Absence Of Anatomical Abnormalities Research Articles

Contemporary outcomes of surgical decompression for functional popliteal entrapment syndrome

BackgroundFunctional popliteal entrapment syndrome (FPES) is an under-recognized source of leg pain caused by dynamic compression of the popliteal vessels by surrounding musculature in the absence of anatomic abnormality. Late recognition and difficulty capturing this entity across imaging modalities can lead to significant morbidity in an often young and active patient population. Surgical outcomes and optimal diagnostic strategies remain uncertain. MethodsWe performed a retrospective cohort study of all patients undergoing surgical decompression for FPES at an academic medical center between 2018 and 2022. Preoperative symptoms, patient characteristics, imaging, operative details, and follow-up were captured. The primary outcome was symptomatic improvement at last clinic visit. Secondary outcomes included symptomatic improvement at 6 months and postoperative complications. ResultsA total of 24 extremities (16 patients) were included. The mean ± standard deviation age was 23.3 ± 6.4 years and 75.0% of patients were female. The median symptom duration before decompression was 27 months (interquartile range, 10.7-74.6 months). Preoperative symptom severity in the affected extremity was as follows: 33.3% limited from peak exercise, 25% unable to exercise, and 41.7% with debilitating symptoms that affected activities of daily living. Preoperative imaging with provocative maneuvers included duplex ultrasound (87.5%), magnetic resonance angiography (100%), and digital subtraction angiography (100%). Using digital subtraction angiography as the gold standard, the sensitivity for detection of FPES was 85.7% for duplex examination and 58.3% for magnetic resonance angiography. The median follow-up was 451 days (interquartile range, 281-635 days). Most patients demonstrated durable improvement in the affected extremity, with 29.2% realizing complete resolution of symptoms and 37.5% reporting symptomatic improvement at last clinic visit for a total of 66.7%; 20.8% had initial improvement, but developed recurrent symptoms and were found to have elevated compartment pressures consistent with chronic exertional compartment syndrome and were treated with formal fasciotomy. Repeat decompression was required in one extremity (4.2%) owing to recurrent symptoms. Two patients (8.3%) had minimal or no improvement in their affected extremity and workup for the cause of continued discomfort was ongoing. ConclusionsDelays in diagnosis of FPES are common. Provocative maneuvers until replication of symptoms across multiple imaging modalities may be necessary to reliably identify the disease process. Surgical decompression improved or completely resolved symptoms in two-thirds of extremities. Treating physicians should maintain suspicion for comorbid chronic exertional compartment syndrome, especially if symptoms recur or persist after decompression.

Lung Hot Spot Without Corresponding Computed Tomography Abnormality on Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: Artifactual or Real, Iatrogenic or Pathologic?

Focal lung uptake without corresponding lesions or abnormalities on computed tomography (CT) scan poses a dilemma in the interpretation of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). A limited number of case reports have previously suggested an artifactual or iatrogenic nature of the uptake. In the present study, 8 relevant cases were included within a retrospective search of the database. Medical records were reviewed for follow-up radiological and pathologic information. In 7 of 8 cases with focal increased FDG uptake but no corresponding lesions or abnormalities on CT scan, the lung hot spots were artifactual or iatrogenic upon follow-up diagnostic chest CT or repeated PET/CT or both the scans. Microemboli were most likely a potential cause of the pulmonary uptake, with or without partial paravenous injection. One case in the series had a real pulmonary lesion demonstrated on follow-up PET/CT scans and on surgical pathology, although the initial integrated CT and follow-up diagnostic chest CT scans revealed negative findings to demonstrate pulmonary abnormalities corresponding to the hot spot on the PET scan. In conclusion, the finding of a lung hot spot in the absence of anatomical abnormality on FDG PET/CT was most likely artifactual or iatrogenic, but it might also represent a real pulmonary lesion. Nonvisualization of anatomical abnormality could be because of its small size and position directly overlying a segmental vessel. Further image follow-up is necessary and important to clarify the nature of the uptake.

Popliteal vein compression syndrome pathophysiology and correlation with popliteal compartment pressures.

The link between obesity and popliteal vein compression syndrome (PVCS) has been documented, but thepathophysiological mechanism is unclear. The aim of this study is to understand the pathogenesis of PVCS by assessing popliteal compartment pressures (PCP). Twenty-three limbs (15 patients) were included. Eleven limbs were ultrasonically diagnosed with PVCS and underwent popliteal vein decompression. The control group consisted of 12 limbs with functional popliteal artery entrapment. Perioperatively, PCP measurements were obtained. The body mass index (BMI) was calculated and the clinical symptoms were documented (CEAP). The median BMI for the PVCS group was 32 (range, 26-45.8) compared with 28 (range, 19-31) for the control group (P= .05). In PVCS, the popliteal vein internal diameter was 9.4 mm (range, 8.0-20.0 mm) upon knee flexion, compared with 0 mm (range, 0.0-0.1 mm) upon kneeextension. Upon knee flexion, there was no difference inpressure (PVCS 10.0 [range, 4-20] vs control 11.5 [range, 3-22]; P= .95). Upon knee extension, the median PCP in the PVCS group was 53 cm H2O (range, 38-76 cm H2O) compared with 26 cm H2O (range, 17-43 cm H2O) in the control group (P< .001). PVCS is associated with high popliteal compartment pressures compared with controls. The pathophysiology of popliteal obstruction, in the absence of anatomical abnormalities, is related to an increase in popliteal compartment pressure while standing due an increase of the popliteal fat pad, related to high BMI.

Fluorodeoxyglucose uptake in absence of CT abnormality on PET-CT: What is it?

The purpose of this article is to provide a pictorial review of the findings and interpretative pitfalls about focal fluorodeoxyglucose (FDG) uptake in the absence of corresponding computer tomography (CT) lesion or abnormality on an integrated positron emission tomography (PET)-CT. The integrated CT images in the PET-CT scanner allow correct co-registration and fused imaging of anatomical and functional data. On FDG PET-CT imaging, a real pathologic process often demonstrates abnormal uptake associated with a visible corresponding CT lesion or abnormality. When focal uptake is seen on PET imaging but no corresponding anatomic abnormality is visualized on the integrated CT, one should always be aware of possible mis-registration or mismatch of the PET and CT images due to the patient's respiratory or body motion. While most of the hot spots in the absence of corresponding anatomic abnormalities are artefactual or secondary to benign etiologies, some may represent small sized or early staged neoplasm or metastases, especially in the gastrointestinal tract and skeletons. Caution should be exercised to simply diagnose a pathology based on the presence of the uptake only, or exclude the disease based on the absence of anatomic abnormality.

A guideline for the inpatient care of children with pyelonephritis

BACKGROUND AND OBJECTIVES:Febrile urinary tract infections and pyelonephritis are common in children and frequently lead to hospitalization for management, especially in the child who appears toxic. The American Academy of Pediatrics (AAP) practice parameter on the diagnosis, treatment and evaluation of the initial urinary tract infection in febrile infants and young children provides experience and evidence-based guidelines for the practitioner caring for children between the ages of 2 months to 2 years. No established guideline exists for older children and the AAP guideline does not specifically focus on inpatient care.METHODS:We conducted a comprehensive review of recently published literature and practice guidelines to develop a consensus on the inpatient diagnosis and management of children with pyelonephritis.RESULTS:Eight recommendations are proposed for the diagnosis and management, including revised guidelines for the imaging studies postpyelonephritis on the basis of current best evidence.CONCLUSION:Proper diagnosis of pyelonephritis, timely initiation of appropriate therapy and identification of children at risk for renal injury will help to reduce immediate as well as long-term complications due to chronic kidney disease.

Myofilament Ca2+ sensitization causes susceptibility to cardiac arrhythmia in mice

In human cardiomyopathy, anatomical abnormalities such as hypertrophy and fibrosis contribute to the risk of ventricular arrhythmias and sudden death. Here we have shown that increased myofilament Ca2+ sensitivity, also a common feature in both inherited and acquired human cardiomyopathies, created arrhythmia susceptibility in mice, even in the absence of anatomical abnormalities. In mice expressing troponin T mutants that cause hypertrophic cardiomyopathy in humans, the risk of developing ventricular tachycardia was directly proportional to the degree of Ca2+ sensitization caused by the troponin T mutation. Arrhythmia susceptibility was reproduced with the Ca2+-sensitizing agent EMD 57033 and prevented by myofilament Ca2+ desensitization with blebbistatin. Ca2+ sensitization markedly changed the shape of ventricular action potentials, resulting in shorter effective refractory periods, greater beat-to-beat variability of action potential durations, and increased dispersion of ventricular conduction velocities at fast heart rates. Together these effects created an arrhythmogenic substrate. Thus, myofilament Ca2+ sensitization represents a heretofore unrecognized arrhythmia mechanism. The protective effect of blebbistatin provides what we believe to be the first direct evidence that reduction of Ca2+ sensitivity in myofilaments is antiarrhythmic and might be beneficial to individuals with hypertrophic cardiomyopathy.

MRI findings of the pituitary gland in short children born small for gestational age (SGA) in comparison with growth hormone‐deficient (GHD) children and children with normal stature

Disturbances in the GH/IGF-I axis are reported in 25-60% of short children born small for gestational age (SGA). We hypothesized that these abnormalities might be related to abnormalities in the pituitary region. Therefore, the results of magnetic resonance imaging (MRI) of short SGA children were compared to MRI results of other groups of short children and to normal controls. MRI was performed in four groups of short children: SGA children without GH deficiency (SGA group; n = 17), SGA children with isolated GH deficiency (SGA + IGHD group; n = 10), non-SGA children with isolated GH deficiency (IGHD group; n = 24) and non-SGA children with multiple pituitary hormone deficiencies (MPHD group; n = 15). MRI was also performed in children with normal stature (control group; n = 13). Pituitary height (PH) and thickness of the pituitary stalk (PS) were measured and their relationship with the maximum GH peak during a GH stimulation test, serum IGF-I and IGFBP-3 levels was evaluated. Short SGA children either with or without IGHD did not show major anatomical abnormalities in the hypothalamic-pituitary region in contrast to 58% of the non-SGA IGHD children and 87% of the MPHD children who had anatomical abnormalities. PH in SGA children without GHD was normal whereas it was significantly lower in SGA children with IGHD. The lowest PHs were measured in non-SGA children with MPHD. A moderate decrease in PH was associated with significantly lower maximum serum GH peaks and lower serum IGF-I and IGFBP-3 levels. Measuring PHs in children with less severe GHD, who underwent MRI as part of the diagnostic process, might support the diagnosis of GHD even in the absence of anatomical abnormalities. Our study demonstrates that there is no indication to perform MRI of the pituitary region in short children born SGA without GHD.

Utilisation of animal manures and sewage sludges for growing vegetables

Activated sludge, digested sludge, chicken manure and pig manure were used as soil additives for the growth of a local vegetable, flowering Chinese Cabbage, Brassica parachinensis. Edaphic properties of the waste-amended soils were measured. It was found that animal manures supported better growth than sewage sludges. Vegetables treated with animal manures had higher productivity, earlier maturity, absence of anatomical abnormalities and lower heavy metal contents. Application of chicken manure to agricultural land is a common practice of the local farmers. However, pig manure produced higher yields of the vegetable than chicken manure. This indicated that pig manure also has a high potential as a fertiliser. Recycling of pig manure is highly essential as some of the streams in the New Territories of Hong Kong are grossly polluted by pig manure. The inferior growth of the vegetables harvested from sewage sludge amended soils was correlated with the edaphic properties of the sewage sludge amended soils. Such soils were lower in pH, conductivity and extractable phosphate, but higher in heavy metal content. Because of the high uptake of heavy metals in the sludge-grown vegetables, it is suggested that sewage sludge should be used as a soil additive only for non-edible crops. Furthermore, caution should be taken if crops like carrots were planted, due to the higher uptake of heavy metals in the root portion.