Current internationally-accepted directives recommend routine colonoscopy following an acute episode to confirm the diagnosis and rule out malignancy,
given the frequent similarities between the clinical-radiological presentations of acute diverticulitis and colon cancer.
This recommendation is based on studies performed prior to the use of high-quality CT,
in cases in which evidence of low performance of CT orient a diagnosis of malignancy or benignancy was found.
One example of the scenario described are the results published by Chintapalli et al (6).
They performed a retrospective analysis of 58 CT’s,
and identified findings that would orient a diagnosis of diverticulitis and of malignancy (Table 1). (Figures 1 to 9 illustrate representative cases of sigmoiditis/acute diverticulitis and colon adenocarcinoma with their orienting CT findings)
Table 1: Guiding radiological findings in CT.
Acute diverticulitis /sigmoiditis
Affectation of a colon segment greater than 10 cm
Affectation of a colon segment smaller than 5 cm.
These are absolutely current,
and are used today in radiological practice.
in a later study (7),
the same author prospectively studied 72 cases using these radiological criteria in CT,
obtaining a correct diagnosis of diverticulitis in 16/40 (40%) and colon cancer in 21/32 (66%) cases.
It is likely that these results are obsolete,
as it could be expected that a superior performance would be attained with the use of high-quality CT.
A recent publication (8) achieved better results with the morphological analysis and added optimistic results with the functional study of perfusion CT (PCT).
This study featured a prospective study of both techniques,
with PCT showing blood volume and flow higher in cases of cancer than those of diverticulitis.
Using a threshold volume of 4.8 mL/100 for threshold flow of 60.2 mL/100 g/min,
they achieved sensitivity (Se.) of 80% and specificity (Sp.) of 70 and 75% respectively for cancer diagnoses.
On another note,
the classical morphological signs of CT had the following results: compromised segment <5 cm of colon (Se.
presence of mass (Se.
90%) and pericolonic adenopathies (Se.
But when studying the interpretation of overall CT morphological findings,
97.5% of the cancer cases and 92% of the acute diverticulitis cases were correctly classified.
It is interesting to underscore that in all of the cases of error in the morphological interpretation,
the correct diagnosis would have been reached if the study had been complemented with the functional information provided by PCT.
The CT-colonoscopy (CCT) is also seen as a viable alternative to colonoscopy in patients with suspicion of diverticular disease.
One example of this is the prospective evaluation that compared colonoscopy and CCT.
108 patients were studied with both modalities (half of the patients had a colonoscopy prior to the CCT and the other half in the opposite order).
of CCT in the detection of diverticular disease was 99% and 67%,
but no cases of cancer were detected in this patient group,
and therefore it was not possible to analyze this variable (9).
Another technique with promising results,
but that needs more evidence from studies with higher N values is the use of MRI.
A small study published in 2013 (10) compared the performance of CT findings,
the T2- weighted MRI and diffusion-weighted MRI.
30 patients were studied; 15 with sigmoid cancer and 15 with a recent episode of acute diverticulitis/sigmoiditis,
using both techniques.
The correct diagnosis of CT for cancer and diverticulitis was 66.7% (10/15) and 93.3% (14/15),
On the other hand,
with MRI it was 100% (14/14) and 100% (14/14),