Multiparametric MRI of solid renal masses: pearls and pitfalls

Functional imaging [diffusion-weighted imaging (DWI) and dynamic contrast enhancement (DCE)] techniques combined with T2-weighted (T2W) and chemical-shift imaging (CSI), with or without urography, constitutes a comprehensive multiparametric (MP) MRI protocol of the kidneys. MP-MRI of the kidneys can be performed in a time-efficient manner. Breath-hold sequences and parallel imaging should be used to reduce examination time and improve image quality. Increased T2 signal intensity (SI) in a solid renal nodule is specific for renal cell carcinoma (RCC); whereas, low T2 SI can be seen in RCC, angiomyolipoma (AML), and haemorrhagic cysts. Low b-value DWI can replace conventional fat-suppressed T2W. DWI can be performed free-breathing (FB) with two b-values to reduce acquisition time without compromising imaging quality. RCC demonstrates restricted diffusion; however, restricted diffusion is commonly seen in AML and in chronic haemorrhage. CSI must be performed using the correct echo combination at 3 T or T2* effects can mimic intra-lesional fat. Two-dimensional (2D)-CSI has better image quality compared to three-dimensional (3D)-CSI, but volume averaging in small lesions can simulate intra-lesional fat using 2D techniques. SI decrease on CSI is present in both AML and clear cell RCC. Verification of internal enhancement with MRI can be challenging and is improved with image subtraction. Subtraction imaging is prone to errors related to spatial misregistration, which is ameliorated with expiratory phase imaging. SI ratios can be used to confirm subtle internal enhancement and enhancement curves are predictive of RCC subtype. MR urography using conventional extracellular gadolinium must account for T2* effects; however, gadoxetic acid enhanced urography is an alternative. The purpose of this review it to highlight important technical and interpretive pearls and pitfalls encountered with MP-MRI of solid renal masses.

Ten uncommon and unusual variants of renal angiomyolipoma (AML): radiologic-pathologic correlation

Classic (triphasic) renal angiomyolipoma (AML) is currently classified as a neoplasm of perivascular epithelioid cells. For diagnosis of AML, the use of thin-section non-contrast enhanced CT (NECT) improves diagnostic accuracy; however, identifying gross fat within a very small AML is challenging and often better performed with chemical-shift MRI. Although the presence of gross intra-tumoural fat is essentially diagnostic of AML; co-existing intra-tumoural fat and calcification may represent renal cell carcinoma (RCC). Differentiating AML from retroperitoneal sarcoma can be difficult when AML is large; the feeding vessel and claw signs are suggestive imaging findings. AML can haemorrhage, with intra-tumoural aneurysm size >5 mm a more specific predictor of future haemorrhage than tumor size >4 cm. Diagnosis of AML in the setting of acute haemorrhage is complex; comparison studies or follow-up imaging may be required. Not all AML contain gross fat and imaging features of AML without visible fat overlap with RCC; however, homogeneity, hyperdensity at NECT, low T2-weighted signal intensity and, microscopic fat are suggestive features. Patients with tuberous sclerosis often demonstrate a combination of classic and minimal fat AML, but are also at a slightly increased risk for RCC and should be imaged cautiously. Several rare pathological variants of AML exist including AML with epithelial cysts and epithelioid AML, which have distinct imaging characteristics. Classic AML, although benign, can be locally invasive and the rare epithelioid AML can be frankly malignant. The purpose of this review is to highlight the imaging manifestations of 10 uncommon and unusual variants of AML using pathological correlation.

Characterization of small (<4cm) solid renal masses by computed tomography and magnetic resonance imaging: Current evidence and further development

Diagnosis of renal cell carcinomas (RCC) subtypes on computed tomography (CT) and magnetic resonance imaging (MRI) is clinically important. There is increased evidence that confident imaging diagnosis is now possible while standardization of the protocols is still required. Fat-poor angiomyolipoma show homogeneously increased unenhanced attenuation, homogeneously low signal on T2-weighted MRI and apparent diffusion coefficient (ADC) map, may contain microscopic fat and are classically avidly enhancing. Papillary RCC are also typically hyperattenuating and of low signal on T2-weighted MRI and ADC map; however, their gradual progressive enhancement after intravenous administration of contrast material is a differentiating feature. Clear cell RCC are avidly enhancing and may show intracellular lipid; however, these tumors are heterogeneous and are of characteristically increased signal on T2-weighted MRI. Oncocytomas and chromophobe tumors (collectively oncocytic neoplasms) show intermediate imaging findings on CT and MRI and are the most difficult subtype to characterize accurately; however, both show intermediately increased signal on T2-weighted with more gradual enhancement compared to clear cell RCC. Chromophobe tumors tend to be more homogeneous compared to oncocytomas, which can be heterogeneous, but other described features (e.g. scar, segmental enhancement inversion) overlap considerably between tumors. Tumor grade is another important consideration in small solid renal masses with emerging studies on both CT and MRI suggesting that high grade tumors may be separated from lower grade disease based upon imaging features.

Perceptions of vascular access for intravenous systemic therapy and risk factors for lymphedema in early-stage breast cancer-a patient survey

Background

The choice of vascular access for systemic therapy administration in breast cancer remains an area of clinical equipoise, and patient preference is not consistently acknowledged. Using a patient survey, we evaluated the patient experience with vascular access during treatment for early-stage breast cancer and explored perceived risk factors for lymphedema.

Methods

Patients who had received systemic therapy for early-stage breast cancer were surveyed at 2 Canadian cancer centres.

Results

Responses were received from 187 patients (94%). The route of vascular access was peripheral intravenous line (IV) in 24%, a peripherally inserted central catheter (picc) in 42%, and a surgically inserted central catheter (port) in 34%. Anthracycline-based regimens were associated with a greater use of central vascular access devices (cvads- that is, a picc or port; 86/97, 89%). Trastuzumab use was associated with greater use of ports (49/64, 77%). Although few patients (7%) reported being involved in the decisions about vascular access, most were satisfied or very satisfied (88%) with their access type. Patient preference centred mainly on avoiding delays in the initiation of chemotherapy. Self-reported rates of complications (183 evaluable responses) were infiltration with peripheral IVs (9/44, 20%), local skin infections with piccs (7/77, 9%), and thrombosis with ports (4/62, 6%). Perceived risk factors for lymphedema included use of the surgical arm for blood draws (117/156, 75%) and blood pressure measurement (115/156, 74%).

Conclusions

Most patients reported being satisfied with the vascular access used for their treatment. Improved education and understanding about the evidence-based requirements for vascular access are needed. Perceived risk factors for lymphedema remain variable and are not evidence-based.

Cerebellar Purkinje cells provide target support over a limited spatial range: evidence from lurcher chimeric mice

The distribution of Purkinje cells, granule cells, and olivary neurons was quantitatively analyzed in a lurcher +/Lc in equilibrium C3H/HeJ chimera in which the surviving wild type Purkinje cells were unilaterally distributed in the left hemicerebella. The left hemisphere of this mouse contains 7600 Purkinje cells, approximately 10% of the number of Purkinje cells in inbred C3H/HeJ mice. The right hemisphere contains 300 Purkinje cells, all of which are found within 200 microns of the midline. As in other +/Lc in equilibrium wild type chimeras, the ratio of granule cells to Purkinje cells is increased in the left hemisphere, reflecting increased granule cell survival. In the right hemisphere, however, the number of granule cells is reduced to that found in +/Lc mutants. In the inferior olive, almost twice as many neurons are found in the right nucleus as opposed to the left nucleus. As the projections of olivary neurons are crossed, the number of olivary neurons is increased in the nuclei that project to the cerebellar hemisphere containing Purkinje cells compared to the olivary nuclei that project to the cerebellar hemisphere with almost no Purkinje cells. The preferential survival of granule cells and olivary neurons that either occupy or project to the hemicerebellum containing Purkinje cells suggests that the availability of trophic support from target Purkinje cell neurons is spatially restricted.

Reporting bias in imaging: higher accuracy is linked to faster publication

OBJECTIVES

The objective of this study was to evaluate whether higher reported accuracy estimates are associated with shorter time to publication among imaging diagnostic accuracy studies.

METHODS

We included primary imaging diagnostic accuracy studies, included in meta-analyses from systematic reviews published in 2015. For each primary study, we extracted accuracy estimates, participant recruitment periods and publication dates. Our primary outcome was the association between Youden's index (sensitivity + specificity - 1, a single measure of diagnostic accuracy) and time to publication.

RESULTS

We included 55 systematic reviews and 781 primary studies. Study completion dates were missing for 238 (30%) studies. The median time from completion to publication in the remaining 543 studies was 20 months (IQR 14-29). Youden's index was negatively correlated with time from completion to publication (rho = -0.11, p = 0.009). This association remained significant in multivariable Cox regression analyses after adjusting for seven study characteristics: hazard ratio of publication was 1.09 (95% CI 1.03-1.16, p = 0.004) per unit increase for logit-transformed estimates of Youden's index. When dichotomizing Youden's index by a median split, time from completion to publication was 20 months (IQR 13-33) for studies with a Youden's index below the median, and 19 months (14-27) for studies with a Youden's index above the median (p = 0.104).

CONCLUSION

Imaging diagnostic accuracy studies with higher accuracy estimates were weakly associated with a shorter time to publication.

KEY POINTS

• Higher accuracy estimates are weakly associated with shorter time to publication. • Lag in time to publication remained significant in multivariate Cox regression analyses. • No correlation between accuracy and time from submission to publication was identified.

Building sickness, are symptoms related to the office lighting?

Office lighting has been suggested as one of the possible factors in producing 'building sickness'. Health questionnaires were completed by 106 out of 109 (97%) workers in six randomly sampled multi-occupied offices in each of two buildings, one air-conditioned and one naturally ventilated. There was a significantly higher prevalence of work-related headache and work-related lethargy in the air-conditioned building than in the naturally ventilated one. There was also less daylight in the air-conditioned building and lower mean luminance and illuminance of the work positions despite there being more lights on (p less than 0.01). The workers had a greater dislike of fluorescent lighting (p less than 0.01) and overall found the lighting to be less comfortable (p less than 0.01) and glare readings were higher. The workers perceived their control of lighting as poorer (p less than 0.001) and consequently there was less agreement about it (p less than 0.001). Those with work-related headache found the lighting less comfortable (p = 0.059) and perceived more glare (p less than 0.05). This study suggests the need to maximize the use of natural light from untinted windows, to reduce the impingement of fluorescent tubes on the line of sight and to return the control of levels of lighting to each individual worker.

A survey of social outcome in schizophrenia in Tasmania

OBJECTIVE

To survey the social outcome of patients with schizophrenia attending State mental health facilities in southern Tasmania.

METHOD

Using the Statewide Mental Health Register, patients using inpatient and outpatient facilities who received a diagnosis of schizophrenia between 1981 and 1988 were identified (n = 771), and demographic and illness measures, and admissions and length of inpatient stay were compiled. The Life Skills Profile (LSP) was completed by mental health personnel for the 247 who were regular attenders or inpatients in 1991.

RESULTS

Social morbidity as indexed by the LSP was highest in psychiatric hospital inpatients and patients in long-term rehabilitation programs, and lower in patients attending community centres. The majority of patients in suburban settings and attending community centres lived with their families, whereas patients in the inner city or in the rehabilitation service were mainly in hostel accommodation or living alone. Patients with schizophrenia attending State services were of a similar age range but had a longer duration of illness and more admissions, and had spent more days in hospital than patients who were not in regular contact with the service.

CONCLUSIONS

The distribution of social morbidity in schizophrenia confirms that the public health system is supporting a group with high social morbidity. Patients with the highest morbidity are receiving the highest levels of care and intervention.

Oxytocin: oxytocic of choice in first trimester

Either oxytocin (10 U) or ergometrine (0.25 mg) was given intravenously to patients having suction curettage for termination of pregnancy. There was significantly less blood lost and a lower incidence of vomiting in the group receiving oxytocin.