Non-traumatic lower abdominal pain: ultrasonographic and clinical differential diagnosis

Lower abdominal pain is frequently reported and has a diverse differential diagnosis. In cases with atypical presentation and nonspecific findings, further imaging evaluation is required to confirm the clinical suspicion and to distinguish between self-limiting disorders and those requiring immediate intervention. In line with European guidelines, transabdominal ultrasonography is recommended as a first-line imaging modality for clinically suspected acute appendicitis and acute diverticulitis, which respectively represent the predominant causes of right and left lower quadrant abdominal pain. It is similarly the preferred method for evaluating suspected obstetric/gynecologic and genitourinary diseases. Computed tomography is utilized as a secondary option when ultrasonography results are inconclusive. This pictorial essay illustrates the sonographic features of the most common conditions associated with lower abdominal pain and outlines the clinical characteristics of each entity.

Performance of thoracic ultrasonography compared with chest radiography for the detection of rib fractures using computed tomography as a reference standard

OBJECTIVE

Although there is growing evidence that ultrasonography is superior to X-ray for rib fractures' detection, X-ray is still indicated as the most appropriate method. This has partially been attributed to a lack of studies using an appropriate reference modality. We aimed to compare the diagnostic accuracy of ultrasonography and X-ray in the detection of rib fractures, considering CT as the reference standard.

MATERIALS AND METHODS

Within a 2.5-year period, all consecutive patients with clinically suspected rib fracture(s) following blunt chest trauma and available posteroanterior/anteroposterior X-ray and thoracic CT were prospectively studied and planned to undergo thoracic ultrasonography, by a single operator. All imaging examinations were evaluated for cortical rib fracture(s), and their location was recorded. The cartilaginous rib portions were not assessed. CTs and X-rays were evaluated retrospectively. Concomitant thoracic/extra-thoracic injuries were assessed on CT. Comparisons were performed with the Mann-Whitney U test and Fisher's exact test.

RESULTS

Fifty-nine patients (32 males, 27 females; mean age, 53.1 ± 16.6 years) were included. CT, ultrasonography, and X-ray (40 posteroanterior/19 anteroposterior views) diagnosed 136/122/42 rib fractures in 56/54/27 patients, respectively. Ultrasonography and X-ray had sensitivity of 100%/40% and specificity of 89.7%/30.9% for rib fractures' detection. Ultrasound accuracy was 94.9% compared to 35.4% for X-rays (P < .001) in detecting individual rib fractures. Most fractures involved the 4th-9th ribs. Upper rib fractures were most commonly overlooked on ultrasonography. Thoracic cage/spine fractures and haemothorax represented the most common concomitant injuries.

CONCLUSION

Ultrasonography appeared to be superior to X-ray for the detection of rib fractures with regard to a reference CT.

Deep learning enables the differentiation between early and late stages of hip avascular necrosis

OBJECTIVES

To develop a deep learning methodology that distinguishes early from late stages of avascular necrosis of the hip (AVN) to determine treatment decisions.

METHODS

Three convolutional neural networks (CNNs) VGG-16, Inception ResnetV2, InceptionV3 were trained with transfer learning (ImageNet) and finetuned with a retrospectively collected cohort of (n = 104) MRI examinations of AVN patients, to differentiate between early (ARCO 1-2) and late (ARCO 3-4) stages. A consensus CNN ensemble decision was recorded as the agreement of at least two CNNs. CNN and ensemble performance was benchmarked on an independent cohort of 49 patients from another country and was compared to the performance of two MSK radiologists. CNN performance was expressed with areas under the curve (AUC), the respective 95% confidence intervals (CIs) and precision, and recall and f1-scores. AUCs were compared with DeLong's test.

RESULTS

On internal testing, Inception-ResnetV2 achieved the highest individual performance with an AUC of 99.7% (95%CI 99-100%), followed by InceptionV3 and VGG-16 with AUCs of 99.3% (95%CI 98.4-100%) and 97.3% (95%CI 95.5-99.2%) respectively. The CNN ensemble the same AUCs Inception ResnetV2. On external validation, model performance dropped with VGG-16 achieving the highest individual AUC of 78.9% (95%CI 51.6-79.6%) The best external performance was achieved by the model ensemble with an AUC of 85.5% (95%CI 72.2-93.9%). No significant difference was found between the CNN ensemble and expert MSK radiologists (p = 0.22 and 0.092 respectively).

CONCLUSION

An externally validated CNN ensemble accurately distinguishes between the early and late stages of AVN and has comparable performance to expert MSK radiologists.

CLINICAL RELEVANCE STATEMENT

This paper introduces the use of deep learning for the differentiation between early and late avascular necrosis of the hip, assisting in a complex clinical decision that can determine the choice between conservative and surgical treatment.

KEY POINTS

• A convolutional neural network ensemble achieved excellent performance in distinguishing between early and late avascular necrosis. • The performance of the deep learning method was similar to the performance of expert readers.

Ultrasound-guided hydrodilatation for adhesive capsulitis: capsule-preserving versus capsule-rupturing technique

OBJECTIVE

To compare the clinical efficacy of capsule-rupturing versus capsule-preserving ultrasound-guided hydrodilatation in patients with shoulder adhesive capsulitis (AC). To determine potential factors affecting the outcome over a 6-month follow-up.

MATERIALS AND METHODS

Within a 2-year period, 149 consecutive patients with AC were prospectively enrolled and allocated into (i) group-CR, including 39 patients receiving hydrodilatation of the glenohumeral joint (GHJ) with capsular rupture and (ii) group-CP, including 110 patients treated with GHJ hydrodilatation with capsular preservation. Demographics, affected shoulder, and AC grade were recorded. Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and visual analog scale (VAS) were used for clinical assessment at baseline/1/3/6 months. Comparisons were performed with Mann-Whitney U test and Kolmogorov-Smirnov test. Linear regression was used to identify predictors of outcome. P value < 0.05 defined significance.

RESULTS

DASH and VAS scores in both groups improved significantly compared to baseline (P < 0.001) and were significantly lower in the CP compared to CR group at all time-points following intervention (P < 0.001). Capsule rupture was a significant predictor of DASH score at all time-points (P < 0.001). DASH scores correlated to initial DASH score at all time-points (P < 0.001). DASH/VAS scores at 1 month were correlated to the AC grade (P = 0.025/0.02).

CONCLUSION

GHJ hydrodilatation results in pain elimination and functional improvement till the mid-term in patients with AC, with improved outcome when adopting the capsule-preserving compared to the capsule-rupturing technique. Higher initial DASH score is predictive of impaired functionality in the mid-term.

Postoperative Bowel Obstruction as a Rare Complication of an Abdominal Drain

Although routine intra-abdominal drain insertion following surgery represents a common practice worldwide, its utility has been questioned during the last decades. Several comparative studies have failed to document significant benefits from routine draining, and drain insertion has been correlated with various complications as well. Drain-related complications include, but are not limited, to infection, bleeding, and tissue erosion. Herein, we present the case of a 32-year-old patient with perforated peptic ulcer and purulent peritonitis, whose postoperative course was complicated by early mechanical bowel obstruction due to an abdominal drain. A high level of clinical suspicion, along with accurate imaging diagnosis, dictated prompt removal of the drain, which resulted in immediate resolution of the patient's symptoms. We aim to increase the clinical awareness of this rare complication related to intra-abdominal drain utilization with this report.

Performance of Ultrasonography in the Diagnosis of Acute Colonic Diverticulitis

OBJECTIVES

Computed tomography is regarded as the reference-standard imaging modality for the assessment of acute left-sided colonic diverticulitis (ALCD). However, its utility may be impaired by cost issues, limited availability, radiation exposure, and contrast-related adverse effects. Ultrasonography is increasingly advocated as an alternative technique for evaluating ALCD, although there is variation regarding its accuracy in disease diagnosis and staging and in determining alternative diagnoses. The aim of this study was to assess the performance of ultrasonography in diagnosing ALCD, differentiating complicated from non-complicated disease and defining alternative diseases related to left lower quadrant pain.

METHODS

Within a 2-year period, all consecutive adult patients with clinically suspected ALCD and available abdominal computed tomography were prospectively evaluated and planned to undergo an abdominal ultrasonographic examination, tailored to the assessment of left lower quadrant. Computed tomography (CT) was regarded as the reference standard.

RESULTS

A total of 132 patients (60 males, 72 females; mean age: 61.3 ± 11 years) were included. The sensitivity, specificity, and area under curve of ultrasonography for diagnosing ALCD were 88.6, 84.9, and 86.8%, with positive and negative predictive values of 89.7 and 83.3%, respectively. The method had sensitivity, specificity, and area under curve of 77.8, 100, and 88.9%, respectively, for defining complicated disease. The area under the curve for the identification of alternative diseases in patients with left lower quadrant pain was 90.9%.

CONCLUSIONS

Ultrasonography has high diagnostic accuracy for diagnosing ALCD, differentiating complicated from non-complicated disease and establishing alternative diagnoses related to left lower quadrant pain. A low threshold to get a CT should be maintained as not to miss cases that may mimic ALCD.

Long-Term Outcomes of Ultrasound-Guided Hydrodistension for Adhesive Capsulitis: A Prospective Observational Study

Ultrasound-guided hydrodistention has been established as an effective minimally invasive treatment option for glenohumeral joint adhesive capsulitis (AC). Nonetheless, the long-term outcomes of the procedure have not yet been established. A total of 202 patients with AC were prospectively recruited and followed up for a total of 2 years. Pain and functionality were assessed with the use of the visual analogue scale (VAS) and the disabilities of the arm, shoulder, and hand (DASH) score, respectively, at the beginning and the end of the follow-up period. The relapse of AC over the 2-year period and the effect of diabetes were also evaluated in the treatment cohort. The Mann-Whitney U test was used to compare mean scores at the two time points, and Cox survival analysis and χ2 test were used to assess the effect of diabetes on AC relapse. VAS and DASH scores were significantly lower at 2 years compared with the beginning of the follow-up period (p < 0.001). Diabetes was diagnosed in 38/202 patients (18.8%) and was found to be significantly associated with recurrence of the disease (p < 0.001). In conclusion, in this observational study, we have demonstrated that ultrasound-guided hydrodistention is linked to excellent long-term outcomes for the treatment of AC, which are significantly worse in patients with diabetes.

The Role of Imaging in the Pre- and Postoperative Evaluation of Inguinal Hernia

Inguinal hernia repair is the most frequently performed surgical procedure. Imaging has a fundamental role in initial assessment and postoperative evaluation of inguinal hernias. Clinical implications of radiology in the preoperative setting include diagnosis of occult/complicated hernias and enhancement of diagnostic certainty. Postoperatively, imaging may assist the detection and characterization of complications. Familiarity with the normal appearance of the postoperative groin area and surgical techniques is required to avoid misinterpretation. This pictorial essay provides an overview of the expected postoperative imaging findings and highlights the role of imaging in the pre- and postoperative evaluation of inguinal hernias, with emphasis on ultrasonography.

Ultrasound-guided hydrodistension for adhesive capsulitis: a longitudinal study on the effect of diabetes on treatment outcomes

OBJECTIVE

The effect of diabetes on adhesive capsulitis (AC) and its impact on the outcomes of ultrasound (US)-guided hydrodistension of the glenohumeral joint are still unclear. We aimed to identify predictors of US-guided hydrodistension outcomes, while assessing the performance of the method in diabetic compared to non-diabetic patients.

MATERIALS AND METHODS

A total of 135 patients with AC who underwent US-guided hydrodistension were prospectively included. Demographics and factors linked to chronic inflammation and diabetes were recorded and patients were followed-up for 6 months. Functionality and pain were evaluated with the Disabilities of the Arm, Shoulder and Hand (DASH) and the Visual Analogue Scale (VAS) score. Statistical analysis was performed with Mann-Whitney U test, linear, and binary logistic regression.

RESULTS

Diabetes was identified in 25/135 patients (18.5%). Diabetic patients had worse DASH and VAS score at presentation (P < 0.0001) and presented with a higher grade of AC (P < 0.0001) and lower range of motion (P < 0.01) compared to non-diabetics. Higher DASH (P = 0.025) and VAS scores (P = 0.039) at presentation were linked to worse functionality at 6 months. Presence and duration of diabetes, and the number of hydrodistension repeats, correlated with worse VAS and DASH scores at 6 months. The number of procedure repeats was the only independent predictor of complete pain resolution at 6 months (OR 0.418, P = 003).

CONCLUSION

Diabetes is linked to more severe AC at presentation and worse outcomes in patients undergoing US-guided hydrodistension. In resistant cases, repeating the intervention is independently linked to worse outcomes for at least 6 months post-intervention.

Imaging of Anatomical Variants Around the Hip

Considering the current widespread use of imaging as an integral part of managing hip pain, variable hip geometries and anatomical variants are increasingly being detected. These variants are commonly found in the acetabulum and proximal femur, as well as the surrounding capsule-labral tissues. The morphology of specific anatomical spaces confined by the proximal femur and the bony pelvis may also vary significantly among individuals. Familiarity with the spectrum of imaging appearances of the hip is necessary to identify variant hip morphologies with or without potential clinical relevance and reduce an unnecessary work-up and overdiagnosis. We describe anatomical variations and variable morphologies of the bony structures comprising the hip joint and the soft tissues, around the hip. The potential clinical significance of these findings is further analyzed in conjunction with the patient's profile.

The role of MRI and Ultrasonography in Diagnosis and Treatment of Glenohumeral Joint Adhesive Capsulitis

Adhesive capsulitis is a common disorder of the glenohumeral joint. Delayed diagnosis is the result of overlapping signs and symptoms with other disorders affecting the shoulder. Typically, the disease shows gradual progression of pain and loss of the range of motion. The hallmark of the physical examination is limitation of both passive and active motion without any associated degenerative changes on plain radiographs. Conservative and/or surgical treatments have shown conflicting results. Poor outcome may be related to co-morbid factors mainly including prolonged immobilization, rotator cuff pathology and diabetes mellitus among others. This review will present the current literature data on the natural history and pathophysiology of the disease, and will highlight the role of imaging in the prompt and accurate diagnosis as well as in the imaged-guided treatment with emphasis on ultrasonography.

Ultrasound-Guided Hydrodistension for Adhesive Capsulitis: Is There Any Adjunct Effect of Immediate Post-Procedural Manipulation Over Instructed Physical Therapy?

OBJECTIVES

To compare the additive value of immediate post-procedural manipulation versus physiotherapy, following ultrasound (US)-guided hydrodistention of the glenohumeral joint (GHJ) in patients with adhesive capsulitis (AC) and define predictors of outcome.

METHODS

Within a 19-month period, 161 consecutive patients with AC were prospectively enrolled and allocated to two groups according to treatment, based on patients' individual preferences: 1) group-I, US-guided hydrodistension plus immediate post-procedural manipulations and 2) group-II, US-guided hydrodistension plus supervised physiotherapy program. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and a visual analog scale (VAS) were used for clinical assessment at baseline (immediately after treatment), 1, 3, and 6 months. Comparisons were performed with Mann-Whitney U test and Kolmogorov-Smirnov test. Linear regression was used to identify predictors of outcome. P value <.05 defined significance.

RESULTS

GHJ hydrodistension with manipulation or physiotherapy was linked to clinical improvement at all follow-up time-points. DASH scores of group-I remained constantly lower than DASH scores of group-II at all time-points (P < .001). VAS scores were lower in group-I than group-II at 1 and 3 months (P < .001 and P = .0019, respectively). Both groups had improved to a similar degree with respect to pain at 6 months (P = .29). The performance of post-interventional manipulations was predictive of improved shoulder functionality (as assessed with DASH scores) at all time-points, while low-grade disease and milder symptoms at presentation were associated with improved short-term pain.

CONCLUSIONS

Immediate post-procedural manipulations appeared to be superior to physiotherapy following GHJ hydrodistension for AC in terms of shoulder functionality during a 6-month follow-up period. Post-interventional manipulations, the stage of AC and lower DASH and VAS scores at presentations were predictive of improved outcome.

Differentiation between subchondral insufficiency fractures and advanced osteoarthritis of the knee using transfer learning and an ensemble of convolutional neural networks

PURPOSE

Subchondral insufficiency fractures (SIF) and advanced osteoarthritis (OA) of the knee are usually seen in conjunction with bone marrow lesions (BMLs) and their differentiation may pose a significant diagnostic challenge. We aimed to develop a convolutional neural network (CNN) ensemble which could successfully differentiate between these two entities.

MATERIALS AND METHODS

A total of 212 knees with SIF and 102 knees with advanced OA with BMLs were retrospectively included. Coronal fat suppressed PD-w images were augmented, resized and normalized, reaching a total of 1174 images. Data was used to fine-tune three ImageNet-pretrained CNNs (VGG-16, InceptionV3 and Inception-ResNet-V2). Agreement of at least two networks was recorded as the decision of the network ensemble. Ensemble performance was compared to that of two MSK radiologists on the validation set. Receiver operating characteristics (ROC) curves and the respective areas under the curve (AUC) were used to evaluate human and machine performance.

RESULTS

InceptionV3 achieved the highest AUC (93.68%) and VGG-16 the lowest AUC (82.18%) among individual CNNs. CNN ensemble achieved the highest overall performance with an AUC of 95.97%. The first of the two MSK radiologists achieved a performance similar to the ensemble, reaching an AUC of 91.95%. The second radiologist achieved lower AUC of 82.76% which was lower than both the other specialist and the ensemble (P < 0.001).

CONCLUSION

A CNN ensemble was highly accurate in differentiating between SIF and OA, achieving a higher or equal performance to MSK radiologists.

Performance of Lung Ultrasound for Monitoring Interstitial Lung Disease

OBJECTIVES

In this study, we sought to assess the validity of lung ultrasound (LUS) during the follow-up of patients with a wide spectrum of interstitial lung diseases (ILDs).

METHODS

Twenty-four patients (13 males, 11 females; mean age ± SD, 65.4 ± 14.3 years; age range, 40-84 years) with a diagnosis of ILDs who were admitted to the Interstitial Lung Disease Unit were prospectively enrolled. Patients were examined with a 56-lung intercostal space LUS protocol in lateral decubitus position, at baseline, 6-months, and 1-year. The LUS score was defined as the sum of B-lines counted in each intercostal space. All patients underwent complete pulmonary function tests at baseline and follow-up time-points. High-resolution computed tomography (HRCT) was performed at baseline and during follow-up, according to personalized patients' needs. All HRCT studies were graded according to the Warrick scoring system (WS).

RESULTS

Pooled data analysis showed a significant correlation between WS and LUS scores (P < .001). For separate time-point analysis, a significant correlation between LUS scores and WS was found at baseline (P < .001) and 1 year (P = .005). LUS scores negatively correlated with alveolar volume (VA) (P < .046) and diffusing capacity for carbon monoxide (DLCO) (P < .001) at 6 months and with transfer coefficient of the lung for carbon monoxide (KCO) (P < .031) and DLCO (P = .002) at 12-months. A multivariate regression model showed DLCO to be an independent predictor of LUS score at 1 year (P = .026).

CONCLUSIONS

Our results highlight the validity and potential applicability of LUS for disease monitoring in a wide spectrum of ILDs.

Predicting long-term outcomes of ultrasound-guided percutaneous irrigation of calcific tendinopathy with the use of machine learning

OBJECTIVE

To evaluate the performance of two machine learning models in predicting the long-term complete pain resolution in patients undergoing ultrasound-guided percutaneous irrigation of calcific tendinopathy (US-PICT).

MATERIALS AND METHODS

Within a 3-year period, 100 consecutive patients who underwent US-PICT for rotator cuff disease were prospectively enrolled. The location, maximum diameter, and type of each calcification were recorded. The degree of calcium retrieval was graded as complete or incomplete. Shoulder pain was assessed with the visual analogue scale (VAS) at baseline, 1-week, 1-month, and 1-year post-treatment. Measurements related to procedural details, patient, and calcification characteristics were used to construct a machine learning model for the prediction of pain at 1-year post-US-PICT. Two distinct models were built, one including VAS data at 1 week and another additionally including pain data at 1-month post-treatment. Variable importance analysis was performed for the 1-week model. Model performance was evaluated by using receiver operating characteristics (ROC) curves and the respective areas under the curve (AUC).

RESULTS

The model exhibited an AUC of 69.2% for the prediction of complete pain resolution at 1 year. The addition of VAS scores at 1 month did not significantly alter the performance of the algorithm. Age and baseline VAS scores were the most important variables for classification performance.

CONCLUSION

The presented machine learning model exhibited an AUC of almost 70% in predicting complete pain resolution at 1 year. Pain data at 1 month do not appear to improve the performance of the algorithm.

Knee Capsule Anatomy: An MR Imaging and Cadaveric Study

This research focuses on the anatomical insertion of the synovial capsule around the knee. The attachments of the capsule were measured in 50 knee MR imaging studies with large intraarticular effusion. Corresponding measurements were performed in 20 fresh frozen cadaveric specimens, for validation. Femoral and tibial capsular reflections were defined as the distances between the attachment sites of the capsule and the femoral or tibial joint line and they were recorded in three coronal planes (anterior/middle/posterior). On MR imaging, the lateral/medial femoral capsular reflection mean values were 6.5/4.57 cm, 2.74/1.74 cm and 1.52/1.99 cm in the anterior, middle and posterior plane, respectively. MR imaging-based measurements did not differ significantly compared to corresponding cadaveric measurements. The mean values of the lateral/medial tibial capsular reflection on MR imaging were 0.09/0.11 cm, 0.34/0.26 cm and 0.62/0.34 cm in the anterior, middle and posterior plane, respectively. On cadaveric dissection, the maximum mean value was 1.45 cm, measured on the lateral side of the anterior plane. Apart from the lateral aspect of the posterior plane, MR imaging measurements were significantly lower, compared to the corresponding cadaveric measurements. The greatest femoral and tibial capsular reflections were found on the anterior and lateral side of the anterior plane. MR imaging appears to underestimate the distal extent of the knee capsule. Anatomical details of the knee capsule should be considered for safe insertion of external fixator pins.

MRI findings of acute anterior instability of the knee in the absence of recent trauma

BACKGROUND

Anterior knee instability is usually encountered in the context of trauma, with the clinical examination and imaging focusing on anterior cruciate ligament (ACL) disruption. Limited data exist on magnetic resonance imaging (MRI) of acute anterior knee instability in the absence of recent trauma.

PURPOSE

To provide the first comprehensive account of MRI findings in acute anterior knee laxity in the absence of acute trauma and to evaluate predictors of ACL integrity and pain.

MATERIAL AND METHODS

A total of 84 consecutive patients with non-traumatic knee instability were prospectively studied. Instability was assessed with Lachman's, pivot shift, and Lelli's tests. MRI findings were recorded, and ACL integrity was surgically confirmed in all 24 cases of MRI suggesting tear and in 21/60 cases of MRI suggesting no tear. Binary logistic regression models were used to identify predictors of ACL tears and pain, and Mann-Whitney U test served for comparisons between continuous variables. The study was approved by the institutional review board.

RESULTS

Osteoarthritis and notch bony outgrowth (NBO) were present in 44% and 42.9% of all knees, respectively. NBO did not correlate with osteoarthritis (P = 0.606). NBO (odds ratio [OR] = 4.157; P = 0.016) and ACL grafts (OR = 9.277; P = 0.01) predisposed to non-traumatic ACL tears (torn in 28.6% of total cases). Presence of osteoarthritis was predictive of pain (OR = 17.671; P < 0.001).

CONCLUSION

We present a comprehensive analysis of MRI findings in clinically significant non-traumatic anterior instability, showing that NBO and ACL grafts predispose in non-traumatic ACL tears, whereas osteoarthritis is the only predictor of pain.

Advancing COVID-19 differentiation with a robust preprocessing and integration of multi-institutional open-repository computer tomography datasets for deep learning analysis

The coronavirus pandemic and its unprecedented consequences globally has spurred the interest of the artificial intelligence research community. A plethora of published studies have investigated the role of imaging such as chest X-rays and computer tomography in coronavirus disease 2019 (COVID-19) automated diagnosis. Οpen repositories of medical imaging data can play a significant role by promoting cooperation among institutes in a world-wide scale. However, they may induce limitations related to variable data quality and intrinsic differences due to the wide variety of scanner vendors and imaging parameters. In this study, a state-of-the-art custom U-Net model is presented with a dice similarity coefficient performance of 99.6% along with a transfer learning VGG-19 based model for COVID-19 versus pneumonia differentiation exhibiting an area under curve of 96.1%. The above was significantly improved over the baseline model trained with no segmentation in selected tomographic slices of the same dataset. The presented study highlights the importance of a robust preprocessing protocol for image analysis within a heterogeneous imaging dataset and assesses the potential diagnostic value of the presented COVID-19 model by comparing its performance to the state of the art.

Interpretable artificial intelligence framework for COVID-19 screening on chest X-rays

COVID-19 has led to an unprecedented healthcare crisis with millions of infected people across the globe often pushing infrastructures, healthcare workers and entire economies beyond their limits. The scarcity of testing kits, even in developed countries, has led to extensive research efforts towards alternative solutions with high sensitivity. Chest radiological imaging paired with artificial intelligence (AI) can offer significant advantages in diagnosis of novel coronavirus infected patients. To this end, transfer learning techniques are used for overcoming the limitations emanating from the lack of relevant big datasets, enabling specialized models to converge on limited data, as in the case of X-rays of COVID-19 patients. In this study, we present an interpretable AI framework assessed by expert radiologists on the basis on how well the attention maps focus on the diagnostically-relevant image regions. The proposed transfer learning methodology achieves an overall area under the curve of 1 for a binary classification problem across a 5-fold training/testing dataset.

Spectrum of skeletal disorders during the peripartum period: MRI patterns

Pregnancy is a normal condition in which a combination of biomechanical and hormonal changes may result in a wide spectrum of skeletal disorders. Skeletal overloading due to postural and weight changes, combined with increased ligamentous laxity stemming from the action of relaxing and the risk of pregnancy-related osteoporosis during childbearing, childbirth, and postpartum, have been associated with various pathologies. Owing to the heterogeneity of proposed contributing factors, skeletal lesions in the peripartum period may be related to different pathogenesis depending on the metabolic status of the patient and the degree of biomechanical stress; thus, a fatigue or insufficiency discrimination is not always easy to make. When combined with clinical data, magnetic resonance imaging (MRI) is a powerful tool in clarifying the cause of skeletal pain in the majority of patients or alerting clinicians to proceed to further investigations. Early detection and tailored treatment are important in order to avoid disease progression and long-term restriction of daily activities which may have an adverse impact on the relationship between the mother and the newborn. This pictorial essay provides an overview of the MRI characteristics and pattern of involvement of skeletal lesions presenting during the peripartum period, combined with demographic data and dual-energy X-ray absorptiometry (DEXA) measurements.

MR Imaging of the Hip: An Update on Bone Marrow Edema

Bone marrow edema (BME) represents a frequent and easily detected MR imaging finding that is recognized as a common source of pain. It is considered a nonspecific finding that constitutes a central component of a wide spectrum of pathologies affecting the hip joint, showing high variability in terms of prognosis and treatment requirements. Solid knowledge of the various BME patterns and associated imaging findings indicative of these conditions can aid in differentiation. Additionally, correlation with clinical and laboratory data are essential for arriving at a final diagnosis in several cases. In this review, we describe the disease characteristics and imaging findings and also highlight the differential diagnostic clues regarding common hip disorders associated with BME including avascular necrosis, transient osteoporosis, stress injuries, and infectious/inflammatory disorders.

Paroxysmal cough and left sacroiliac joint pain in a 50-year-old Caucasian man

A 50-year-old Caucasian man who was a lifelong nonsmoker presented with a 3-year history of paroxysmal dry cough, fatigue, nonspecific myalgias, muscle weakness of the lower extremities and left sacroiliac joint pain. Initially, he was reviewed by a pulmonologist and subsequently he was referred to the Dept of Thoracic Medicine (Heraklion University Hospital, Heraklion, Greece) for further investigation. His medical history was remarkable for the presence of arterial hypertension on treatment with amlodipine and irbesartan.

Can you diagnose this patient with pulmonary symptoms, thoracic and laboratory test abnormalities and sacroiliac joint pain?http://ow.ly/LPyy30kaViz

Lung Ultrasonography in Patients With Idiopathic Pulmonary Fibrosis: Evaluation of a Simplified Protocol With High-Resolution Computed Tomographic Correlation

OBJECTIVES

To compare a simplified ultrasonographic (US) protocol in 2 patient positions with the same-positioned comprehensive US assessments and high-resolution computed tomographic (CT) findings in patients with idiopathic pulmonary fibrosis.

METHODS

Twenty-five consecutive patients with idiopathic pulmonary fibrosis were prospectively enrolled and examined in 2 sessions. During session 1, patients were examined with a US protocol including 56 lung intercostal spaces in supine/sitting (supine/sitting comprehensive protocol) and lateral decubitus (decubitus comprehensive protocol) positions. During session 2, patients were evaluated with a 16-intercostal space US protocol in sitting (sitting simplified protocol) and left/right decubitus (decubitus simplified protocol) positions. The 16 intercostal spaces were chosen according to the prevalence of idiopathic pulmonary fibrosis-related changes on high-resolution CT. The sum of B-lines counted in each intercostal space formed the US scores for all 4 US protocols: supine/sitting and decubitus comprehensive US scores and sitting and decubitus simplified US scores. High-resolution CT-related Warrick scores (J Rheumatol 1991; 18:1520-1528) were compared to US scores. The duration of each protocol was recorded.

RESULTS

A significant correlation was found between all US scores and Warrick scores and between simplified and corresponding comprehensive scores (P < .0001). Decubitus simplified US scores showed a slightly higher correlation with Warrick scores compared to sitting simplified US scores. Mean durations of decubitus and sitting simplified protocols were 4.76 and 6.20 minutes, respectively (P < .005).

CONCLUSIONS

Simplified 16-intercostal space protocols correlated with comprehensive protocols and high-resolution CT findings in patients with idiopathic pulmonary fibrosis. The 16-intercostal space simplified protocol in the lateral decubitus position correlated better with high-resolution CT findings and was less time-consuming compared to the sitting position.

Modified Lung Ultrasonographic Technique for Evaluation of Idiopathic Pulmonary Fibrosis: Lateral Decubitus Position

OBJECTIVES

To compare lung ultrasonography (US) in the sitting or supine positions and the lateral decubitus position, with regard to the feasibility, duration, patient convenience, and assessment of B-lines, in patients with idiopathic pulmonary fibrosis.

METHODS

Twenty consecutive patients with idiopathic pulmonary fibrosis were prospectively enrolled. Lung US included scanning of 56 intercostal spaces. Each patient was examined twice by 2 protocols. During protocol 1, patients were examined in the supine and sitting positions for the anterior and dorsal chest, respectively. During protocol 2, patients were examined in the left lateral decubitus position for the evaluation of the right hemithorax and the reverse. Total, anterior, and posterior US scores resulted from the sum of B-lines at the whole, anterior, and posterior chest, respectively. High-resolution computed tomography (CT) was considered the reference standard. The duration of each protocol was recorded. Patients were questioned about which protocol they preferred.

RESULTS

There was no difference regarding feasibility between the protocols. A significant correlation was found between total US scores for both protocols and high-resolution CT findings (P < .0001), with protocol 2 showing a slightly higher correlation. A positive correlation was found between the protocols regarding total, anterior, and posterior US scores (P < .0001). The mean duration of protocol 2 was less than that of protocol 1 (P < .005). Nineteen patients (95%) reported a preference for protocol 2.

CONCLUSIONS

Lung US in the lateral decubitus position seems to be faster and more convenient. There appears to be no difference regarding feasibility and the number of B-lines, whereas it shows slightly higher correlation with high-resolution CT, compared with the sitting or supine positions in patients with idiopathic pulmonary fibrosis.

Hydroxyapatite deposition disease around the hip: outcomes of CT-guided treatment

PURPOSE

Hydroxyapatite deposition disease (HADD) around the hip joint is a self-limiting condition usually treated conservatively. The aim of the present study is to directly compare the outcomes of CT-guided and conservative treatments in cases of refractory hip HADD.

METHODS

Two groups of patients with refractory hip HADD were prospectively constructed from a pool of 484 patients referred for greater trochanter pain syndrome, based on the presence of calcifications around the hip and the failure of conservative treatment. Study group included 22 hips, which underwent CT-guided barbotage and steroid injection treatment, whereas control group consisted of 28 hips that were treated conservatively. Evaluation of the outcome of both groups was performed over a one-year follow-up period with the use of a score measuring clinical improvement in terms of pain and functional impairment.

RESULTS

Three weeks after the initiation of treatment, study group exhibited significantly higher scores compared with the control group (P < 0.001). Improvement scores of the control group were similar to the study group after three months of treatment (P > 0.1).

CONCLUSION

CT-guided treatment provides relief of debilitating symptoms in the acute phase.

Calcific tendinopathy of the shoulder with intraosseous extension: outcomes of ultrasound-guided percutaneous irrigation

OBJECTIVES

Rotator cuff calcific tendinopathy (RCCT) with intraosseous extension is a rare complication of tendinous and peritendinous involvement. The purpose of our study is to evaluate the outcome of ultrasound-guided percutaneous irrigation of calcific tendinopathy (US-PICT) in patients with intraosseous involvement.

MATERIALS AND METHODS

From January 2011 to June 2014, patients with a clinical and imaging diagnosis of RCCT were prospectively categorised in two groups based on imaging findings: group A (10 patients) with intraosseous RCCT and group B (control group 35 patients) without osseous involvement. US-PICT followed by subacromial injection was applied to all patients in groups A and B. During a 1-year follow-up, treatment outcome in terms of pain and functional improvement was evaluated at 3 weeks, 3 months, 6 months, and 1 year, with the use of a four-grade scale. The study has been approved by our hospital's ethics committee.

RESULTS

Mean improvement scores of group A were significantly lower than those of group B at all time points (p < 0.0001). Improvement of group B was noted mainly within the first 3 months post-treatment (p = 0.016).

CONCLUSION

Outcomes of ultrasound-guided treatment in cases of RCCT with intraosseous extension are significantly less favourable than in purely tendinous or peritendinous disease.

MR imaging of transient osteoporosis of the hip: an update on 155 hip joints

PURPOSE

Transient osteoporosis of the hip (TOH) presents with acute onset pain and bone marrow edema (BMe) on MR imaging. The purpose of this study is to revise the MR imaging characteristics of TOH by analyzing the data derived from 155 hip examinations. We also sought to explore the relationship between the duration of symptoms and the presence of sparing and subchondral fractures.

MATERIALS AND METHODS

MR images of 155 hips (141 TOH patients) were retrospectively evaluated for the presence of insufficiency fractures and the morphology of BMe. Sparing of the medial bone marrow of the femoral head was recorded together with demographic and clinical data. Progression to regional migratory osteoporosis (RMO) and postpartum cases were also recorded.

RESULTS

Our population consisted of 76.4% male and 23.6% female patients. RMO progression was recorded in 19.4% and 4 postpartum cases displayed bilateral disease. Sparing of the medial bone marrow was present at 87.7% of patients and disappeared as the disease progressed (P=0.005). BMe was restricted within the femoral head in 11.0%, extended to the femoral neck in 40% and to the femoral shaft in 49% of the cases studied. Subchondral fractures were present at 48.7% of the hips.

CONCLUSION

This study describes TOH patient characteristics, the MR imaging findings (BMe pattern, microfractures), their association with symptom duration and the chance of progressing to RMO.