Impact of clinical information on CT diagnosis by radiologist and subsequent clinical management by physician in acute abdominal pain.

OBJECTIVE: The impact of clinical information on radiological diagnoses and subsequent clinical management has not been sufficiently investigated. This study aimed to compare diagnostic performance between radiological reports made with and without clinical information and to evaluate differences in the clinical management decisions based on each of these reports. METHODS: We retrospectively reviewed 410 patients who presented with acute abdominal pain and underwent unenhanced (n = 248) or enhanced CT (n = 162). Clinical information including age, sex, current and past history, physical findings, and laboratory tests were collected. Six radiologists independently interpreted CTs that were randomly assigned with or without clinical information, made radiological diagnoses, and scored the diagnostic confidence level. Four general and emergency physicians simulated clinical management (i.e., followed up in the outpatient clinic, hospitalized for conservative therapy, or referred to other departments for invasive therapy) based on reports made with or without the clinical information. Reference standards for the radiological diagnoses and clinical management were defined by an independent expert panel. RESULTS: The radiological diagnoses made with clinical information were more accurate than those made without clinical information (93.7% vs. 87.8%, p = 0.008). Median interpretation time for radiological reporting with clinical information was significantly shorter than that without clinical information (median 122.0 vs. 139.0 s, p < 0.001). Clinical simulation better matched the reference standard for clinical management when radiological diagnoses were made with reference to clinical information (97.3% vs. 87.8%, p < 0.001). CONCLUSION: Access to adequate clinical information enables accurate radiological diagnoses and appropriate subsequent clinical management of patients with acute abdominal pain. KEY POINTS: • Radiological interpretation improved diagnostic accuracy and confidence level when clinical information was provided. • Providing clinical information did not extend the interpretation time required by radiologists. • Radiological interpretation with clinical information led to correct clinical management by physicians.

Pseudo-pneumatosis of the gastrointestinal tract: its incidence and the accuracy of a checklist supported by artificial intelligence (AI) techniques to reduce the misinterpretation of pneumatosis.

PURPOSE: To assess the incidence of erroneous diagnosis of pneumatosis (pseudo-pneumatosis) in patients who underwent an emergency abdominal CT and to verify the performance of imaging features, supported by artificial intelligence (AI) techniques, to reduce this misinterpretation. METHODS: We selected 71 radiological reports where the presence of pneumatosis was considered definitive or suspected. Surgical findings, clinical outcomes, and reevaluation of the CT scans were used to assess the correct diagnosis of pneumatosis. We identified four imaging signs from literature, to differentiate pneumatosis from pseudo-pneumatosis: gas location, dissecting gas in the bowel wall, a circumferential gas pattern, and intramural gas beyond a gas-fluid/faecal level. Two radiologists reevaluated in consensus all the CT scans, assessing the four above-mentioned variables. Variable discriminative importance was assessed using the Fisher exact test. Accurate and statistically significant variables (p-value < 0.05, accuracy > 75%) were pooled using boosted Random Forests (RFs) executed using a Leave-One-Out cross-validation (LOO cv) strategy to obtain unbiased estimates of individual variable importance by permutation analysis. After the LOO cv, the comparison of the variable importance distribution was validated by one-sided Wilcoxon test. RESULTS: Twenty-seven patients proved to have pseudo-pneumatosis (error: 38%). The most significant features to diagnose pneumatosis were presence of dissecting gas in the bowel wall (accuracy: 94%), presence of intramural gas beyond a gas-fluid/faecal level (accuracy: 86%), and a circumferential gas pattern (accuracy: 78%). CONCLUSION: The incidence of pseudo-pneumatosis can be high. The use of a checklist which includes three imaging signs can be useful to reduce this overestimation.

Split-bolus CTA for mesenteric ischemia with a single scan opacifying arterial and mesenteric venous systems.

OBJECTIVE: To evaluate the diagnostic accuracy of split-bolus single-scan computed tomography angiography (CTA) protocol for evaluation of acute mesenteric ischemia and alternate diagnoses. MATERIALS AND METHODS: In this IRB-approved, HIPAA-compliant retrospective study, consecutive patients from 21 October 2016 to 6 May 2018 evaluated for mesenteric ischemia with split-bolus CTA (a single scan in concurrent arterial and portal venous phase) in a single tertiary academic institution were included. Intravenous contrast was administered on weight-based basis. Quantitative and qualitative assessments of superior mesenteric artery (SMA) and superior mesenteric vein (SMV) attenuation and patency were performed by two independent reviewers. CT imaging findings were correlated with clinical reference outcomes. RESULTS: One hundred fifty-four patients (age 66.3 ± 14.1 years, BMI 27.3 ± 6, 86 (56%) female) were included. CTA studies were performed with a volumetric CT dose index of 15.9 ± 5.5 mSv and dose length product of 1042.9 ± 389.4 mGy cm. Average intravenous contrast volume administered was 164.3 ± 12.1 cc. SMA attenuation was 263.6 ± 92.4HU, SMV was 190 ± 50.2HU. Qualitative assessment of SMA and SMV showed good opacification in all patients. 17/154 (11%) patients were diagnosed on CT with mesenteric ischemia; in 6/154 (4%), CTA studies were indeterminate; in 131/154 (85%), CTA confidently ruled out mesenteric ischemia. Alternate diagnoses were made in 38/154 (25%) patients. Using composite clinical outcomes as a reference standard, sensitivity of split-bolus CTA protocol for diagnosis of mesenteric ischemia is 100% (95% CI 79-100%), and specificity is 99% (95% CI 96-100%). CONCLUSIONS: Split-bolus CTA has high sensitivity and specificity for diagnosis of acute mesenteric ischemia. KEY POINTS: • Split-bolus CTA protocol for mesenteric ischemia has great diagnostic accuracy with lower radiation exposure and fewer images to interpret compared with standard multiphasic CTA.

RETROUTERINE PERFORATED GANGRENOUS APPENDICITIS.

We present an atypical case of retrouterine gangrenous perforated appendicitis with Douglas abscess in a 33-year-old woman, with clinical picture developing over two weeks. Laparotomy and appendectomy with abdominal drainage and antibiosis were performed and resulted in complete recovery.

[Gynecological acute abdomen in patients age under 18: an analysis of 237 cases].

Objective: To investigate the constituent ratio, clinical manifestation, diagnosis and treatment of gynecologic acute abdomen in patients age under 18. Methods: A retrospective study was conducted on 237 patients under 18 years old who had been admitted in Rizhao People's Hospital from June 2013 to November 2016. The patients were divided into two groups: groupⅠ (under ten years old, 49 cases) and group Ⅱ (ten to eighteen years old, 188 cases) . The first visit departments, constituent ratio, clinical manifestations and treatment methods of the two groups were summarized and analyzed. Results: The proportion of first visit department was gynecology department in the group Ⅰwas lower than that in group Ⅱ [18.4% (9/49) versus 69.1% (130/188) , P<0.01]. The proportion of diseases in the two groups was different; the proportion of ovarian tumors (59.2%, 29/49) , genital malformations (10.2%, 5/49) and ovarian torsions (10.2%, 5/49) in group Ⅰ were significantly higher than those in group Ⅱ, while the pregnancy related diseases in group Ⅱ (37.2%, 70/188) was significantly higher than that in group Ⅰ (P<0.01) . Conclusions: Clinicians should pay enough attention to the acute abdomen caused by gynecological factors in childhood and adolescence. The differential diagnosis of acute abdomen should pay attention to. In the choice of treatment methods, we should give full consideration to the special age, and try to maintain their normal growth and physiological function.

T1 bright appendix sign to exclude acute appendicitis in pregnant women.

OBJECTIVE: To evaluate the diagnostic value of the T1 bright appendix sign for the diagnosis of acute appendicitis in pregnant women. MATERIAL AND METHODS: This retrospective study included 125 pregnant women with suspected appendicitis who underwent magnetic resonance (MR) imaging. The T1 bright appendix sign was defined as a high intensity signal filling more than half length of the appendix on T1-weighted imaging. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the T1 bright appendix sign for normal appendix identification were calculated in all patients and in those with borderline-sized appendices (6-7 mm). RESULTS: The T1 bright appendix sign was seen in 51% of patients with normal appendices, but only in 4.5% of patients with acute appendicitis. The overall sensitivity, specificity, PPV, and NPV of the T1 bright appendix sign for normal appendix diagnosis were 44.9%, 95.5%, 97.6%, and 30.0%, respectively. All four patients with borderline sized appendix with appendicitis showed negative T1 bright appendix sign. CONCLUSION: The T1 bright appendix sign is a specific finding for the diagnosis of a normal appendix in pregnant women with suspected acute appendicitis. KEY POINTS: • Magnetic resonance imaging is increasingly used in emergency settings. • Acute appendicitis is the most common cause of acute abdomen. • Magnetic resonance imaging is widely used in pregnant population. • T1 bright appendix sign can be a specific sign representing normal appendix.

Diagnostic accuracy of low-dose CT compared with abdominal radiography in non-traumatic acute abdominal pain: prospective study and systematic review.

OBJECTIVES: Abdominal radiography is frequently used in acute abdominal non-traumatic pain despite the availability of more advanced diagnostic modalities. This study evaluates the diagnostic accuracy of low-dose CT compared with abdominal radiography, at similar radiation dose levels. METHODS: Fifty-eight patients were imaged with both methods and were reviewed independently by three radiologists. The reference standard was obtained from the diagnosis in medical records. Sensitivity and specificity were calculated. A systematic review was performed after a literature search, finding a total of six relevant studies including the present. RESULTS: Overall sensitivity with 95 % CI for CT was 75 % (66-83 %) and 46 % (37-56 %) for radiography. Specificity was 87 % (77-94 %) for both methods. In the systematic review the overall sensitivity for CT varied between 75 and 96 % with specificity from 83 to 95 % while the overall sensitivity for abdominal radiography varied between 30 and 77 % with specificity 75 to 88 %. CONCLUSIONS: Based on the current study and available evidence, low-dose CT has higher diagnostic accuracy than abdominal radiography and it should, where logistically possible, replace abdominal radiography in the workup of adult patients with acute non-traumatic abdominal pain. KEY POINTS: • Low-dose CT has a higher diagnostic accuracy than radiography. • A systematic review shows that CT has better diagnostic accuracy than radiography. • Radiography has no place in the workup of acute non-traumatic abdominal pain.

Computed Tomography (CT) Findings of a Diagnostic Dilemma: Atypically Located Acute Appendicitis.

BACKGROUND: Acute appendicitis is an emergent surgically treated disease generally represented by right lower abdominal pain. The most common location of the appendix is descending intraperitoneal. However, it can also show atypical locations such as inguinal canal, femoral canal, subhepatic, retrocecal, intraperitoneal abdominal midline and left side in situs inversus or intestinal malrotation patients. Atypical location can lead to atypical clinical presentations. Ultrasonography is the first choice modality for imaging. However, it can be insufficient for demonstration of the appendix. Therefore, computed tomography (CT) is needed for further examination. We aim to review the CT findings of atypically located acute appendicitis with cases and remind the clinicians and radiologists the importance of the prompt diagnosis. CASE REPORT: We presented five atypically-located appendix cases, including four with acute appendicitis that presented to our emergency department with acute abdominal pain. Two of the acute appendicitis cases had normal, the other two had elevated white blood cell count, but all of them had elevated CRP. Ultrasonography imaging was performed as a first-line imaging modality. Because of the inconclusive results of both clinical-laboratory findings and ultrasonography, CT imaging was performed. Abdominal CT demonstrated all of the atypically localised appendices successfully, which were left-sided in a malrotated patient, retrocecal, subhepatic, retrocecal ascending, intraperitoneal abdominal midline localised. CONCLUSIONS: Atypically located acute appendicitis can show atypical presentation and result in misdiagnosis. If ultrasonograpgy is inconclusive, we suggest abdominal CT in such confusing, complicated cases, because misdiagnosis or delay in the right diagnosis can result in complications and increased morbidity and mortality rates.

Torsion of a Wandering Spleen Presenting as Acute Abdomen.

BACKGROUND: Wandering spleen is a rare condition which if uncorrected, can result in torsion and infarction. Clinical presentation of a wandering spleen can vary from asymptomatic abdominal mass to acute abdominal pain. Radiological investigations play a pivotal role in diagnosis as the clinical diagnosis is usually impossible. CASE REPORT: We present a case of wandering spleen with torsion and complete infarction that occurred in a 32-year-old multiparous female. The diagnosis was established preoperatively on colour Doppler and CT of the abdomen with subsequent confirmation on surgery. CONCLUSIONS: Wandering spleen is a rare clinical condition which can present as acute abdomen. An increased awareness of this entity together with the timely use of ultrasound and CT of the abdomen can play an important role in preoperative diagnosis and surgical management.

Large Gastric Perforation Sealed by Splenic Lysis: Emphasis on Indirect Signs - A Rare Case Report.

BACKGROUND: Gastric perforation is a life-threatening condition, requiring early and reliable discovery. The delay before surgical treatment is a strong determinant of poor outcome, associated complications and hospitalization costs. By using ultrasound and multi-detector computed tomography (MDCT) we can further evaluate undiagnosed cases of silent gastric perforations presenting with non-specific acute abdomen. Here we bring forth the role of a radiologist in cases of perforation which present with indirect signs involving the organs forming the stomach bed, like the spleen, pancreas and kidney. CASE REPORT: A 25-year-old male patient presented with an acute onset of severe upper abdominal pain radiating to the back and vomiting. MDCT of the abdomen was done which revealed atrophic pancreas with organized collection in the sub-capsular location indenting the superior pole of the left kidney. Spleen was not visualized. The most striking imaging finding in that case was destruction of the splenic parenchyma with protrusion of the remaining tissue into the stomach lumen. The hypothesis behind this was a cascade of events which started with gastric perforation, spillage of highly destructive gastric juice over the stomach bed and finally becoming silent with rapid sealing of the defect by the omentum and the spleen. CONCLUSIONS: Acute abdomen is a diagnostic challenge to a clinician and radiologist with gastric perforation being a great mimicker of other urgent abdominal pathologies. To avoid a delayed diagnosis or a misdiagnosis, familiarity with typical and atypical imaging features is essential as in our case of splenic lysis. It acted as the 2(nd) policeman and provided a great clue to solve the diagnostic dilemma.

Torsion of the greater omentum secondary to omental lymphangioma in a child: a case report.

BACKGROUND: Omental cyst and omental torsion both are uncommon but important causes of acute abdomen with a difficult clinical diagnosis due to nonspecific features. Here we report a case of an eight year old child with acute abdominal pain referred for USG and CT scan which revealed two cysts in greater omentum leading to secondary omental torsion. CASE REPORT: An eight year old male child presented to casualty with severe pain abdomen since 1 day. There was no history of vomiting or altered bowel habits. The patient was febrile with tachycardia on arrival. On examination rigidity and tenderness all over abdomen were present. Serum amylase was within normal range. USG and CECT abdomen were done subsequently. USG showed two well defined cystic lesions in lower abdomen with presence of some internal echogenic debris and calcified foci in their dependent part. There was also presence of omentum with a whirl of blood vessels seen along anterior abdominal wall leading to these lesions suggesting torsion. On colour Doppler the presence of blood flow within the whirl of vessels was seen. Mild amount of free fluid was also seen in the peritoneal cavity. On CECT abdomen the findings of omental cysts and torsion of greater omentum with free fluid in abdomen were confirmed. The cysts measured 60×55 and 65×55mm on CT. The patient was taken for an emergency laparotomy for indication of acute generalized peritonitis. Two large omental cysts were found in the pelvic cavity along with torsed greater omentum along with 150 ml of hemorrhagic fluid in peritoneal cavity. The cysts and twisted necrotic part of the greater omentum were excised at surgery. No postoperative complications were observed. Histopathologic examination was suggestive of lymphangioma of omentum. CONCLUSIONS: Lymphangioma of the omentum is an not very uncommon however acute presentation with omental torsion and infarction is an unusual entity. Optimal utilization of preoperative imaging with USG, Doppler and contrast enhanced CT scan can provide correct diagnosis.

Mesenteric cystic lymphangioma in adults: a rare entity presenting as acute abdomen - a report of two cases.

Lymphangiomas are rare benign tumors that mainly involve the head and neck region in pediatric patients. Lymphangiomas of the small bowel mesentery in adults are rarer. We present two cases of mesenteric lymphangioma with acute abdominal pain on presentation. Case 1: A 38-year-old female presented with abdominal pain, vomiting, fever, and difficult evacuation. On abdominal examination, she had an ill-defined, tender lump, and radiological findings raised a possibility of perforation peritonitis. Thus, exploratory laparotomy was planned. Per-operatively, a mesenteric mass was found, which, on histopathological evaluation, was found to be a mesenteric lymphangioma involving the bowel. Case 2: A 27-year-old male presented with abdominal pain and difficult evacuation. Radiological evaluation revealed a multilobulated lesion involving the mesentery and with differential diagnoses of mesenteric fibromatoses and inflammatory pseudotumor. Histopathological assessment of the resected mass revealed a lymphangioma that was limited to the mesentery. Owing to their rarity and non-specific presentation, mesenteric lymphangiomas are often misdiagnosed on clinical examination and imaging. Thus, histopathological examination is the gold standard to reach a definitive diagnosis.

[Spontaneous splenic rupture. Case report and literature review]. / Ruptura esplénica espontánea. Reporte de caso y revisión de la literatura.

Background: Spontaneous splenic rupture is often life threatening due to delay in diagnosis and treatment. Abdominal pain, Kehr's sign, nausea, bloating, altered consciousness, and intestinal obstruction may be present. In larger splenic lesions, signs of peritonitis and hypovolemic shock are present. Contrast-enhanced computed tomography is the election study. Diagnosis is confirmed by negative viral serology and normal spleen on gross and histopathologic inspection. The most frequent treatment in splenectomy. Clinic case: A 30-year-old male with no medical history presented with generalized abdominal pain accompanied by Kehr's sign. He is diagnosed with ruptured spleen by contrast-enhanced computed tomography and successfully treated with splenectomy. He was discharged 6 days after surgery. Conclusions: Spontaneous rupture of the spleen is uncommon, but with high morbidity and mortality. It must be a differential diagnosis in the face of abdominal and/or chest pain, and the corresponding imaging studies should be carried out if the patient's conditions allow it, or their search during an exploratory laparotomy.

Introducción: la ruptura esplénica espontánea frecuentemente es mortal debido a la demora en el diagnóstico y tratamiento. Se puede presentar dolor abdominal, signo de Kehr, náuseas, distensión abdominal, alteración de la consciencia y obstrucción intestinal. En lesiones esplénicas más grandes, se presentan signos de peritonitis y shock hipovolémico. El estudio de elección es la tomografía computarizada contrastada. El diagnóstico se confirma por serología viral negativa y bazo normal en la inspección macroscópica e histopatológica. El tratamiento más frecuente es la esplenectomía. Caso clínico: paciente hombre de 30 años de edad, sin antecedentes patológicos, con dolor abdominal generalizado, acompañado del signo de Kehr. Es diagnosticado con ruptura de bazo por tomografía computarizada contrastada y tratado exitosamente con esplenectomía. Se egresa a los 6 días postquirúrgicos. Conclusiones: la ruptura espontánea del bazo es poco común, pero con alta morbimortalidad. Debe ser un diagnóstico diferencial ante un dolor abdominal y/o torácico, y realizar los estudios de imagen correspondientes si las condiciones del paciente lo permiten o bien su búsqueda durante una laparotomía exploratoria.

Peritoneal sarcoidosis that simulates peritoneal carcinomatosis: a case report.

Sarcoidosis is a multisystem inflammatory disorder of unknown cause characterized by the formation of pleomorphic, non-caseating granulomas with predominantly pulmonary involvement. Although abdominal sarcoidosis represents 30% of extrapulmonary manifestations, peritoneal involvement is extremely rare. We will describe a rare case of peritoneal sarcoidosis simulating carcinomatosis in a young patient with abdominal pain who underwent laparoscopic examination.

La sarcoidosis es un trastorno inflamatorio multisistémico de causa desconocida que se caracteriza por la formación de granulomas pleomórficos, no caseificantes, con afectación predominantemente pulmonar. Aunque la sarcoidosis abdominal representa el 30% de las manifestaciones extrapulmonares, la afectación peritoneal es extremadamente rara. Describiremos un caso poco frecuente de sarcoidosis peritoneal simulando carcinomatosis en una paciente joven con dolor abdominal sometida a exploración laparoscópica.

[Cecal volvulus: one case and literature review]. / Vólvulo cecal: un caso y revisión de la literatura.

Background: Cecal volvulus is a rare disease that causes intestinal obstruction. It has various congenital and acquired risk factors. It is frequently associated with abnormal cecal fixation, and it is caused by torsion of the cecum in one of its three axes. It is not different from other causes of intestinal obstruction, but a delay in its diagnosis can lead to ischemia, necrosis and colon perforation. Its management depends on the viability of the tissues, ranging from untwisting and cecopexy to hemicolectomy with or without anastomosis. We present a case of caecal volvulus (caecal bascule) and review the literature as well. Clinical case: 43-year-old female, who was admitted to an emergency department with data of intestinal obstruction. A simple tomography of the abdomen was performed, where a dilated colon and an image that resembles an inverted coffee bean were identified. An exploratory laparotomy was performed, identifying a bascule-type cecal volvulus, without vascular compromise. Devolvulation, decompression through appendectomy, and caecopexy were performed. After the surgical event, the patient recovered without incident and was discharged with adequate controls by external consultation. Conclusions: Cecal volvulus is a cause of intestinal obstruction with a low incidence, which is why early recognition and treatment are key to avoiding the complications that its evolution entails. This type of disease should be among our differential diagnoses, since treatment is surgical and delay leads to a high mortality rate.

Introducción: el vólvulo cecal es una enfermedad poco común que causa obstrucción intestinal. Tiene diversos factores de riesgo congénitos y adquiridos. Se suele asociar a una fijación cecal anormal y se produce por la torsión del ciego en alguno de sus tres ejes. No se diferencia de otras causas de obstrucción intestinal, pero un retraso en su diagnóstico puede derivar en isquemia, necrosis y perforación del colon. El manejo depende de la viabilidad de los tejidos y va desde la destorsión y cecopexia hasta la hemicolectomía con o sin anastomosis. Se presenta un caso de vólvulo cecal (báscula cecal) y se hace una revisión del tema. Caso clínico: mujer de 43 años que ingresó a un servicio de urgencias con datos de obstrucción intestinal. Se realizó tomografía simple de abdomen donde se identificó dilatación del colon e imagen que semejaba un grano de café invertido. Se hizo laparotomía exploradora y se identificó vólvulo cecal del tipo báscula, sin compromiso vascular. Se realizó desvolvulación, descompresión a través de apendicectomía, y cecopexia. Posterior a evento quirúrgico, la paciente se recuperó sin incidentes y fue dada de alta con controles adecuados por consulta externa. Conclusiones: el vólvulo cecal es una causa de obstrucción intestinal con baja incidencia, por lo que el reconocimiento y tratamiento precoz son claves para evitar las complicaciones que conlleva su libre evolución. Este tipo de enfermedad debe de estar entre nuestros diagnósticos diferenciales, ya que el tratamiento es quirúrgico y el retraso conlleva a una alta tasa de mortalidad.

Infective endocarditis with embolic renal infarct presenting as acute abdomen.

Infective endocarditis (IE) is a disease that is rare but potentially fatal and challenging to diagnose. A 28-year-old man with sickle cell trait and a history of intravenous drug use presented with abdominal pain and hematuria mimicking a surgical abdomen. The preliminary diagnosis was cholecystitis or perforated viscus. The chest radiograph was indicative of pulmonary septic emboli. Computed tomography was initially thought to show pyelonephritis, but further review of images revealed renal infarct. The patient was found to have endocarditis which resulted in an embolic renal infarct. The patient recovered remarkably well after 60 days of intravenous antibiotics. This case demonstrates that a surgical abdomen may also be a sign of endocarditis, and multiple imaging studies may be required to confirm the diagnosis. In patients such as intravenous drug users with an increased risk of IE, unexplained flank pain should raise a suspicion of acute renal infarction.

Superior Mesenteric Artery Thrombosis for Emergency Laparotomy in Covid-19 Patient: A Case Report.

The novel coronavirus disease 2019 (COVID-19) pandemic has caused significant morbidity and mortality worldwide. The most common symptoms include fever, cough, and shortness of breath (predominantly involving pulmonary function). However, there are lesser-known presentations that affect other systems too. Vascular complications have been reported in the literature focusing on venous thrombosis, which appears to be more common than arterial thrombosis. Among arterial thrombosis, mainly lower limb involvement is reported so far. Here, we report an unusual presentation in COVID-19, which presented with acute abdomen due to superior mesenteric artery thrombosis without respiratory symptoms. We report this case as a varied form of coronavirus complication presentation and highlight the need for eternal vigilance and a reactive approach for early diagnosis.

Towards a benchmark of abdominal CT use during duty shifts: 15-year sample from the Netherlands.

PURPOSE: To investigate temporal changes in the utilization and patient impact of abdominal CT during duty shifts in the past 15 years. METHODS: This study included a random sample of 1761 abdominal CT scans that were made during evening and night duty shifts in a tertiary care center between 2005 and 2019. RESULTS: The number of CT scans significantly increased (almost threefold) between 2005 and 2019 (Mann-Kendall tau of 0.829, P < 0.001). The proportion of negative CT scans (i.e., the absence of findings related to the reason that the CT scan was made and no disease deterioration or other new and clinically relevant findings compared to a previous imaging examination when available) was 40.0% (700/1749) in the entire 15-year study frame and did not significantly change over time (Mann-Kendall tau of - 0.219, P = 0.276). The overall frequency of same-day hospital discharge after negative CT was 20.6% (150/729) in the past 15 years and showed a significant increase over time (Mann-Kendall tau of 0.505, P = 0.010). The overall proportion of CT scans with incidental findings was 3.4% (60/1761) and remained statistically stable over the past 15 years (Mann-Kendall tau of - 0.057, P = 0.804). CONCLUSION: Over the past 15 years, the number of CT scans and the frequency of same-day hospital discharge after negative CT have increased, while the proportions of negative CT scans and incidental findings have remained stable in our tertiary care center. The data from this study can be used for interinstitutional benchmarking to define, monitor, and improve the appropriateness of imaging utilization.

[Congenital renal arteriovenous fistula: a rare cause of acute abdomen and a review of its literature]. / Fístula arteriovenosa renal congénita: una causa rara de abdomen agudo y revisión de la literatura.

Introduction: Congenital renal arteriovenous fistula is an abnormal connection between the arterial and venous system. Since the first case described in 1928 by Varela et al, no more than 200 cases have been published. Material and methods: A 45-year-old woman consulted for severe abdominal and low-back pain associated with arterial hypertension. The CT scan showed an infrarenal retroperitoneal lesion with invasion of neighboring structures. Results: During the abdominal exploration, a vascular-looking lesion of 60 x 34 x 41 mm was identified. It was associated with right nephrectomy. Discussion: The etiology of congenital fistulas remains unknown; it is believed that a congenital arterial aneurysm erodes into an adjacent vein and gradually increases its size. Other authors believe that the fistula exists since birth and gradually increases its size until it causes symptoms. Conclusion: Congenital arteriovenous fistulas are rare entities, representing less than 25% of all renal arteriovenous malformations.

Introducción: La fístula arteriovenosa renal congénita es una conexión anómala entre el sistema arterial y venoso. Desde el primer caso descrito en 1928 por Varela y cols, no más de 200 casos han sido publicados. Material y Método: Mujer de 45 años consultó por dolor abdominal y lumbar severo, asociado a hipertensión arterial. En tomografía computada se observó lesión retroperitoneal infrarrenal con invasión de estructuras vecinas. Resultados: En exploración abdominal se identificó lesión de aspecto vascular de 60 x 34 x 41 mm. Se asoció a nefrectomía derecha. Discusión: La etiología de las fístulas congénitas sigue siendo desconocida, se cree que un aneurisma arterial congénito erosiona hacia una vena adyacente y aumenta su tamaño lentamente. Otros autores creen que la fístula existe desde el nacimiento e incrementa progresivamente de tamaño hasta producir síntomas. Conclusión: Las fístulas arteriovenosas congénitas son entidades raras, representando menos del 25% del total de las malformaciones arteriovenosas renales.

Mesenteric cystic lymphangioma in adults: a rare entity presenting as acute abdomen - a report of two cases

ABSTRACT Lymphangiomas are rare benign tumors that mainly involve the head and neck region in pediatric patients. Lymphangiomas of the small bowel mesentery in adults are rarer. We present two cases of mesenteric lymphangioma with acute abdominal pain on presentation. Case 1: A 38-year-old female presented with abdominal pain, vomiting, fever, and difficult evacuation. On abdominal examination, she had an ill-defined, tender lump, and radiological findings raised a possibility of perforation peritonitis. Thus, exploratory laparotomy was planned. Per-operatively, a mesenteric mass was found, which, on histopathological evaluation, was found to be a mesenteric lymphangioma involving the bowel. Case 2: A 27-year-old male presented with abdominal pain and difficult evacuation. Radiological evaluation revealed a multilobulated lesion involving the mesentery and with differential diagnoses of mesenteric fibromatoses and inflammatory pseudotumor. Histopathological assessment of the resected mass revealed a lymphangioma that was limited to the mesentery. Owing to their rarity and non-specific presentation, mesenteric lymphangiomas are often misdiagnosed on clinical examination and imaging. Thus, histopathological examination is the gold standard to reach a definitive diagnosis.