Knee landmarks detection via deep learning for automatic imaging evaluation of trochlear dysplasia and patellar height

OBJECTIVES

To develop and validate a deep learning-based approach to automatically measure the patellofemoral instability (PFI) indices related to patellar height and trochlear dysplasia in knee magnetic resonance imaging (MRI) scans.

METHODS

A total of 763 knee MRI slices from 95 patients were included in the study, and 3393 anatomical landmarks were annotated for measuring sulcus angle (SA), trochlear facet asymmetry (TFA), trochlear groove depth (TGD) and lateral trochlear inclination (LTI) to assess trochlear dysplasia, and Insall-Salvati index (ISI), modified Insall-Salvati index (MISI), Caton Deschamps index (CDI) and patellotrochlear index (PTI) to assess patellar height. A U-Net based network was implemented to predict the landmarks' locations. The successful detection rate (SDR) and the mean absolute error (MAE) evaluation metrics were used to evaluate the performance of the network. The intraclass correlation coefficient (ICC) was also used to evaluate the reliability of the proposed framework to measure the mentioned PFI indices.

RESULTS

The developed models achieved good accuracy in predicting the landmarks' locations, with a maximum value for the MAE of 1.38 ± 0.76 mm. The results show that LTI, TGD, ISI, CDI and PTI can be measured with excellent reliability (ICC > 0.9), and SA, TFA and MISI can be measured with good reliability (ICC > 0.75), with the proposed framework.

CONCLUSIONS

This study proposes a reliable approach with promising applicability for automatic patellar height and trochlear dysplasia assessment, assisting the radiologists in their clinical practice.

CLINICAL RELEVANCE STATEMENT

The objective knee landmarks detection on MRI images provided by artificial intelligence may improve the reproducibility and reliability of the imaging evaluation of trochlear anatomy and patellar height, assisting radiologists in their clinical practice in the patellofemoral instability assessment.

KEY POINTS

• Imaging evaluation of patellofemoral instability is subjective and vulnerable to substantial intra and interobserver variability. • Patellar height and trochlear dysplasia are reliably assessed in MRI by means of artificial intelligence (AI). • The developed AI framework provides an objective evaluation of patellar height and trochlear dysplasia enhancing the clinical practice of the radiologists.

Imaging evaluation of patellofemoral joint instability: a review

The multifactorial origin of anterior knee pain in patellofemoral joint disorders leads to a demanding diagnostic process. Patellofemoral misalignment is pointed out as one of the main causes of anterior knee pain. The main anatomical risk factors of patellofemoral instability addressed in the literature are trochlear dysplasia, abnormal patellar height, and excessive tibial tubercle-trochlear groove distance. Diagnostic imaging of the patellofemoral joint has a fundamental role in assessing these predisposing factors of instability. Extensive work is found in the literature regarding the assessment of patellofemoral instability, encompassing several metrics to quantify its severity. Nevertheless, this process is not well established and standardized, resulting in some variability and inconsistencies. The significant amount of scattered information regarding the patellofemoral indices to assess the instability has led to this issue. This review was conducted to collect all this information and describe the main insights of each patellofemoral index presented in the literature. Five distinct categories were created to organize the patellofemoral instability indices: trochlear dysplasia, patellar height, patellar lateralization, patellar tilt, and tibial tubercle lateralization.

Pancreas Burkitt primary lymphoma in pediatric age

We present an the case of an eight-year-old Portuguese boy with no history of traveling, admitted with non-specific abdominal pain. An analytic study revealed high levels of lipase and amylase. Ultrasound, abdominal computerized tomography (CT), and an abdominal magnetic resonance imaging (MRI), were performed. The imaging findings are suggestive of a pancreatic tumor which is an extremely rare entity in children. A biopsy was performed by opened surgery and identified a Burkitt lymphoma.

A 22nd case report of extrauterine adenomyoma of the abdominal wall

An adenomyoma of the uterus is a nodular tumor-like mass of benign endometrial glands, endometrioid stroma and smooth muscle tissue. Extra-uterine adenomyoma is an extremely rare tumor. The majority of the cases described was from ovary and located in the pelvis. We present a case of a 70 years old woman with clinical and radiological suspicious of disseminated malignancy. In the abdominal wall, a 5-cm nodule of larger dimension detected by computed tomography-scan was biopsied for accessibility reasons. The morphological and immunohistochemical features of the biopsy led us to propose the diagnosis of an extrauterine adenomyoma. This article reports the 22nd case of extrauterine adenomyoma, a rare and poorly understood tumor that could be imagiologically and clinically indistinguishable from a metastasis.

Long-Term Effects of Insulin Therapy, Islet Transplantation, and Pancreas Transplantation in the Prevention of Glomerular Changes in Kidneys of Alloxan-Induced Diabetic Rats

Groups of inbred alloxan-induced diabetic rats were treated with insulin (I), islets (IT), or pancreas transplantation (PT). Nondiabetic (N) and untreated diabetic (D) control groups were concurrently included. Each group was divided into five subgroups of 10 rats and killed after follow-up of 1, 3, 6, 9, and 12 months. Clinical and laboratory parameters were recorded, and kidney ultrastructural and morphometric analyses performed in each 12-month subgroup, namely glomerular basement membrane (GM) thickening, podocyte number, and number/extension of slit diaphragms (S). Rats from the I group showed poor metabolic control of diabetes compared with N group control rats. However, successfully transplanted rats (IT and PT) had complete restoration to normal levels for all metabolic parameters. GM thickening was significantly higher in diabetic compared with control rats. In contrast, the numbers of podocytes and slits as well as slit extensions were significantly decreased. Insulin therapy did not prevent any alterations upon comparison of diabetic vs control rats. Despite good metabolic control in IT rats, the degree of kidney lesion control never compared with that achieved in PT rats. In this group all glomerular changes were similar to the age-dependent lesions observed in control rats. We conclude that either IT or PT may be a good option for diabetes treatment, although pancreas transplantation seems to be the most effective treatment to control chronic complications.

[Renal arterial thrombosis and the antiphospholipid antibody syndrome: a case report]

OBJECTIVE: To describe an unusual case with clinical features of the antiphospholipid syndrome. DESCRIPTION: White child, two years and six months old, with renal failure, renal arterial thrombosis, and diagnosis of antiphospholipid syndrome was hospitalized with a history of abdominal pain, pallor, lethargy, and anuria for 36 hours. On physical examination, the patient showed malnutrition, high blood pressure, moderate edema, and hypochondrial pain. Laboratory findings included: urea=112mg/dl, serum creatinine= 4.5 mg/dl, blood pH= 7.47, blood bicarbonate= 12.8 mmol/L, K=7.2 mEq/L. Peritoneal dialysis was started and maintained for 11 days. After 7 weeks, the patient still needed anti-hypertensive drugs and the renal function was still abnormal. Renal biopsy was performed and revealed renal infarction. The result of Doppler ultrasonography revealed absent renal blood flow on the right side. Renal arteriography showed total occlusion of the right renal artery. Results for collagen diseases were negative. A right nephrectomy was performed and the blood pressure was controlled. The child was hospitalized again at 5 years and 8 months old with episodes of absence seizures and abdominal and precordial pain. Anticardiolipin antibody test was positive. The child is now 7 years old, asymptomatic, with negative anticardiolipin antibody, and has been under regular follow-up. COMMENTS: Children with arterial thrombosis should be investigated for a possible association with the antiphospholipid antibody syndrome even in the absence of collagen disease.

Effect of long-term treatment with insulin and/or acarbose on glomerular basement membrane thickening in alloxan-diabetic rats

Acarbose is a competitive inhibitor of the intestinal alpha-glycosidases, that can delay absorption of intestinal carbohydrates causing their malabsorption. In the present paper we studied the effects of insulin, acarbose and their association on glomerular basement membrane thickening in alloxan-diabetic rats. Twenty-five male and female Wistar rats, approximately 3 months old at the beginning of the experiment, were assigned randomly to each of five experimental groups: normal control rats, alloxan-diabetic control rats, alloxan-diabetic rats treated with acarbose, alloxan-diabetic rats treated with insulin, and alloxan-diabetic rats treated with insulin plus acarbose. Alloxan was administered in a single i.v. dose of 442 mg/kg body weight. Insulin was given subcutaneously at doses of 18 to 30 IU/kg corrected daily on the basis of glycosuria and ketonuria. Acarbose was given mixed with rat chow in a dose of 50 mg/100 g chow. Body weight, water and food intake and diuresis, as well as blood and urine glucose were determined after 1, 3, 6, 9, and 12 months of treatment. Glomerular basement membrane (GBM) thickening was determined by electron microscopy at the same times. Clear clinical and laboratory signs of severe diabetes, with blood glucose levels above 200 mg/dl and urine glucose above 3000 mg/dl, were observed in all alloxan-diabetic control rats, in all periods of follow-up, whereas administration of insulin or acarbose reduced the blood glucose levels of treated groups. The most satisfactory control of blood and urine glucose was observed in animals treated with both insulin and acarbose. However, diarrhea was observed in diabetic rats treated with acarbose associated or not with insulin. GBM thickening was correlated with age in all groups. Beginning at six months after diabetes induction, the GBM of untreated diabetic rats was significantly thicker (mean +/- SEM, 4.446 +/- 0.45 mm) than that of normal rats (2.977 +/- 0.63mm). Both insulin and acarbose prevented GBM thickening and their combination induced thickening similar to the age dependent thickening observed for normal rats of the same age. We conclude that acarbose when combined with insulin may be a good option in the control of diabetes and its renal complications.

[Medullary sponge kidney, nephrolithiasis, hypercalciuria and hyperuricosuria in a child. Report of a case and follow-up]

The medullary sponge kidney is rare in children and may present it self with hematuria and nephrolithiasis. We report a case of medullary sponge kidney in a child with nephrolithiasis, hypercalciuria, hyperuricosuria and prolonged treatment which avoided the recurrence of nephrolithiasis.