16). Compared with non-responsive patients (n = 23), responsive patients showed a significant decrease in tumor enhancement on 1-month follow-up CT after RT in both objective and subjective analyses (each P < 0.001).

Conclusion

The change in contrast enhancement of HCC seen on the 1-month follow-up CT in patients after local RT may be used as an early predictor of final treatment response.     

Automatic bone and plaque removal using dual energy CT for head and neck angiography: Feasibility and initial performance evaluation

Purpose

We sought to evaluate the feasibility and efficiency of dual energy (DE) bone and plaque removal in head and neck CT angiography.

Materials and methods

20 patients with suspected carotid stenoses received head and neck DE-CTA as part of their pre-interventional workup. Visual grading using multiplanar reformations (MPR), thick slab maximum intensity projections (MIP) and quantitative vessel analysis (QVA) of stenoses was performed prior and after DE bone removal. Results were evaluated for the detection of relevant stenoses (vessel area reduction >70%). Vessel segmentation errors were analyzed.

Results

Segmentation errors occurred in 19% of all vessel segments. Nevertheless, most post-bone removal artifacts could be recognized using the MPR technique for reading. Compared to MPR reading prior to bone removal, sensitivity, specificity, positive and negative predictive values after bone removal were 100%, 98%, 88% and 100% for MPR reading and 100%, 91%, 63% and 100% for exclusive MIP reading, respectively. There was a good agreement between the QVA results prior and post-DE plaque removal (r² = 0.8858).

Conclusion

DE bone and plaque removal for head and neck angiography is feasible and offers a rapid and highly sensitive overview over vascular head and neck studies. Due to a slightly limited specificity of the MIP technique due to segmentation errors, possible stenoses should be verified and graded using MPR techniques.     

Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), after slipped capital femoral epiphysis

Objective

The aim of this study was to assess the glycosaminoglycan (GAG) content in hip joint cartilage in mature hips with a history of slipped capital femoral epiphysis (SCFE) using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC).

Methods

28 young-adult subjects (32 hips) with a mean age of 23.8 ± 4.0 years (range: 18.1-30.5 years) who were treated for mild or moderate SCFE in adolescence were included into the study. Hip function and clinical symptoms were evaluated with the Harris hip score (HHS) system at the time of MRI. Plain radiographic evaluation included Tonnis grading, measurement of the minimal joint space width (JSW) and alpha-angle measurement. The alpha-angle values were used to classify three sub-groups: group 1 = subjects with normal femoral head-neck offset (alpha-angle <50°), group 2 = subjects with mild offset decrease (alpha-angle 50°-60°), and group 3 = subjects with severe offset decrease (alpha-angle >60°).

Results

There was statistically significant difference noted for the T1_Gd values, lateral and central, between group 1 and group 3 (p-values = 0.038 and 0.041). The T1_Gd values measured within the lateral portion were slightly lower compared with the T1_Gd values measured within the central portion that was at a statistically significance level (p-value <0.001). HHS, Tonnis grades and JSW revealed no statistically significant difference.

Conclusion

By using dGEMRIC in the mid-term follow-up of SCFE we were able to reveal degenerative changes even in the absence of joint space narrowing that seem to be related to the degree of offset pathology. The dGEMRIC technique may be a potential diagnostic modality in the follow-up evaluation of SCFE.