[Rectal cancer update: postneoadjuvant staging]

Over the last two decades, magnetic resonance imaging (MRI) has continuously been gaining influence in modern management of rectal cancer. Bringing morphological and functional features together improves the differentiation of responders from nonresponders, provides for accurate surgical planning, intensified radiation therapy regimes, and watch-and-wait strategies. A shift from TNM staging towards risk stratification of rectal cancer patients, patient selection to increasingly individualized therapies, and intensified surveillance has contributed to the transformation of rectal MRI into a true gamechanger.

Value of high-field magnetic resonance imaging for diagnosis and classification of acute colonic diverticulitis

OBJECTIVES

Due to limited and outdated literature, the role of magnetic resonance imaging (MRI) in the diagnostic work-up of acute colonic diverticulitis (ACD) is still under debate. The purpose of this study was to compare the performance of modern high-field MRI and multidetector computed tomography (MDCT) in the diagnosis and classification of ACD.

METHODS

In our prospective study 24 emergency patients with the clinical diagnosis of ACD received MDCT and high-field MRI. Imaging features of ACD were assessed and categorized according to the classification of diverticular disease (CDD) by three independent readers. Results were matched with the final clinical report.

RESULTS

MRI with a specialized examination protocol clearly depicted all relevant findings of ACD. Statistical analysis resulted in an almost perfect strength of agreement between CT and MRI across all readers for the final CDD category (κ = 0.94) and the stage-related image features (κ = 0.98). Moderate agreement was seen for the detection of micro-abscesses (κ = 0.78), with a slight advantage for MRI.

CONCLUSION

Modern high-field MRI is fully comparable to MDCT in the assessment of ACD and has the potential to serve as a first-line imaging tool.

[Diverticular disease: stage-related diagnostic imaging]

BACKGROUND

Diverticular disease frequently leads to emergency admissions. Clinical parameters are not sufficiently accurate to determine the extent of acute colonic diverticulitis, thus a quick, reproducible and valid diagnostic imaging procedure is required.

OBJECTIVE

In the following, the imaging methods commonly used for the diagnostic work-up and staging of diverticulitis are presented and classified in the context of the data situation and clinical reality.

RESULTS

Multidetector computed tomography (MDCT) is the current diagnostic gold standard for the imaging evaluation of diverticulitis and the basis for guideline-conform treatment decisions according to the classification of diverticular disease (CDD).

DISCUSSION

The role of magnetic resonance imaging (MRI) in the evaluation of diverticulitis will have to be investigated but a more profound integration of this method can already be predicted. Point-of-care ultrasound for initial diagnosis and follow-up assessment will become more important, analogous to FAST in trauma patients.

Changes in intra- and extramyocellular lipids in morbidly obese patients after non-surgical weight loss-a pilot study using magnetic resonance spectroscopy

BACKGROUND & AIMS

Lipid accumulation in muscles is common in obesity and associated with increased risks for insulin resistance. However, the impact of weight loss and exercise on muscle fat content is not clear due to inconsistent data. We used magnetic resonance spectroscopy (MRS) to compare the intra- (IMCL) and extramyocellular lipid (EMCL) proportions in the musculus tibialis anterior of extremely obese patients before and after weight loss.

METHODS

Nineteen non-diabetic patients with a Body Mass Index (BMI) ≥ 40 kg/m² who participated in a non-surgical multimodal weight loss program were recruited. Metabolite ratios of IMCL and EMCL (metabolite/creatine) were assessed using 3 T ¹H-MRS before therapy and after 6 months. The primary outcome comprised changes in IMCL and body cell mass. Additionally, changes of IMCL and EMCL were compared with changes in standard clinical measures, i.e., BMI, body composition, blood pressure and functional exercise capacity.

RESULTS

After 6 months the relative weight loss was 24.8% (127.6 kg, 48.5 kg/m² vs. 96 kg, 36.5 kg/m²). All standard clinical measures were significantly improved. MRS data from 10 patients provided complete and evaluable data sets. IMCL was reduced by nearly 50% (p < .05). The reduction of EMCL was not significant (p = .106). An explorative correlation analysis between changes of IMCL and changes of the standard measures did not reveal any significance.

CONCLUSIONS

Significant reductions of IMCL following a successful conservative weight loss intervention are detectable by using MRS. These changes may have the potential to serve as an additional marker of clinically meaningful obesity treatment.

A very rare cause of low-back pain and sciatica: deep vein thrombosis due to absence of the inferior vena cava mimicking the clinical and radiological signs of lumbar disc herniation

The authors report a very rare cause of low-back pain and sciatica in a patient with iliac vein thrombosis attributed to absence of the infrarenal segment of the inferior vena cava (IVC) with massively dilated venous collaterals draining via a paraspinal plexus into the azygous system. This 21-year-old man presented with acute low-back pain radiating to the left ventral thigh. The initial CT scan revealed an intraspinal lesion that mimicked lumbar disc herniation. Further clarification revealed an iliac vein thrombosis, which was triggered by the absence of the infrarenal segment of the IVC, a very rare vascular anomaly. Collateral venous return was developed and led to lumbar varicosities and epidural vein engorgements. Laboratory examinations revealed factor V mutation as a predisposing factor for thrombosis. The patient's symptoms were relieved with anticoagulation and antiinflammatory therapy. Absence of the infrarenal IVC associated with iliac vein thrombosis should be regarded as a very rare cause of radicular and low-back pain, and this condition can mimic the clinical and radiological signs of lumbar disc herniation. Sciatica might be the first clinical manifestation of this rare venous anomaly.

High-dose chemotherapy and autologous stem-cell transplantation without consolidating radiotherapy as first-line treatment for primary lymphoma of the central nervous system

Thirteen patients (age 38-67 years) with primary lymphoma of the central nervous system (CNS) were treated with methotrexate and cytarabine/thiotepa induction-chemotherapy followed by high-dose carmustine/thiotepa and autologous stem-cell transplantation. Radiotherapy was restricted to patients who did not respond completely to chemotherapy. With a median follow up of 25 months, 3-year DFS and OS was 77%.