Israel Medical Association Journal

Background: Coronavirus disease-2019 (COVID-19) chest computed tomography (CT) involves ground-glass opacity (GGO) and denser consolidations, which are crucial for diagnosis.

Objectives: To determine optimal window settings for characterization and detection of GGO and dense consolidation on CT imaging in COVID-19 patients using a Simplex-based approach.

Methods: The study included 54 conventional CTs of COVID patients in two phases. First, CT images of 14 patients with GGO and 4 with dense consolidation were included. Seven radiologists evaluated representative images in different windows of varied width and center. They were graded for adequacy of characterization and detection. A Simplex algorithm was used to iteratively determine the optimal window settings. Surface response maps expressing the relationship between window settings and overall reader grades were constructed. Next, the reviewers compared manufacturer recommendations to the new optimal windows found on CT images of 40 patients.

Results: Overall, 12 different window settings were evaluated over a total of 1176 reads. Optimal characterization and detection of pure GGO was seen with a center of 630 HU and width 1460 HU, producing higher grades for both detection and characterization than the manufacturer window settings (P = 0.005). Optimal windowing for dense consolidation was like manufacturer measures (-585 HU and 1800 HU). In phase 2, an overwhelming preference of 78% favoring the optimal window compared to conventional settings was found.

Conclusions: GGO lung opacities characteristic for COVID-19 can be best seen using a lower CT windowing width than the manufacturer's recommendations, unlike denser consolidations, possibly due to differences in underlying pathophysiology.

Background: On 7 October 2023, an armed conflict erupted between Hamas and Israel, leading to numerous combat casualties.

Objectives: To describe computed tomography (CT) findings of combat casualties at a tertiary medical center during the first 3 months of the conflict.

Methods: A retrospective observational study was conducted on patients admitted between 7 October 2023 and 7 January 2024. Adults with conflict-related trauma who underwent chest, abdomen, and pelvis (body) trauma protocol CT scans were included.

Results: Of 272 patients who underwent body trauma protocol CT, 112 combat-related adults were included, mean age of 27 years and one female. In total, 82 patients (73%) underwent additional scans of the head and neck or extremities. Fractures were observed in 53 patients (47%). Vascular injuries were present in 40 patients (35%). Limb injuries were most common, affecting 37 patients (33%), which prompted a protocol update. Lung injuries were the most common in body CT: 30 patients (27%). Head and neck injuries were seen in 21 patients (18%). Multisystem trauma was present in 24 patients (21%). A total of 83 patients (74%) underwent surgery, mostly orthopedic/soft tissue surgeries (63%); 15 (13%) underwent abdominal surgery, with bowel injuries confirmed in eight cases.

Conclusions: CT scans are an important tool in conflict trauma management. Limb injuries were the most frequent, necessitating protocol adjustments. Lung injuries were the most common body injury; 21% of patients had multisystem trauma. Most patients required surgery.

Background: Management of patients with reported iodinated contrast media (ICM) allergy is not supported by sufficient data. It is assumed that these patients are at risk for severe reactions, and that premedication provides protection.

Objective: To examine current practice and prognosis in hospitalized patients with ICM allergy.

Methods: In this retrospective study, we analyzed data of 17,356 patients who were hospitalized between 2018 and 2022 and referred for imaging. No-allergy and allergy groups were matched by age, sex, co-morbidities, and indications for imaging. Statistical analysis compared demographic, clinical, and imaging-related parameters.

Results: Our study included records of 501 patients with ICM allergy and 16,855 with no allergy. Patients with allergy were older (70.92 ± 16.25 vs. 59.02 ± 23.74 years, P < 0.001), female preponderance (male proportion 42.5% vs. 54%, P < 0.001), and those with increased cardiovascular and metabolic co-morbidities. The rate of ICM injection was similar among patients with ICM allergy (34%) and no allergy (36%). Most patients with ICM allergy did not receive premedication. Allergic patients demonstrated increased mortality (25.9% vs. 16.5%, P < 0.001); however, this result was not associated with the diagnosis of allergy, anaphylactic reactions, or premedication.

Conclusions: ICM allergy is mostly reported in patients with advanced age and multiple co-morbidities. Mortality was not increased when compared to matched non-allergic individuals. Among patients with reported allergy who were injected with ICM, anaphylaxis was not a cause of death, although fewer than half received premedication. Prospective trials are warranted to revise the clinical approach to ICM allergy.

Background: Cloacal malformation represents the rarest and most complex congenital anorectal malformation in females and is characterized by the convergence of urinary, gynecological, and intestinal systems within a single common channel. Three-dimensional computed tomography reconstruction (3D CT cloacagram) has emerged as a valuable method for anatomical assessment and preoperative planning.

Objectives: To evaluate our experience with 3D CT cloacagram and assess its results.

Methods: This retrospective case series included all patients with cloacal malformation who underwent preoperative 3D CT cloacagram at a single institution during 2019–2023. Collected data included patient characteristics, timing of the 3D CT cloacagram, results of the 3D CT cloacagram, comparison with endoscopic results, surgical procedures, and postoperative outcome.

Results: Six patients with cloacal malformation were included in this study, including two with posterior cloaca. The median common channel length on 3D CT cloacagram was 24.5 mm (range 9–48 mm) and the median urethral length was 15.5 mm (range 13-24 mm). The surgical approach involved a combined abdominoperineal approach in three patients and posterior sagittal anorectal vaginal urethral plasty in one patient. Two patients were awaiting surgical reconstruction at the time of publication.

Conclusions: Our implementation of 3D cloacagram has facilitated precise measurements of both the urethra and common channel lengths, two key factors in formulating surgical strategies for cloacal reconstruction. Moreover, this technique has markedly improved our capacity for surgical planning contributing to colorectal, gynecological, and urological perspectives.

Background: Syncope is responsible for approximately 1–3% of all emergency department (ED) visits and up to 6% of all hospital admissions in the United States. Although often of no long-term consequence, syncope can be the first presentation of a range of serious conditions such as strokes, tumors, or subarachnoid hemorrhages. Head computed tomography (CT) scanning is therefore commonly ordered in the ED for patients presenting with syncope to rule out any of these conditions, which may present without other associated physical or neurological findings on initial examination. However, the diagnostic yield of head CTs in patients presenting with syncope is unclear.

Objectives: To determine the diagnostic yield of head CT in the ED in patients with syncope.

Methods: We conducted an observational analytical retrospective cross-sectional study on 360 patients diagnosed with syncope who underwent a head CT to determine the diagnostic yield of syncope to determine whether head CT is necessary for every patient presenting with syncope to the ED.

Results: The total of new CT findings was 11.4%. Percentages varied between men (12.8%) and women (9.7%), P = 0.353. There were no significant differences between sexes regarding the findings in head CT, yet the incidence increased, especially among elderly males.

Conclusions: Age had a more significant impact on diagnostic yield of syncope than head CT. The use of a head CT scan as a routine diagnosis tool in patients with syncope is unjustifiable unless there is an indication based on medical history or physical examination.

Metastatic spinal cord compression (MSCC) is a medical emergency requiring rapid diagnosis and intervention to avoid irreversible neurological damage [1]. While MSCC is best diagnosed by magnetic resonance imaging (MRI), this modality is often limited and is usually preceded by a computed tomography (CT) scan of the spine.

Background: Computed tomography (CT) is the main diagnostic modality for detecting pancreatic adenocarcinoma.

Objectives: To assess the frequency of missed pancreatic adenocarcinoma on CT scans according to different CT protocols.

Methods: The medical records of consecutive pancreatic adenocarcinoma patients were retrospectively collected (12/2011–12/2015). Patients with abdominal CT scans performed up to a year prior to cancer diagnosis were included. Two radiologists registered the presence of radiological signs of missed cancers. The frequency of missed cancers was compared between portal and pancreatic/triphasic CT protocols.

Results: Overall, 180 CT scans of pancreatic adenocarcinoma patients performed prior to cancer diagnosis were retrieved; 126/180 (70.0%) were conducted using pancreatic/triphasic protocols and 54/180 (30.0%) used portal protocols. The overall frequency of missed cancers was 6/180 (3.3%) in our study population. The frequency of missed cancers was higher with the portal CT protocols compared to the pancreatic/triphasic protocols: 5/54 (9.3%) vs. 1/126 (0.8%), P = 0.01. CT signs of missed cancers included small hypodense lesions, peri-pancreatic fat stranding, and dilated pancreatic duct with a cut-off sign.

Conclusions: The frequency of missed pancreatic adenocarcinoma is higher on portal CT protocols. Physicians should consider the cancer miss rate on different CT protocols.

Recent studies using propensity score matching have clearly indicated that contrast nephropathy following computed tomography occurs in hospitalized patients with advanced chronic kidney disease (eGFR < 30 ml/min/1.73 m²) and that this iatrogenic complication is likely underestimated because of concomitant renal functional recovery, unrelated to the imaging procedure. These findings should be considered regarding contrast-enhanced studies in such patients.

Fever of unknown origin (FUO) is defined as the repeated occurrence of elevated body temperature above 38.3°C (101°F) lasting for at least 3 weeks with no clear diagnosis despite a thorough investigation of more than one-week duration. FUO cases could be categorized into three major etiologies: infectious, neoplastic, and systemic inflammatory. Despite novel diagnostic modalities, clinicians still encounter a significant number of unresolved FUO cases, accounting for as many as 50% of cases [1]. Prolonged futile FUO investigations may be a source of frustration for many clinicians [2]. We described a unique cause for FUO that shares the complexity of the diagnostic workup and emphasizes the importance of ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (PET/CT) modality in the process of investigating FUO.

Background: Unilateral intratonsillar abscess (ITA) is an underreported, well-known complication of acute tonsillitis. The prevalence of unilateral ITA compared to peritonsillar abscess (PTA) is 1:14. However, bilateral ITA is an extremely rare entity, with only four cases reported thus far.

Objectives: To describe past cases and our experience, elaborating the diagnostic challenge and the surgical treatment for bilateral ITA.

Methods: We conducted a literature search in the PubMed database using the key words intra-tonsillar abscess, tonsillar abscess, bilateral tonsillar abscess, bilateral intra-tonsillar abscess and bilateral peritonsillar abscess. Our search was limited to the years 1980 to 2020.

Results: We found that only four cases of bilateral ITA were previously published. All were characterized by a delay in diagnosis with a median of 10 days (4–14 days), symmetrical oral cavity appearance, enlarged bilateral kissing tonsils, and subsequent treatment by surgical drainage/paracentesis. Respiratory compromise was a concern in most cases. Our patient was treated with bilateral quinsy tonsillectomy and had a prompt recovery.

Conclusions: Bilateral ITA is a rare, deceiving entity, with a diagnosis delay attributed to the symmetrical oral bulging. We present the fifth case reported and the first ever reported in a pediatric patient. We describe the assumed pathogenesis and the main characteristics among all five patients, emphasizing the important role of a high index of suspicion and appropriate imaging, guiding to proper diagnosis and treatment.

Background: Acute mesenteric ischemia (AMI) is a medical condition with high levels of morbidity and mortality. However, most patients suspected of AMI will eventually have a different diagnosis. Nevertheless, these patients have a high risk for co-morbidities.

Objectives: To analyze patients with suspected AMI with an alternative final diagnosis, and to evaluate a machine learning algorithm for prognosis prediction in this population.

Methods: In a retrospective search, we retrieved patient charts of those who underwent computed tomography angiography (CTA) for suspected AMI between January 2012 and December 2015. Non-AMI patients were defined as patients with negative CTA and a final clinical diagnosis other than AMI. Correlation of past medical history, laboratory values, and mortality rates were evaluated. We evaluated gradient boosting (XGBoost) model for mortality prediction.

Results: The non-AMI group comprised 325 patients. The two most common groups of diseases included gastrointestinal (33%) and biliary-pancreatic diseases (27%). Mortality rate was 24.6% for the entire cohort. Medical history of chronic kidney disease (CKD) had higher risk for mortality (odds ratio 2.2). Laboratory studies revealed that lactate dehydrogenase (LDH) had the highest diagnostic ability for predicting mortality in the entire cohort (AUC 0.70). The gradient boosting model showed an area under the curve of 0.82 for predicting mortality.

Conclusions: Patients with suspected AMI with an alternative final diagnosis showed a 25% mortality rate. A past medical history of CKD and elevated LDH were associated with increased mortality. Non-linear machine learning algorithms can augment single variable inputs for predicting mortality.

Mesenteric venous thrombosis (MVT) refers to acute, subacute, or chronic thrombosis and occlusion of the mesenteric veins. MVT is an uncommon disorder, with an estimated incidence of is 2.7 per 100,000 patient-years. It accounts for 1 in 5000 to 15,000 inpatient admissions [1,2].

Background: The current approach to performing sacral neuromodulation consists of a two-stage procedure, the first of which includes insertion of the sacral electrode under fluoroscopic visualization of the S3 foramen. Alternatively, in certain situations computed tomography (CT)-guided insertion can be used.

Objectives: To evaluate the use of CT in cases of reinsertion of the electrode due to infection, dislocation, or rupture.

Methods: Medical records of patients who underwent neuromodulation device reinsertion between 2005 and 2016 for fecal incontinence were reviewed. Study outcomes included procedure course, successful placement, and long-term treatment success.

Results: During the study period, we inserted a neuromodulation device in 67 patients. A CT-guided insertion of a sacral electrode was performed in 10 patients. In nine patients, the insertion and the final location of the electrode were successful. In one patient, the electrode migrated upward due to a malformation of the S3 foramen on both sides and had to be placed in S4. In a mean follow-up of 68.4 ± 30.0 months following the re-insertion, there was a significant reduction in the number of incontinence episodes per day (P < 0.001) and the number of pads used per day (P = 0.002).

Conclusions: CT-guided insertion of a sacral electrode is a safe and promising option, especially in recurrent and or selected cases