Uni-hemispheric hyperperfusion in the early postictal state: case report

Background

In the emergency setting of acute ischemic stroke, seizures have been reported in up to 4% of patients. In the absence of arterial occlusion, seizures may also cause abnormalities in CT perfusion in 78% of cases when the time window from onset to imaging is short. Both hyperperfusion and hypoperfusion in the postictal state have been described. Also, though rarely reported, postictal perfusion changes can be uni-hemispheric. In these cases, perfusion maps should be analyzed thoroughly, since perfusion reconstruction software relies heavily on a “normal” contralateral perfusion status.

Case presentation

A 39-year-old man was found on the ground with a minor head injury. On admission, his reactions were generally slow, but there were no other neurological symptoms, and blood pressure was low. The patient had a history of primary generalized epilepsy and admitted to dropping off his anti-epileptic medication. He was transferred to the radiological department for imaging but shortly before began to experience generalized onset tonic-clonic seizures which were brought under control by intravenous therapy with 10 mg diazepam. After approximately 15 min, a multimodal CT scan was performed, revealing marked changes in the perfusion of the brain hemispheres and posterior fossa, with sharp delimitation at the midline. Blood gas analysis was congruent with respiratory acidosis. Clinically, the patient remained awake without developing any new symptoms. He gradually recovered over the following 3 h and, against our medical recommendation, discharged himself from the hospital.

Conclusions

To the authors’ knowledge, this is the first report of an early postictal state describing sharply delimited uni-hemispheric hyperperfusion and hemispheric alteration of the cerebellum with an equally split rhombencephalon. Surprisingly, these changes were not associated with any focal neurological signs. To prevent misdiagnosis of perfusion alterations in seizures, radiologists and neurologists should be aware of the limitations of CT perfusion maps and software reconstructions. Novel use of CT perfusion reconstruction using peak enhancement helped in identifying the cerebral pathology.

[Nonocclusive mesenteric ischemia (NOMI): Modern diagnostic and therapeutic interventional strategies from a radiological point of view]

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI), a rare form of mesenteric perfusion, is associated with a high mortality rate, especially when the diagnosis is delayed.

OBJECTIVE

Optimizing the diagnostic workup and the use of modern diagnostic possibilities are needed to reduce mortality and morbidity.

RECOMMENDED APPROACH

Recent studies recommend not yet standardized integration of computed tomography into the diagnostic workup. This paper gives an overview of the current data for the diagnosis of NOMI.

Abdominal and pelvic CT: is positive enteric contrast still necessary? Results of a retrospective observational study

PURPOSE

Evaluation of diagnostic accuracy of abdominal CT depending on the type of enteric contrast agent.

METHODS AND MATERIALS

Multislice CTs of 2,008 patients with different types of oral preparation (positive with barium, n = 576; neutral with water, n = 716; and no enteric contrast, n = 716) were retrospectively evaluated by two radiologists including delineation of intestinal segments and influence on diagnosis and diagnostic reliability exerted by the enteric contrast, using a three-point scale. Furthermore, diagnostic reliability of the delineation of selected enteric pathologies was noted. CT data were assigned into groups: oncology, inflammation, vascular, pathology, trauma and gastrointestinal pathology.

RESULTS

Delineation of the bowel was clearly practicable across all segments irrespective of the type of enteric contrast, though a slight impairment was observed without enteric contrast. Although delineation of intestinal pathologies was mostly classified "clearly delimitable" more difficulties occurred without oral contrast (neutral/positive/no contrast, 0.8 %/3.8 %/6.5 %). Compared to examinations without enteric contrast, there was a significant improvement in diagnosis that was even increased regarding the reader's diagnostic reliability. Positive opacification impaired detection of mucosal enhancement or intestinal bleeding.

CONCLUSION

Water can replace positive enteric contrast agents in abdominal CTs. However, selected clinical questions require individual enteric contrast preparations. Pathology detection is noticeably impaired without any enteric contrast.

Radiological evaluation of the therapeutic response of malignant diseases: status quo, innovative developments and requirements for radiology

In consequence of the rapid development of newer targeted and personalized tumor therapies, radiology as an essential component of the treatment concept of numerous malignant diseases needs to improve in order to adequately capture and evaluate the effects, but also the side effects of these novel therapeutic agents. The early recognition of therapy response or failure is crucial for the optimal planning of the further treatment and can therefore have direct impact on the chances of recovery and the survival time of oncological patients. In previous years, the goal of medical imaging was to just qualitatively assess the increase or reduction in the size of tumors and their metastases, which was often achieved by a simple subjective estimation of the tumor findings by the diagnosing radiologist. Nowadays, radiology is faced with the challenge of evaluating changes during therapy quantitatively and of visualizing therapeutic effects that are more discrete (e. g. necrosis, altered tumor perfusion). The importance of an adequate assessment of therapy response is further underlined by the fact that in these days, a good portion of oncological patients are enrolled in clinical trials, in which the quantitative radiological evaluation of malignant disorders is an important surrogate parameter. On the basis of this development, the demands for radiology to provide more sophisticated assessments of therapy response and documentation of imaging findings have been constantly growing. The following article provides an overview of the established and still widely spread but in particular also the latest imaging modalities and evaluation criteria with regard to oncological diseases as well as of the increasing demands on radiology that result from these developments. Beyond that, future advancements in tumor imaging are taken into account and the new challenges these developments will bring are discussed.

KEY POINTS

• In the era of personalized medicine, evaluation criteria that are individually adapted to the respective patient are required.• Radiology needs to substantially contribute to oncological treatment concepts and the evaluation of therapeutic response.

Therapy response evaluation of malignant lymphoma in a multicenter study: comparison of manual and semiautomatic measurements in CT

PURPOSE

Comparison of manual one-/bi-dimensional measurements versus semi-automatically derived one-/bi-dimensional and volumetric measurements for therapy response evaluation of malignant lymphoma during CT follow-up examinations in a multicenter setting.

MATERIALS AND METHODS

MSCT data sets of patients with malignant lymphoma were evaluated before (baseline) and after two cycles of chemotherapy (follow-up) at radiological centers of five university hospitals. The long axis diameter (LAD), the short axis diameter (SAD) and the bi-dimensional WHO of 307 target lymph nodes were measured manually and semi-automatically using dedicated software. Lymph node volumetry was performed semi-automatically only. The therapeutic response was evaluated according to lymphoma-adapted RECIST.

RESULTS

Based on a single lymph node, semi-automatically derived multidimensional parameters allowed for significantly more accurate therapy response classification than the manual or the semi-automatic unidimensional parameters. Incorrect classifications were reduced by up to 9.6%. Compared to the manual approach, the influence of the study center on correct therapy classification is significantly less relevant when using semi-automatic measurements.

CONCLUSION

Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients by approximately 9.6% in the multicenter setting in comparison to linear parameters. Semi-automatic quantitative software tools may help to significantly reduce wrong classifications that are associated with the manual assessment approach.

KEY POINTS

► Semi-automatic volumetry and bi-dimensional WHO significantly reduce the number of incorrectly classified lymphoma patients ► Manual lymph node evaluation with uni-dimensional parameters is inferior to semi-automatic analysis in a multicenter setting ► Semi-automatic quantitative software tools should be introduced in clinical study evaluation.

[Hygienic aspects in radiology: what the radiologist should know]

Hospital hygiene is of pivotal importance in radiology departments, where patient throughput is high and staff come into direct contact with both inpatients and outpatients. Every member of the medical and technical team should be aware of all the general and specific hygiene requirements and ensure that they are considered during the daily routine. Failure to do so on the part of just one individual can result in bacterial contamination in the department, exposing both patients and staff to the risk of infection. For the purposes of performing examinations and interventions in infectious patients, the hospital hygienist and medical hygiene officer should introduce appropriate organisational structures to ensure that an appropriate level of hygiene is guaranteed and can be adapted to each patient. This will ensure a minimal degree of disruption to work flow in the radiology department. It is of particular importance that medical and technical staff receive regular hygiene training and instruction. Such training ensures that members of staff are fully aware of the hygiene requirements, are responsibly engaged and that they each possess the expertise and confidence to deal with general and specific hygiene issues in any particular case.

Cognitive impairment in HIV infection is associated with MRI and CSF pattern of neurodegeneration

BACKGROUND AND PURPOSE

Biomarkers as indicators for the progression of human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain still elusive. We performed a cross-sectional study to analyze the correlation between cognitive impairment, abnormalities in magnetic resonance imaging (MRI), and cerebrospinal fluid (CSF) markers of neurodegeneration in HIV-infected patients.

METHODS

We enrolled 94 patients (82 men and 12 women; mean age 45 ± 10 years) with HIV infection, but without opportunistic infections of the CNS. All patients underwent MRI and CSF analysis. The global pattern of white matter signal intensity abnormalities, the index of atrophy, the severity of periventricular white matter abnormalities, and the severity of basal ganglia signal changes were analyzed. We measured CSF markers of neurodegeneration (total tau, phospho-tau, beta-amyloid). The findings of this evaluation were correlated with demographic and infection parameters of the patients in blood and CSF.

RESULTS

We found a highly significant correlation between the severity of global brain atrophy, basal ganglia signal changes, and cognitive impairment in HIV-infected patients. Furthermore, cognitive impairment was significantly correlated with total tau, but not with phospho-tau or A-beta-amyloid in CSF analysis.

CONCLUSIONS

Our results confirm the significant correlation between MRI changes and cognitive impairment in HIV infection. Furthermore, we could show that global brain atrophy and signal changes in basal ganglia are the typical MRI pattern in HAND. The correlation between cognitive impairment and total tau, but not phospho-tau, supports the hypothesis that HAND are not a subtype of Alzheimer's dementia.

Diagnostic and radiological management of cystic pancreatic lesions: important features for radiologists

Cystic pancreatic neoplasms are often an incidental finding, the frequency of which is increasing. The understanding of such lesions has increased in recent years, but the numerous types of lesions involved can hinder differential diagnosis. They include, in particular, intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN), and mucinous cystic neoplasms (MCN). Knowledge of their histological and radiological structure, as well as distribution in terms of localization, age, and sex, helps to differentiate such tumours from common pancreatic pseudocysts. Several types of cystic pancreatic neoplasms can undergo malignant transformation and, therefore, require differentiated radiological management. This review aims to develop a broader understanding of the pathological and radiological characteristics of cystic pancreatic neoplasms, and provide a guideline for everyday practice based on current concepts in the radiological management of the given lesions.

[Thoracic radiology in the intensive care unit]

The clinical evaluation of the intensive care unit patient is based upon multiple parameters, including portable chest x-ray examination. Knowledge of the methods, capabilities, and limitations is prerequisite for a legally correct and medically reasonable approach. This report provides basic knowledge about pleural und pulmonary pathologies, e.g., pneumothorax, pleural effusion, atelectasis, aspiration, pneumonia, lung edema, and acute respiratory distress syndrome.

[Differential diagnosis and radiological management of cystic pancreatic lesions]

Cystic pancreatic lesions are often discovered incidentally as an asymptomatic finding, at a rate which is increasing considerably. In recent years the understanding of such tumors has become clearly differentiated. The spectrum of relevant lesions includes in particular the intraductal papillary mucinous neoplasm (IPMN), serous cystic neoplasm (SCN) and mucinous cystic neoplasm (MCN). With certain knowledge of their histological and radiomorphological structure as well as their distribution in terms of location, age and sex, such tumors are easy to differentiate and demarcate from common pancreatic pseudocysts. This also implies the fundamental understanding of complementary endoscopic procedures such as endosonography, which enables aspiration of the content of the cyst. A number of cystic pancreatic lesions have the potential to undergo malignant transformation along the adenoma-carcinoma sequence and therefore necessitate a differentiated approach to their radiological management. This review aims to develop a broad understanding of the pathological and radiomorphological characteristics of cystic pancreatic lesions and provides advice regarding procedures, particularly with respect to incidentally detected lesions.

Prediction of lymph node metastases in NSCLC. Three dimensional anatomical parameters do not substitute FDG-PET-CT

PURPOSE

To distinguish between benign and malignant mediastinal lymph nodes in patients with NSCLC by comparing 2D and semi-automated 3D measurements in FDG-PET-CT.

PATIENTS, MATERIAL, METHODS

FDG-PET-CT was performed in 46 patients prior to therapy. 299 mediastinal lymph-nodes were evaluated independently by two radiologists, both manually and by semi-automatic segmentation software. Longest-axial-diameter (LAD), shortest-axial-diameter (SAD), maximal-3D-diameter, elongation and volume were obtained. FDG-PET-CT and clinical/FDG-PET-CT follow up examinations and/or histology served as the reference standard. Statistical analysis encompassed intra-class-correlation-coefficients and receiver-operator-characteristics-curves (ROC).

RESULTS

The standard of reference revealed involvement in 87 (29%) of 299 lymph nodes. Manually and semi-automatically measured 2D parameters (LAD and SAD) showed a good correlation with mean intraclass coefficients of .80 and .72, respectively. Semi-automated prediction revealed the highest areas-under-the-ROC-curve for volume (.75, 95%CI: .69-81) and SAD (.75, 95%CI: .70-.81). AUC for LAD and maximal-3D diameter were about .68. Substantially lower accuracies were found for elongation (.57, 95%CI: .50-.64).

CONCLUSION

Optimized semi-automated three dimensional parameters by CT cannot approximate reported data on FDG-PET-CT for lymph node assessment in NSCLC. SAD remains the most accurate and at the same time simple to achieve anatomical criterion for definition of NSCLC target lesions.

Magnetic resonance angiography follow-up examinations to detect iatrogenic pseudoaneurysms following otorhinolaryngological surgery

Endoscopic endonasal surgery on a 36-year-old man was complicated by perforation of the right internal carotid artery. The immediate, substantial haemorrhage was controlled by packing the sphenoid sinus. Intra-arterial angiography of the right internal carotid artery showed small irregularities proximal to the ophthalmic artery. A follow-up examination two weeks later documented a large pseudoaneurysm in the initially irregular arterial segment, which was successfully treated by endovascular coiling. This case report illustrates the need for angiographic follow-up examinations following traumatic intracranial vessel injury in order to identify late pseudoaneurysm development.

[Automatic injectors in magnetic resonance imaging and computed tomography: pilot study on hygienic aspects]

PURPOSE

To evaluate hygienic conditions using automatic injectors in magnetic resonance imaging (MRI) and computed tomography (CT) during clinical routine.

MATERIALS AND METHODS

The surfaces of medical devices (e. g., control console) and the palms of the technical and medical staff were microbiologically analyzed by taking imprints before and after hygienic education. In addition, the injector syringes for contrast medium (CM) and saline were checked for microbiological contamination following multiple (MRI: 14 h; CT 8 h) and single use. Furthermore, the potential of retrograde contamination from the patient along the tube was analyzed.

RESULTS

A bacterial contamination with typical dermal bacteria was documented for the surfaces of the medical devices, the palms of the technical and medical staff, and the injection syringes following multiple use (MRI: 10/10 CM syringes, 6/10 saline syringes; CT: 8/10 CM syringes, 5/10 saline syringes). Correct hand disinfection in combination with single use of syringes avoided bacterial colonization. Retrograde bacterial contamination from the patient was not observed.

CONCLUSION

Regular hygienic teaching sessions for technical and medical staff in MRI and CT departments using automatic injectors should be mandatory. Furthermore, the multiple use of syringes should be avoided until investigations addressing the potential of bacterial contamination are performed.