Vol 49, No 1 (2021)

Aim: To assess the specificity of COVID-19- associated pneumonia detection by radiologists using a chest CT scan.

Materials and methods: From mid-February to early March 2020, 65  patients have been retrospectively selected from the Moscow City Clinical Hospital database; all of them had been treated in an inpatient facility with a  verified diagnosis of COVID-19. In addition, 75  patients from the Unified Radiological Information Service have been randomly selected. In December 2019, these outpatients had been sent by an attending physician for a  chest CT scan with suspected pneumonia. The imaging studies showed non-specific inflammation signs in the lungs. All 140  scans were analyzed by seven radiologists from different Russian cities, who independently categorized each study as “COVID-19” or “Other pneumonia”.

Results: Chest computed tomography had a  92%  specificity in the differential diagnosis of COVID-19-associated pneumonia, and its specificity in the general population is expected to be at least 80% with a high probability. The inter-rater variability was low (coefficient of variation for specificity 12.6%). The sensitivity in our study was 76.2%, and the coefficient of variation for sensitivity 23.5%. These findings are generally consistent with other studies. The primary study limitation is the absence of a sample with confirmed pneumonia caused by other viruses.

Conclusion: Chest CT is highly specific for the detection of COVID-19-associated pneumonia.

Rationale: A  standard algorithm for the assessment of patients with breast trauma does not exist, as such trauma usually does not incur any significant health problems. However, according to existing clinical and work-up data and various radiological signs, posttraumatic abnormalities of the breast can mimic cancer lesions and complicate the differential diagnosis for a radiologist.

Aim: To evaluate the potential of digital mammography and breast ultrasound examination in the identification of breast posttraumatic abnormalities and to describe their semiotics.

Materials and methods: The study included 150  female patients aged 40  to 86  years (mean±SD, 60±11.9 years) with a history of breast trauma. Digital mammography with tomosynthesis (combined mode) and multiparametric ultrasound were able to identify breast abnormalities in 62 patients. The results of all assessments (n=62) were interpreted according to BI-RADS. Should any confirmation of the abnormalities be necessary, fine needle aspiration biopsy or core-biopsy with stereotaxic or ultrasound control were performed.

Results: At mammography, the typical posttraumatic abnormality in the breast was fat necrosis (n=54). It was represented as nodular masses with round (20/34; 58.8%) or oval shape (13/34; 38.2%) and circumscribed margins. In most cases, the masses contained eggshell calcification (27/34; 79.4%). In 35.1%  (19/54) of the cases fat necrosis was represented by various calcifications. At ultrasound, fat necrosis could be identified as avascular (40/40; 100%), mostly round (26/40; 65.0%), less frequently oval (12/40; 30.0%), and hypoechoic (19/40; 47.5%) masses with circumscribed margins. Atypical signs of fat necrosis (BIRADS 4) were found in 16.1% (10/62) of the cases, in which  7  (11.2%) core-biopsies with ultrasound control and  3  (4.8%) stereotaxic biopsies were performed. In all the cases, breast fat necrosis was confirmed, with various ratios of fibrous and necrotic fat tissue and lymphoid infiltration.

Conclusion: In most cases, standard radiological methods used in the diagnostic algorithm for posttraumatic breast lesions are sufficient for the diagnosis. In uncertain diagnostic cases, morphological verification seems necessary.

Background: Growing glioblastoma is associated with an impairment of the blood brain barrier and increased hemodynamic parameters (CBV, CBF), which is related to advanced tumor angiogenesis. Arterial spin labeling (ASL) perfusion, an additional study to the routine intravenous contrast-enhanced magnetic resonance imaging (MRI), may be a technique for assessment of hemodynamics and identification of the residual tumor tissue.

Aim: To study the potential of native ASL to assess hemodynamic parameters and detect residual tumor tissue in the patients who had undergone surgical resection of glioblastoma.

Materials and methods: At 2 to 4  weeks after surgery for glioblastoma grade IV, brain MRI with native ASL perfusion and subsequent intravenous contrast enhancement was performed in 63  patients. Cerebral blood flow (CBF) values were measured in three areas of interest: in the presumptive tumor tissue (PTT) with maximal perfusion, in the postoperative scar tissue (PST) and in the deep white matter (DWM) of the contralateral hemisphere.

Results: According to their CBF values, all patients were categorized into two groups. Group 1 included 43  patients (68.3%) with mean CBF in PTT of 135.4±41.3  ml/100  Gr/min (min 73.9, max 255.9). These values were 5 to 6-fold higher than the CBF values in the PST and 6 to 8-fold higher than those in DWM. Group  2 included 20  patients (31.7%) without any areas of abnormal CBF increase in PST, with its mean value of 22.1±5.6  ml/100  Gr/min (min 13.9, max 37.1), which was close to the CBF level in DWM (19.8±4.6  ml/100  Gr/min, p=0.06). There were no between-group differences for the CBF values in PST (p=0.6), and DWM (p=0.7).

Conclusion: ASL MR perfusion technique has good potential for the identification of residual tumor tissue after surgical resection of glioblastoma and can be an alternative to contrast enhancement during long-term follow up.

Rationale: The prevalence of malformation of internal carotid arteries (ICA) in the population amounts to 46%. In 4 to 16% of the cases, it is associated with clinical manifestations of cerebrovascular insufficiency. Hemodynamic changes in the abnormal arterial vasculature and neurological symptoms are the main indications for surgical intervention. Computed tomography (CT) angiography has shown its high information value in the assessment of ICA occlusions; however, its informativity in the diagnosis of ICA malformations has not been established.

Aim: To assess ICA and brain matter in the patients with abnormal tortuosities, both isolated and combined with occlusion, by CT angiography.

Materials and methods: We performed a  retrospective analysis of medical files of 58 inpatients, who underwent ultrasound examination and CT angiography of extra and intracranial parts of brachycephalic arteries with 256  slice multidetector computer scanner (Philips iCT). CT angiography included native imaging, and contrast-enhanced arterial and venous phases. We assessed the impact of ICA abnormalities on the degree of brain matter lesions in patients with isolated ICA malformations (n=27) and with combination of ICA malformations with its occlusion (n=31).

Results: In the group of the patients with isolated ICA malformations, there were no brain focal lesions in 14, small vessel focal lesions and single liquor cysts in 9, and areas and zones of cystic and glial abnormalities in 4. The most frequent in this group were S-like and C-like malformations, together with 2  saccular aneurysms (one of them true and one false). In the group of patients with combination of abnormal ICA tortuosities and occlusions, there were areas and zones of cystic and glial abnormalities in 7, various degrees of small vessel disease and few liquor cysts in 18, and no abnormal brain matter foci in 6. No ICA malformations in combination with true or false aneurysms were found. The patients with combination of ICA malformations and stenosis, the signs of chronic brain ischemia were more advanced, compared to those in the patients with isolated ICA malformations (p=0.012).

Conclusion: CT angiography is a highly informative method for the assessment of carotid arteries and brain matter in patients with ICA malformations. The combination with ICA malformations and occlusion is associated with more advanced lesions of brain matter.

Meniere's disease is characterized by vertigo, inconsistent hearing loss and progressive deterioration of audiological and vestibular functions. The attacks of Meniere's disease occur without obvious triggers and disrupt social adaptation of patients. Radiation diagnostic methods have not been included into the list of diagnostic criteria by the European Consensus on Diagnosis and Management of Meniere's disease (2018). However, a  number of studies have been published recently that indicate the feasibility of in vivo anatomical identification of endolymphatic hydrops, as the main disease substrate seen using contrast-enhanced magnetic resonance imaging. Due to the progress in radiological visualization of the inner ear, some patterns have been identified and new data obtained for Meniere's disease. The choice of the best route for contrast administration (intratympanic or intravenous) is a matter of active debate. There is no consensus on the criteria for the assessment of hydrops' grade. Future developments of the technique are associated with improvements of diagnostic procedures and protocols, use of new contrast agents and diagnostic algorithms developed with consideration of the otological problem of patients.

The diagnosis of multiple sclerosis (MS) is quite challenging due to its variable clinical manifestations and lack of a  definitive test. Magnetic resonance imaging (MRI) is one of the tools to confirm the diagnosis and also helps in differential diagnosis with other disorders and in exclusion of MS-mimicking diseases. In this article, based on the analysis of clinical cases, we discuss the differential diagnosis of MS with the following non-tumorous multifocal brain lesions: vascular abnormalities caused by hypoxia and ischemia, cerebral autosomal dominant angiopathy with subcortical infarctions and leukoencephalopathy, Susac syndrome, primary angiitis of the central nervous system, and neurosarcoidosis. We present both MRI criteria for MS and disorders that have similar MRI signs, and additional clinical and laboratory data that is essential for correct diagnosis.

Herewith we would like to inform our readers that the final version of the article doi: 10.18786/2072-0505-2021-49-001, published online on 02.03.2021, was replaced with a  corrected version on 15.03.2021. The corrected version, according to the authors request, includes the following changes: the author list and the affiliations, authors' contributions, acknowledgements sections.

The article should be cited as “Korb TA, Gavrilov PV, Chernina VYu, Blokhin IA, Aleshina OO, Mokienko OA, Morozov SP, Gombolevskiy VA. Specificity of chest computed tomography in COVID-19-associated pneumonia: a  retrospective study. Almanac of Clinical Medicine. 2021;49. doi: 10.18786/2072-0505-2021-49-001.