Caprini versus Padua venous thromboembolism risk assessment scores: A comparative study in hospitalized patients at a tertiary center.

OBJECTIVES: To assess and compare the Caprini and Padua risk assessment models (RAMs) for predicting venous thromboembolism (VTE) in hospitalized patients. METHODS: We retrospectively reviewed 28 VTE and 450 non-VTE patients hospitalized at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, in 2019. Their baseline medical, demographic, and radiological reports were recorded. We compared Caprini scores (defined at admission) and Padua scores (calculated retrospectively) for their ability to predict VTE. A cumulative risk score was created by adding the individual scores for each risk factor. We also analyzed the sensitivity, specificity, and diagnostic accuracy of the RAM scores. RESULTS: Major differences in risk factors were shown between patients with and without VTE. Previous VTE was significantly associated with a higher risk of VTE (28.6%), as was reduced mobility (57.1%), acute infection (25%), high Caprini score (50%), and high Padua score (64.3%, p<0.05). The sensitivity of the Caprini score (96%) was higher than that of the Padua score (64.3%), as was the specificity (92.1% vs. 46.9%), positive predictive value (93% vs. 7%), and accuracy (94.1% vs. 47.9%). The specificity of the Caprini score was higher than that of the Padua score in Critical Care, Gynecology/Obstetrics, and Surgical departments. The Caprini RAM showed the lowest level of specificity in the medical department. CONCLUSION: The Caprini RAM demonstrated higher sensitivity, specificity, and predictive accuracy than did the Padua RAM and thus distinguished low and high VTE risk in hospitalized patients.

Effectiveness of radiology modalities in diagnosing and characterizing brain disorders.

OBJECTIVES: To observe the accuracy of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans in evaluating neurological disorders. METHODS: This retrospective research used CT or MRI to diagnose and characterize brain disorders. Patients' records suffering from neurological disorders were considered eligible for inclusion, regardless of the time of appearance of symptoms, the severity of their symptoms, or their final clinical diagnosis. The exclusion criteria for this study involved patients who did not undergo either a CT or MRI scan. A chi-square test was performed to observe the association between the study variables. A total of 3155 cases were analyzed. RESULTS: The most prevalent comorbid was dyslipidemia 670 (21.6%) followed by hypertension 548 (17.6%). Overall brain disorders were confirmed in 2426 (77%) patients. It was observed that half of the patients 1543 (48.9%) were diagnosed with stroke. It was found that the accuracy of CT and MRI was 78% and 74% respectively. The association of modalities, patient type, and gender with the confirmation of diseases was not found significant (p=>0.05). CONCLUSION: Our study revealed that CT and MRI were accurate by more than 75% and no difference was between both techniques to detect neurological disorders.

Up-to-Date Diagnostic CT Standards for Acute Appendicitis: Wall Thickness and Intraluminal Fluid Thickness.

Acute appendicitis is a prevalent condition that requires accurate and timely diagnosis and management to avoid potential complications. Classically, the diagnosis of appendicitis is made using the appendicular outer-to-outer wall diameter. In this study, we examined the sensitivity and specificity of computed tomography (CT) scans for diagnosing acute appendicitis using wall thickness and lumen thickness rather than diameter. This study included data from 350 patients who presented to the emergency department with clinically suspected acute appendicitis. All patients underwent a CT scan, and 62 radiologically positive patients underwent surgery. A radiological diagnosis was made using the conventional outer-to-outer wall diameter with a cut-off of 6 mm for a positive diagnosis. These 62 positive CT scans were reviewed and compared with surgical results. The study showed that a threshold of 2.25 mm for appendicular lumen thickness is an excellent diagnostic tool for acute appendicitis, demonstrating a high sensitivity of 96.4% and a lower specificity of 67%. In contrast, 1.6 mm wall thickness indicates acute appendicitis, with 81.8% sensitivity and 84% specificity. However, the wall thickness remains inferior to the conventionally used measurement of 6.75 mm for appendicular diameter, with a sensitivity of 87.5% and a specificity of 100%.

Accuracy of Four-Dimensional Computed Tomography and Different Imaging Modalities in Primary Hyperparathyroidism.

Background This study aimed to compare the accuracy of different imaging modalities in the preoperative localization of parathyroid pathology in primary hyperparathyroidism. Methodology This prospective study enrolled 70 patients who were biochemically diagnosed with primary hyperparathyroidism between 2021 and 2022 at our center. Patients underwent scanning using three imaging modalities, namely, Tc99m sestamibi scan (sestamibi), parathyroid ultrasonography, and four-dimensional computed tomography (4DCT). A descriptive analysis was performed to determine and compare the respective localizing sensitivities. Results The most common site of parathyroid adenoma (PA) was the left inferior parathyroid gland, seen in 28 (40%) patients. Three patients had false-positive imaging studies with no parathyroid pathology identified surgically or on histological examination. The median levels of parathyroid hormone decreased significantly (p < 0.001) after the surgery, with a median of 24.3 (1.90-121). Furthermore, 4DCT accomplished a sensitivity of 97.14% for diagnosing the side and 94.03% for overall localization of PA. This sensitivity was superior to the sensitivity of ultrasonography and sestamibi scan to detect the side and quadrant of the adenoma. 4DCT was significantly higher in sensitivity when compared to the combination of ultrasound and sestamibi (p < 0.001). Conclusions 4DCT yielded the highest sensitivity in localizing parathyroid pathology from the imaging modalities studied with the lowest false-negative rate. Using ultrasound with 4DCT could be the most cost-effective combination for detecting primary hyperparathyroidism.

Reference for Normal Diameters of the Abdominal Aorta and Common Iliac Arteries in the Saudi Population.

The abdominal aorta is the largest artery in the abdomen. It then bifurcates giving the two common iliac arteries. Knowing the normal abdominal aorta diameter is a basis for diagnosing abdominal aortic aneurysms (AAAs) and subsequently developing an optimal management plan. In order to diagnose AAA, one must have a reference for the normal abdominal aortic diameter that represents the anatomical variation in the population being studied. The aim of this research is to establish normal abdominal aortic diameters in the Saudi population.

Comparison of Ultrasound and Computed Tomography Scanning Accuracy in Diagnosing Acute Appendicitis at King Abdulaziz University Hospital.

BACKGROUND: Choosing the most effective and accurate preoperative modality is one of the most significant tools in the clinical diagnosis of acute appendicitis (AA) to prevent negative appendectomies, diagnosis confusion, and delayed treatment. This decision making remains challenging to emergency physicians and surgeons which lead this study to determine the sensitivity and specificity of ultrasound (US) and computed tomography (CT) in predicting AA using pathology reports as a reference at King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. METHODS: This study was conducted retrospectively at the Emergency Department, KAUH in Jeddah, Saudi, Arabia using 351 medical records with a clinical picture of acute appendicitis and no history of trauma. The sensitivity and specificity were calculated for ultrasound and computed tomography imaging. The positive predictive values (PPV) and negative predictive value (NPV) were also evaluated. RESULTS: Out of the total 351 patients included in this study, 83 patients underwent surgical appendectomies and the pathology results revealed that 64 patients were diagnosed with AA while 19 showed a normal appendix. Of the 64 patients, 18 underwent US imaging while 62 underwent CT imaging. Compared to pathology results, US imaging results revealed that 12 out of 14 positive patients (85.7%) and only two out of four negative patients (50.0%) were correctly predicted while two out of 14 positive patients (14.3%) and two out of four negative patients (50.0%) were falsely diagnosed. On the other hand, CT imaging results revealed that 46 out of 49 positive patients (93.9%) and 9 out of 13 negative patients (69.2%) were correctly predicted while only three out of 49 positive patients (6.1%) and only four out of 13 negative patients (30.8%) were incorrectly diagnosed. CONCLUSION: Having an accuracy of 88.71%, sensitivity of 92.00%, and specificity of 75.00%, CT imaging was found to be more effective and accurate than US imaging which was only 77.78% accurate, 85.71% sensitive, and 50.00% specific. Statistical analyses also revealed that US results have a significant difference with pathology results (P= 0.130) while CT result has no significant difference (P <0.001).

Diagnostic Accuracy of Various Radiological Measurements in the Evaluation and Differentiation of Flatfoot: A Cross-Sectional Study.

Arch angle is used to indicate flatfoot, but in some cases, it is not easily defined. The presence of flatfoot deformity remains difficult to diagnose due to a lack of reliable radiographic assessment tools. Although various assessment methods for flatfoot have been proposed, there is insufficient evidence to prove the diagnostic accuracy of the various tools. The main purpose of the study was to determine the best radiographic measures for flatfoot concerning the arch angle. Fifty-two feet radiographs from thirty-two healthy young females were obtained. Five angles and one index were measured using weight-bearing lateral radiographs; including arch angle, calcaneal pitch (CP), talar-first metatarsal angle (TFM), lateral talar angle (LTA), talar inclination angle (TIA) and navicular index (NI). Receiver-operating characteristics were generated to evaluate the flatfoot diagnostic accuracy for all radiographic indicators and Matthews correlation coefficient was calculated to determine the cutoff value for each measure. The strongest correlation was between arch angle and CP angle [r = -0.91, p ≤ 0.0001, 95% confidence interval (CI) (from -0.94 to -0.84)]. Also, significant correlations were found between arch angle and NI [r = 0.62, p ≤ 0.0001, 95% CI (0.42 to 0.76)], and TFM [r = 0.50, p ≤ 0.0001, 95% CI (from 0.266 to 0.68)]. Furthermore, CP (cutoff, 12.40) had the highest accuracy level with value of 100% sensitivity and specificity followed by NI, having 82% sensitivity and 89% specificity for the cutoff value of 9.90. In conclusion, CP angle is inversely correlated with arch angle and considered a significant indicator of flatfoot. Also, the NI is easy to define radiographically and could be used to differentiate flat from normal arched foot among young adults.

Magnetic resonance enterography and bowel ultrasonography in Saudi Arabian patients with Crohn's disease: A correlation study.

Background: Crohn's disease (CD) is a complex autoimmune disease that results in chronic inflammation of the gastrointestinal tract. CD activity is determined through clinical, laboratory, endoscopic, and radiological evaluations. Studies that examine the data of radiological modalities of evaluation are lacking, particularly in Saudi Arabia. This study compares magnetic resonance enterography (MRE) and ultrasonography (US) findings among patients diagnosed with CD, to uncover a possible correlation between these techniques. Methods: All patients were assessed for disease activity using MRE and US. Results: A total of 376 patients with CD were recruited. The mean age was 14.9 ± 4.3 years (range, 8-27 years), and males constituted 64% (n = 239) of the cohort. Overall, a strong positive correlation was found between US and MRE evaluations of disease activity (r = 0.83, P < 0.001). US activity correlated positively with MRE findings of enlarged lymph nodes (P < 0.001), bowel wall enhancement (P < 0.001), distal jejunal thickness (P < 0.001), and distal ileal thickness (P < 0.001). The mean difference in wall thickness was significant based on gender (P < 0.001), age in proximal jejunal thickness (P < 0.001), and distal ileal thickness (P = 0.011). Conclusions: MRE and US correlate significantly as imaging techniques for the assessment of CD activity.

Enhancement of Anemia Detection by Correlating Computed Tomography Findings of Abdominal Aorta and Inferior Vena Cava With Laboratory Investigations.

Anemia affects approximately a quarter of the global population, and improved detection may reduce the associated morbidity and mortality. This study investigated correlations between the results of laboratory hematological determinations of hemoglobin levels and attenuation values measured in the lumina of the abdominal aorta and inferior vena cava (IVC) via unenhanced computed tomography (CT) with the aim of expanding diagnostic options for anemia. The data of 423 patients who underwent abdominal unenhanced CT examinations and laboratory examinations at a tertiary hospital were retrospectively evaluated. CT data were collected using a standard abdominal protocol without contrast. The 151 patients who met the inclusion criteria were categorized by hemoglobin values as follows: <8 (severe anemia), 8-10.9 (moderate anemia), 10.9-12 (mild anemia in females), 10.9-13 (mild anemia in males), and >13 g/dL (non-anemic). The mean CT attenuation values in the aorta and IVC were 37.7 and 36.1 Hounsfield units (HU), respectively. A regression analysis performed to evaluate the correlation and predictability of hemoglobin-based aortic and IVC density yielded a coefficient of determination, R2: 0.42 (F ratio: 149.23, p < 0.0001). The highest contribution in the dependent variable (hemoglobin) was reported to IVC density, showing a significant positive correlation between hemoglobin and IVC density. Our study results demonstrate significant correlations between the densities of the aorta, IVC, and hemoglobin value. Accordingly, radiologists and clinicians can use these readily available values to facilitate diagnosis and patient care.

Malignant degeneration of mature cystic teratoma of the ovary with small bowel metastasis incidental serous cystadenoma collision tumor of the right ovary.

Mature Cystic Ovarian Teratoma (MCOTs) are the most common benign ovarian neoplasms, representing around 20% of all ovarian neoplasms with middle age women representing the majority of patients. They usually include two germ cell layers being well differentiated and rarely they demonstrate malignant transformation with squamous cell carcinoma being the most common malignant transformation. In our case, we report an interesting case of a 45 years old lady who was unfortunate to have a MCOT with malignant degeneration and distant metastasis. We concluded that MCOT malignant degeneration is rare, however, if not caught early, mortality can be high. MCOT, Ovary, Small Bowel, Teratoma, Collision tumor.

Magnetic resonance imaging in the management of Crohn's disease: a systematic review and meta-analysis.

OBJECTIVES: Crohn's disease (CD) is a condition that can occur in any part of the gastrointestinal tract, although usually forms in the colon and terminal ileum. Magnetic resonance imaging (MRI) has become a beneficial modality in the evaluation of small bowel activity. This study reports on a systematic review and meta-analysis of magnetic resonance enterography for the prediction of CD activity and evaluation of outcomes and possible complications. METHODS: Following the PRISMA guidelines, a total of 25 low-risk studies on established CD were selected, based on a QUADAS-II score of ≥ 9. RESULTS: A sensitivity of 90% was revealed in a pooled analysis of the 19 studies, with heterogeneity of χ2 = 81.83 and I2 of 80.3%. Also, a specificity of 89% was calculated, with heterogeneity of χ2 = 65.12 and I2 of 70.0%. CONCLUSION: It was concluded that MRI provides an effective alternative to CT enterography in the detection of small bowel activity in CD patients under supervision of radiologist for assessment of disease activity and its complications. Its advantages include the avoidance of radiation exposure and good diagnostic accuracy.

Inflammatory Myofibroblastic Tumor of the Porta Hepatis: A Case Report.

A 43-year-old man presented with painless jaundice. Imaging revealed a porta hepatis mass compressing the common bile duct. Endoscopic biopsy was negative for malignancy. Complete surgical resection was performed. Pathological assessment showed IGg4 negative inflammatory myofibroblastic tumor.

Bowel Damage at Diagnosis Using the Lémann Index Score in Saudi Arabian Patients With Crohn's Disease.

Background Advanced bowel damage caused by Crohn's disease (CD) in the form of strictures and penetrating lesions has been associated with future surgical resection. However, in general, the degree of bowel damage in patients with CD is not examined at the time of diagnosis, and the natural history of CD may differ phenotypically between patients from Arabic countries as compared to patients from Europe and North America. Thus, we aimed to assess the degree of structural bowel damage in Saudi Arabian CD patients at diagnosis. We used the Lémann Index (LI) score, an instrument that measures cumulative digestive tissue damage by magnetic resonance enterography (MRE) and endoscopy, to establish any possible association between the duration of symptoms and the degree of bowel damage. Method This retrospective study was conducted by reviewing the data of all CD patients following up at King Abdulaziz University Hospital (KAUH) that were investigated by endoscopy and MRE at baseline. MRE-LI was calculated by scoring previous surgery, disease location and extension, and intestinal complications. A LI score of >2.0 was set as the cut-off point for bowel damage. Descriptive statistics were used to provide an overview of demographic and clinical characteristics, and hypothesis testing was applied to identify associations. Result Eighty-three patients with CD were included in this study. Fifty point six percent (50.6%) of the cohort comprised females and the median age was 27 years. With regards to CD location and extension, 34.9% showed ileal disease (L1), 9.6% showed colonic CD (L2), whereas 55.4% had ileocolonic involvement (L3). Moreover, 48.2% of patients presented with non-complicated behavior (B1), 25.3% had at least one stricture (B2), and 26.5% showed a penetrating phenotype (B3). Perianal CD was observed in 2.4% of subjects and 62.7% had undergone bowel resection. Mean LI was 2.4 (±2.6) with 34 patients (39.8%) exhibiting an LI score indicative of advanced bowel damage at the time of diagnosis. The duration of symptoms did not correlate with the degree of bowel damage according to the LI score. Conclusion A significant proportion of patients with CD presented with advanced bowel damage at the time of diagnosis, suggesting that a severe form of CD may be endemic in Saudi Arabia.

Recurrent aggressive angiomyxoma presented with perianal mass and typical imaging swirl sign.

INTRODUCTION: Aggressive angiomyxoma is a rare pelvic neoplasm that arises commonly in middle aged women and usually has delayed presentation due to its typically silent and slow growing behavior. CLINICAL PRESENTATION: A 47-year-old woman presented at our hospital with recurrent attacks of pelvic pain and a perianal bulge. Her past medical history was relevant due to previous en bloc resection of a right ovarian angiomyxoma. Current cross sectional imaging, including computed tomography and magnetic resonance imaging, was performed and showed evidence of local recurrence. Various available treatment options were offered to the patient. DISCUSSION: The imaging features of the aggressive angiomyxoma were peculiar and showed a swirl and lamellate appearance in T1 and T2 weighted images. CONCLUSION: A locally aggressive tumor with benign histopathology and swirl sign in imaging is highly suggestive of aggressive angiomyxoma.

Biliary anatomy and pancreatic duct variations: A cross-sectional study.

BACKGROUND/AIM: Biliary tree and pancreatic duct can appear in different variations whose proper understanding is obligatory for surgeons. Magnetic resonance cholangiopancreatography (MRCP) is considered a safe and accurate tool for evaluating biliary tree and pancreatic duct. Typical anatomy for right hepatic duct (RHD) and left hepatic duct (LHD) is reported as 57% and 63%, respectively. The most common (4-10%) pancreatic anomaly is divisum. In the present study, we evaluated and determined the prevalence of biliary tree and pancreatic duct variations among patients at a university hospital. MATERIALS AND METHODS: The MRCP records of 370 patients from 2015 to 2017 were obtained for cross-sectional study. Images were retrospectively reviewed for variations by two independent senior radiologists. Demographic data were obtained for all the patients. Huang et al. classification was used for RHD and LHD variations. The cystic duct was reported based on its course and insertion pattern. The pancreatic duct was observed for the presence of divisum, its course, and configuration. RESULTS: Three hundred and twenty-five patients were included in the final study. Most commonly observed variant for RHD were A1 (34.2%) and A2 (32.2%). For LHD, B1 (71.4%) was the most common variant. Cystic duct insertion was commonly seen as right lateral insertion (27.7%). Pancreatic divisum was observed in 0.6% of cases. Nationality, origin, and gender-specific variations were obtained. CONCLUSION: Variations in biliary anatomy and pancreatic duct are very diverse and extend from the intrahepatic biliary system down to the pancreas. Performing a similar study on a larger population is mandatory to illustrate the range of variations present within the community.

A New Model for Predicting Rate of Penetration Using an Artificial Neural Network.

The drilling rate of penetration (ROP) is defined as the speed of drilling through rock under the bit. ROP is affected by different interconnected factors, which makes it very difficult to infer the mutual effect of each individual parameter. A robust ROP is required to understand the complexity of the drilling process. Therefore, an artificial neural network (ANN) is used to predict ROP and capture the effect of the changes in the drilling parameters. Field data (4525 points) from three vertical onshore wells drilled in the same formation using the same conventional bottom hole assembly were used to train, test, and validate the ANN model. Data from Well A (1528 points) were utilized to train and test the model with a 70/30 data ratio. Data from Well B and Well C were used to test the model. An empirical equation was derived based on the weights and biases of the optimized ANN model and compared with four ROP models using the data set of Well C. The developed ANN model accurately predicted the ROP with a correlation coefficient (R) of 0.94 and an average absolute percentage error (AAPE) of 8.6%. The developed ANN model outperformed four existing models with the lowest AAPE and highest R value.

The Influence of Gender on the Choice of Radiology as a Specialty Among Medical Students in Saudi Arabia: Cross-Sectional Study.

BACKGROUND: Medical undergraduates are the future doctors of the country. Therefore, determining how medical students choose their areas of specialty is essential to obtain a balanced distribution of physicians among all specialties. Although gender is a significant factor that affects specialty choice, the factors underlying gender differences in radiology are not fully elucidated. OBJECTIVE: This study examined the factors that attracted medical students to and discouraged them from selecting diagnostic radiology and analyzed whether these factors differed between female and male medical students. METHODS: This cross-sectional study conducted at King Abdulaziz University Hospital in Jeddah, Saudi Arabia, used an electronic questionnaire sent to medical students from all medical years during February 2018. Subgroup analyses for gender and radiology interest were performed using the chi-square test and Cramér's V test. RESULTS: In total, 539 students (276 women; 263 men) responded. The most common factor preventing students from choosing radiology as a career was the lack of direct patient contact, which deterred approximately 47% who decided against considering this specialty. Negative perceptions by other physicians (P<.001), lack of acknowledgment by patients (P=.004), and lack of structured radiology rotations (P=.007) dissuaded significantly more male students than female students. Among those interested in radiology, more female students were attracted by job flexibility (P=.01), while more male students were attracted by focused patient interactions with minimal paperwork (P<.001). CONCLUSIONS: No significant difference was found between the genders in terms of considering radiology as a specialty. Misconception plays a central role in students' judgment regarding radiology. Hence, early exposure to radiology, assuming a new teaching method, and using a curriculum that supports the active participation of students in a radiology rotation are needed to overcome this misconception.

Pancreatoblastoma: A Case Report.

Pancreatoblastoma (PB), also known as infantile pancreatic carcinoma, is an exceedingly rare pancreatic tumor in childhood, which is considered a malignant exocrine pancreatic tumor. Some cases have been reported in Saudi Arabia. Although PB primarily presents during childhood, it may occur in adults too. PB tends to be less hostile in infants and children when compared to adults. Histologically, PB is characterized by distinguished acinar and squamoid cell differentiation. Most of these tumors develop in the head of the pancreas and increase alpha-fetoprotein in up to 68% of patients. Ultrasound and CT scan play a significant role in preoperative diagnosis, which is often quite difficult. The best treatment is surgical removal of the pancreas. The role of adjuvant chemotherapy or radiotherapy is still under consideration due to a minor number of patients treated. Chemotherapy regimens consisting of cyclophosphamide, etoposide, doxorubicin, and cisplatin have been used in the neoadjuvant setting with anecdotal benefit. It was found that a poorer prognosis was associated with patients who had metastasis, and patients who could not be operated on surgically.

Awareness of Interventional Radiology Among Medical Students at a Saudi Medical School: Clerkship versus Pre-clerkship Years.

OBJECTIVES: We sought to assess the awareness of interventional radiology (IR) as a specialty among medical students and determine any difference between the clerkship and pre-clerkship years. METHODS: We conducted a cross-sectional, survey-based study in February 2018 at King Abdulaziz University, Jeddah, Saudi Arabia. Five hundred and forty-two medical students were enrolled. The survey consisted of 17 items canvassing student awareness of and interest in IR. The data were compared using the chi-square test. RESULTS: A large proportion of the respondents (n = 199, 36.7%) rated their knowledge of IR as poor, and 85 (15.7%) reported that they knew nothing about IR. Only 87 students (16.1%) responded that they would consider a career in radiology. The most common reason for not considering IR was lack of knowledge (42.9%). Students in their clerkship years had more interest and exposure to IR than pre-clerkship students (73.0%, p < 0.001 and 55.7%, p = 0.030, respectively). Awareness of IR was significantly more common among those interested in diagnostic radiology and IR (65.5%, p < 0.001 and 61.5%, p = 0.010, respectively). CONCLUSIONS: Awareness of and exposure to IR is poor among medical students, and can only be increased by a direct contribution from IR physicians to the undergraduate curriculum. Lack of a unified radiology curriculum in medical schools across the country should be addressed by the Council of Deans of Saudi Medical Schools. Involvement of the Saudi Interventional Radiology Society and Radiological Society of Saudi Arabia is essential.

Gas containing renal stone - case report.

Gas-containing stones are extremely rare. The formation of renal stones, including the presence of free gas within the stone, is overall poorly understood. The presence of free gas in the collecting system of the urinary tract indicates emphysematous pyelonephritis, in the absence of prior surgical intervention, gastrointestinal fistula, or urinary bladder catheterization. Here, we present the tenth case of gas-containing renal stones, as detected by computed tomography, and discuss the main diagnostic features to differentiate gas-containing stones from emphysematous pyelonephritis.