Assessment of clinically significant urolithiasis positivity rate using CT KUB for suspected renal colic.

BACKGROUND: Unenhanced low-dose computed tomography of the kidneys, ureter and bladder (CT KUB) is the gold standard diagnostic imaging modality in the assessment of suspected renal colic. As the radiation dose is not negligible, it is important to monitor the diagnostic yield of CT KUBs. The aim of this study is to evaluate the diagnostic yield of CT KUB studies performed for suspected renal colic in patients presenting to the emergency department. METHODS: A retrospective review was performed of 500 patients who underwent CT KUB for suspected renal colic over a seven month period from June 2019 to January 2020. Clinical information and imaging was reviewed for each patient. Statistical analysis was performed using GraphPad Prism 8 (GraphPad Software, San Diego, CA, USA). RESULTS: Forty-nine percent of patients in the series were female (248/500) and the mean age was 45. The positivity rate for obstructing ureteral calculus was 34% (169/500). Concerningly, there was a significantly lower positivity rate in females compared to males (19% versus 48%; p < 0.0001) which raises the issue of unnecessary radiation exposure to this cohort. In the 200 female patients who were negative for obstructing urolithiasis, the mean age was 43. Females also had a significantly higher rate of negative CT KUB (62% versus 37%; p < 0.0001) where no underlying alternative pathology was diagnosed. CONCLUSIONS: Women are less likely than men to have obstructing urolithiasis on CT KUB for suspected renal colic. This difference is not accounted for by a higher rate of alternative diagnoses among female patients. The findings of this study should prompt clinicians to exercise caution when considering this imaging modality in this patient cohort.

Magnetic resonance imaging of the midfoot and forefoot: normal variants and pitfalls.

Magnetic resonance imaging of the midfoot and forefoot are increasingly requested examinations for a variety of symptoms. This region has its own particular anatomic variants, which the interpreting radiologist needs to be aware of, including accessory ossicles, sesamoid variants, and tarsal coalitions. In addition, certain pulse sequences used in this region are predisposed to artifact, which may lead to false-positive findings. These topics are discussed in this content in addition to the inclusion of pointers to help avoid pitfalls in interpretation of common diseases.

The role of whole-body imaging in the diagnosis, staging, and follow-up of multiple myeloma.

Multiple myeloma is one of the most common hematological malignancies and accounts for significant morbidity and mortality. In the past, detection of myelomatous deposits by radiography was the main method of radiological assessment in this disease. However, in recent years the introduction of whole-body imaging techniques, specifically low-dose whole-body computed tomography, whole-body magnetic resonance imaging, and positron emission tomography, has facilitated a more comprehensive assessment of this heterogeneous and often diffuse disease. Each of these whole-body imaging techniques has specific applications and limitations in the assessment of multiple myeloma that the interpreting radiologist and referring clinician need to be aware of. As these techniques gain further acceptance in the radiology and hematology communities, their use in the assessment of multiple myeloma is likely to increase further.

Whole-body imaging modalities in oncology.

This article outlines the expanding approaches to whole-body imaging in oncology focusing on whole-body MRI and comparing it to emerging applications of whole-body CT, scintigraphy, and above all PET CT imaging. Whole-body MRI is widely available, non-ionizing and rapidly acquired, and inexpensive relative to PET CT. While it has many advantages, WBMRI is non-specific and, when compared to PET CT, is less sensitive. This article expands each of these issues comparing individual modalities as they refer to specific cancers.

The influence of reduced hamstring length on patellofemoral joint stress during squatting in healthy male adults.

Increased patellofemoral joint (PFJ) stress has been implicated in the development of PFJ pathologies. Previous studies have identified a relationship between reduced hamstring length and patellofemoral pain syndrome. Hamstring stretching is also recommended in the management thereof. However, the relationship between reduced hamstring length and PFJ stress has not been explored in vivo during activities that load the PFJ, such as squatting. The objective of this study was to determine if persons with reduced hamstring length demonstrate increased PFJ stress during squatting compared with individuals without reduced hamstring length. Eight participants with, and eight participants without, reduced hamstring length were assessed to determine their PFJ contact area using magnetic resonance imaging, and their PFJ reaction force during squatting using motion analysis. Data collected were entered into a biomechanical model to calculate medial, lateral and total PFJ stress. It was found that participants with reduced hamstring length had significantly greater total (393.39 Pa/kg vs. 213.01 Pa/kg) and lateral (311.23 Pa/kg vs. 142.55 Pa/kg) PFJ stress at 60 degrees knee flexion during squat descent and ascent (427.75 Pa/kg vs. 255.64 Pa/kg and 337.75 Pa/kg vs. 170.63 Pa/kg, respectively). This was due to significantly increased PFJ reaction force at 60 degrees knee flexion during squat descent (12.18 N/kg vs. 7.21 N/kg) and ascent (13.03 N/kg vs. 8.72 N/kg), and lower medial PFJ contact area at 60 degrees knee flexion (88 mm(2) vs. 160 mm(2)). The results of this study demonstrate a relationship between reduced hamstring length and increased PFJ stress during squatting due to increased PFJ reaction force and reduced medial PFJ contact area.

Association of glenoid morphology and anterosuperior labral variation.

OBJECTIVE: The objective of this study was to determine whether glenoid morphology correlates with anterosuperior labral variation. METHODS: Eighty-eight direct shoulder magnetic resonance arthrograms were retrospectively reviewed. Sagittal oblique images were assessed for the presence or absence of anterosuperior glenoid concavity. Evaluation of axial images was performed, separately classifying the anterosuperior labrum into 1 of 4 categories: no variation, diminutive labrum, sublabral foramen, or Buford complex. RESULTS: In 88 shoulders, there were 13 notched glenoids (15%). In this group, 3 (23%) had a Buford complex, 2 (15%) had a sublabral foramen, and 4 (31%) had a diminutive labrum. There were 75 ovoid glenoids (85%). In this group, 3 (4%) had a Buford complex, 8 (11%) had a sublabral foramen, and 7 (9%) had a diminutive labrum. There was a significant association (P = 0.001) between notched glenoid morphology and developmental variation of the anterosuperior labrum. CONCLUSIONS: The presence of anterior glenoid concavity is significantly associated with overlying labral variation, which may be of use in discriminating labral pathology from developmental variation.

Whole-Body MRI versus PET in assessment of multiple myeloma disease activity.

OBJECTIVE: The purpose of this study was to compare FDG PET; whole-body MRI; and the reference standard, bone marrow aspiration and biopsy, to determine the best imaging technique for assessment of disease activity in multiple myeloma. SUBJECTS AND METHODS: Twenty-four patients (13 women, 11 men; mean age, 67.1 years; range, 44-83 years) with bone marrow biopsy-proven multiple myeloma were included in the study. All patients underwent PET/CT and whole-body MRI within 10 days of each other. Eight patients underwent more than one follow-up PET/CT and whole-body MRI examination, for a total of 34 pairs of images. Activity was defined as lesions with a maximum standardized uptake value greater than 2.5 at PET and as evidence of marrow packing at whole-body MRI. PET and whole-body MRI results were correlated with findings at bone marrow aspiration biopsy. RESULTS: PET had a sensitivity of 59%, specificity of 75%, positive predictive value of 81%, and negative predictive value of 50% (p = 0.08). Whole-body MRI had a sensitivity of 68%, specificity of 83%, positive predictive value of 88%, and negative predictive value of 59% (p = 0.01). In 62% of cases, PET and whole-body MRI findings were concordant. When PET and whole-body MRI findings were concordant and positive, no false-positive results were found, yielding a specificity and a positive predictive value of 100% (p = 0.04). CONCLUSION: Whole-body MRI performed better than PET in the assessment of disease activity, having a higher sensitivity and specificity. The positive predictive value of whole-body MRI in the assessment of active disease was high at 88%. When used in combination and with concordant findings, PET and whole-body MRI were found to have a specificity and positive predictive value of 100%, which may be of value to clinicians assessing the effectiveness of aggressive and expensive treatment regimens.

Shoulder, hip, and knee arthrography needle placement using fluoroscopic guidance: practice patterns of musculoskeletal radiologists in North America.

OBJECTIVE: The aim of this study was to evaluate the range of techniques used by radiologists performing shoulder, hip, and knee arthrography using fluoroscopic guidance. MATERIALS AND METHODS: Questionnaires on shoulder, hip, and knee arthrography were distributed to radiologists at a national radiology meeting. We enquired regarding years of experience, preferred approaches, needle gauge, gadolinium dilution, and volume injected. For each approach, the radiologist was asked their starting and end needle position based on a numbered and lettered grid superimposed on a radiograph. RESULTS: Sixty-eight questionnaires were returned. Sixty-eight radiologists performed shoulder and hip arthrography, and 65 performed knee arthrograms. Mean experience was 13.5 and 12.8 years, respectively. For magnetic resonance arthrography, a gadolinium dilution of 1/200 was used by 69-71%. For shoulder arthrography, an anterior approach was preferred by 65/68 (96%). The most common site of needle end position, for anterior and posterior approaches, was immediately lateral to the humeral cortex. A 22-gauge needle was used by 46/66 (70%). Mean injected volume was 12.7 ml (5-30). For hip arthrography, an anterior approach was preferred by 51/68 (75%). The most common site of needle end position, for anterior and lateral approaches, was along the lateral femoral head/neck junction. A 22-gauge needle was used by 53/68 (78%). Mean injected volume was 11.5 ml (5-20). For knee arthrography, a lateral approach was preferred by 41/64 (64%). The most common site of needle end position, for lateral and medial approaches, was mid-patellofemoral joint level. A 22-gauge needle was used by 36/65 (56%). Mean injected volume was 28.2 ml (5-60). CONCLUSION: Arthrographic approaches for the shoulder, hip, and knee vary among radiologists over a wide range of experience levels.

Anatomy, pathology, and MRI findings in the sports hernia.

"Sports hernia" is a frequently used term on athletic injury reports and in the sportscasting media, but its true definition remains elusive in the medical literature. Magnetic resonance imaging (MRI) is a useful tool in the evaluation of clinical athletic pubalgia, yet specific pathologies associated with this commonly encountered syndrome are poorly described in the imaging literature. In this article we review the musculoskeletal anatomy of the pubic region as well as several reproducible patterns of pathology on MRI we have encountered in patients with a clinical diagnosis of sports hernia.