Nationwide Provision of Radiologically-guided Interventional Measures for the Supportive Treatment of Tumor Diseases in Germany - An Analysis of the DeGIR Registry Data

PURPOSE

 In addition to direct oncologic therapy, interventional radiology plays an important supportive role in oncologic therapy primarily guided by other disciplines. These supporting measures include diagnostic punctures, drainages, biliary interventions, central venous access including port implantations, osteoplasties, pain therapies etc.). This study investigated the extent to which these radiologically guided supportive measures are available in Germany.

MATERIAL AND METHODS

 All interventional procedures documented in the DeGIR-registry (excluding transhepatic portosystemic shunts) of the years 2018 and 2019 were recorded (DeGIR-module C). A breakdown of the documented interventions was performed based on federal states as well as 40 individual regions (administrative districts and former administrative districts).

RESULTS

 A total of 136,328 procedures were recorded at 216 centers in DeGIR Module C in 2018 and 2019. On average, 389 cases were documented per hospital in 2018 and 394 cases in 2019; the increase per hospital from 2019 is not statistically significant but is relevant in the aggregate when new participating centers are included, with an overall increase of 10 % (6,554 more cases than the previous year). Normalized to one million inhabitants, an average of 781 procedures took place across Germany in 2018 and 860 in 2019. Districts with no registered procedures are not found for Module C.Indications for Module C interventions were mostly interdisciplinary in 2018 and 2019. In this context, the quality of outcome was very high; for the procedures drain placement, marking and biopsy the technical success was 99 %, while the complication rate was lower than 1 %.

CONCLUSION

 The structural analysis of this work concludes that in Germany there is good nationwide availability of radiologically guided supportive measures in oncological therapy. Accordingly, the training situation for prospective interventional radiologists is good, as the distribution to centers with high experience is excellent. In addition, the overall outcome quality of radiology-guided interventions is very high.

KEY POINTS

· In Germany, there is good nationwide coverage of radiologically guided supportive interventions in oncological therapy.. · The training situation for prospective interventional radiologists is good, as the distribution to centers with high experience is excellent.. · The overall outcome quality of radiology-guided interventions is very high..

CITATION FORMAT

· Nadjiri J, Schachtner B, Bücker A et al. Nationwide Provision of Radiologically-guided Interventional Measures for the Supportive Treatment of Tumor Diseases in Germany - An Analysis of the DeGIR Registry Data. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1735-3615.

Availability of Interventional Oncology in Germany in the Years 2018 and 2019 - Results from a Nationwide Database (DeGIR Registry Data)

OBJECTIVE

 Over the past few decades, radiology has established itself in tumor therapy through interventional oncology including innovative and efficient procedures for minimalinvasive treatment of various tumor entities besides the "classic" therapeutic options such as surgery, chemotherapy and radiotherapy.Aim of this study was to evaluate the extent to which interventional oncology can provide nationwide care using the data from the register of the German Society for Interventional Radiology and Minimally Invasive Therapy (DeGIR registry), which records radiological interventions as part of quality assurance.

METHODS

 The numbers of interventions of participating clinics, which were recorded as part of module D (oncological procedures including TACE or other tumor-specific embolization, ablation, percutaneous tumor therapy) and identified by the DeGIR registry between 2018 and 2019, were analyzed retrospectively. The collected intervention data were evaluated regarding federal states and 40 smaller regions (administrative districts and former administrative districts).

RESULTS

 In 2018, 11 653 oncological interventions in 187 clinics were recorded by the DeGIR registry. In 2019, the number of participating clinics rose to 216 and the number of oncological interventions increased by 6 % to 12 323. The average number of oncological interventions per clinic decreased slightly from 62.5 (2018) to 57.1 (2019). The DeGIR requirement for being certified as a training center was met by 116 clinics in 2018 including 31 clinics with more than 100 interventions and 129 clinics in 2019 including 36 with more than 100 interventions. Oncological interventions have been performed in each of the 40 regions. An average of 599 interventions per region (standard deviation of 414) was recorded in the period between 2018 and 2019.

CONCLUSION

 Based on the distribution of the documented oncological interventions at federal state level as well as the district level, the supply of interventional tumor therapy depends on the geographical location. Therefore, the demand of oncological interventions might not be sufficiently covered in some regions.

KEY POINTS

· Interventional-oncological tumor therapies are performed throughout Germany. · Looking at the notable geographical differences, the need for interventional oncological procedures does not seem to be sufficiently met.. · In order to improve the comprehensive provision of oncological interventions, the training of interventional radiologists should be promoted further..

CITATION FORMAT

· Radosa CG, Nadjiri J, Mahnken AH et al. Availability of Interventional Oncology in Germany in the Years 2018 and 2019 - Results from a Nationwide Database (DeGIR Registry Data). Fortschr Röntgenstr 2022; DOI: 10.1055/a-1729-0951.

Availability of interventional-radiological revascularization procedures in Germany - an analysis of the DeGIR Registry Data 2018/19

PURPOSE

 Peripheral artery disease (PAD) is a common condition with high socio-economic relevance. Therefore, qualified nationwide provision of interventional treatments of PAD is important for maintaining a high quality medical service in Germany.

MATERIALS AND METHODS

 All data on revascularization procedures from the quality management system of the German interventional radiological society (DeGIR) for the years 2018 and 2019 were retrospectively analysed. Number and distribution of DeGIR certified endovascular specialists and treatment centres was mapped. Documented procedures were broken down to the level of administrative districts. Absolute number of revascularization procedures and normalized number per one million inhabitants were computed.

RESULTS

 In 2019 there were 57 732 revascularization procedures from 228 participating centres performed by DeGIR certified interventional radiologists. A median of 62 recanalization procedures were documented per centre. 36 centres were considered to be high volume centres, with more than 500 procedures each. On a regional level in the years 2018 and 2019 combined a median (range) of 2324 (323-12 518) revascularization procedures per administrative district were performed by DeGIR certified interventional radiologist.

CONCLUSION

 There is a comprehensive nationwide high quality interventional-radiology service for the provision of revascularization procedures available in Germany.

KEY POINTS

  · In Germany there is a nationwide comprehensive infratsructure for the interventional-radiological treatment of PAD. · The volume of interventional-radiological treatments for PAD is growing. · There is a sufficient number of training and treatment centres for the delivery of interventional radiology procedures.

CITATION FORMAT

· Mahnken AH, Nadjiri J, Schachtner B et al. Availability of interventional-radiological revascularization procedures in Germany - an analysis of the DeGIR Registry Data 2018/19. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1535-2774.

[Comparison of radiation exposure in common hepatic interventions : A retrospective analysis of DeGIR registry data]

Hintergrund

Die transarterielle Chemoembolisation (TACE) oder auch Gallenganginterventionen stellen häufige Leberinterventionen dar.

Ziel der Arbeit

In dieser retrospektiven Studie soll die Strahlenexposition der Patienten mit einem hepatischen Eingriff in Abhängigkeit von Art und Feinziel der Intervention analysiert und verglichen werden.

Material und Methoden

Dies ist eine Analyse von 7003 DeGIR-Registerdatensätzen aus den Jahren 2016 bis 2018 für TACE und Gallenganginterventionen. Das Dosisflächenprodukt (DFP) und die Durchleuchtungszeit (DL) sowie die Interventionsart und das anatomisch definierte Feinziel der Interventionen wurden erfasst.

Ergebnisse

Insgesamt lagen Dosiswerte für 4985 durchgeführte TACE und 2018 Gallenganginterventionen vor. Bei Gallenganginterventionen lag der Median des DFP bei 2594 (Interquartilbereich [IQR] = 1174–5858) cGy*cm². Bei der TACE betrug der Median des DFP 11.632 [IQR = 5530–22.800] cGy*cm² und lag damit signifikant höher als bei Gallenganginterventionen (p < 0,0001). Gallengangeingriffe mit dem höchsten DFP sind Interventionen am Ductus hepaticus, während Eingriffe mit der längsten DL an der Hepatikusgabel stattfinden.

Diskussion

Die individuelle Strahlendosis für einen Patienten bei einer Leberintervention hängt weniger von der Komplexität des Eingriffs bzw. Durchleuchtungszeit ab, sondern von der Art des Eingriffs und vom Feinziel der Intervention. Die vorliegenden Dosisdaten können eine Hilfe sein, die Strahlenexposition bei einer Leberintervention bereits vor dem Eingriff grob abzuschätzen.

Availability of Transcatheter Vessel Occlusion Performed by Interventional Radiologists to Treat Bleeding in Germany in the Years 2016 and 2017 - An Analysis of the DeGIR Registry Data

PURPOSE

 Acute bleeding is a life-threatening condition that can be effectively treated minimally invasively by interventional radiologists using transcatheter vessel occlusion (TCVO). The purpose of this study was to evaluate the availability of TCVO performed by interventional radiologists in Germany based on the DeGIR registry.

MATERIALS AND METHODS

 TCVO interventions from the years 2016 and 2017 were included (DeGIR module B). The number of interventions was assessed by state and region.

RESULTS

 TCVO interventions were reported by 242 clinics in Germany. 16 763 module B interventions were reported in 2016 and 16 399 in 2017. DeGIR requirements for certification as a training center were fulfilled by 160 facilities in 2016 and by 162 facilities in 2017. Normalized to one million citizens, an average of 211 TCVO interventions were performed in 2016 and 200 in 2017 (standard deviation was 101 and 109); the median was 202 and 222, respectively. In all regions TCVO interventions were reported. Only a minimal number of small regions showed a lower number of clinics offering TCVO interventions.

CONCLUSION

 The results from the DeGIR registry indicate comprehensive nationwide availability of TCVO performed by interventional radiologists with the necessary experience in Germany on the state level for the treatment of acute bleeding. Furthermore, the distribution of facilities fulfilling the requirements of training centers allows for good educational possibilities for young interventional radiologists in Germany. Only the distribution of clinics offering TCVO in a few small regions might lead to increased transfer times in the case of acute bleeding.

KEY POINTS

· As a treatment for life-threatening acute bleeding in Germany, transcatheter vessel occlusion led by interventional radiologists is readily available on the state level.. · Furthermore, the distribution of facilities fulfilling the requirements of training centers allows for good educational possibilities for young interventional radiologists in Germany.. · Due to the good training conditions in Germany, it might be possible to further improve the situation in smaller regions by training more interventional radiologists and employing them in regions with less coverage..

CITATION FORMAT

· Nadjiri J, Schachtner B, Bücker A et al. Availability of Transcatheter Vessel Occlusion Performed by Interventional Radiologists to Treat Bleeding in Germany in the Years 2016 and 2017 - An Analysis of the DeGIR Registry Data. Fortschr Röntgenstr 2020; 192: 952 - 960.

Restaging of patients with lymphoma

Aim: Assessment of the clinical benefit of i.v. contrast enhanced diagnostic CT (CE-CT) compared to low dose CT with 20 mAs (LD-CT) without contrast medium in combined [18F]-FDG PET/CT examinations in restaging of patients with lymphoma. Patients, methods: 45 patients with non-Hodgkin lymphoma (n = 35) and Hodgkin's disease (n = 10) were included into this study. PET, LD-CT and CECT were analyzed separately as well as side-by-side. Lymphoma involvement was evaluated separately for seven regions. Indeterminate diagnoses were accepted whenever there was a discrepancy between PET and CT findings. Results for combined reading were calculated by rating indeterminate diagnoses according the suggestions of either CT or PET. Each patient had a clinical follow-up evaluation for >6 months. Results: Region-based evaluation suggested a sensitivity/specificity of 66/93% for LD-CT, 87%/91% for CE-CT, 95%/96% for PET, 94%/99% for PET/LD-CT and 96%/99% for PET/CE-CT. The data for PET/CT were obtained by rating indeterminate results according to the suggestions of PET, which turned out to be superior to CT. Lymphoma staging was changed in two patients using PET/ CE-CT as compared to PET/LD-CT. Conclusion: Overall, there was no significant difference between PET/LD-CT and PET/CE-CT. However, PET/CE-CT yielded a more precise lesion delineation than PET/LD-CT. This was due to the improved image quality of CE-CT and might lead to a more accurate investigation of lymphoma.

Immediate and 12 months follow up of function and lead integrity after cranial MRI in 356 patients with conventional cardiac pacemakers

BACKGROUND

Conventional cardiac pacemakers are still often regarded as a contraindication to magnetic resonance imaging (MRI). We conducted this study to support the hypothesis that it is safe to scan patients with cardiac pacemakers in a 1.5 Tesla MRI, if close supervision and monitoring as well as adequate pre- and postscan programming is provided.

METHODS

We followed up 356 patients (age 61.3 ± 9.1 yrs., 229 men) with single (n = 132) or dual chamber (n = 224) cardiac pacemakers and urgent indication for a cranial MRI for 12 months. The scans were performed at 1.5T. During the scan patients were monitored with a 3-lead ECG and pulse oximetry. Prior to the scan pacemakers were programmed according to our own protocol.

RESULTS

All 356 scans were completed without complications. No arrhythmias were induced, programmed parameters remained unchanged. No pacemaker dysfunction was identified. Follow-up examinations were performed immediately, 2 weeks, 2, 6, and 12 months after the scan. There was no significant change of pacing capture threshold (ventricular 0.9 ± 0.4 V@0.4 ms, atrial 0.9 ± 0.3 V@0.4 ms) immediately (ventricular 1.0 ± 0.3 V@0.4 ms, atrial 0.9 ± 0.4 V@0.4 ms) or at 12 months follow-up examinations (ventricular 0.9 ± 0.2 V@0.4 ms, atrial 0.9 ± 0.3 V@0.4 ms). There was no significant change in sensing threshold (8.0 ± 4.0 mV vs. 8.1 ± 4.2 mV ventricular lead, 2.0 ± 0.9 mV vs. 2.1 ± 1.0 mV atrial lead) or lead impedance (ventricular 584 ± 179 Ω vs. 578 ± 188 Ω, atrial 534 ± 176 Ω vs. 532 ± 169 Ω) after 12 months.

CONCLUSIONS

This supports the evidence that patients with conventional pacemakers can safely undergo cranial MRI in a 1.5T system with suitable preparation, supervision and precautions. Long term follow-up did not reveal significant changes in pacing capture nor sensing threshold.

Focal subarachnoid haemorrhage mimicking transient ischaemic attack--do we really need MRI in the acute stage?

Background

Acute non-traumatic focal subarachnoid haemorrhage (fSAH) is a rare transient ischaemic attack (TIA)-mimic. MRI is considered to be indispensable by some authors in order to avoid misdiagnosis, and subsequent improper therapy. We therefore evaluated the role of CT and MRI in the diagnosis of fSAH patients by comparing our cases to those from the literature.

Methods

From 01/2010 to 12/2012 we retrospectively identified seven patients with transient neurological episodes due to fSAH, who had received unenhanced thin-sliced multiplanar CT and subsequent MRI within 3 days on a 1.5 T scanner. MRI protocol included at least fast-field-echo (FFE), diffusion-weighted imaging (DWI), T2-weighted fluid-attenuated inversion recovery (FLAIR) and time-of-flight (TOF) MRA sequences. By using MRI as gold-standard, we re-evaluated images and data from recent publications regarding the sensitivity to detect fSAH in unenhanced CT.

Results

fSAH was detected by CT and by FFE and FLAIR on MRI in all of our own cases. However, DWI and T2w-spin-echo sequences revealed fSAH in 3 of 7 and 4 of 6 cases respectively. Vascular imaging was negative in all cases. FFE-MRI revealed additional multiple microbleeds and superficial siderosis in 4 of 7 patients and 5 of 7 patients respectively. Including data from recently published literature CT scans delivered positive results for fSAH in 95 of 100 cases (95%), whereas MRI was positive for fSAH in 69 of 69 cases (100%).

Conclusions

Thin-sliced unenhanced CT is a valuable emergency diagnostic tool to rule out intracranial haemorrhage including fSAH in patients with acute transient neurological episodes if immediate MRI is not available. However, MRI work-up is crucial and mandatorily has to be completed within the next 24–72 hours.

[Quality report 2011 of the German Society of Interventional Radiology (DeGIR)--part 2. Endovascular treatment of aortic aneurysms (EVAR)]

PURPOSE

To analyze the quality of treatment for endovascular aortic aneurysm repair using the data of the DeGIR quality management system.

MATERIALS AND METHODS

A retrospective analysis of all data registered in the DeGIR quality management system of the year 2011 was performed regarding the treatment quality for endovascular aortic aneurysm repair. Registry of data within this system was voluntary. Quality aims of correct indication, treatment strategy and results were examined. Special interest was directed towards treatment success, complication rates and radiation exposure.

RESULTS

Out of 82,881 data sets from the year 2011 overall 1167 cases of EVAR were registered. 12.4% of these cases encompassed emergency treatments. The most frequent indication was an abdominal aneurysm with 85% of cases. The median aortic diameter was 56.5 mm. 253 cases showed an aortic diameter between 50 and 55 mm. Technical success was achieved in 94.6% of all cases including emergency indications for aortic rupture. The overall complication rate of all cases was 4% with 2.5% major complications. Examining only the elective cases a mortality rate of 0.34% was found. EVAR of ruptured aneurysms yielded a mortality rate of 12%. Median dose area product and fluoroscopy time were 10,676.5 cGy × cm2 und 17.32 min respectively.

CONCLUSION

Data analysis of the DeGIR quality management system proved a very high technical success rate for the registered cases of endovascular aortic aneurysm repair accompanied by a low complication rate. Improvement of data quality will need further mandatory fields within the software to be implemented.

KEY POINTS

The voluntary DeGIR quality management system has reached a high acceptance among radiologists. Endovascular aortic aneurysm repair by radiologists has shown a very high technical success rate and a very low complication rate.

[Quality report 2011 of the Germyn Society of Interventional Radiology (DeGIR) - report about treatment quality of minimal invasive procedures]

In 1994 the German Society of Interventional Radiology (DeGIR) introduced a voluntary quality mangement program. Out of a total of 82 881 of the year 2011, 36 467 patients, who received interventional recanalisation of pelvic or lower extremity arteries were chosen for an in depth analysis. In 33 104 (90.8 %) cases indication for interventional treatment was determined by at least one further discipline or even a multidisciplinary conference. Most treated patients were classified as Fontaine II or higher. Technical success rate over all procedures and regions was 96.2 % showing a very low failure rate of only 3.8 %. The overall complication rate was 3.2 %, periinterventional morbidity (complication C, D or E according to SIR classification) was 1.37 % and periinterventional mortality was 0.07 % (24 cases). X-ray exposure was recorded as well showing an average fluoroscopy time of 12 minutes and a dose-area product of 5034 cG × cm2. The voluntary quality management system was well accepted by the interventional radiologists. The software allows to compare the individual data of a single institution with the pooled data of all 192 participating radiology departments.

Intraoperative computed tomography angiography with computed tomography perfusion imaging in vascular neurosurgery: feasibility of a new concept

OBJECT

In vascular neurosurgery, there is a demand for intraoperative imaging of blood vessels as well as for rapid information about critical impairment of brain perfusion. This study was conducted to analyze the feasibility of intraoperative CT angiography and brain perfusion mapping using an up-to-date multislice CT scanner in a prospective pilot series.

METHODS

Ten patients with unruptured aneurysms underwent intraoperative scanning with a 40-slice sliding-gantry CT scanner. Multimodal CT acquisition was obtained in 8 patients consisting of dynamic perfusion CT (PCT) scanning followed by intracranial CT angiography. Two of these patients underwent CT angiography and PCT 2 times in 1 session as a control after repositioning cerebral aneurysm clips. In another 2 patients, CT angiography was performed alone. The quality of all imaging obtained was assessed in a blinded consensus reading performed by an experienced neurosurgeon and an experienced neuroradiologist. A 6-point scoring system ranging from excellent to insufficient was used for quality evaluation of PCT and CT angiography.

RESULTS

In 9 of 10 PCT data sets, the quality was rated excellent or good. In the remaining case, the quality was rated insufficient for diagnostic evaluation due to major streak artifacts induced by the titanium pins of the head clamp. In this particular case, the quality of the related CT angiography was rated good and sufficient for intraoperative decision making. The quality of all 12 CT angiography data sets was rated excellent or good. In 1 patient with an anterior communicating artery aneurysm, PCT scanning led to a repositioning of the clip because of an ischemic pattern of the perfusion parameter maps due to clip stenosis of an artery. The subsequent PCT scan obtained in this patient revealed an improved perfusion of the related vascular territory, and follow-up MR imaging showed only minor ischemia of the anterior cerebral artery territory.

CONCLUSIONS

Intraoperative CT angiography and PCT scanning were shown to be feasible with short acquisition time, little interference with the surgical workflow, and very good diagnostic imaging quality. Thus, these modalities might be very helpful in vascular neurosurgery. Having demonstrated their feasibility, the impact of these methods on patients' outcomes has now to be analyzed prospectively in a larger series.

Intraoperative computed tomography with integrated navigation system in a multidisciplinary operating suite

OBJECTIVE

We report our preliminary experience in a prospective series of patients with regard to feasibility, work flow, and image quality using a multislice computed tomographic (CT) scanner combined with a frameless neuronavigation system (NNS).

METHODS

A sliding gantry 40-slice CT scanner was installed in a preexisting operating room. The scanner was connected to a frameless infrared-based NNS. Image data was transferred directly from the scanner into the navigation system. This allowed updating of the NNS during surgery by automated image registration based on the position of the gantry. Intraoperative CT angiography was possible. The patient was positioned on a radiolucent operating table that fits within the bore of the gantry. During image acquisition, the gantry moved over the patient. This table allowed all positions and movements like any normal operating table without compromising the positioning of the patient. For cranial surgery, a carbon-made radiolucent head clamp was fixed to the table.

RESULTS

Experience with the first 230 patients confirms the feasibility of intraoperative CT scanning (136 patients with intracranial pathology, 94 patients with spinal lesions). After a specific work flow, interruption of surgery for intraoperative scanning can be limited to 10 to 15 minutes in cranial surgery and to 9 minutes in spinal surgery. Intraoperative imaging changed the course of surgery in 16 of the 230 cases either because control CT scans showed suboptimal screw position (17 of 307 screws, with 9 in 7 patients requiring correction) or that tumor resection was insufficient (9 cases). Intraoperative CT angiography has been performed in 7 cases so far with good image quality to determine residual flow in an aneurysm. Image quality was excellent in spinal and cranial base surgery.

CONCLUSION

The system can be installed in a preexisting operating environment without the need for special surgical instruments. It increases the safety of the patient and the surgeon without necessitating a change in the existing surgical protocol and work flow. Imaging and updating of the NNS can be performed at any time during surgery with very limited time and modification of the surgical setup. Multidisciplinary use increases utilization of the system and thus improves the cost-efficiency relationship.

Dual-energy CT angiography of the lung in patients with suspected pulmonary embolism: initial results

To evaluate the feasibility of dual-energy CT angiography (CTA) of the lung in patients with suspected pulmonary embolism (PE). 24 patients with suspected PE were examined with a single-acquisition, dual-energy CTA protocol (A-system: 140 kV/65 mAsref, B-system: 80kV/190 mAsref) on a dual-source CT system. Lung perfusion was visualized by color-coding voxels containing iodine and air using dedicated dual-energy postprocessing software. Perfusion defects were classified by two blinded radiologists as being consistent or non-consistent with PE. Subjective image quality of perfusion maps and CTA was rated using a 5-point scale (1: excellent, 5: poor). The reading of a third independent radiologist served as the standard of reference for the diagnosis of PE. In all patients with PE (n=4), perfusion defects classified as being consistent with PE were identified in lung areas affected by PE. Both readers did not record perfusion defects classified as being consistent with PE in any of the patients without PE. Thus, on a per patient basis the sensitivity and specificity for the assessment of PE was 100% for both readers. On a per segment basis the sensitivity and specificity ranged between 60-66.7% and 99.5-99.8%. The interobserver agreement was good (k= 0.81). Perfusion defects rated as non-consistent with PE were most frequently caused by streak artifacts from dense contrast material in the great thoracic vessels. The median score of the image quality of both the perfusion maps and CTA was 2. In conclusion, dual-energy CTA of pulmonary embolism is feasible and allows the assessment of perfusion defects caused by pulmonary embolism. Further optimization of the injection protocol is required to reduce artifacts from dense contrast material.

Inadvertent Intra-Arterial Contrast Agent Injection Mimicking Bilateral Occlusion of the Internal Carotid Arteries in a Patient With Suspected Stroke on Maximum-Slope, Nondeconvolution Perfusion Computed Tomography

Background and Purpose— Inadvertent contrast agent injection in the left cubital artery may lead to decisively altered perfusion parameters in stroke CT. These effects have not previously been described.

Summary of Case— A 77-year-old woman with a suspected stroke underwent subsequent stroke CT imaging. No signs of intracranial hemorrhage or acute cerebral ischemia were noted on nonenhanced CT. Qualitative analysis of perfusion CT using the maximum slope model demonstrated an extremely delayed and decreased perfusion of the territories of the anterior circulation system and higher values of cerebral blood flow and blood volume of the posterior circulation system mimicking a bilateral occlusion of the internal carotid arteries. CT angiography revealed no relevant stenoses or occlusions of the internal carotid arteries. Intensive investigation into the potential causes of these controversial findings showed that the contrast medium was administered into the left brachial artery due to inadvertent arterial placement of the antecubital catheter.

Conclusions— It is important to be familiar with this unusual constellation of perfusion parameters to avoid diagnostic uncertainty in patients with an inadvertent intra-arterial application of contrast agent.

White and gray matter abnormalities in the brain of patients with fibromyalgia: a diffusion-tensor and volumetric imaging study

OBJECTIVE

To use a combination of magnetic resonance diffusion-tensor imaging (MR-DTI) and MR imaging of voxel-based morphometry (MR-VBM) in patients with fibromyalgia syndrome (FMS) to determine microstructural and volume changes in the central neuronal networks involved in the sensory-discriminative and affective-motivational characteristics of pain, anxiety, memory, and regulation of the stress response.

METHODS

Thirty female patients with FMS and 30 healthy female control subjects were studied. Predefined areas of the brain were measured for volume of gray matter by MR-VBM and for diffusivity and fractional anisotropy (FA) by MR-DTI. Higher FA values and reduced diffusivity are thought to reflect increased complexity of brain-tissue microstructure.

RESULTS

MR-VBM and MR-DTI demonstrated a striking pattern of changes in brain morphology in patients with FMS. Both thalami, the thalamocortical tracts, and both insular regions showed significant decreases in FA. In contrast, increases in FA and decreases in gray matter volume were seen in the postcentral gyri, amygdalae, hippocampi, superior frontal gyri, and anterior cingulate gyri. Increased pain intensity scores were correlated with changes in MR-DTI measurements in the right superior frontal gyrus. Increased fatigue was correlated with changes in the left superior frontal and left anterior cingulate gyrus, and self-perceived physical impairment was correlated with changes in the left postcentral gyrus. Higher intensity scores for stress symptoms were correlated negatively with diffusivity in the thalamus and FA in the left insular cortex. No relationship was found between MR-VBM measurements and symptom intensity scores.

CONCLUSION

MR-DTI allows the visualization of microstructural changes in the brain of patients with FMS, appears to be more sensitive than MR-VBM, and may serve as an additional diagnostic technique in FMS and probably other dysfunctional pain syndromes.

Impact of RIS/PACS integrated speech recognition on report availability

First adopted by radiology more than 25 years ago, speech recognition (SR) technology has been significantly improved. State-of-the-art SR systems are characterized by extensive vocabularies and advanced mathematical language models which theoretically allow for mean recognition rates far beyond 90%. Commercial arguments for SR implementation are a reduction of report turnaround times (RTT) and cost savings by the elimination of transcriptionist services. In contrast, the (potential) negative impact of front-end SR on radiologists' productivity has been discussed extensively in the literature. This study was conducted in a 1400 bed university hospital and aims to retrospectively evaluate the effect of an SR system on report availability and RTT over a 1.5 year period after integration into a preexisting RIS/PACS installation. Front-end SR with editing of the draft report by the radiologist (night and weekend reports) and back-end SR with correction of the draft report (put out by the recognition servers) by transcriptionists (reports generated during routine working time) were utilized.

[The diagnostic value of dual-energy CT and 3 Tesla MRI in the diagnosis of German Mardi Gras donuts--where is the mustard, where is the custard and where is the jam?]

PURPOSE

As a Mardi Gras joke, the original jam or custard fillings of German Mardi Gras donuts are frequently replaced with mustard which cannot be identified on the outside of the donut. The aim of our study was to evaluate the impact of modern CT and MRI techniques on the diagnostic evaluation of donuts filled with mustard, jam or custard.

MATERIALS AND METHODS

4 commercially available donuts were included in the study. One was filled with custard (PK) and one with jam (MK). Two donuts were specifically prepared and filled with Bavarian mustard (SK1) or extra-hot (SK2) mustard. 3 Tesla MRI was performed with T 2- and T 1-weighted STIR, diffusion and susceptibility-weighted (SWI) sequences. In addition, the donuts underwent dual-energy CT.

RESULTS

PK was able to be easily differentiated from the other donuts due to its hyperintensity in the STIR sequences and hypointensity in the T 1-weighted sequences. MK was able to be differentiated from S 1K and S 2K on the basis of its diffusion properties. S 1K demonstrated a pronounced heterogeneity of its matrix, especially in SWI. In CT, PK showed a pronounced hypoattenuation with negative Hounsfield units in contrast to the strongly hyperdense MK, S 1K and S 2K. S 1K and S 2K demonstrated X-ray attenuation considerably dependent on the X-ray energy.

CONCLUSION

Donuts filled with jam, custard or mustard can be readily differentiated by modern MRI and CT techniques. Therefore, eating a mustard-filled donut can be reliably avoided.

Value of automatic bone subtraction in cranial CT angiography: comparison of bone-subtracted vs. standard CT angiography in 100 patients

Non-contrast-enhanced cranial computed tomography (NECT) and CT angiography (CTA) are the most frequently used modalities in the triage of patients with acute ischemic and hemorrhagic stroke. CTA bone removal can improve the delineation of vasculature closely adjacent to bony structures, which is sometimes limited in standard CTA. The aim of this study was the evaluation of the clinical benefit of bone subtraction (BS) regarding delineation of cerebral vasculature, reading time and depiction of vascular pathologies compared to standard CTA without BS. A total of 100 patients who underwent NECT and supraaortic CTA on a 64-slice CT system were retrospectively included in the study. Bone removal was performed by subtraction of the NECT data from the CTA data using a dedicated workstation. Standard and BS CTA of each patient was reviewed for delineation of cerebral vasculature (grading scale from 1 = "excellent delineation" to 10 = "hardly any delineation"), reading time and depiction of vascular pathologies (standardized catalog) by two blinded readers. For BS data sets, the quality of BS was rated by a combination of the criteria complete bone removal, depiction of vascular structures and sufficient quality for diagnostic evaluation. The use of BS significantly reduced reading time from 4.60 min to 3.49 min (p<0.001). Performing BS, the quality of vascular delineation of the cerebral arteries, cerebral veins and cavernous segment of the ICA increased significantly as compared to standard CTA (1.70 vs. 2.70; 2.60 vs. 4.12; 2.35 vs. 4.40, all p<0.001). Consensus reading showed 41 pathologies in 35 patients. Diagnosis was missed or wrong overall in 15 cases, with 3 missed aneurysms (CTA: 2 vs. BS: 1), 8 wrong stenotic findings (CTA: 3 vs. BS: 5) and 4 missed partial thromboses (CTA: 2 vs. BS: 2). Performing BS in supraaortic CTA for the evaluation of cerebral vasculature reduces reading time and improves delineation of vessels. Diagnostic accuracy in general is not improved by BS, as the diagnostic accuracy of stenotic vessel alterations is reduced by potential truncation artifacts, but the detection rate of cerebral aneurysms slightly increases.

Restaging of patients with lymphoma. Comparison of low dose CT (20 mAs) with contrast enhanced diagnostic CT in combined [18F]-FDG PET/CT

AIM

Assessment of the clinical benefit of i.v. contrast enhanced diagnostic CT (CE-CT) compared to low dose CT with 20 mAs (LD-CT) without contrast medium in combined [(18)F]-FDG PET/CT examinations in restaging of patients with lymphoma.

PATIENTS, METHODS

45 patients with non-Hodgkin lymphoma (n=35) and Hodgkin's disease (n=10) were included into this study. PET, LD-CT and CE-CT were analyzed separately as well as side-by-side. Lymphoma involvement was evaluated separately for seven regions. Indeterminate diagnoses were accepted whenever there was a discrepancy between PET and CT findings. Results for combined reading were calculated by rating indeterminate diagnoses according the suggestions of either CT or PET. Each patient had a clinical follow-up evaluation for >6 months.

RESULTS

Region-based evaluation suggested a sensitivity/specificity of 66/93% for LD-CT, 87%/91% for CE-CT, 95%/96% for PET, 94%/99% for PET/LD-CT and 96%/99% for PET/CE-CT. The data for PET/CT were obtained by rating indeterminate results according to the suggestions of PET, which turned out to be superior to CT. Lymphoma staging was changed in two patients using PET/CE-CT as compared to PET/LD-CT.

CONCLUSION

Overall, there was no significant difference between PET/LD-CT and PET/CE-CT. However, PET/CE-CT yielded a more precise lesion delineation than PET/LD-CT. This was due to the improved image quality of CE-CT and might lead to a more accurate investigation of lymphoma.

Material differentiation by dual energy CT: initial experience

The aim of this study was to assess the feasibility of a differentiation of iodine from other materials and of different body tissues using dual energy CT. Ten patients were scanned on a SOMATOM Definition Dual Source CT (DSCT; Siemens, Forchheim, Germany) system in dual energy mode at tube voltages of 140 and 80 kVp and a ratio of 1:3 between tube currents. Weighted CT Dose Index ranged between 7 and 8 mGy, remaining markedly below reference dose values for the respective body regions. Image post-processing with three-material decomposition was applied to differentiate iodine or collagen from other tissue. The results showed that a differentiation and depiction of contrast material distribution is possible in the brain, the lung, the liver and the kidneys with or without the underlying tissue of the organ. In angiographies, bone structures can be removed from the dataset to ease the evaluation of the vessels. The differentiation of collagen makes it possible to depict tendons and ligaments. Dual energy CT offers a more specific tissue characterization in CT and can improve the assessment of vascular disease. Further studies are required to draw conclusions on the diagnostic value of the individual applications.

Intraprocedural thrombus formation during coil placement in ruptured intracranial aneurysms: treatment with systemic application of the glycoprotein IIb/IIIa antagonist tirofiban

BACKGROUND AND PURPOSE

When using detachable coils to treat intracranial aneurysms, thromboembolism is the most feared and frequently reported complication during or after endovascular therapy. The purpose of this study was to document the therapeutic effect of tirofiban on patency of the parent vessel, rate of rebleedings, and outcome of the patients in the setting of acute subarachnoidal hemorrhage.

METHODS

A patient data base was retrospectively reviewed to identify patients in whom thrombus occurred during endovascular treatment of ruptured cerebral aneurysms within a 34-month period and who were treated with tirofiban. All patients underwent anticoagulation with heparin during endovascular treatment procedures. Sixteen patients (age range, 52.9 +/- 10.7 years; 10 women, 6 men) were identified with intraprocedural thrombus formation. The patency of the parent vessel was assessed in a retrospective analysis blinded to outcome. Eight patients received ventriculostomy and had a follow-up CT.

RESULTS

Local nonocclusive thrombus at the coil surface was detected in 5 patients, in all of whom the thrombus was dissolved. In 10 patients, partial or total occlusion of the parent vessel occurred during the intervention; in 8 of these, the vessel was recanalized completely and in 2 drug administration was assisted by mechanical means. In 1 patient, however, the occlusion persisted. No periprocedural rebleedings of the ruptured aneurysm occurred; 3 of 8 ventriculostomies had clinically silent small local bleedings.

CONCLUSION

The use of tirofiban in the setting of endovascular treatment of ruptured intracranial aneurysms to dissolve platelet aggregation seems relatively safe and effective.

Introducing a Freely Accessible Internet Database for Identification of Cerebral Aneurysm Clips to Determine Magnetic Resonance Imaging Compatibility

OBJECTIVE

Knowledge of the magnetic properties of cerebral aneurysm clips in patients undergoing magnetic resonance imaging (MRI) is imperative. In daily practice, however, it is often impossible to derive this information from previous medical records. The aim of this study was to develop a freely accessible internet database to identify unknown cerebral aneurysm clips on the basis of conventional x-ray images of the cranium and to provide reliable information about their magnetic properties to allow safe MRI investigations in these patients.

METHODS

The 17 most commonly used clip series of the past 50 years were selected. The ferromagnetic properties of 47 example clips were examined by means of the Food and Drug Administration-approved "deflection angle test." An HTML-based database has been developed using standard x-ray images in two planes and photographs of the clips. Furthermore, details about alloy, ferromagnetic properties, MRI compatibility, year of construction, and other characteristics identifiable on x-rays were included.

RESULTS

Seven aneurysm clips (of four clip models) were judged to be not MRI-compatible. The database named "ClipFinder" allows easy identification of cerebral aneurysm clips on standard cranial x-rays by comparing the films with the databank images supported by information on unique features of the clip design.

CONCLUSION

On exemplary applications, ClipFinder provides a fast and easy-to-use database to identify unknown cerebral aneurysm clips via the internet and determine their MRI compatibility. The reliability of the identification system needs to be further evaluated in clinical practice before it can be recommended for widespread use.