Clinical management of COVID-19: Experiences of the COVID-19 epidemic from Groote Schuur Hospital, Cape Town, South Africa.

The SARS-CoV-2 pandemic has presented clinicians with an enormous challenge in managing a respiratory virus that is not only capable of causing severe pneumonia and acute respiratory distress syndrome, but also multisystem disease. The extraordinary pace of clinical research, and particularly the surge in adaptive trials of new and repurposed treatments, have provided rapid answers to questions of whether such treatments work, and has resulted in corticosteroids taking centre stage in the management of hospitalised patients requiring oxygen support. Some treatment modalities, such as the role of anticoagulation to prevent and treat potential thromboembolic complications, remain controversial, as does the use of high-level oxygen support, outside of an intensive care unit setting. In this paper, we describe the clinical management of COVID-19 patients admitted to Groote Schuur Hospital, a major tertiary level hospital at the epicentre of South Africa's SARS-CoV-2 epidemic during its first 4 months.

[Analysis of the quality of life of patients with osteoid osteoma before and after radiofrequency ablation treatment]. / Analyse der Lebensqualität von Patienten mit Osteoidosteom vor und nach Behandlung mittels Radiofrequenzablation.

BACKGROUND: The aim of this study was to investigate the effectiveness of the treatment of osteoid osteomas (OO) by radiofrequency ablation (RFA). In particular, the recurrence rate and the improvement in the quality of life as assessed by the reduction of pain intensity were evaluated. METHODS: Retrospective analysis of 26 patients after RFA of an OO and prospective analysis of 14 patients using a self-developed quality of life questionnaire. The questionnaire, the electronic patient file and the histopathological findings were processed. RESULTS: An average of 22 months passed between the first onset of complaints and the causative treatment by RFA. After RFA, there was a significant reduction in pain symptoms and thus an increase in the quality of life. These results confirm that RFA from OO is a safe and efficient treatment procedure. DISCUSSION: In order to avoid long-term conservative treatment attempts and to reduce effects on the musculoskeletal system, a timely RFA of OO should be performed after diagnosis.

[Clinically relevant incidental cardiovascular findings in CT examinations]. / Klinisch relevante kardiovaskuläre Zufallsbefunde bei CT­Untersuchungen.

BACKGROUND AND METHOD: Incidental cardiovascular findings are a frequent phenomenon in computed tomography (CT) examinations. As the result of a dedicated PubMed search this article gives a systemic overview of the current literature on the most important incidental cardiovascular findings, their prevalence and clinical relevance. RESULTS: The majority of incidental cardiovascular findings are of only low clinical relevance; however, highly relevant incidental findings, such as aortic aneurysms, thromboses and thromboembolic events can also occasionally be found, especially in oncology patients. CONCLUSION: The scans from every CT examination should also be investigated for incidental findings as they can be of decisive importance for the further clinical management of patients, depending on their clinical relevance.

[Molecular imaging of head and neck cancers : Perspectives of PET/MRI]. / Molekulare Bildgebung bei Kopf-Hals-Tumoren : Perspektive der PET-MRT.

BACKGROUND: The (18)F-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG-PET/CT) procedure is a cornerstone in the diagnostics of head and neck cancers. Several years ago PET-magnetic resonance imaging (PET/MRI) also became available as an alternative hybrid multimodal imaging method. OBJECTIVE: Does PET/MRI have advantages over PET/CT in the diagnostics of head and neck cancers? MATERIAL AND METHODS: The diagnostic accuracy of the standard imaging methods CT, MRI and PET/CT is depicted according to currently available meta-analyses and studies concerning the use of PET/MRI for these indications are summarized. RESULTS: In all studies published up to now PET/MRI did not show superiority regarding the diagnostic accuracy in head and neck cancers; however, there is some evidence that in the future PET/MRI can contribute to tumor characterization and possibly be used to predict tumor response to therapy with the use of multiparametric imaging. CONCLUSION: Currently, (18)F-FDG-PET/CT is not outperformed by PET/MRI in the diagnostics of head and neck cancers. The additive value of PET/MRI due to the use of multiparametric imaging needs to be investigated in future research.

Interventional Ischemic Stroke Treatment--A (R)evolution.

UNLABELLED: In recent years ischemic stroke caused by an intracranial vessel occlusion has become a treatable disease. Over decades intravenous thrombolysis by recombinant tissue plasminogen activator was the only accepted causal treatment of ischemic stroke supported by the results of randomized, controlled trials. However, there has been continuous development of endovascular treatment strategies over recent years. Today there are 5 prospective, randomized multicenter studies showing the highly significant superiority of endovascular, mechanical recanalization over intravenous thrombolysis in cases of acute occlusion of an intracranial vessel of the anterior circulation. In all those studies endovascular treatment resulted in a tremendous increase in functional independence together with a reduction of mortality without a significant increase in complications. This article reviews the developments resulting in the current data and gives an overview of the present studies focusing on endovascular stroke treatment. KEY POINTS: • In the last 20 years ischemic stroke due to an main stem occlusion has become a potentially treatable disease. • Several in 2015 published randomized Multicenter trials could prove the superiority of endovascular, mechanical recanalization over i.v. thrombolysis alone. • Acute ischemic stroke due to a main stem occlusion should be treated with swift endovascular stent-retriever based recanalization in specialized neurovascular centers.

Sequential therapy with cyclophosphamide and mycophenolic acid in patients with progressive immunoglobulin A nephropathy: a long-term follow-up.

In progressive immunoglobulin (Ig)A nephropathy (IgAN), cyclophosphamide pulse therapy (CyP), high-dose intravenous immunoglobulins (IVIg) and mycophenolic acid (MPA) have been used to stop progressive loss of renal function, but disease progression may occur after the end of the initial treatment. Here, we report the long-term follow-up of patients with progressive IgAN with MPA as maintenance therapy after CyP (CyP-MPA). In a median observation time of 6·2 years, we analysed the slopes of the loss of renal function of 47 patients with biopsy-proven IgAN and treated with CyP. Thirty-one patients with further progression were treated with MPA maintenance for a median time of 5·2 years. Follow-up was compared with symptomatic therapy and IVIg as historically matched control groups. Median loss of renal function was reduced significantly from 0·9 ml/min to 0·1 ml/min per month with CyP (P < 0·05), and with MPA in patients with a relapse from -0·4 ml/min to -0·1 ml/min per month (P < 0·05) until the end of the study. Proteinuria decreased significantly from 1·6 g/l to 1·0 g/l after CyP, and during MPA treatment to 0·6 g/l (P = 0·001 Friedman test). Median renal survival time was in patients with CyP 10·5 years (range = 3·2-17·8), with CyP-MPA 10·7 years (range = 8·3-13·1), with IVIg 4·7 years (range = 2·6-6·6), and in untreated patients 1·2 years (range = 0·8-1·6; log-rank test P < 0·01). In patients with progressive IgAN, our long-term follow-up observation indicates that sequential CyP-MPA therapy maintains renal survival significantly.

Simultaneous [18F]FDG-PET/MRI: Correlation of Apparent Diffusion Coefficient (ADC) and Standardized Uptake Value (SUV) in Primary and Recurrent Cervical Cancer.

OBJECTIVES: Previous non-simultaneous PET/MR studies have shown heterogeneous results about the correlation between standardized uptake values (SUVs) and apparent diffusion coefficients (ADCs). The aim of this study was to investigate correlations in patients with primary and recurrent tumors using a simultaneous PET/MRI system which could lead to a better understanding of tumor biology and might play a role in early response assessment. METHODS: We included 31 patients with histologically confirmed primary (n = 14) or recurrent cervical cancer (n = 17) who underwent simultaneous whole-body 18F-FDG-PET/MRI comprising DWI. Image analysis was performed by a radiologist and a nuclear physician who identified tumor margins and quantified ADC and SUV. Pearson correlations were calculated to investigate the association between ADC and SUV. RESULTS: 92 lesions were detected. We found a significant inverse correlation between SUVmax and ADCmin (r = -0.532, p = 0.05) in primary tumors as well as in primary metastases (r = -0.362, p = 0.05) and between SUVmean and ADCmin (r = -0.403, p = 0.03). In recurrent local tumors we found correlations for SUVmax and ADCmin (r = -0.747, p = 0.002) and SUVmean and ADCmin (r = -0.773, p = 0.001). Associations for recurrent metastases were not significant (p>0.05). CONCLUSIONS: Our study demonstrates the feasibility of fast and reliable measurement of SUV and ADC with simultaneous PET/MRI. In patients with cervical cancer we found significant inverse correlations for SUV and ADC which could play a major role for further tumor characterization and therapy decisions.

Validating New Software for Semiautomated Liver Volumetry--Better than Manual Measurement?

PURPOSE: This prospective study compared a manual program for liver volumetry with semiautomated software. The hypothesis was that the semiautomated software would be faster, more accurate and less dependent on the evaluator's experience. MATERIALS AND METHODS: Ten patients undergoing hemihepatectomy were included in this IRB approved study after written informed consent. All patients underwent a preoperative abdominal 3-phase CT scan, which was used for whole liver volumetry and volume prediction for the liver part to be resected. Two different types of software were used: 1) manual method: borders of the liver had to be defined per slice by the user; 2) semiautomated software: automatic identification of liver volume with manual assistance for definition of Couinaud segments. Measurements were done by six observers with different experience levels. Water displacement volumetry immediately after partial liver resection served as the gold standard. The resected part was examined with a CT scan after displacement volumetry. RESULTS: Volumetry of the resected liver scan showed excellent correlation to water displacement volumetry (manual: ρ = 0.997; semiautomated software: ρ = 0.995). The difference between the predicted volume and the real volume was significantly smaller with the semiautomated software than with the manual method (33% vs. 57%, p = 0.002). The semiautomated software was almost four times faster for volumetry of the whole liver (manual: 6:59 ± 3:04 min; semiautomated: 1:47 ± 1:11 min). CONCLUSION: Both methods for liver volumetry give an estimated liver volume close to the real one. The tested semiautomated software is faster, more accurate in predicting the volume of the resected liver part, gives more reproducible results and is less dependent on the user's experience. KEY POINTS: Both tested types of software allow exact volumetry of resected liver parts. Preoperative prediction can be performed more accurately with the semiautomated software. The semiautomated software is nearly four times faster than the tested manual program and less dependent on the user's experience.

[The future of bedside chest radiography: Comparative study of mobile flat-panels and needle-image plate storage phosphor systems]. / Die Zukunft der Thoraxbettaufnahme: Vergleichende Untersuchung von mobilen Flachdetektoren und Speicherfoliensystemen mit Nadelkristalldetektoren.

BACKGROUND: Chest radiography is the most common diagnostic modality in intensive care units with new mobile flat-panels gaining more attention and availability in addition to the already used storage phosphor plates. PURPOSE: Comparison of the image quality of mobile flat-panels and needle-image plate storage phosphor system in terms of bedside chest radiography. MATERIALS AND METHODS: Retrospective analysis of 84 bedside chest radiographs of 42 intensive care patients (20 women, 22 men, average age: 65 years). All images were acquired during daily routine. For each patient, two images were analyzed, one from each system mentioned above. Two blinded radiologists evaluated the image quality based on ten criteria (e.g., diaphragm, heart contour, tracheal bifurcation, thoracic spine, lung structure, consolidations, foreign material, and overall impression) using a 5-point visibility scale (1 = excellent, 5 = not usable). RESULTS: There was no significant difference between the image quality of the two systems (p < 0.05). Overall some anatomical structures such as the diaphragm, heart, pulmonary consolidations and foreign material were considered of higher diagnostic quality compared to others, e.g., tracheal bifurcation and thoracic spine. CONCLUSIONS: Mobile flat-panels achieve an image quality which is as good as those of needle-image plate storage phosphor systems. In addition, they allow immediate evaluation of the image quality but in return are much more expensive in terms of purchase and maintenance.

[Spondylosclerosis hemispherica: a rare radiological syndrome of the spine]. / Spondylosclerosis hemispherica: Ein seltenes bildmorphologisches Syndrom der Wirbelsäule.

BACKGROUND: Spondylosclerosis hemispherica is a rare syndrome of the spine and was described first by Dihlmann. The typical radiographic appearance is a hemispherical sclerosis of the vertebral body, which is accompanied by pain in the affected region. Usually it appears at the lower lumbar spine. The etiology varies and includes degenerative disk diseases, scoliosis, bacterial infections, ankylosing spondylitis, osteoid osteoma, and malignant diseases.The radiological findings of 2 patients with spondylosclerosis hemispherica are presented and the current literature discussed. MATERIAL AND METHODS: Two women (33 and 60 years old) with spondylosclerosis hemispherica of the lower spine suffered from low back pain and fulfilled all criteria of Dihlmann's description. Malignant disease was excluded in both cases with a broad diagnostic workup (lab values, x-ray, CT scan, MRI) and in one case a biopsy from the affected vertebra was taken. RESULTS: In both cases all radiological findings demonstrated the typical changes of spondylosclerosis hemispherica with sclerosis of the vertebra body and erosions at the upper and inferior end plates. Malignant disease was excluded in one case with a biopsy and in the other case with noninvasive diagnostic procedures. Both patients were treated nonsurgically. During clinical follow-up, the patients were in a good condition with decreasing regional low back pain and no ongoing radiological changes in the affected vertebral bodies. CONCLUSION: Spondylosclerosis hemispherica is a syndrome with a typical radiographic appearance. The etiology of spondylosclerosis hemispherica is manifold; however, malignancy must be excluded. In most cases, noninvasive diagnostics are sufficient to rule out malignant growth even in cases with concomitant degenerative changes of the affected segment. Thus, there is no need for a biopsy except in cases with ambiguous results. Subsequently, close clinical and radiological follow-up of the patients with spondylosclerosis hemispherica is necessary.

Value of endorectal magnetic resonance imaging at 3T for the local staging of prostate cancer.

PURPOSE: To assess the accuracy of endorectal 3 T magnetic resonance imaging (MRI) in detecting extracapsular extension (ECE) and seminal vesicle invasion (SVI) of prostate cancer (PCa). MATERIALS AND METHODS: 38 consecutive patients with biopsy-proven PCa underwent multiparametric endorectal MRI at 3 T prior to prostatectomy. Two readers (A with nine years of experience and B with four) used established criteria for ECE and SVI to diagnose the extent of local disease in six regions (apical, dorsolateral, basal; left and right each) with the highest chance of ECE. The standard of reference was provided by intraoperative frozen section analysis and prostatectomy specimens. RESULTS: Histopathology revealed ECE in 15 of the 222 regions (10 of 37 patients) and SVI in 8 of 74 potential regions (5 of 37 patients). The sensitivity, specificity, and accuracy in detecting ECE for reader A/B were 93%/67%, 92%/95% and 92%/93% per region and 90%/80%, 74%/82% and 78%/81% per patient, respectively. The corresponding values for the detection of SVI were 80%/100%, 96%/99% and 95%/97%, respectively. CONCLUSION: Endorectal 3 T MRI is a highly reliable noninvasive technique for the local staging of PCa. KEY POINTS: ► Endorectal 3 T MRI provided high accuracy for the local staging of prostate cancer. ► The sensitivity in detecting extracapsular tumor growth per patient was 80% or higher. ► The specificity in detecting extracapsular extension (pT3 stage) was good.

Initial clinical results of simultaneous 18F-FDG PET/MRI in comparison to 18F-FDG PET/CT in patients with head and neck cancer.

PURPOSE: The aim of this study was to evaluate the diagnostic capability of simultaneous (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/MRI compared to (18)F-FDG PET/CT as well as their single components in head and neck cancer patients. METHODS: In a prospective study 17 patients underwent (18)F-FDG PET/CT for staging or follow-up and an additional (18)F-FDG PET/MRI scan with whole-body imaging and dedicated examination of the neck. MRI, CT and PET images as well as PET/MRI and PET/CT examinations were evaluated independently and in a blinded fashion by two reader groups. Results were compared with the reference standard (final diagnosis determined in consensus using all available data including histology and follow-up). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. RESULTS: A total of 23 malignant tumours were found with the reference standard. PET/CT showed a sensitivity of 82.7%, a specificity of 87.3%, a PPV of 73.2% and a NPV of 92.4%. Corresponding values for PET/MRI were 80.5, 88.2, 75.6 and 92.5%. No statistically significant difference in diagnostic capability could be found between PET/CT and PET/MRI. Evaluation of the PET part from PET/CT revealed highest sensitivity of 95.7%, and MRI showed best specificity of 96.4%. There was a high inter-rater agreement in all modalities (Cohen's kappa 0.61-0.82). CONCLUSION: PET/MRI of patients with head and neck cancer yielded good diagnostic capability, similar to PET/CT. Further studies on larger cohorts to prove these first results seem justified.

Quantitative image quality measurements of a digital breast tomosynthesis system.

PURPOSE: The aim of this study was to measure the image quality of a digital breast tomosynthesis (DBT) system quantitatively. MATERIALS AND METHODS: The signal transfer property (STP), modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) of the Hologic Selenia Dimensions breast tomosynthesis system were measured according to established methods. The NPS was calculated from two-dimensional (2 D) fast Fourier transform (FFT) of flat field images. The presampling MTF of the system was determined for 2 D standard projection mammography and 3 D breast tomosynthesis mode using the edge method. The DQE was derived for different detector air kerma (DAK) values from NPS and MTF measurements. RESULTS: The detector response function was linear for both two-dimensional (2 D) standard projection mammography and three-dimensional (3 D) breast tomosynthesis modes. The gradient of the detector response in the 3 D imaging mode was higher than the gradient in the 2 D imaging mode by a factor of 3.1. The MTF values measured at the Nyquist frequency were 32 % and 39 % in 2 D and 3 D imaging modes, respectively. The DQE was saturated at an air kerma value approximately 3.5 times lower in 3 D mode than in 2 D mode. The measured maximum DQE value was 54 %. CONCLUSION: The measured DQE values were comparable with breast tomosynthesis systems from other companies (Siemens, GE).

Performance of an automatic dose control system for CT: patient studies.

PURPOSE: To study the effect of an automatic dose control (ADC) system with adequate noise characteristic on the individual perception of image noise and diagnostic acceptance compared to objectively measured image noise and the dose reductions achieved in a representative group of patients. MATERIALS AND METHODS: In a retrospective study two matched cohorts of 20 patients each were identified: a manual cohort with exposure settings according to body size (small - regular - large) and an ADC cohort with exposure settings calculated by the ADC system (DoseRight 2.0™, Philips Healthcare). For each patient, 12 images from 6 defined anatomic levels from contrast-enhanced scans of chest and abdomen/pelvis were analyzed by 4 independent readers concerning image noise and diagnostic acceptance on a five-point Likert scale and evaluated for objectively measured image noise. Radiation exposure was calculated from recorded exposure data. RESULTS: Use of the ADC system reduced the average effective dose for patients by 36 % in chest scans (3.2 vs. 4.9 mSv) and by 17 % in abdomen/pelvis scans (7.6 vs. 8.3 mSv). Average objective noise was slightly lower in the manual cohort (11.1 vs. 12.8 HU), correlating with a slightly better rating in subjective noise score (4.4 vs. 4.2). However, diagnostic acceptance was rated almost equal in both cohorts with excellent image quality (4.6 vs. 4.5). CONCLUSION: Use of an ADC system with adequate noise characteristic leads to significant reductions in radiation exposure for patients while maintaining excellent image quality.

Average glandular dose in digital mammography and breast tomosynthesis.

PURPOSE: To determine the average glandular dose (AGD) in digital full-field mammography (2 D imaging mode) and in breast tomosynthesis (3 D imaging mode). MATERIALS AND METHODS: Using the method described by Boone, the AGD was calculated from the exposure parameters of 2247 conventional 2 D mammograms and 984 mammograms in 3 D imaging mode of 641 patients examined with the digital mammographic system Hologic Selenia Dimensions. The breast glandular tissue content was estimated by the Hologic R2 Quantra automated volumetric breast density measurement tool for each patient from right craniocaudal (RCC) and left craniocaudal (LCC) images in 2 D imaging mode. RESULTS: The mean compressed breast thickness (CBT) was 52.7 mm for craniocaudal (CC) and 56.0 mm for mediolateral oblique (MLO) views. The mean percentage of breast glandular tissue content was 18.0% and 17.4% for RCC and LCC projections, respectively. The mean AGD values in 2 D imaging mode per exposure for the standard breast were 1.57 mGy and 1.66 mGy, while the mean AGD values after correction for real breast composition were 1.82 mGy and 1.94 mGy for CC and MLO views, respectively. The mean AGD values in 3 D imaging mode per exposure for the standard breast were 2.19 mGy and 2.29 mGy, while the mean AGD values after correction for the real breast composition were 2.53 mGy and 2.63 mGy for CC and MLO views, respectively. No significant relationship was found between the AGD and CBT in 2 D imaging mode and a good correlation coefficient of 0.98 in 3 D imaging mode. CONCLUSION: In this study the mean calculated AGD per exposure in 3 D imaging mode was on average 34% higher than for 2 D imaging mode for patients examined with the same CBT.