Correction to: Is liver lesion characterisation by simplified IVIM DWI also feasible at 3.0 T?

The original version of this article, published on 08 April 2019, unfortunately contained a mistake. The following correction has therefore been made in the original: The caption of Fig. 2 is wrong. The corrected version is given below.

Is liver lesion characterisation by simplified IVIM DWI also feasible at 3.0 T?

OBJECTIVE: To evaluate simplified intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) for liver lesion characterisation at 3.0 T and to compare it with 1.5 T. METHODS: 3.0-T DWI data from a respiratory-gated MRI sequence with b = 0, 50, 250, and 800 s/mm2 were analysed in 116 lesions (78 patients) and 27 healthy livers. Apparent diffusion coefficient ADC = ADC(0,800) and IVIM-based parameters D1' = ADC(50,800), D2' = ADC(250,800), f1' = f(0,50,800), f2' = f(0,250,800), D*' = D*(0,50,250,800), ADClow = ADC(0,50), and ADCdiff = ADClow-D2' were calculated voxel-wise and analysed on per-patient basis. Results were compared with those of 173 lesions (110 patients) and 40 healthy livers at 1.5 T. RESULTS: Focal nodular hyperplasias were best discriminated from all other lesions by f1' and haemangiomas by D1' with an area under the curve (AUC) of 0.993 and 1.000, respectively. For discrimination between malignant and benign lesions, ADC was best suited (AUC of 0.968). The combination of D1' and f1' correctly identified more lesions as malignant or benign than the ADC (99.1% vs 88.8%). Discriminatory power for differentiating malignant from benign lesions tended to be higher at 3.0 T than at 1.5 T. CONCLUSION: Simplified IVIM is suitable for lesion characterisation at 3.0 T with a trend of superior diagnostic accuracy for discriminating malignant from benign lesions compared with 1.5 T. KEY POINTS: • Simplified IVIM is also suitable for liver lesion characterisation at 3.0 T. • Excellent accuracy was reached for discriminating malignant from benign lesions. • The acquisition of only three b-values (0, 50, 800 s/mm 2 ) is required.

Accurate IVIM model-based liver lesion characterisation can be achieved with only three b-value DWI.

OBJECTIVE: The objective of this study was to evaluate a simplified intravoxel incoherent motion (IVIM) approach of diffusion-weighted imaging (DWI) with four b-values for liver lesion characterisation at 1.5 T. METHODS: DWI data from a respiratory-gated MRI sequence with b = 0, 50, 250, 800 s/mm2 were retrospectively analysed in 173 lesions and 40 healthy livers. The apparent diffusion coefficient ADC = ADC(0,800) and IVIM-based parameters D1' = ADC(50,800), D2' =ADC(250,800), f1', f2', D*', ADClow = ADC(0,50), and ADCdiff=ADClow-D2' were calculated voxel-wise without fitting procedures. Differences between lesion groups were investigated. RESULTS: Focal nodular hyperplasias were best discriminated from all other lesions by f1' with an area under the curve (AUC) of 0.989. Haemangiomas were best discriminated by D1' (AUC of 0.994). For discrimination between malignant and benign lesions, ADC(0,800) and D1' were best suited (AUC of 0.915 and 0.858, respectively). Discriminatory power was further increased by using a combination of D1' and f1'. CONCLUSION: IVIM parameters D and f approximated from three b-values provided more discriminatory power between liver lesions than ADC determined from two b-values. The use of b = 0, 50, 800 s/mm2 was superior to that of b = 0, 250, 800 s/mm2. The acquisition of four instead of three b-values has no further benefit for lesion characterisation. KEY POINTS: • Diffusion and perfusion characteristics are assessable with only three b-values. • Association of b = 0, 50, 800 s/mm2is superior to b = 0, 250, 800 s/mm2. • A fourth acquired b-value has no benefit for differential diagnosis. • For liver lesion characterisation, simplified IVIM analysis is superior to ADC determination. • Simplified IVIM approach guarantees numerically stable, voxel-wise results and short acquisition times.

Lymphatic Interventions for Treatment of Chylothorax.

PURPOSE: To determine effectiveness of lymphatic interventional procedures for treatment of chylothorax. MATERIAL AND METHODS: Analysis of interventions performed from 2001 to 2014. RESULTS: In 21 patients with therapy resistant chylothorax a lymphatic radiological intervention was attempted, which could be performed in 19 cases: 17 thoracic duct embolizations (15 transabdominal, one transzervical and one retrograde transvenous procedure), 2 percutaneous destructions of lymphatic vessels, one CT-guided injection of ethanol next to a duplicated thoracic duct. Fourteen of seventeen (82.3 %) of the technically successful embolizations lead to clinical cure. This encluded three patients with prior unsuccessful surgical thoracic duct ligation. Also the injection of ethanol was clinically effective. Complications were a bile peritonitis requiring operation, and one clinical deterioration of unknown cause. CONCLUSION: Interventional lymphatic procedures allow for effective treatment in many cases of chylothorax, and should be considered early during treatment. KEY POINTS: • Thoracic duct embolization is an effective treatment method for chylothorax. • If embolization is impossible, percutaneous lymphatic destruction or injection of sclerosants/tissue adhesive next to the thoracic duct may be tried.

Percutaneous CT-Guided Radiofrequency Ablation of Solitary Small Renal Masses: A Single Center Experience.

PURPOSE: To analyze the outcome of patients undergoing percutaneous CT-guided radiofrequency ablation (RFA) of small renal masses (SRM) at a single center during a ten-year time period. MATERIALS AND METHODS: Patient records of renal RFAs (07/2003 - 11/2013) were reviewed. Indications were SRM suspicious of malignancy on imaging and one of the following: severe comorbidity; old age; solitary kidney; impaired renal function; patient wish. Biopsy was performed at the time of RFA. Patients were excluded if no follow-up was available. Patient and procedural characteristics were recorded. Survival rates were calculated using the Kaplan-Meier's method and compared with log-rank or cox tests. RESULTS: 38 patients (16 females, mean age 70.0 years [range 52 - 87]) presenting with a solitary SRM were included in the study. Biopsy showed malignancy in 29 patients; 9 had benign tumors. 26 patients suffered from cardiovascular, respiratory or hepatic comorbidities. Technical success (complete ablation on first follow-up) was achieved in 95 % of cases. Two major complications (bowel perforation; hematothorax) occurred. The 3- and 7-year overall survival (OS) [any cause] rates were 73.4 ±â€Š0.8 % and 50.3 ±â€Š1.0 %, respectively (mean follow-up 54.6 months, range 1 - 127). 4 recurrences and 2 metastases were observed. The presence of comorbidities was the only independent predictor of OS. There was no difference in survival between patients with benign and malignant tumors. CONCLUSION: RFA of SRM is successful in a large percentage of cases with a low complication rate and durable local control. As RFA is typically performed in multimorbid patients, overall survival seems to depend primarily on comorbidities rather than cancer progression. Key Points • RFA of SRM is technically successful in the majority of cases. • RFA leads to a high degree of local tumor control. • Post-RFA most patients ultimately die of comorbidities. • Overall survival post-RFA does not significantly differ between benign and malignant tumors in multimorbid patients.

Diffusion-weighted MR neurography of the brachial and lumbosacral plexus: 3.0 T versus 1.5 T imaging.

PURPOSE: To compare intraindividually the nerve conspicuity of the brachial and lumbosacral plexus on diffusion-weighted (DW) MR neurography (MRN) at two different field strengths. MATERIALS AND METHODS: 16 healthy volunteers were investigated at 3.0 T and 1.5 T applying optimized variants of a DW spin-echo echo-planar imaging sequence with short TI inversion recovery fat suppression. Full-volume (FV) and curved sub-volume (CSV) maximum intensity projection (MIP) images were reconstructed and nerve conspicuity was visually assessed. Moreover, visible length and sharpness of the nerves were quantitatively analyzed. RESULTS: On FV MIP images, nerve conspicuity at 3.0 T compared to 1.5 T was worse for brachial plexus (P=0.00228), but better for lumbosacral plexus (P=0.00666). On CSV MIP images, nerve conspicuity did not differ significantly for brachial plexus, but was better at 3.0 T for lumbosacral plexus (P=0.00091). The visible length of the analyzed nerves did not differ significantly with the exception of some lumbosacral nerves, which were significantly longer at 3.0 T. The sharpness of all investigated nerves was significantly higher at 3.0 T by about 40-60% for cervical and 97-169% for lumbosacral nerves. CONCLUSION: DW MRN imaging at 3.0 T compared to 1.5 T is superior for lumbosacral plexus, but not for brachial plexus.

Diffusion-weighted magnetic resonance imaging of breast lesions: the influence of different fat-suppression techniques on quantitative measurements and their reproducibility.

OBJECTIVE: The aim of this study was to evaluate the influence of different fat-suppression techniques on quantitative measurements and their reproducibility when applied to diffusion-weighted imaging (DWI) of breast lesions. METHODS: Twenty-five patients with different types of breast lesions were examined on a clinical 1.5-T magnetic resonance imaging (MRI) system. Two diffusion-weighted sequences with different fat-suppression methods were applied: one with spectral presaturation by inversion recovery (SPIR), and one with short-TI inversion recovery (STIR). The acquisition of both sequence variants was repeated with modified shim volume. Lesion-to-background contrast (LBC), apparent diffusion coefficients (ADC) ADC(0,1000) and ADC(50,1000), and their coefficients of variation (CV) were determined. RESULTS: In four patients, the image quality of DWI with SPIR was insufficient. In the other 21 patients, 46 regions of interest (ROI), including 11 malignant and 35 benign lesions, were analysed. The LBC, ADC(0,1000) and ADC(50,1000) values, which did not differ between initial and repeated measurements, were significantly higher for STIR than for SPIR. The mean CV improved from 10.8 % to 4.0 % (P = 0.0047) for LBC, from 6.3 % to 2.9 % (P = 0.0041) for ADC(0,1000), and from 6.3 % to 2.6 % (P = 0.0049) for ADC(50,1000). CONCLUSION: For STIR compared to SPIR fat suppression, improved lesion conspicuity, higher ADC values, and better measurement reproducibility were found in breast DWI. KEY POINTS: • Quality of fat suppression influences quantitative DWI breast lesion measurements. • In breast DWI, STIR fat suppression worked more reliably than SPIR. • Lesion-to-background contrast and its reproducibility were significantly higher with STIR fat suppression. • Lesional ADCs and their reproducibility were significantly higher with STIR fat suppression.

High temporal and high spatial resolution MR angiography (4D-MRA).

In the first decade of the twenty-first century, whole-body magnetic resonance scanners with high field strengths (and thus potentially better signal-to-noise ratios) were developed. At the same time, parallel imaging and "echo-sharing" techniques were refined to allow for increasingly high spatial and temporal resolution in dynamic magnetic resonance angiography ("time-resolved" = TR-MRA). This technological progress facilitated tracking the passage of intra-venously administered contrast agent boluses as well as the acquisition of volume data sets at high image refresh rates ("4D-MRA"). This opened doors for many new applications in non-invasive vascular imaging, including simultaneous anatomic and functional analysis of many vascular pathologies including arterio-venous malformations. Different methods were established to acquire 4D-MRA using various strategies to acquire k-space trajectories over time in order to optimize imaging according to clinical needs. These include "keyhole"-based techniques (e. g. 4D-TRAK), TRICKS - both with and without projection - and HYPR-reconstruction, TREAT, and TWIST. Some of these techniques were first introduced in the 1980 s and 1990 s, were later enhanced and modified, and finally implemented in the products of major vendors. In the last decade, a large number of studies on the clinical applications of TR-MRA was published. This manuscript provides an overview of the development of TR-MRA methods and the 4D-MRA techniques as they are currently used in the diagnosis, treatment and follow-up of vascular diseases in various parts of the body.

Intravoxel incoherent motion model-based liver lesion characterisation from three b-value diffusion-weighted MRI.

OBJECTIVE: To evaluate intravoxel incoherent motion (IVIM) model-based liver lesion characterisation from three b-value diffusion-weighted imaging (DWI). METHODS: The 1.5-T DWI data from a respiratory gated spin-echo echo-planar magnetic resonance imaging sequence (b = 0, 50, 800 s/mm(2)) were retrospectively analysed in 38 patients with different liver lesions. Conventional apparent diffusion coefficient ADC = ADC(0,800) as well as IVIM-based parameters D' = ADC(50,800), ADC_low = ADC(0,50), and f' were calculated voxel-wise. Sixty-one regions of interest in hepatocellular carcinomas (HCCs, n = 24), haemangiomas (HEMs, n = 11), focal nodular hyperplasias (FNHs, n = 11), and healthy liver tissue (REFs, n = 15) were analysed. Group differences were investigated using Student's t-test and receiver-operating characteristic (ROC) analysis. RESULTS: Mean values ± standard deviations of ADC, D', ADC_low (in 10(-5) mm(2)/s), and f' (in %) for REFs/FNHs/HEMs/HCCs were 130 ± 11/143 ± 27/168 ± 16/113 ± 25, 104 ± 12/123 ± 25/162 ± 18/102 ± 23, 518 ± 66/437 ± 97/268 ± 69/283 ± 120, and 18 ± 3/14 ± 4/6 ± 3/9 ± 5, respectively. Differences between lesions and REFs were more significant for IVIM-based parameters than for conventional ADC. ROC analysis showed the best discriminability between HCCs and FNHs for ADC_low and f' and between HEMs and FNHs or HCCs for D'. CONCLUSION: Three instead of two b-value DWI enables a numerically stable and voxel-wise IVIM-based analysis for improved liver lesion characterisation with tolerable acquisition time. KEY POINTS: • Quantitative analysis of diffusion-weighted MRI helps liver lesion characterisation. • Analysis of intravoxel incoherent motion is superior to apparent diffusion coefficient determination. • Only three b-values enable separation of diffusion and microcirculation effects. • The method presented is numerically stable, with voxel-wise results and short acquisition times.

Transperineal MR-guided stereotactic prostate biopsy utilizing a commercially available anorectal biopsy device.

PURPOSE: To evaluate the feasibility of transperineal MR-guided prostate biopsy using a stereotactical targeting system originally designed for anorectal usage. MATERIALS AND METHODS: A commercially available DynaTRIM MR targeting system (Invivo corp., Gainesville FL, USA) originally designed only for anorectal application was used on a 70 cm wide-bore, whole-body 3 Tesla MR-system (Ingenia, Philips Healthcare, Best, NL). Transperineal biopsy was performed following mulitparametric MR imaging for targeting of the lesion. RESULTS: The anorectal device allowed for correct localization and successful MR-guided transperineal biopsy of the targeted lesion. CONCLUSION: MR-guided transperineal biopsy is feasible using a commercially available anorectal stereotactic biopsy device. This may lead to a broader acceptance of this approach for targeted prostate biopsies.

Noninvasive evaluation of cerebral arteriovenous malformations by 4D-MRA for preoperative planning and postoperative follow-up in 56 patients: comparison with DSA and intraoperative findings.

BACKGROUND AND PURPOSE: 4D-MRA is a promising technique in the diagnosis and follow-up of cAVMs. The purpose of this study was to compare 4D-MRA in the pre- and postoperative evaluation of cAVMs with DSA or intraoperative findings as the standards of reference regarding qualitative and quantitative parameters. MATERIALS AND METHODS: Fifty-six consecutive patients with cAVMs (30 women) underwent both 4D-MRA and DSA. Preoperative 4D-MRA was excluded from analysis in 1 patient (movement artifacts). Twenty-five patients underwent surgery on cAVMs and underwent both imaging modalities pre- and postoperatively. 4D-MRA was performed with either 0.5-mol/L gadolinium-diethylene-triamine pentaacetic acid (group 1: voxel size, 1.1 × 1.1 × 1.4 mm(3); 608 ms/dynamic frame; 19 patients) or 1.0-mol/L gadobutrol (group 2: voxel size, 1.1 × 1.1 × 1.1 mm(3); 572 ms/dynamic frame; additional alternating view sharing; 37 patients). Two readers independently reviewed 4D-MRA and DSA regarding the Spetzler-Martin classification, arterial feeders, and postoperative residual filling. Vessel sharpness, vessel diameter, and VBC of 4D-MRA were quantified. RESULTS: Preoperative Spetzler-Martin classification 4D-MRA and DSA ratings matched in 55/55 patients (Spetzler-Martin grades: I, 12; II, 22; III, 15; IV, 5; V, 1), and 93/100 arterial feeders were correctly identified by preoperative 4D-MRA (7 additional arterial feeders identified by DSA only: group 1, 3/19; group 2, 4/36). Postoperative 4D-MRA and DSA matched in 25/25 patients (residual filling, 1/25). Vessel sharpness and diameters did not differ substantially between the 2 groups. VBC was significantly higher in group 2 (P < .005). CONCLUSIONS: 4D-MRA is a reliable tool that allows predicting Spetzler-Martin classification and postoperative residual filling; it hence allows substituting DSA in the pre- and postoperative evaluation of patients with cerebral AVMs.

Analysing the response in R2* relaxation rate of intracranial tumours to hyperoxic and hypercapnic respiratory challenges: initial results.

OBJECTIVE: To investigate the response in R2* relaxation rate of human intracranial tumours during hyperoxic and hypercapnic respiratory challenges. METHODS: In seven patients with different intracranial tumours, cerebral R2* changes during carbogen and CO(2)/air inhalation were monitored at 3 T using a dynamic multigradient-echo sequence of high temporal and spatial resolution. The R2* time series of each voxel was tested for significant change. Regions of interest were analysed with respect to response amplitude and velocity. RESULTS: The tumours showed heterogeneous R2* responses with large interindividual variability. In the 'contrast-enhancing' area of five patients and in the 'non-tumoral' tissue most voxels showed a decrease in R2* for carbogen. For the 'contrast-enhancing' area of two patients hardly any responses were found. In areas of 'necrosis' and perifocal 'oedema' typically voxels with R2* increase and no response were found for both gases. For tissue responding to CO(2)/air, the R2* changes were of the same order of magnitude as those for carbogen. The response kinetic was generally attenuated in tumoral tissue. CONCLUSION: The spatially resolved determination of R2* changes reveals the individual heterogeneous response characteristic of intracranial human tumours during hyperoxic and hypercapnic respiratory challenges.

Visualization of the Adamkiewicz artery in patients with acute stanford a dissections: a prospective 64-row multi-detector CT study.

PURPOSE: To evaluate the detectability of the Adamkiewicz artery (AA) in patients with acute Stanford type A aortic dissections with multi-detector computed tomography (MDCT). MATERIALS AND METHODS: 51 patients with Stanford type A dissection underwent contrast-enhanced 64-row MDCT of the entire aorta (collimation 64 x 0.625 mm; rotation time 0.4sec; 120 kV; 300 mAs). The visualization of the AA, its origin, and whether it originated from the true or false lumen were analyzed using source and multiplanar reformation images. RESULTS: A single anterior radicular artery that formed a hairpin turn constituting the anterior spinal artery was visualized in 36 (70 %) patients. Thirty (83 %) of these arteries originated from the left side, and 35 (97 %) originated between the level T 7 and L 2. Twenty-three (64 %) arteries originated from the true and 13 (36 %) from the false lumen. Two AAs in the same patient were not observed. CONCLUSION: MDCT depicts the AA in a high percentage of patients with acute Stanford type A aortic dissection.

Treatment of high output cardiac failure by flow-adapted hepatic artery banding (FHAB) in patients with hereditary hemorrhagic telangiectasia.

Involvement of abdominal organs in Osler's disease may lead to the development of hepatic arteriovenous shunts with a dilatation of the hepatic artery. Right and subsequent global heart failure due to cardiac valvular insufficiency, pulmonary artery hypertension, and hepatomegaly as well as increased cardiac output may result. This hyperdynamic hepatic blood flow can be reduced by ligature or banding of the hepatic artery or by orthotopic liver transplantation. We report on two female patients suffering from Osler's disease (68 and 76 years old) with severe heart insufficiency (NYHA III-IV) caused by the high hepatic shunt volumes. A gradual banding of the hepatic artery directed by intraoperative flow measurement in the hepatic artery and control of the systemic hemodynamics by Swan-Ganz or COLD catheters was performed in these patients. The banding was achieved by encasing the hepatic artery in a PTFE cuff (length, 1.0 cm). The high cardiac output could be reduced from 11.2 to 7.0 l/min and from 10.7 to 6.0 l/min, respectively. The respective hepatic artery flow was reduced from 2.0 to 0.3 l/min and from 4.0 to 0.7 l/min. An improvement of heart insufficiency, a reduction in the severity of the cardiac valvular insufficiency, and a reduction of the pulmonary arterial hypertension could be already observed intraoperatively. One patient died of right cardiac failure after an orthotopic liver transplantation 7 months later. The other one died 3 years after the banding. The banding of the hepatic artery controlled by hepatic arterial flow measurement can be considered as an effective and safe palliative procedure in intrahepatic HHT compared to therapeutic alternatives such as hepatic artery ligation or embolization.

[Mayer-Rokitansky-Küster-Hauser syndrome with aortic isthmus stenosis]. / Mayer-von Rokitansky-Küster-Hauser Syndrom mit Aortenisthmusstenose.

HISTORY AND CLINICAL FINDINGS: A 32-year-old woman with Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS) was admitted to our out-patient department for further assessment of chest pain and arterial hypertension. At the age of three months the patient had undergone cardiovascular surgery, but further details were not known. Arterial blood pressure was 180/110 mmHg. Noninvasive blood pressure measurements revealed a difference of 20 mmHg between the upper and lower limbs. INVESTIGATIONS: Echocardiography showed left ventricular concentric hypertrophy. The chest X-ray revealed notching of the ribs. Computed tomography of the chest showed a widened aortic root. The magnetic resonance angiography demonstrated coarctation of the aorta with large collaterals. TREATMENT AND COURSE: The patient had a resection of the aortic coarctation. Postoperatively the blood pressure returned to normal values. CONCLUSION: To our knowledge this is the first report of coarctation of the aorta in a patient with MRKHS. We suggest that patients with MRKHS and arterial hypertension should be screened for cardiovascular malformations. Because they are noninvasive and diagnostically accurate, ordinary blood pressure measurements and NMR-angiography are valuable tools in the diagnosis of cardiovascular malformations.

Magnetic resonance (MR) imaging and MR angiography for evaluation and follow-up of hepatic artery banding in patients with hepatic involvement of hereditary hemorrhagic telangiectasia.

BACKGROUND: We describe findings obtained by magnetic resonance angiography (MRA) and magnetic resonance imaging (MRI) for evaluation and follow-up after hepatic artery banding in patients with hepatic involvement of hereditary hemorrhagic telangiectasia (HHT). METHODS: Abdominal MRA and liver MRI were performed in three patients with HHT as clinically defined by Curacao criteria. One patient underwent MRA and MRI twice for preinterventional evaluation and follow-up, one patient for preinterventional evaluation, and one patient for postinterventional evaluation. Hepatic vascular involvement of the disease and postinterventional vascular anatomy were evaluated by two radiologists by consensus. RESULTS: Hepatic vascular involvement with perfusion disorders and arteriosystemic shunts was found in all three patients. MRA and MRI allowed diagnostic characterization of hepatic vascular disease (three of three), preinterventional evaluation of complex vascular anatomy and variants (two of two), and postinterventional follow-up of hepatic artery banding (two of two). CONCLUSION: In preinterventional evaluation and postinterventional follow-up, MRA and MRI allows characterization of complex hepatic vascular alterations of HHT and, hence, is an alternative to other imaging modalities in the diagnosis, clinical decision making, and follow-up of HHT.

[Is the renal excretion of orally applied diatrizoate (Gastrografin) a reliable marker of gastrointestinal perforation or dehiscence of a gastrointestinal anastomosis?]. / Renale Diatrizoatexkretion (Gastrografin) als diagnostisch verwertbarer Hinweis auf ösophagogastrointestinale Nahtdehiszenzen und Perforationen?

PURPOSE: Renal excretion of orally or rectally applied Gastrografin is reported to be a reliable indicator of a perforation or a postoperative anastomotic dehiscence of the GI-tract. The study was conducted to determine whether increased attenuation of the urine measured by CT after oral or rectal application of Gastrografin can give reliable evidence of any leakage from the gastrointestinal tract. MATERIALS AND METHODS: Urine samples of 33 patients, who underwent a Gastrografin-enhanced fluoroscopic examination of the esophagus or the GI-tract for different clinical reasons, were examined by CT. The samples had been taken immediately before and 60 to 90 minutes after application of 100 ml Gastrografin. The results were compared with those of 5 healthy volunteers, who took urine samples before, 30, 60, 90, and 120 minutes after drinking 100 ml of Gastrografin. RESULTS: Maximal attenuation of the volunteers' urine samples was achieved 60 to 90 minutes after Gastrografin application with a mean of 50 Hounsfield units (HU), SD = 17 HU. The urine of three patients with radiologically proven fistula or dehiscence of a GI-tract anastomosis had no relevant increase in attenuation. Three other cases without any clinical or radiological evidence of an anastomotic leak had a substantial increase in the attenuation of the urine probes (87, 110, and 290 HU, respectively). CONCLUSION: The CT-measured urine samples as evidence of renal excretion of orally or rectally applied Gastrografin are not reliable for the detection of leaks from the GI-tract.

Sensitivity encoding (SENSE) for high spatial resolution time-of-flight MR angiography of the intracranial arteries at 3.0 T.

PURPOSE: 1) To evaluate feasibility of sensitivity encoding (SENSE) for high spatial resolution intracranial 3D time-of-flight (TOF) MR angiography at 3.0 T using a 1024 imaging matrix and 2) to compare image quality and diagnostic yield with 3.0 T TOF MRA without SENSE. METHODS: In a prospective study TOF MR angiography of the circle of Willis was performed with SENSE in 24 patients on a clinical whole body 3.0 T MR system (Intera, Philips Medical Systems, NL). In the SENSE protocol (S-MRA), a SENSE factor of 2.5 was used to shorten acquisition time and to increase the anatomic coverage (5:12 min.; 150 slices). A matrix of 832 x 572 was acquired and reconstructed to 1024 yielding a non-zerofilled voxel size of 0.30 x 0.44 x 1.00 mm(3) (0.13 mm(3)). Two readers were asked to review the images regarding the presence of vascular disease, and to rate, in consensus, the quality of the angiograms on a 5-point scale (5 = excellent through 1 = non-diagnostic). Results were compared with the results in 15 subjects who underwent intracranial TOF MRA at 3.0 T without SENSE (NS-MRA: acquisition time, 7:57 min.; 100 slices). Digital subtraction angiography (DSA) served as standard of reference in the 4/24 patients in whom vascular disease was identified. RESULTS: S-MRA at 3.0 T was judged to provide image quality that was adequate for diagnosis or better in 24/24. Median score of image quality of S-MRA and NS-MRA were 5 and 5, respectively. In the 4 patients with DSA correlation, a total of 8 pathologic findings (7 steno-occlusive diseases, 1 aneurysm) were correctly identified on S-MRA. CONCLUSION: The use of SENSE for intracranial TOF MRA at very high imaging matrix is feasible at 3.0 T. Compared to the imaging technique without SENSE, it allows TOF MRA with substantially reduced acquisition time, and with substantially increased anatomic coverage while maintaining image quality of NS-MRA.

[Gastric outlet obstruction in chronic granulomatous disease]. / Akute Magenausgangsstenose - eine Manifestation der septischen Granulomatose.

We report the case of a three year old dystrophic boy who suffered from vomiting, loss of weight and fever. In the history there were several episodes of severe infections which had repeatedly lead to hospitalisation. The cause of the actual disorder was a gastric manifestation of chronic granulomatous disease, which led by an inflammatory thickening of the gastric wall to a gastric outlet obstruction. Treatment with prednisone and gamma interferon normalised the thickness of the gastric wall and gastric outlet function. A prophylactic treatment with antibiotic and antifungeal agents was started. During the following 13 months no further severe infections were observed. We discuss incidence, kinds of manifestation, diagnostics and therapeutical options of the disease and give an overview of the literature.

[Is a dynamic MRI examination of the pancreas still necessary?]. / Ist eine dynamische Untersuchung des Pankreas in der MRT verzichtbar?

PURPOSE: Evaluation of the diagnostic potential of a dynamic MR examination of the pancreas. MATERIAL AND METHODS: Retrospective study on 49 patients who underwent MRI of the pancreas (2 insulinomas, 2 cystadenomas, 19 pancreatic carcinomas, 26 patients with chronic pancreatitis). Interpretation was done in two steps: Initial evaluation of T2-weighted TSE-sequences, T1-weighted gradient echo sequences before and after injection of Gadolinium-DTPA i. v. Afterwards, additional evaluation of a dynamic contrast-enhanced MRI series of the pancreas with four dynamic scans. RESULT: Dynamic MR examination of the pancreas is useful in case of insulinomas. However, in case of pancreatic cancer an additional dynamic MR examination of the pancreas does not provide further clinically relevant information. CONCLUSION: In patients with a suspicion of pancreatic cancer, the injection of contrast material should preferably be used for the performance of a contrast-enhanced MR angiography at the expense of a dynamic MR examination.