All that glitters are not gold: holds true in female adnexal lesions

Background

Adnexal mass lesions are commonly encountered pathologies that creates diagnostic challenges for radiologist. Diffusion weighted imaging is a vital tool in the radiologist armamentarium for improving the diagnostic accuracy of adnexal lesions other than routine spine echo sequences.

Main body

Functional information about the lesion regarding the mobility of the water molecules in its tissue is assessed by diffusion weighted imaging. In addition to the solid malignant neoplasm, normal blood, fat, necrosis and pus also shows restricted diffusion.

Conclusion

All the lesion that shows restriction in the DWI are not malignant, but converse is mostly true. Knowledge regarding the non-malignant lesion in the ovary that shows restricted diffusion will give a clue in diagnosis, management and treatment of the adnexal lesions.

Acute Omental Infarction Mimicking Acute Appendicitis

Acute abdominal pain is a common cause of visits to the emergency department. Acute appendicitis remains the most common indication for abdominal surgical intervention in the pediatric age group. However, several conditions may present with a clinical picture similar to that of acute appendicitis. We report the case of a 7-year-old girl with a history of right lower quadrant abdominal pain of two days in duration. The pain was associated with vomiting and was exacerbated by movement. Abdominal examination revealed a localized tenderness in the right iliac fossa with guarding, giving the impression of acute appendicitis. After a thorough investigation, the patient was diagnosed as having acute omental infarction given the radiological findings seen in the computed tomography scan. The patient was successfully managed conservatively with analgesics and anti-inflammatory drugs. Physicians should keep a high index of suspicion for this condition when encountering a patient presenting with an acute right lower quadrant abdominal pain. Imaging modalities play a pivotal role in making the diagnosis.

Ovarian torsion: developing a machine-learned algorithm for diagnosis

BACKGROUND

Ovarian torsion is a common concern in girls presenting to emergency care with pelvic or abdominal pain. The diagnosis is challenging to make accurately and quickly, relying on a combination of physical exam, history and radiologic evaluation. Failure to establish the diagnosis in a timely fashion can result in irreversible ovarian ischemia with implications for future fertility. Ultrasound is the mainstay of evaluation for ovarian torsion in the pediatric population. However, even with a high index of suspicion, imaging features are not pathognomonic.

OBJECTIVE

We sought to develop an algorithm to aid radiologists in diagnosing ovarian torsion using machine learning from sonographic features and to evaluate the frequency of each sonographic element.

MATERIALS AND METHODS

All pediatric patients treated for ovarian torsion at a quaternary pediatric hospital over an 11-year period were identified by both an internal radiology database and hospital-based International Statistical Classification of Diseases and Related Health Problems (ICD) code review. Inclusion criteria were surgical confirmation of ovarian torsion and available imaging. Patients were excluded if the diagnosis could not be confirmed, no imaging was available for review, the ovary was not identified by imaging, or torsion involved other adnexal structures but spared the ovary. Data collection included: patient age; laterality of torsion; bilateral ovarian volumes; torsed ovarian position, i.e. whether medialized with respect to the mid-uterine line; presence or absence of Doppler signal within the torsed ovary; visualization of peripheral follicles; and presence of a mass or cyst, and free peritoneal fluid. Subsequently, we evaluated a non-torsed control cohort from April 2015 to May 2016. This cohort consisted of sequential girls and young adults presenting to the emergency department with abdominopelvic symptoms concerning for ovarian torsion but who were ultimately diagnosed otherwise. These features were then fed into supervised machine learning systems to identify and develop viable decision algorithms. We divided data into training and validation sets and assessed algorithm performance using sub-sets of the validation set.

RESULTS

We identified 119 torsion-confirmed cases and 331 torsion-absent cases. Of the torsion-confirmed cases, significant imaging differences were evident for girls younger than 1 year; these girls were then excluded from analysis, and 99 pediatric patients older than 1 year were included in our study. Among these 99, all variables demonstrated statistically significant differences between the torsion-confirmed and torsion-absent groups with P-values <0.005. Using any single variable to identify torsion provided only modest detection performance, with areas under the curve (AUC) for medialization, peripheral follicles, and absence of Doppler flow of 0.76±0.16, 0.66±0.14 and 0.82±0.14, respectively. The best decision tree using a combination of variables yielded an AUC of 0.96±0.07 and required knowledge of the presence of intra-ovarian flow, peripheral follicles, the volume of both ovaries, and the presence of cysts or masses.

CONCLUSION

Based on the largest series of pediatric ovarian torsion in the literature to date, we quantified sonographic features and used machine learning to create an algorithm to identify the presence of ovarian torsion - an algorithm that performs better than simple approaches relying on single features. Although complex combinations using multiple-interaction models provide slightly better performance, a clinically pragmatic decision tree can be employed to detect torsion, providing sensitivity levels of 95±14% and specificity of 92±2%.

Contribution of diffusion-weighted imaging to conventional MRI for detection of haemorrhagic infarction in ovary torsion

Background

To assess the role of DWI in differentiation haemorrhagic ovary infarction from non-haemorrhagic one.

Methods

For this prospectively designed study, of 117 female patients who presented with acute lower quadrant pain and underwent MRI for suspicion of ovary torsion, results of only 29 patients (mean age, 24.7; SD, ±5.7; age range, 18–37), with surgical and pathological confirmation of adnexal torsion, were included to the study. All patients underwent DWI after conventional MRI. Quantitative and qualitative analysis of both the torsed and contralateral normal ovary were performed. Results of conventional MRI and DWI were noted.

Results

At operation 15 patients were found to have haemorrhagic infarction while 14 had non-haemorrhagic infarction. Of the 29 patients, 17 torsed ovaries could be salvaged in a viable state. We found statistically significant correlation of the ADC values, between haemorrhagic and non-haemorrhagic ovary infarction. The ADC values were significantly lower in patients with haemorrhagic infarction than non-haemorrhagic ones (p < 0.001). Using an ADC threshold of 1.27, the sensitivity of DWI for haemorrhagic infarction was 0.93 and specificity 0.85.

Conclusion

DWI may be used with a significant success for the preoperative diagnosis of haemorrhagic infarction. This may be alerting for pre-emptive surgery in avoiding serious complications and preventing irreversible structural damage of the ovary.

Sonography of Abdominal Pain in Children: Appendicitis and Its Common Mimics

Abdominal pain is very common in the pediatric population (<18 years of age). Sonography is a safe modality that can often differentiate the frequently encountered causes of abdominal pain in children. This pictorial essay will discuss the sonographic findings of acute appendicitis, including the imaging appearance of a perforated appendicitis. It will also present the sonographic features of the relatively common mimics of appendicitis, such as mesenteric adenitis/gastroenteritis, intussusception, Meckel diverticulum, and ovarian torsion.

A normal ovary in an abnormal location: A case of torsion

The clinical and radiologic diagnosis of adnexal torsion is challenging. The patient's history, physical examination, and laboratory evaluation may overlap significantly with other causes of abdominal pain. Ultrasound is the most common radiologic tool to assess for torsion, and the imaging findings can be equally equivocal. We present a case of adnexal torsion in an 18-year-old emergency room patient with abdominal pain, diagnosed by ultrasound based solely on an abnormal medial position of the ovary-a finding that has been only rarely mentioned in the literature, and never in isolation.

Extra-appendiceal findings in pediatric abdominal CT for suspected appendicitis

BACKGROUND

Much has been written regarding the incidence, types, importance and management of abdominal CT incidental findings in adults, but there is a paucity of literature on incidental findings in children.

OBJECTIVE

We sought to determine the prevalence and characteristics of extra-appendiceal and incidental findings in pediatric abdominal CT performed for suspected appendicitis.

MATERIALS AND METHODS

A retrospective review was performed of abdominal CT for suspected appendicitis in a pediatric emergency department from July 2010 to June 2012. Extra-appendiceal findings were recorded. Any subsequent imaging was noted. Extra-appendiceal findings were divided into incidental findings of doubtful clinical significance, alternative diagnostic findings potentially providing a diagnosis other than appendicitis explaining the symptoms, and incidental findings that were abnormalities requiring clinical correlation and sometimes requiring further evaluation but not likely related to the patient symptoms.

RESULTS

One hundred sixty-five children had abdominal CT for suspected appendicitis. Seventy-seven extra-appendiceal findings were found in 57 (34.5%) patients. Most findings (64 of 77) were discovered in children who did not have appendicitis. Forty-one of these findings (53%) could potentially help explain the patient's symptoms, while 30 of the findings (39%) were abnormalities that were unlikely to be related to the symptoms but required clinical correlation and sometimes further work-up. Six of the findings (8%) had doubtful or no clinical significance.

CONCLUSION

Extra-appendiceal findings are common in children who undergo abdominal CT in the setting of suspected appendicitis. A significant percentage of these patients have findings that help explain their symptoms. Knowledge of the types and prevalence of these findings may help radiologists in the planning and interpretation of CT examinations in this patient population.

Sonographic diagnosis of ascariasis causing small bowel obstruction

Acute right lower quadrant pain is a common, but nonspecific presenting symptom of a wide variety of diseases in children. Sonography (US) can play a significant role in the accurate and early diagnosis of right lower quadrant pain. In this article, we report a case of small bowel obstruction due to intestinal ascariasis diagnosed at bedside US and confirmed by MRI and describe a new US sign of intestinal ascariasis.